eastern africa: kenya, uganda, united republic ......epidemics of variola major had occurred in...

INTRODUCTION

This chapter describes the development ofsmallpox eradication programmes in 5 con-tiguous countries of eastern Africa-Burundi, Kenya, Rwanda, Uganda and theUnited Republic of Tanzania' (Fig. 19 .1). In1970 their combined population amounted to42 million and their total land area to1 818 000 square kilometres . In comparison,adjacent Zaire to the west had half as large apopulation in 1970 but an area 25% greater.

The infrastructure of transport andcommunication services was better developedthan in the countries of western and centralAfrica ; moreover, government and private

' The United Republic of Tanzania was formed in 1964 by theunion of Tanganyika, Zanzibar and Pemba . Although its officialname is used elsewhere in this book, it is, for brevity, referred toas "Tanzania" in the text and tables of this chapter. The islandsof Zanzibar and Pemba experienced no smallpox and conductedno special eradication programme.

CHAPTER 19

EASTERN AFRICA : KENYA,UGANDA, UNITED REPUBLIC OFTANZANIA, RWANDA AND

BURUNDIContents

945

health centres, clinics, dispensaries and hos-pitals were more numerous . Vaccination,with liquid vaccine, had been practised moreor less extensively throughout most parts ofthese countries for more than 50 years, mostvaccinations being given when outbreaks ofsmallpox occurred . Some health facilitiesoffered vaccination to any patients attendingthem, but the vaccine was generally stored atroom temperature and its potency was there-fore presumably low or nil .

Among the many health problems in thesecountries, smallpox in the early 1960s had notbeen of high priority except in Tanzania .Epidemics of variola major had occurred inprevious decades but, more recently, in allcountries except Tanzania, variola minorwith a low case-fatality rate prevailed . Forexample, during the period 1961-1965, 1182cases with only 6 deaths were reported fromKenya, and between 1961 and 1964 Ugandarecorded 1960 cases and 4 deaths . However,Uganda in 1965 and Kenya in 1966 began to

PageIntroduction 945Smallpox control activities before 1969 946Agreements to undertake eradication programmes 948Provision of freeze-dried vaccine 951The vaccination campaigns 952

Kenya 954Uganda 956Tanzania 957Rwanda and Burundi 959

Smallpox occurrence, 1969-1970 962Importations into Uganda 964Importations into Kenya 965Conclusion 967

946

Fig . 19 .1 . Eastern Africa and adjacent countries .

experience an increasing number of deathsdue to smallpox and consequently took agreater interest in controlling the disease . InTanzania, a more severe form of smallpox hadbeen prevalent, with recorded case-fatalityrates of 5-7%. Even so, the problem was notlarge when viewed against the greater threatsposed by malaria, tuberculosis and severalother infectious diseases . Vaccination cam-paigns, however, were an integral part ofpublic health activities because of the fear ofrecurrence of epidemics of the virulent vari-ola major . With substantial commerce andtravel between eastern Africa and Asia andthe generally held belief that severe variolamajor prevailed elsewhere in Africa, there wasreason to maintain adequate levels of vac-cinial immunity .

After 1967, when the Intensified Pro-gramme began, all 5 countries agreed toundertake eradication programmes whichwould include systematic national vaccina-tion campaigns employing, for the first time,freeze-dried vaccine of acceptable quality .WHO provided each country with advisers,all the requisite transport, equipment andsupplies (including vaccine) and reimbursedthe governments for the costs of petrol andvehicle maintenance. The countries madeavailable a small cadre of national personnel,but little else. Each conducted effectivenational smallpox vaccination campaigns,

SMALLPOX AND ITS ERADICATION

which, in Kenya, Rwanda and Tanzania, werecarried out in conjunction with the admin-istration of BCG (antituberculosis) vaccine tochildren under 15 years of age .

Smallpox vanished quickly, transmissionbeing interrupted by the end of 1970, wellbefore the systematic vaccination campaignsreached most areas and, indeed, before effec-tive programmes of surveillance and contain-ment had been developed . After 1970, im-portations from the Sudan occurred alongUganda's northern border, and importationsfrom Ethiopia and Somalia along Kenya'snorth-eastern borders . The outbreaks were allin sparsely populated areas ; none resulted inlarge numbers of cases or persisted for longperiods.

The mass vaccination campaigns differedsomewhat in character from one country tothe next, as each was adapted to the nature ofthe health services and the political structureof the country concerned . Information aboutthe epidemiological characteristics ofsmallpox in eastern Africa is scarce, however,because little was done to improve thenational reporting systems or systematicallyto investigate suspected cases until after 1970,when transmission had been interrupted.

The rapidity and ease with which smallpoxtransmission was interrupted in these coun-tries, as well as many others in Africa, weresurprising. At the time, the situation servedto engender an unwarranted confidencethat smallpox eradication could be readilyachieved with only a modest incrementalinvestment of resources, even in programmesin which performance was marginal . In Africaitself notably in Ethiopia, Somalia and theSudan-this belief later proved to beunfounded .

SMALLPOX CONTROL ACTIVITIESBEFORE 1969

In 1967, when the Intensified SmallpoxEradication Programme began, the countriesof eastern Africa reported a total of only 2221cases (Table 19 .1) . In a population which thennumbered almost 38 million, this figure wasnot large . Moreover, the number of recordedcases was diminishing rapidly, from 5607 in1965 to 4163 cases in 1966 . Of the 5 countries,only Rwanda reported no cases whatsoeverduring the period 1966-1968 but it wasprovisionally categorized as an endemiccountry, since it was difficult to believe that a

a No cases officially recognized .b Imported cases .C including 23 cases resulting from Importations .

country completely surrounded by heavilyinfected areas could be free of smallpox . Notuntil 1969 was it learned that it wasgovernment policy to report only cases thatwere confirmed by laboratory examination.Because no specimens were examined, nocases were reported .

Vaccination was provided routinely in allcountries, the number performed annuallybeing equivalent to about 10-20% of thepopulation (Table 19.2). Undoubtedly manyof the vaccinations were unsuccessful becauseof the use of vaccine that was subpotent at thetime of administration . Kenya, Tanzania andUganda used liquid vaccine produced at theMedical Research Laboratory in Nairobi or atthe Lister Institute, England. Althoughusually stored under refrigeration in thecapital city, the vaccine was exposed toambient temperatures during shipment andrarely refrigerated at any of the intermediatedistribution points or in health centres . Thiswas a problem, because liquid vaccinebecomes inactive within 3 days or less atambient temperatures when it is not refriger-ated. No data are available regarding theproportion of successful vaccinations becausevaccinees were not examined to determinewhether their vaccinations had taken. Until1965, Rwanda and Burundi also used liquidvaccine, produced at a laboratory in Rwandaor imported from Belgium . In 1965, theRwanda laboratory began producing areasonably satisfactory freeze-dried vaccine,but the vials in which it was distributed wereso large that the amount of vaccine eachcontained was sufficient, after reconstitution,

for 600 doses or more. This was not much ofan improvement, because freeze-driedvaccine, after reconstitution, loses its potencywithin 24 hours unless it is refrigerated, andfew health centres had refrigerators whichfunctioned properly. Rarely did any healthunit have cause to vaccinate more than a fewpersons a day but the staff continued to usethe reconstituted vaccine until each vial wasempty. In 1968, for example, a WHOsmallpox eradication adviser observed at ahospital in Rwanda that a vial containingvaccine reconstituted 3 months earlier wasstill in use .

In each of the countries, mass campaignswere conducted from time to time in specificareas when epidemics occurred. For suchcampaigns, vaccine was shipped to the fielddirect from the laboratories and was morelikely to have been of adequate potency at thetime of administration than vaccine whichhad been kept for weeks or even months athealth centres. Only one country-wide massvaccination campaign-in Uganda-hadbeen carried out since the 1950s . In 1965, thenumber of reported smallpox cases and deathsin Uganda increased . The Ministry of Health,fearing epidemic variola major, launched anational campaign . Between August 1965 andFebruary 1966, 7.5 million persons werevaccinated, a total equivalent to more than90% of the country's population at the time .The cost of vaccine alone, most of which waspurchased from the United Kingdom,amounted to more than US$200 000. A surveyconducted by Ladnyi in 1966 revealed vac-cination scars in 88% of children in primary

19. EASTERN AFRICA 947

Table 19.1 . Eastern Africa: population and number of reported cases of smallpox, 1965-1977

YearNumber of cases

Kenya Uganda Tanzania

Rwanda Burundi1970 population (thousands)

1 1 290 9 806 13 513

3 718 3 456

1965

276 1 351 2762

5 12131966

159 614 3 027

a 363

1967

153 365 1629

a 741968

87 55 455

a 3011969

14 9b 117

107 1081970

0 2b 32C

253 1971971

46b l9b 0

0 01972

0 16b 0

0 01973

Ib 0 0

0 01974

3b 0 0

0 01975

0 0 0

0 01976

Ib 0 0

0 01977

5b 0 0

0 0

948

m

V

S

Cb

r

CD

CY

Ar

C0

o NO 000-

aEz

dEz

NE

z

aE_z

0I-

C0

o ;

000-

`o

0 Q =7

d

tTCO

dr=

EW 0 O w

E


- V1 N

N O 2 0 N ul 0 N.00-

.0 n'1 .0•

N t+t ~ 00 1~ f .'1

7 m 0 N - N l'1D

1 n 7 O O PD W CD T m N•

N O N N- N

OIL-T ~0]T

vt N T 'O r(+1 O N7- N O . D . 0! n

•

N N N (N N -

N -N--

OD

T v7 1N 0 0) - O]vt'040 (N N 4T'04) Ua--0)

T .0T .0- v-v N OT mf.- - - `0 vt N -

N .0 v N l{ m y-0. V1 ~ .0 N- - - N

- N O G D mN -a-Nv N -

I.O7T0-NMT T T T T T T

schools, but in only 61 % of people attendingclinics at 6 hospitals. The examination of 33patients with smallpox revealed that 8 hadbeen unsuccessfully vaccinated 1-3 monthsbefore. It was apparent that the campaign hadbeen far less successful than the coveragemight suggest .

The impression that a more severe form ofsmallpox had appeared in Uganda is borne outby the available records. Up to 1965, deathsfrom smallpox had been infrequent inUganda, but in 1965 the case-fatality rateincreased to nearly 5 % and remained highuntil transmission was interrupted (Table19.3). During the following year, the case-fatality rate in Kenya also increased, withboth cases and deaths occurring primarily inareas adjacent to Uganda . Kenya, too,undertook a mass campaign-in NyanzaProvince, which borders on Uganda. Be-tween March and April 1966, 670 000 personswere vaccinated. In the same year, 500 000people in Burundi and 6 million in Tanzaniawere vaccinated during mass campaigns .

From 1966 onwards, the case-fatality ratesin Uganda and Kenya were characteristic ofthose observed with the African strain ofvariola major. This strain had been prevalentin neighbouring Tanzania and Zaire, fromwhich it had presumably been introduced .Nothing can be said of the status of Rwandaor Burundi at this time, because no cases wereofficially recognized by Rwanda and deathswere not registered in Burundi .

AGREEMENTS TO UNDERTAKEERADICATION PROGRAMMES

•

N - N N -

•

•

N V N m- m 7

In October 1965, Ladnyi was assigned byWHO to Nairobi as an intercountry smallpoxadviser in the eastern portion of Africa . Hewas responsible for providing advice on thedevelopment of smallpox eradicationprogrammes to the 19 countries of eastern,central and southern Africa in WHO'sAfrican Region that lay to the south of theSudan, Ethiopia and Somalia (which at thattime all formed part of the Organization'sEastern Mediterranean Region) . An epide-miologist based in Liberia was assignedsimilar functions in the western portion of

Africa. The initiative by the Regional Officefor Africa to provide regional smallpox eradi-cation programme advisers antedated thedecision of the Nineteenth World HealthAssembly in May 1966 to allocate special

Plate 19 .1 . In Rwanda and throughout eastern Africa, mass vaccination had traditionally been used to controlthe spread of smallpox . Villagers willingly assembled at collecting points to be vaccinated .

funds for eradication ; they were, in fact, thefirst WHO regional smallpox eradication staffto be appointed. Ladnyi immediately em-barked on a series of visits to each of thecountries, beginning in 1966, with Burundi,Kenya, Malawi, Tanzania, Uganda andZambia.

At the start, he could do little except offeradvice, since the resources allocated to thesmallpox eradication programme by WHOwere so limited . Moreover, because mostcountries did not consider smallpox an impor-tant problem, few were interested in

Table 19 .3. Kenya, Uganda and Tanzania: number of cases of and deaths from smallpox, and case-fatality rates,1961-1970

a Cases imported from the Sudan and Rwanda .

19. EASTERN AFRICA

developing programmes, or, indeed, were ableto do so without special assistance .The above-mentioned decision of the

Nineteenth World Health Assembly to allo-cate funds for smallpox eradication from theOrganization's 1967 regular budget madeit possible to launch many nationalprogrammes. Surprisingly, however, exceptfor those from Zaire and Zambia, no requestsfor assistance were received by WHO fromany of the countries in central, eastern orsouthern Africa. Meanwhile, during 1966 and1967, programmes throughout western

949

Kenya Uganda Tanzania

Year Numberof

cases

Numberof

deaths

Case-fatalityrate(%)

Numberof

cases

Numberof

deaths


Numberof

cases

Numberof

deaths


1961-1964 906 4 0 .4 1 960 4 0.2 4 373 249 5 .7

1965 276 2 0 .7 1351 63 4.7 2 762 213 7 .71966 159 9 5 .7 614 25 4.1 3027 171 5 .71967 153 18 11 .8 365 24 6 .6 1629 50 3 .11968 87 3 3 .4 55 5 9 .1 455 16 3 .51969 14 0 0 9a 0 0 117 I 0.91970 0 0 - 2a 0 0 32 0 0

950


Africa began to develop with assistance pro-vided by the USA (see Chapter 17) . Smallpoxeradication staff from WHO Headquartersasked the regional office to contact theeastern and southern African countries toascertain their interest in developing eradica-tion programmes. However, the regionaloffice pointed out that, as a matter of policy,it responded only to requests for assistanceinitiated by the countries themselves . In part,this policy derived from the views of theDirector-General of WHO. In meetings withhis regional directors in 1966, he had urgedextreme caution about imposing another massprogramme on Member states, after theexperience with malaria eradication. Theregional directors, in turn, had conveyedthis to the WHO representatives in thecountries themselves . Because the Director-General regarded smallpox eradication asimprobable, he believed that such a pro-gramme would only divert national resourcesfrom more important activities (see Chapter10). The WHO smallpox eradication staff inGeneva, on the other hand, maintained thatthe decision to undertake global smallpoxeradication had received the unanimous ap-proval of the World Health Assembly ; fundshad been appropriated for this purpose andthus it seemed only reasonable to contact theendemic countries to assess their intentionsand needs . To expect the African countriesthemselves to respond spontaneously to newprogramme directions seemed unrealistic . Allwere newly independent, beset with problemsand struggling to bring order into chaoticbureaucracies. These arguments were,however, of no avail .

Ladnyi, as a member of the regional officestaff, had his hands tied ; there was little hecould do to overcome the apparent impasse inthe initiation of eradication programmes in

Table 19 .4 . WHO support for the programmes in eastern Africa, 1967-1974 (US$)a

a Excluding the cost of vaccine .

central, eastern and southern Africa, withoutdirectly flouting the policy of the regionaloffice. The problem of how to approach thecountries was resolved when the regionaloffice agreed that a medical officer fromHeadquarters, Dr Stephen Falkland, ac-companied by Ladnyi, could visit a number ofAfrican countries early in 1967 so that theDirector-General could report to the WorldHealth Assembly in May of that year on eachcountry's smallpox status and intendedactivities, if any, in accordance with theAssembly's request of 1966 . Dr Falkland wasspecifically directed that under nocircumstances should he propose to anycountry that it should undertake a pro-gramme. In the event of a display of interest,however, he carried with him a draft letterrequesting assistance, prepared for the signa-ture of the minister of health, as well as a draftplan of operations which could be readilyadapted to the specific conditions of eachcountry. He made brief visits to Burundi,Kenya, Rwanda, Tanzania and Uganda, all ofwhich expressed interest in initiatingsmallpox eradication programmes and whichforthwith sent formal requests to WHO forassistance .

Of the 5 countries dealt with in the presentchapter, only Tanzania viewed smallpox as animportant problem . However, to undertakeeradication programmes, it was unnecessaryfor the governments concerned to commitsubstantial national resources. For each pro-gramme WHO agreed to provide an adviser,vehicles (including in some instances, motorcycles and bicycles), refrigerators, campingequipment, vaccine and bifurcated needles, aswell as a sum of money to cover the costs ofpetrol and vehicle maintenance . Thecountry's obligation was primarily to providea small cadre of national staff . To offset the

Year Kenya Uganda Tanzania Rwanda Burundi Total

1967 1914 0 85 592 0 0 87 5061968 51 934 0 1 10 781 33 180 52 912 248 8071969 41 279 79 482 86 900 23 784 61 733 293 1781970 52 006 20 216 80 663 24 417 46 306 223 6081971 60 473 18 031 72 393 52 456 54 874 258 2271972 30 514 18 374 75 168 32 71 1 29 941 186 7081973 14 919 0 89 980 20 999 15 217 141 1151974 11 690 0 0 0 0 11 690Total 264 729 136 103 601 477 187 547 260 983 1 450 839

Per head of population 0.023 0 .014 0 .045 0 .050 0 .073

additional expenditures necessary for salariesof these workers, WHO made availablevaccine and transport, which hitherto hadbeen at the charge of the government . In all,the Organization provided US$1 450 839 insupport of programmes in eastern Africa, asum equivalent to US$0.01-0.07 per head ofpopulation (Table 19 .4). The individual gov-ernments disbursed no more-and in mostcases less-to eradicate smallpox than theyhad spent on controlling the disease .

PROVISION OF FREEZE-DRIEDVACCINE

The acquisition of adequate supplies offreeze-dried vaccine and their distributionpresented a problem to WHO throughoutmost of the global eradication programme(see Chapter 11). In the countries of easternAfrica, as well as many of those in central andsouthern Africa, there were unique diffi-culties which required special solutions .

Attempts were made in all endemic areas topromote the local production of vaccine, butit was not practicable for every country to doso because of the considerable cost and effortneeded to establish and maintain a laboratory .For some 50 years, the Kenyan MedicalResearch Laboratory had been producingliquid vaccine, which it sold to Tanzania andUganda. Thus, it seemed logical to supply thislaboratory with equipment and consultantassistance so that it might serve as a regionalresource for the production of freeze-driedvaccine. UNICEF provided US$20 000 forthe necessary equipment and in January 1967WHO made available the services of aconsultant. By April 1967, the laboratory,directed by Dr Geoffrey Timms, had suc-ceeded in producing 4 experimental batchesof freeze-dried vaccine and by October 1968was producing sufficient vaccine of a consis-tently high quality to meet all Kenya's needs .As production increased, it became possible tosupply neighbouring countries, but herein laya quandary. Kenya needed to charge for thevaccine to recover production expenses .WHO's stock of vaccine, however, was beingprovided through voluntary contributionsand then distributed free of charge to allendemic countries to encourage its use . Unlessthis had been done, many governments,lacking reserves of convertible currency,would have continued to use locally producedliquid vaccine. The purchase of vaccine from

19. EASTERN AFRICA

95 1

Kenya by WHO was not feasible, becauseseveral producers in Europe were anxious tosell vaccine and such a move might haveendangered the donation programme (seeChapter 11) ; thus, WHO had adopted thepolicy of purchasing no vaccine whatsoever .The problem was ultimately solved bysupplying Kenya with almost all the materialsneeded for vaccine production, thus enablingit to produce additional vaccine which couldbe donated to WHO for use in other Africancountries. In all, WHO provided some 31million doses of vaccine for use in thecountries of eastern Africa (Table 19 .5), ofwhich 15 million doses were produced inKenya .

The distribution of vaccine in a timelymanner to the numerous African countrieswas a factor that had to be taken into account .Vaccine was in short supply throughout mostof the eradication programme, and it wastherefore not possible to stockpile largereserves in the endemic countries . With theuncertain schedule of vaccination campaigns,the shipment of vaccine had to be planned inadvance. Vaccine donated to WHO duringthe early years came primarily from Europe orNorth America and was maintained in a cold-storage warehouse in Geneva. With the exten-sive air transport network centred in Geneva,it was not difficult to deliver vaccine any-where in the world at 48 hours' notice .Vaccine donated by Kenya, however, wasshipped direct to neighbouring countries tominimize transport costs . Distribution sys-tems were thus in place for national pro-grammes to be sustained without large stock-piles.

A problem which had to be tackled was thatof communication through the official chan-nels of WHO. For an African country toobtain vaccine, the standard procedure calledfor a request to be directed to the WHO

Table 19 .5 . Eastern Africa : freeze-dried vaccinesupplied through WHO, from 1967onwards (thousands of doses)

Year Uganda Tanzania Rwanda Burundi

1967 0 1014 0 10001968 800 0 0 2001969 1 100 2 500 1 050 01970 2 850 2000 500 7251971 1000 1990 0 7581972 495 968 113 3151973 500 820 205 01974 510 1984 280 250After 1974 1 260 4 153 1 148 241

952


Regional Office for Africa in Brazzaville,which would forward it to Geneva . Communi-cation between African countries, however,was often much slower than communicationbetween Africa and Europe, and inevitablythere were delays in processing the requestwithin the regional office . A telegraphicrequest through official channels sometimestook 4-8 weeks before being received inGeneva. Meanwhile, field programmes cameto a halt . The difficulty was resolved simply bysending 2 telegraphic messages-an officialone to the regional office in Brazzaville andan unofficial one to Geneva, on which actionwas promptly taken .Freeze-dried vaccine which had been

contributed to WHO was made available toseveral of the countries for use in their healthservices even before their formal mass vac-cination campaigns began (Table 19 .5). Thisvaccine was first used by Burundi and Tan-zania at the end of 1967 and by Uganda earlyin 1968 . Kenya began using locally producedfreeze-dried vaccine in October 1968 . Tan-zania reverted briefly to the distribution ofliquid vaccine during November 1968, whenit received a bilateral donation of 300000doses, but fortunately no furthercontributions of this type were received .Rwanda continued to use its own locallyproduced freeze-dried vaccine until early1969, when the government was persuaded tostop production and to destroy all existingstocks .

Table 19 .6 . Eastern Africa : number of reported cases of smallpox, by month, 1969-1970

THE VACCINATION CAMPAIGNS

Except for a pilot programme in Tanzaniain 1968, during which 350 000 persons werevaccinated, none of the vaccination cam-paigns began until 1969. Meanwhile, thenumber of reported cases of smallpox inKenya, Tanzania and Uganda fell sharply (seeTable 19.1), from 3800 in 1966 to 2147 in1967 and to only 597 in 1968 . Rwanda, duringthis period, did not officially recognize casesof smallpox ; and little can be said about trendsin Burundi, whose reporting system was lessadequate than the others . During these years,little had been done to change the reportingsystems and there was no organized surveil-lance-containment activity. However, thetrend in incidence was steadily downward andsystems which had detected many cases inprior years were now reporting very few . Themass campaigns in Uganda, Burundi, parts ofTanzania, and in Nyanza Province, Kenya, in1965-1966 were undoubtedly responsible inpart for the decrease in the number ofreported cases. Perhaps of greater importancewas the provision of freeze-dried vaccine foruse by the health services in the control ofoutbreaks and in the limited routine vacci-nation programmes in which some healthcentres were engaged .

However, as we shall see, the vaccinationcampaigns in Kenya and Uganda began aftertransmission had apparently been inter-rupted ; in Tanzania, only 88 additional cases

NOTE: Cases are shown by month of detection ; many of the patients concerned experienced the onset of illness one to several monthsearlier .

a Denotes beginning of mass vaccination programme .b Cases resulting from Importations .

1969Country

Jan . Feb. March Apr . May June July Aug . Sept . Oct. Nov. Dec .

Rwanda 0 0 0 0a 0 6 47 28 15 5 4 2Burundi I 4 0 0 0a 20 40 10 10 8 5 10Tanzania 12 14 5 12 11 7 3 13 4 5 21 9 4Kenya 5 3 5 0 0 0 I 0 0 0a 0 0Uganda 2 6 Ib 0 0 Ib 0 0 0 2b Ib 2b 0

1970Country

Jan. Feb. March Apr. May June July Aug . Sept . Oct . Nov . Dec.

Rwanda 43 186 3 5 0 0 0 3b 5b 8b 0 0Burundi 0 0 3 95 1 7 20 60 5 6 0 0Tanzania I I I 23b 0 0 I 3 2 0 0 0Kenya 0 0 0 0 0 0 0 0 0 0 0 0Uganda 0 Ib 0a Ib 0 0 0 0 0 0 0 0

19. EASTERN AFRICA

200 km

1967 1968

r'

y

U ITEREPUBLIC OF

ZANIA

T-

jar 1 -0KENYA

occurred after the beginning of the campaign,of which 23 are known to have resulted froman importation from Zaire (Table 19 .6). Theendemic spread of smallpox stopped only 13months after the programme had begun inRwanda and after 17 months in the case ofBurundi .

Number of cases0

[l 1 -4950-99

100

953

Fig . 19 .2 . Eastern Africa : number of reported cases of smallpox by administrative area, 1967- 1970 . Thenumbers of cases in Rwanda in 1967 and 1968 are estimated .

The most heavily infected regions in 1967-1968 lay on the shores and in the vicinity ofLake Victoria (Fig . 19.2) and in the south-eastern area of Tanzania near the border withMozambique . The region around Lake Vic-toria was also one of the most densely popu-lated. As programmes began in 1969, Kenya

954


December 1969

200 km

A WHO technical officer from Belize, MrHenry Smith, was recruited to assist in thedevelopment of the Kenya programme . Hearrived in September 1968 and continuedwith the programme until February 1974 .From October 1968 to the end of May 1969,Mr Smith visited all provincial and districtheadquarters, beginning with those in thewest, whence cases were being reported, todemonstrate the use of the new bifurcatedneedle and the freeze-dried vaccine . At thetime of his visit, stocks of liquid vaccine werereplaced with freeze-dried vaccine . Staff inthe districts were then given responsibilityfor training those in peripheral units. InKenya at that time there were 163 healthcentres and 350 dispensary clinics ; their staffreported having vaccinated 1 .5 millionpersons in 1968 and 948 000 in 1969-about25% of the population in all .

The beginning of the mass vaccinationcampaign had to await the delivery of ve-hicles, which usually arrived 12-18 monthsafter they were ordered. The vehicles were

December 1970

E]Mass vaccination in progressMass vacination completed

Fig . 19 .3 . Eastern Africa : status of vaccination campaigns, by administrative area, December 1969 and Decem-ber 1970 .

and Tanzania concentrated their effortsspecifically in these areas (Fig . 19.3) .

Kenya

Plate 19 .2 . Henry C. Smith (b . 1935) served as aWHO technical officer for smallpox eradication inKenya, 1968-1974, before joining the programme inIndia .

delivered in the spring of 1969 and theprogramme began in October in WesternProvince, one of two small but denselypopulated south-western provinces inhabitedby 40% (4.5 million) of Kenya's population .Kenya's last known case of endemic smallpox

occurred 4 months before the programmebegan .

Initially, the staff consisted of 2 supervisorsassigned from the health services and 18Kenyan National Youth Service Volunteers,who had completed elementary school andhad undergone a 1-month training course.The team progressed from district to district .Three weeks before it was to begin work, MrSmith, or sometimes the national programmedirector, met the district medical officer andhealth inspector to plan the campaign .Within the district, vaccinations were givento the inhabitants of one sublocation afteranother-a sublocation being a unit rangingin population size from a few hundred to 4000and administered by a subchief. An assistanthealth inspector who worked in the areacontacted each subchief to explain thepurpose of the programme and to select aplace of assembly for each sector at whichapproximately 300 persons would be expectedto forgather. In the interests of economy ofoperation, the entire team worked in only onesublocation or a few adjacent sublocationseach day. Assembly points included hospitals,health centres, dispensaries, schools, markets,chiefs' houses, shops, bus stops and well-heads. A few days before vaccinations were tobe carried out, the subchief informed peopleof the schedule and the location of assemblypoints. Teachers were asked to pass on thedetails to parents and pupils. On the ap-pointed day, 2 vaccinators (or more, ifattendance was expected to be sizeable) weredispatched to the selected locations by LandRover. One performed vaccinations while theother kept a simple tally by age group of thevaccinees. The vaccination centres were keptopen throughout the entire day in order togive people sufficient time to attend, somebeing obliged to walk as far as 5 kilometres .

Because of the small number of staff, thevaccination campaign progressed so slowly

Table 19.7

a During one period of 6 months .

19. EASTERN AFRICA

955

Eastern Africa : principal components of support to the programmes (exclusive of vaccine)

that, by the spring of 1970, it was estimatedthat 10 years would be required to complete it .Accordingly, it was agreed that moreNational Youth Service Volunteers should berecruited and more supervisors assigned. Bythe end of 1970, the staff complement hadgrown to 50 vaccinators, 18 drivers and 8health inspectors. In addition, it was agreedthat when a team was in an area, local healthstaff who could be spared would work with it .The resources provided to the programme areshown in Table 19 .7. With the increasedcomplement of personnel, it was eventuallypossible to work in 10 districts simul-taneously .

In May 1970, it was decided to administerBCG vaccine concurrently with smallpoxvaccine to children under 15 years of age, andfrom then on the vaccinators worked as 2-man units. One vaccinator administeredsmallpox vaccine in one arm, using thebifurcated needle, and one administered BCGvaccine in the other arm, using a needle andsyringe, and tabulated the numbers vacci-nated. With this staff, between 400 000 and500000 smallpox vaccinations were per-formed monthly. By the end of 1970, thevaccination schedule had been completed inNyanza and Western Provinces as well as inportions of the neighbouring Rift ValleyProvince (see Fig . 19 .3) . In other parts ofKenya the population was vaccinated during1971 and, finally, the coverage was extendedto the numerous inhabitants of Nairobi andits surroundings in 1972. In all, 10 .5 millionvaccinations were performed by the mobileteams and 5 .6 million by the establishedhealth units during this period .

The only departure from the routine oc-curred in March and April 1971, when 2outbreaks, one of 45 cases and one of a singlecase, occurred in the north-eastern part ofKenya as a result of importations fromEthiopia (see Fig. 19.4). The mass vaccination

Kenya Uganda Tanzania Rwanda Burundi

Provided by WHO :Advisers I 0 2 I 1Vehicles 35 26 51 9 13Motor cycles 10 4Bicycles 141 141 108Refrigerators 13 20 82 32 12Annual petrol/vehicle maintenance costs (US$) 6 000 10 000 20 000 15 000 15 000

Provided by government :Number of personnel (maximum) 76 700a 72 27 50

956


campaign in this area had been scheduled tobegin in April and last throughout June 1971,but its date of commencement was advancedto March. Subsequently, 6 vaccination/case-search rounds were conducted in this and 5other northern districts that bordered onEthiopia and the Sudan and were consideredto be at high risk .

Except for Rwanda, none of the 5 countriesfollowed the programme for assessment re-commended in the WHO Handbook forSmallpox Eradication Programmes in EndemicAreas (SE/67.5 Rev.1). The handbook calledfor an assessment team to visit a 10% randomsample of villages 1-2 weeks after vaccinationto determine coverage and the proportion ofpeople successfully vaccinated . As was thecase in a number of countries, health officialsresisted the diversion of personnel and ve-hicles from the vaccination campaign itself .To determine coverage in Kenya, the numbervaccinated was simply compared with theestimated population in the area anunsatisfactory procedure in a country wherecensus data were so imprecise. Approximately100 children were examined one week aftervaccination to determine whether a sufficientproportion had been successfully vaccinated .Definitive information about the degree ofsuccess of the vaccination campaign did notbecome available until the conclusion of theprogramme, when, in 1972, 2 WHO stafffrom the WHO Epidemiological SurveillanceCentre in Nairobi undertook a carefullydesigned cluster sample survey . Approxi-mately 2000 persons were examined in eachof 5 different provinces . The results areshown in Table 19.8 .

The vaccination coverage of individualsaged 5 years and over was satisfactory in theCentral, Eastern and Coast Provinces but notin Western and Nyanza Provinces, in whichthe programme had first been launched andhad been completed in 1970. In these lattertwo provinces, the vaccination coverage ofchildren under 5 years of age was substantially

Table 19 .8. Kenya: results of vaccination scar surveys in 5 provinces, by age group, 1972

below expected levels ; this was partly ac-counted for by the fact that health centreswere vaccinating only about 25-30 % of thoseborn subsequent to the 1970 campaign .

At the conclusion of the campaign, in July1972, 22 sectors were identified, to each ofwhich a team with a vehicle was assigned . Theteams were to proceed from one sublocationto the next, vaccinating those eligible forvaccination and inquiring at schools, marketsand health units about possible cases thatmight have occurred during the preceding 3months. Each team was expected to completea tour of its sector once a year ; in high-riskareas, the schedule was intensified to onceevery 3-6 months. The teams were calledsurveillance teams, but in fact their principalresponsibility was to provide maintenancevaccination. The system remained in oper-ation for little more than a year.

Uganda

Like Kenya, Uganda had a reasonablyextensive network of health centres andclinics and a complex of roads reputed to bethe best in eastern Africa. A mass vaccinationcampaign using liquid vaccine was completedin 1966, following which the number of casesof smallpox diminished to only 365 in 1967and 55 in 1968. Between 600 000 and 900 000persons were being vaccinated annually in thevarious health establishments, and in 1969freeze-dried vaccine supplied by WHO wasintroduced for use throughout the country .Because liquid vaccine had been employed inthe previous vaccination campaign andbecause it was known that many of the vacci-nations had not been successful, Ugandaagreed in mid-1968 to undertake a special 3-year national vaccination campaign . WHOprovided the necessary vehicles and equip-ment. However, the government later decidedto abandon this schedule in order to conduct,in 1970, a national mass vaccination cam-

Agegroup(years)

Western Nyanza Central Eastern Coast

Numberexamined

% withscar

Numberexamined

% withscar

Numberexamined

% withscar

Numberexamined

% withscar

Numberexamined

% withscar

0-4 472 51 .7 444 45 .9 493 76.5 486 76 .1 471 62.05-14 645 77 .8 628 74.7 774 89.2 719 90 .8 570 90 .0515 902 81 .3 943 72 .1 827 86.7 866 83 .8 1 066 89 .3Total 2019 73 .2 2015 67 .8 2094 85.2 2071 84 .4 2 107 83.3

paign to be completed in just 6 months . Tohelp to prepare the work, Dr GeorgijNikolaevskij, of the WHO HeadquartersSmallpox Eradication unit, was detailed toUganda for a 5-month period . He assisted DrYurij Rikushin, a WHO medical officeroriginally assigned to Uganda for BCG vac-cination. District health inspectors in eachdistrict organized the programme, whichrequired the population to assemble for vac-cination at collecting points. Vaccinationstaff were divided into groups of 3 or 4persons who moved from subcounty tosubcounty . In all, some 700 public health staffwere engaged in the campaign . BetweenMarch and August 1970, 8 .5 million vaccina-tions were performed in a population thenestimated to be 9 .8 million . There was nospecial assessment of the campaign to measurethe prevalence of vaccination scars after it hadbeen completed, but most believed that it hadbeen generally well executed. Like the pro-gramme in Kenya, however, it was begunmany months after smallpox transmission hadbeen interrupted .

Following the campaign, vaccinationcontinued to be performed by the varioushealth centres in the country but only100 000-200 000 persons were vaccinatedannually, a figure equivalent to perhaps halfthe number of children born each year. Inaddition, sporadic campaigns which involved

Plate 19 .3 . Yurij P . Rikushin (b . 1923), a WHOmedical officer working in tuberculosis control inUganda, 1965-1971, also acted as the smallpox eradi-cation adviser there and was instrumental in organiz-ing Uganda's 6-month intensive mass vaccinationcampaign .


the vaccination of about 100 000 personswere conducted in areas bordering on theSudan following the importation of casesfrom that country .

Such knowledge as was available regardingthe level of vaccinial immunity at the timewas provided by 2 surveys carried out indifferent parts of northern Uganda (Table19.9).

Both surveys were conducted in areasconvenient of access by road, immediatelyafter special area-wide mass campaigns hadtaken place. One must assume that vaccinialimmunity in more remote areas of thesedistricts and in other parts of Uganda wassubstantially below the levels shown in Table19 .9 .

Tanzania

Of the 5 countries, Tanzania was the onlyone which had expressed genuine enthusiasmabout undertaking a programme . A thousandor more cases of smallpox had been reportedalmost every year since the 1950s, and inmany outbreaks case-fatality rates of 5-10%had been recorded . Vaccination with liquidvaccine had been provided in health centresthroughout the country, but no special pro-gramme had been conducted until 1965-1966, when the number of reported casesincreased to 2762 in 1965 and to 3027 in 1966 .During these 2 years, a mass campaign wasconducted in which 6 million vacci-nations were given and, subsequently, some2-2.5 million vaccinations, with the low-potency liquid vaccine, were performed an-nually in health units, which then consisted of105 hospitals, 54 rural health centres and1442 dispensaries . However, 1629 cases werereported in 1967 and reporting in Tanzaniawas considered to be less complete than inKenya or Uganda .In August 1967, WHO and the govern-

ment agreed on a plan of operations whichprovided for transport, equipment and sup-

Table 19 .9. Northern Uganda : results of vaccinationo

scar surveys, by age group, 1972Q

< 1 120 17 .5 109 51 .41-4 449 82 .6 205 86.85-14 491 90 .8 331 90.3

15 508 95 .0

1 226 97.3

February 1972 April 1972Agegroup

Number % with Number % with(years)

examined scar examined scar

958


plies of freeze-dried vaccine, as well as the Table 19.10 . Tanzania, Geita District : results ofassignment of a WHO medical officer, Dr vaccination scar survey, by age group,R er onne , and a technical office Mr . 1969,G. Michalatos. The WHO staff arrived in thelate spring of 1968, and in July 1968 a pilotproject was begun in Geita District(population, 385 000) in northern Tanzania .This district had reported the highest in-cidence of smallpox of any in the country in1966-1967 and was considered to be one ofthe most difficult in which to work because ofpoor roads and extensive swamps. During a5-month period, a team of 24 vaccinators,a supervisor and 4 drivers performed vacci-nations equal in number to more than 90%of the population .

Lack of government funds then resulted inthe suspension of the campaign for 7 months,until July 1969, when it was resumed in theendemic north-western districts (see Fig.19.2) and at the end of the year in 2 endemicsouth-eastern districts. Three mobile teams,each consisting of 23 persons, conducted thecampaign under the direction of each area'sdistrict health inspector . The teams weresubdivided into 4 units, each comprisinga supervisor and 4 or 5 vaccinators andequipped with a motor vehicle, 2 bicycles anda kerosene-operated refrigerator . Politicalleaders, called "ten-cell chairmen," played animportant role. Each was contacted one ortwo weeks before the team was due to arriveand was asked to prepare a list of all residentsin the area for which he was responsible .When the team arrived, the residents wereassembled and each was summoned by namefor vaccination. The system might appearcumbersome and time-consuming, but in factthe vaccinators consistently averaged morethan 500 vaccinations a day. They continuedto achieve this norm even when, in 1970,they undertook the additional task of ad-ministering BCG vaccine to children under15 years of age . The system was an unusual onebut it worked well in Tanzania, in which thepolitical structure was highly organized . Anindependent cluster sample survey conductedin Geita District by a team from the WHOEpidemiological Surveillance Centre inNairobi revealed that 94% of the personsexamined had vaccination scars at the con-clusion of the programme (Table 19.10) .

Later surveys, conducted during 1970 atthe conclusion of campaigns in 6 regions,revealed comparable results (Table 19 .11) .

Although by the end of 1969 the vacci-nation campaign had been completed in only

Table 19 .1 1 . Tanzania : results of vaccination scarsurveys in 6 regions, by age group,1970

1 district and had just begun in 3 others, thenumber of reported cases of smallpox thatyear decreased to 117. Reporting was stillinadequate, since little had been done toimprove the national reporting system ;however, this was the lowest total of casesever recorded. Even if the reporting systemhad not improved, it certainly did not appearto have deteriorated . Finally, in 1970, theinvestigation of some cases began. Of 3outbreaks examined, 1 (in April) had resultedfrom an importation from neighbouringZaire. Cases were reported from only 4regions (Fig . 19.2), and in September the lastcase was found.

The programme continued, region by re-gion and district by district, at lengthconcluding with the vaccination of thepopulation of the then capital, Dar es Salaam,in August 1973. While in most countries theresidents of the capital city were the first to bevaccinated, they were left until last in Tan-zania, since Dar es Salaam, situated on thecoast, was far away from the known endemicareas . In all, 19 .8 million persons were vacci-nated against smallpox between 1967 and1973 and 3.7 million under 15 years of agereceived BCG vaccine. After September 1970,vaccinators during their visits reported 23

0-4 years All ages

RegionNumberexamined

"/o withscar

Numberexamined

% withscar

Mara 3 251 98 .9 9 423 93 .1West Lake 4 341 96 .0 14 608 95 .4Mtwara 8 116 98 .1 35 482 98 .2Shlnyanga 709 97 .5 1 544 98 .2Tabora 897 91 .8 3 704 97 .2Klgoma 342 93 .0 897 94.9

Agegroup(years)

Numberexamined

With scar

Number

0-4 210 197 93 .85-14 293 283 96.6

15 654 608 93 .0

Total 1 157 1 088 94.0

Plate 19 .4 . Tanzanian posters in Swahili were widelydistributed in 1969, reading : "This is smallpox . Youand your family protect yourselves by getting vacci-nated" .

suspected cases but none proved to besmallpox .

On completion of the programme, mobileteams continued to vaccinate and to search forcases in remote and border areas ; the healthservices vaccinated about a million personseach year thereafter but, as in Kenya andUganda, interest in the programmediminished sharply .

Rwanda and Burundi

The programmes in these densely popu-lated countries, each with some 3 .5 millioninhabitants, were a study in contrasts . In both,the responsibility for operating the pro-gramme was largely delegated to theirrespective WHO smallpox advisers. One ofthese, Dr Celal Algan, was an energeticworker, well acquainted with conditions inthe field, who, with the help of Rwandesestaff, conducted one of the most effectiveprogrammes in Africa. The other, who wasassigned to Burundi, rarely travelled to thefield and had little apparent capacity fororganization ; the programme in Burundireflected these shortcomings .

19. EASTERN AFRICA

959

In both countries, the population lived insmall hamlets and hillside villages scatteredover a tropical and subtropical uplandplateau. Roads were few and often impassableduring the February-May rainy season . Hos-pitals, health centres and dispensaries, someoperated by the government and some bymissionaries or other private voluntaryorganizations, were comparatively numerous .In 1971 there were 157 hospitals, healthcentres and dispensaries in Rwanda and 104hospitals and dispensaries in Burundi. Vac-cination was offered at all these health units ;about 10-15 % of the population were vacci-nated each year . The vaccine used was a liquidproduct which had been manufactured by alaboratory in Butare (Rwanda) since 1953 .Beginning in 1965, this laboratory also pro-duced some freeze-dried vaccine which, as hasbeen mentioned earlier, was prepared in 600-dose vials. These vials contained such a largequantity of vaccine that it was often kept,

o unrefrigerated, for many days or even weeks,with a consequent loss of potency after thefirst day .

Rwanda

Vaccination in Rwanda had been per-formed primarily by 2 teams, each consistingof 3 persons, who shared a vehicle andtravelled regularly to 400 vaccination pointsestablished at health facilities and schools. Asample scar survey conducted in 1968 of10 404 persons in 3 different prefecturesshowed a generally low level of vaccinialimmunity, especially among children (Table19.12) .An agreement was signed with WHO in

April 1968 which provided for theassignment of a WHO medical officer and thesupply of vehicles and equipment, vaccineand needles, as well as for the costs of petroland vehicle maintenance to be met by WHO .However, at the end of 1968, the Ministry of

Table 19 .12. Rwanda: results of vaccination scarsurveys in 3 prefectures, by agegroup, 1968

Age

(yeas)

Numberexamined

% with scar

Kibungo Kigali Gisenyi

0-4 1 920 0 3 255-14 3 482 44 21 79

15 5 002 72 69 85

Total 10 404 48 43 73

960


Health and WHO staff working in thecountry re-evaluated the plan and decided tocombine the field activities with those of aBCG vaccination campaign then under way .Dr Algan, at that time the WHO adviser fortuberculosis control in the country, volun-teered to assume responsibility for bothactivities.

In mid-April 1969, the programme beganoperations with a supervisor and 10vaccinators who worked in pairs, oneadministering BCG vaccine and the other

smallpox vaccine . Only a single vehicle wasavailable, and so the team moved as a group tothe various administrative units (prefectures),where vaccination was performed atcollecting points . Areas from which caseswere reported were attended to first . Hos-pitals and health clinics were supplied withvaccine and encouraged to participate ingiving vaccinations.

As was the practice in other countries, DrAlgan and his Rwandan counterpart heldmeetings with local authorities beforehand to

Plate 19 .5 . A : Celal Algan (b . 1926), previously the WHO medical officer assigned to Rwanda for tuberculosiscontrol, assumed responsibility in 1968 for organizing the smallpox eradication work in a campaign combiningthe administration of smallpox and BCG vaccines . The well-planned, rigorously supervised operation completedits 36-month work plan in half that time, while simultaneously developing an effective surveillance programme .Subsequently, as the WHO regional adviser on smallpox eradication in Africa (1975-1980), Algan organized theextensive activities required for the certification of eradication . B: Land Rovers move out for field work towingtrailers with camping equipment . C: Rwandan vaccination team .

explain the programme and to identify themost suitable collecting points and work outthe best schedule. Local political leaders weregiven the responsibility for convening thepeople on the appropriate day and, later, forthe reporting of smallpox cases . Concurrentassessment of the campaign was by randomsample evaluation to ascertain take rates .

From the beginning, the team workedconscientiously and well, initially averaging750 vaccinations per vaccinator per day andlater as many as 1500 vaccinations pervaccinator per day . The productivity reportedwas in fact so high that the figures wereviewed with scepticism by Ladnyi and WHOHeadquarters staff. Ladnyi, however, con-firmed the validity of the data during a specialvisit, noting in passing that the vaccinatorscomplained only of sore fingers and wonderedwhether thimbles could be provided .

In October 1969, the vehicles intended forthe programme were delivered and, withadditional transport available, the comple-ment of staff was increased to 27 (2 super-visors and 25 vaccinators, 5 of whom servedas drivers) ; the personnel were divided into 3teams, of which 2 were occupied with vacci-nation and the third, headed by Dr Algan,


with surveillance-containment . By the endof 1969, 989000 persons had been vacci-nated against smallpox by the mobile teamsand 54 000 children had been given BCGvaccine .

During 1970, the investigation of 18 re-ported cases led to the discovery of 235additional cases . After April, only 3 outbreaks,consisting of 3, 5 and 8 cases respectively,were discovered ; each had resulted fromimportations from Zaire .

By the end of October 1970, only 18months after the vaccination campaign be-gan, the programme had been completed .During this period, the teams had vaccinatedmore than 3 million persons . A scar surveyconducted in 1971 showed that, of thoseexamined, 87% of children aged 0-4 yearshad vaccination scars, as did 97% of thoseaged 5-14 years and 93% of persons aged 15years and over.

After the programme had been completed,hospitals and clinics continued to administersmallpox and BCG vaccines, while 8 teams,each consisting of 3 vaccinators, travelledthroughout the more remote areas, especiallythose bordering Zaire, to search for cases andto vaccinate.

Plate 19 .6 . The recording form used in vaccination centres in Rwanda . The numbers of smallpox vaccinationsand revaccinations administered could be quickly and easily noted by age group .

962


Table 19 .13 . Burundi : results of vaccination scar surveys in 3 prefectures, by age group, June 1968

Burundi

Vaccination in Burundi had traditionallybeen performed by health units . In 1966,however, 500 000 persons were vaccinatedduring a special mass vaccination campaignundertaken after the occurrence of 1213reported cases of what was said to have beenvariola minor. Sample surveys carried out byLadnyi in 3 prefectures of Burundi in June1968 revealed a remarkably high level ofvaccinial immunity in all age groups in 2 ofthe areas in which the campaign had beenconducted, and satisfactory levels in individ-uals aged 5 years and over in the third area(Table 19 .13) .

A plan of operations for an eradicationprogramme was agreed on and signed inDecember 1967 by WHO and the govern-ment. How much smallpox might be presentwas unknown, since reporting was veryincomplete. Only 74 cases were recorded in1967, but the number rose to 301 in 1968 .

In December 1968, a WHO medical officerarrived on assignment, along with suppliesand equipment. Field activities began in May1969 with 2 (later 4) mobile vaccinationteams, each consisting of a supervisor, 4vaccinators, an enumerator and a driver . Thenumber of staff increased to 31 by mid-1969and to 50 by 1971 . The method of work wassimilar to that in Rwanda although nevercharacterized by the same degree of carefulplanning and diligence. During 1969, only415 705 vaccinations were performed, a num-ber far lower than in Rwanda . Ladnyi, whovisited the programme in February 1970,discovered that none of the vaccine was beingkept under refrigeration, that vaccinatorswere issuing each vaccinee with a signed andofficially stamped certificate of vaccinationand that vehicle maintenance was virtuallynil. The existing stocks of vaccine weredestroyed and new supplies were flown in ;the time-consuming practice of issuingindividual certificates of vaccination wasstopped ; but a proposal to replace the WHOsmallpox adviser was rejected . Fortunately,a new WHO country representative, Dr

Table 19 .14 . Burundi : results of vaccination scarsurvey, by age group, 1973

Christos Karamustakis, arrived at this junc-ture. An intelligent, industrious person whohad worked previously in Zaire and knew thesmallpox programme there, he assumed on apart-time basis an overall supervisory roleand, thereafter, the programme proceededbetter. However, despite a far greatercomplement of personnel than in Rwanda,and despite the absence of the requirement forsimultaneous administration of BCG vaccine,the mass vaccination campaign in Burunditook more than 2 years to complete and didnot conclude until June 1971 .

In all, 2 997 500 vaccinations were per-formed between 1969 and 1971 . No concur-rent assessment of coverage was performed,nor were vaccinations checked to find outwhether they were successful . Following thecampaign, vaccinial immunity was not high,as was revealed in a 1973 sample surveyconducted by a team from the WHO Epi-demiological Surveillance Centre in Nairobi(Table 19.14) .

The local health services were expected tocontinue the vaccination campaign but littlehad been done to obtain their cooperation andthus the number of vaccinations performed in1972 dropped to only 30 000 . Other WHOstaff were brought in to help to organize aneffective reporting and maintenance vaccina-tion programme, and by 1973 reporting hadbegun to improve and the number of vaccina-tions to increase .

SMALLPOX OCCURRENCE, 1969-1970

Only 355 cases were reported from the 5countries in 1969 and 484 cases in 1970. Howaccurately this reflects the true incidence of

Age group(years)

Kitega Ruyigl BururlNumber examined % with scar Number examined with scar Number examined % with scar

0-4 174 7 94 87 125 965-15 539 78 487 95 144 98

16 276 73 347 93 67 82

Age group (years) Number examined % with scar0-4 6 783 5 .95-14 103 815 69.8> 15 90 118 70.0Total 200 716 67.7

smallpox is difficult to assess. The eradicationprogrammes consisted essentially of the tradi-tional mass vaccination campaigns of the past,few of which incorporated either concurrentassessment of coverage or a special surveil-lance-containment element .

A national surveillance programme whichserved to ensure that all suspected cases wereinvestigated and the outbreaks contained wasa difficult concept for the countries to graspand to implement. This was especially true ofthe former colonies of the United Kingdom,since their health services tended to be muchmore decentralized, the primary responsi-bility for health programmes being vested indistrict medical officers . This policy ofdecentralization of authority and responsibil-ity offered many advantages in implementinga variety of programmes but not for thedevelopment of a national surveillance pro-gramme. District medical officers consideredthe control of smallpox to be specifically theirown responsibility and resented the intrusionof a national presence . Where district medicalofficers were competent and diligent, this wasnot a problem ; but many were not, and for allof them smallpox was but one of an array ofproblems and not always of high priority . Areport of the occurrence of smallpox evokedthe typical response that cases occurred in theprovince from time to time.

Ladnyi struggled to try to improve report-ing and surveillance but, with responsibilityfor 19 countries, could devote little time toany single country. Moreover, he had beeninstructed by the regional office that he wasnot to undertake travel unless a visit wasspecifically approved in advance by thecountry and by the regional office, a processwhich he found to require at least 6 months .He ultimately decided to sidestep this restric-tion by sending a telex to the regional officeinforming it of his proposed travel plans andindicating that he would proceed unlessinstructed otherwise within the next 2-3weeks. Rarely did the regional office reply inless than 4-8 weeks to any communication . Apattern therefore evolved in which Ladnyiproposed a trip and, receiving no reply, wentahead with his travel plans and eventuallyreturned to Nairobi. After his return, he oftenreceived a telex advising him not to undertakethe proposed trip .

In 1969, with so few cases being reported ineastern and southern Africa, it seemed thattransmission would be interrupted quicklywhatever the status of the vaccination cam-

19. EASTERN AFRICA

963

paigns. Accordingly, on 4 June 1969, Hender-son wrote to the regional office and toLadnyi in the following terms :

"I believe that it is absolutely, vitally andunequivocally essential that provision be made fora responsible person, preferably a medical officer,to investigate personally each and every case toverify the diagnosis and to assist with or carry outhimself the necessary investigations and contain-ment activities . Any plan not incorporating thisparticular feature is doomed to failure . . .Experience throughout the world both in endemicand in non-endemic areas has clearly shown thatwhen full responsibility is entrusted to the districthealth authorities, the results obtained are highlyirregular and frequently unsatisfactory ."

Interestingly, eastern Africa in particularwas to disprove Henderson's sweepingprediction of failure. The status of smallpox in1969 was anything but clear. Kenya ceased todetect cases that year. Burundi recorded 108cases and Tanzania 117 cases, but in neithercountry was there an adequate surveillanceprogramme. In Rwanda, on the other hand,efforts were made to improve reporting andto investigate outbreaks. There, Dr Algansought to obtain reports from the health unitsand, when outbreaks were found, redirectedthe programme to conduct mass vaccinationin the infected areas. Virtually all cases inRwanda were those detected by the specialteams. It is probable that reporting was alsosomewhat more complete in 1969 in Burundiand Tanzania because vaccination teamsworked in infected areas and detected cases inthe process. However, it is likewise probablethat some of the reported cases weremisdiagnosed cases of chickenpox. Uganda,for example, originally reported 19 cases in1969, but when these were investigated by aWHO consultant, only 9 were found to havebeen smallpox .

In 1970, Kenya reported no cases andUganda only 2 ; the latter, when investigatedby a WHO consultant, were found to havebeen infected in the Sudan and Rwandarespectively. Tanzania detected only 32 cases,the last in September. Twenty-three of thecases occurred following an importation fromZaire ; the others were not investigated. InBurundi vaccination teams found 197 cases,about which nothing more is known ; the lastof them occurred in October. Rwanda re-ported 253 cases in 1970, of which 18 werenotified by the health services and the restdetected by the surveillance team . Transmis-

964

Table 19.15. Rwanda: number of cases of smallpox,

by age group, 1969-1970

a Percentage distribution calculated on total cases with knownage (349).

sion in Rwanda was interrupted in April1970, although 3 outbreaks resulting fromimportations from Zaire occurred betweenAugust and October . Data regarding the agedistribution of cases throughout 1969-1970are available only from Rwanda (Table 19 .15).Virtually all the cases were in children under15 years of age, almost half of them under 5years old .

Increased confidence that reporting wasreasonably complete in 1970 was provided bythe expanding vaccination campaigns, whichserved both to improve vaccinial immunityand to detect any cases that were present . InOctober 1970, the last cases were reportedfrom these 5 countries, but not until nearly ayear later could it be stated with confidencethat transmission had actually beeninterrupted.

The rapid disappearance of smallpox fromthis area was surprising considering theperfunctory surveillance and containmentactivities. Levels of vaccinial immunityvaried widely from place to place but, exceptwhere the systematic vaccination campaignshad been conducted, they were not generallyhigh. Indeed, smallpox had disappeared fromall but the densely populated areas ofBurundi, Rwanda and Tanzania before thecampaigns began. In retrospect, a combina-tion of factors was probably responsible : (1) agenerally scattered population with few largeurban centres ; (2) limited travel by most ofthe population, many of whom respected thenumerous tribal boundaries ; (3) prevalent,although not universal, tribal traditionswhich called for patients to be isolated in aseparate hut and cared for by someone whohad had smallpox ; (4) a comparatively exten-sive network of health centres which, whenfreeze-dried vaccine was made available, suc-cessfully immunized a large proportion ofpeople ; and (5) the presence of a form ofsmallpox which spread less readily than didvariola major in Asia and against which


successful vaccination provided a longer-termimmunity.

After 1970, outbreaks were reported onlyin Kenya and Uganda, in the former follow-ing importations from Ethiopia and Somalia,and in the latter from the Sudan .

IMPORTATIONS INTO UGANDA

It is probable that transmission in Ugandawas interrupted in 1968 . Only 9 cases weredetected in 1969, and although the sources ofthese outbreaks were not clearly traced, 6occurred in Sudanese refugee camps in itsnorthern districts and the other 3 in the southamong refugees from Rwanda . In 1970, 1 caseoccurred in the north in a refugee infected inthe Sudan and 1 case in a person infected inRwanda. During 1971-1972, Uganda re-corded 35 cases, all in its northern districtsamong Sudanese refugees and members ofthe local population who were in contactwith them. These are shown as importedcases in Table 19.1 .

Juba Province in the southern Sudan layjust across Uganda's northern border andthere a protracted civil war had been inprogress. Tens of thousands of Sudaneserefugees had taken up residence in northernUganda and many continued to move backand forth between the two countries. Thehealth services in Juba had been devastated bythe war, vaccinial immunity was low, and,throughout 1972, smallpox was widelyprevalent .

In October 1970, when Uganda had com-pleted its mass vaccination campaign, itreverted to its previous pattern of operations,whereby vaccination was performed at clinicsand health centres ; district health inspectorsassumed responsibility for surveillanceactivities and the containment of anyoutbreaks that were found. WHO recom-mended that a national surveillance teamshould be constituted to improve reportingand to participate in the investigation of anyreported outbreaks, but this advice was notfollowed .

In 1971, 19 cases were reported from thenorthern districts of Acholi and Madi, 15 ofwhich occurred in Sudanese immigrants ; 4local residents were infected by them. In 1972,16 further cases were detected in this samearea, primarily among Sudanese nationals .WHO staff who visited the area discoveredthat containment measures were not

Age group (years) Number %a

< I 50 14 .31-4 112 32 .15-14 162 46 .43 15 25 7 .2Unknown I

I -

Total 360 100 .0

promptly taken, the investigation ofoutbreaks was perfunctory, containment waspoorly executed and a number of cases re-ported locally were not notified to thenational authorities. Fortunately, in thissparsely settled, reasonably well vaccinatedarea, the spread of smallpox was even lessefficient than the performance of the staff .

In early 1973, a special training programmein surveillance-containment was conductedfor the staff in northern Uganda, and in Aprila central surveillance team was constituted toinvestigate all suspected cases. A number ofsuspected cases were competently investi-gated and specimens obtained, but noneproved to be smallpox. Meanwhile, Uganda'sonly remaining endemic neighbours, Zaireand the Sudan, succeeded in interruptingtransmission-Zaire in June 1971 and theSudan in December 1972. Thus, the surveil-lance team began work in Uganda after therisk of importations had all but ceased,ironically paralleling the execution of itsnational vaccination campaign, which beganafter smallpox transmission had beeninterrupted .

IMPORTATIONS INTO KENYA

Kenya, in contrast to Uganda, initially tookmore vigorous steps to improve reporting andestablished a national surveillance team in1970. Six suspected cases were investigated inthat year, all of which proved to bechickenpox . In March 1971, a nomadic herds-man from Ethiopia, travelling while ill,crossed the border and infected residents in avillage some 70 kilometres south of theborder . Subsequently 44 more cases occurredin 3 generations of transmission, 5 of the casesbeing fatal . The large proportion of deathswas unusual for outbreaks in the Kenya-Ethiopia area at this time, but whether theoutbreak was due to variola major rather thanvariola minor is unknown. Mass vaccinationhad not yet been conducted in this area but,because of the outbreak, teams were quicklytransferred to the district. Six thousandpersons were vaccinated in and around thevillage, and the teams subsequently searchedand vaccinated the entire district . No furthercases were discovered .

In April 1971, another case was reportedfrom a village 150 kilometres east of the first(Fig. 19 .4). The patient was an Ethiopianadult visitor who resided just 14 kilometres


Fig . 19 .4 . Kenya: sources of importations of small-pox, 1971 -1976 .

north of the border. More than 95% of thevillage people had already been vaccinatedand no further cases occurred .

The national mass vaccination campaignconcluded in June 1972 and, at that time, thecountry was divided into 22 sectors, each witha mobile surveillance team which was sup-posed to be responsible for surveillance andfor the vaccination of nomadic and othergroups considered likely to import smallpox .By then, Ethiopia was Kenya's only neigh-bour with endemic smallpox.

In Kenya the surveillance programmeproved to be little better than in the othercountries. In part, this can be ascribed to thefact that no surveillance teams had beenestablished before transmission was inter-rupted, and thus they had no experienceeither in the investigation or in the contain-ment of outbreaks. Moreover, the absence ofcases understandably led to complacency .Sustaining interest in smallpox eradicationafter transmission had apparently been inter-rupted was difficult in all countries andespecially difficult in Kenya . Following theoutbreaks in March and April 1971, nofurther cases were detected for more than 2~years .

966

On 30 December 1973, a 25-year-old manwith smallpox was found in Mandera innorth-east Kenya at the border with Ethiopiaand Somalia. He had travelled 150 kilometresfrom an area in Ethiopia in which smallpoxwas known to be occurring . Containmentvaccination was begun, and during the cam-paign a second case was discovered. Thepatient was a 23-year-old woman, who de-veloped rash on 27 January and subsequentlyinfected 2 other people. She had arrived inMandera only 2 days before becoming ill andthus represented a second importation . Thesource was said to be a Kenyan village near theEthiopian border, some 80 kilometres to thewest. The fact that no investigation of thisarea was undertaken (although no furthercases were reported) is indicative of thequality of the surveillance.

Again, 2 years were to elapse without cases .Meanwhile, Ethiopia reported its last cases inAugust 1976. In late September, however,Somalia reported its first cases for almost 2years, in the capital, Mogadishu, supposedlyresulting from importations from Ethiopia .As at the end of December, 39 cases had beenreported, all in Mogadishu (see Chapter 22) .When the report of cases in Somalia wasreceived, a Kenyan team was sent to theborder area to undertake an active search forcases . This team then represented virtually theonly surveillance unit within 150 kilometresor more, since because of fighting in the area,Ethiopian teams had to remain at least thatdistance from the Kenyan border . Somalistaff, if they were finding cases outsideMogadishu, were not reporting them.

That smallpox did not spread into Kenyamust be attributed more to good fortune andto a sparse population than to the work of theinexperienced surveillance team. In Decem-ber 1976, smallpox was again introduced intoMandera District (see Fig . 19.4). From theavailable, and somewhat conflicting, reports,it appears that a 40-year-old Kenyan man,who had been studying in an Islamic schoolnear Mogadishu, became ill with smallpox on26 December . He was then staying with hisbrother in a village, Kalaliyo, 29 kilometreswest of Mandera town ; 3 days later, hetravelled some 35 kilometres south to avillage, Ledi, to stay with his sister, and soonthereafter he returned to Somalia. The healthofficer in Mandera, informed that a caseresembling smallpox had been seen in Ledi,sent a health inspector and a vaccinator . Onarrival, they were told that the patient had


left ; they returned without vaccinating any-one. On 13 January 1977, a subchief reportedthat the patient's sister had developed a rash .This time, the surveillance team went to Ledi,obtained a specimen and departed. Elevendays later, a report was received from aNairobi laboratory that the specimencontained smallpox virus . On 26 January, theteam again went to Ledi and found that thefamily had departed for a village (Kara) some50 kilometres to the north-east. Another dayelapsed before they could be found . Vacci-nation was then begun but 2 daughtersbecame ill with smallpox on 22 and 27January and another daughter (stillunvaccinated) on 7 February. The patientswere advised to stay in the house, but it waslearned later that the mother regularly left thehouse to obtain water from a nearby water-hole frequented by a number of people .

Additional staff were sent from Nairobi toassist, and on 17 February 1977 WHO epi-demiologists well acquainted with surveil-lance and outbreak investigation arrived .Mass vaccination carried out by 6 teams withvehicles in villages and towns accessible byroad had commenced on 28 January. By mid-February, the proportion of the populationvaccinated reached 80% in the main villages,but only 30% in more remote villages. In fact,the 16 inhabitants of a village located just 2kilometres from the outbreak were found, inearly March, not to have been vaccinated atall. Meanwhile, because of heavy rains in thearea, many nomads began moving throughthe area from Ethiopia as well as Somalia. Atthe end of April, a survey of 2256 persons in anearby division revealed that only 527 (23%)had vaccination scars. By the end of February,a search had been organized throughout theeastern part of Mandera District which, byassessment, was reasonably effective . A re-ward of 200 Kenya shillings (US$24) wasoffered to anyone reporting a case. Gradually,monthly searches were extended to otherdistricts bordering on Ethiopia and Somalia,but because of mud, vehicle breakdowns andscarcity of staff, probably not more than a halfto two-thirds of the districts were satisfac-torily searched. The searches continued untilMarch 1978, some 6 months after the lastknown case occurred in Somalia .

It was feared that more cases would befound, but only 1 additional case wasdiscovered by the search teams, in a 25-year-old man who had become ill on 16 December1976. The source of infection was not

Plate 19 .7. The strategy for search activities in Kenya during 1977 was worked out by Jean-Paul Ryst (b . 1939),a WHO consultant, Ziaul Islam (b . 1931), a WHO medical officer for epidemiological surveillance in Africa,1971-1982, and Wilfred Koinange (b . 1939), Director of Health Services of Kenya .

determined although it was considered to beunrelated to this outbreak. Meanwhile, effortswere made to find the original case in Somaliabut it was never discovered .

CONCLUSION

The circumstances attendant on the eradi-cation of smallpox from these 5 countrieswere wholly unlike those encountered in Asiaor South America. In Asia, levels of vaccinialimmunity comparable with, and in manyinstances better than, the levels observed ineastern Africa failed to stop transmission .Only when a fully effective surveillance-containment programme was introducedcould transmission be interrupted . In Brazil,surveillance and containment played a no-tably less important role in eradication, butthere the vaccination campaign was carefullyexecuted with specially trained assessmentteams evaluating the performance of thevaccination teams on a daily basis. In Kenya,Uganda, and Tanzania, smallpox incidencewas diminishing rapidly by the time theIntensified Programme began . In all butlimited areas of Tanzania, and in Rwanda andBurundi, the introduction of freeze-driedvaccine of good quality was all that wasrequired to interrupt transmission ; the exten-sive infrastructure of health services did therest. Mass vaccination campaigns, withneither assessment nor surveillance (except in


Rwanda), served to eliminate smallpox in theother areas .

Whatever the deficiencies of theprogrammes, smallpox transmission wasrapidly interrupted at little cost, with theaddition of only a few experienced healthstaff, a small cadre of minimally trainedvaccinators and encouragement and supportfrom WHO. In retrospect, many factorsaccount for this success : the substitution offreeze-dried for liquid vaccine ; the ready,even enthusiastic, acceptance of vaccinationby most of the population ; the goodcooperation of village leaders, missionaries,teachers and others ; the presence of milderstrains of variola virus which spread lesseasily ; the generally sparse population and theinfrequency with which they travelled overlong distances ; and an extensive network ofhealth centres and clinics, many of whichundertook to control outbreaks when thesewere discovered.

Of particular note in these countries wasthe extraordinarily high productivity of thestaff compared, for example, with that of theircounterparts in the Indian subcontinent.Whereas in the latter group of countries, theperformance of 25 vaccinations by a vacci-nator in one day was considered to be aworthy accomplishment, African vaccinatorsregularly vaccinated on average 500 or moreindividuals a day, the record being achieved inRwanda, where during a particular month,

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the vaccinators, using bifurcated needles,averaged 1508 vaccinations per vaccinatorper day. In the Indian subcontinent, it wasconsidered necessary to have at least 1smallpox vaccinator for every 5000-8000 or20 000 persons, according to circumstances .In the countries of eastern Africa, on theother hand, the total smallpox eradicationstaff, at maximum strength, numbered only 1per 148 000 persons in Kenya, 1 per 180 000in Tanzania and 1 per 136 000 in Rwanda.

The rapidity with which success wasachieved in these and other African countries,at such little cost and with minimum effort,provided enormous encouragement to theglobal eradication programme . To have inter-rupted transmission in countries in whichhealth services were considered to be lesseffective and extensive than in Asia was animportant factor in motivating Asian govern-ments to make a more concerted attack on theproblem .

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eastern africa: kenya, uganda, united republic ......epidemics of variola major had occurred in...

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