Preparedness to poliovirus importation

SIAs

routineHRAs

surveillance

Preparedness to wild poliovirus importation

Isolation of wild poliovirus in polio-free area is a public health emergencyImportation of wild poliovirus cannot be prevented until global polio eradication is achieved, but its spread within the country can be controlled

Pillars for preparedness High quality surveillance: key for early

detection High general population immunity:

achieved by routine and SIAsCountries should monitor population immunity (coverage, vaccination status of AFP cases). Special attention to high risk areas/populations

Key elements of a national plan Monitoring and early detection of

importation Response to importation

Rapid investigation of importation Enhancing surveillance for AFP and

wild poliovirus Immediate and appropriate

immunization response Documenting cessation of

transmission

Monitoring and early detection of importation

High quality AFP surveillance: Certification standard surveillance Appropriate geographic representation Monitoring sub-national level

Mobile and marginalized populations should be identified at borders and in other locations (cover with suitable immunization and surveillance activities)

Border areas: trained surveillance staff, cross- border notification

Hot case concept Timely reporting from the lab

Response to importation Rapid investigation:

Initial investigation & international expert risk assessment should be completed with WHO within 72 hours to establish emergency plan based on Case characteristics, area of transmission, surveillance quality, coverage……etc

Determining origin of virus (epidemiologic and genomic data)

Response to importation Enhanced surveillance:

Checking quality & active retrospective search to ensure it is not missed transmission

Determine extent of circulation and impact of control measures

Exclude re-establishment of virus circulation

Response to importation Enhanced surveillance:

Immediate notification of WHO, partners and neighbours

Immediate call on the identified expert group Informing surveillance staff and major health

facilities Enhancing active surveillance in all districts

around the case Contact sampling Monitoring reports at national/provincial levels Daily reports from critical areas Weekly review of situation by experts

Response to importation Immediate & appropriate immunization

response: Emergency meeting of national/international

experts, decide on response based on local situation within 72 hours

At least 3 large scale H-H rounds using type specific monovalent vaccine (4-6 weeks apart)

1st campaign within 4 weeks of confirmation Potential target: minimum 2 to 5 million <5

years (according to age of cases). In small populations entire country and bordering areas

Response to importation Immediate & appropriate immunization

response: Detailed guidelines in advance (mapping,

estimation of vaccine, teams, training modules, supervision, transport, Soc Mob, IM, Catch up, Cost)

Plan to be shared with WHO/UNICEF immediately to ensure resources (order & delivery of vaccine in 5 working days)

IM should determine level of coverage in HRA. <90% should be revaccinated

If border area involved, cross border coordination with neighbouring countries for SIAs through WHO

Response to importation Document Cessation of transmission

Enhanced surveillance for 12 months after last wild virus. (>2/100,000)

Detailed & comprehensive documentation to describe Detailed epi, clinical and virological data Data on surveillance analysis and quality Surveillance response Immunization response

Practical steps in developing a national plan

Setting Objectives Identification of importation risk

Possible sources HRAs and populations

Surveillance activities in border areas/high risk areas and populations

Measures to ensure high population immunity in these areas

Nomination of a group of experts

EpidemiologistVirologist

Paediatric neurologistCommunication/Soc. Mob

Senior MOH official

Practical steps in developing a national plan

Setting Objectives Identification of importation risk

Possible sources HRAs and populations

Surveillance activities in border areas/high risk areas and populations

Measures to ensure high population immunity in these areas

Nomination of a group of experts Protocol for response Required documentation

Regional Experience Several importations occurred

over years (cross border and distant) with very limiteed local circulation (Iran) or with no secondary cases (Saudi Arabia, Syria, Lebanon and Gaza)

International Spread of Poliovirus

23 countries with imported virus.

Country

Sudan

Yemen

Somalia

SaudiArabia

Oman

Index caseconf

Timely(33)

Delayed(55)

Delayed(58)

Timely(36)

Timely11&7 days

1st Immun.response

Timely 35Limited

tOPV

H-H-NID 40daysmOPV

NID-H-H14 daysmOPV

Preplanned17 000border

17 daysMop-upAug 21

Precedingactivities

NID45 days

after nset

NID-H-H14 daysmOPV

SNID7,8 Haj

9,11 border

NID 4-6 June6-8 July

Response

9 NIDs6 SNIDs

tOPV

8 NIDs2 SNIDs

Most mOPV

6 NIDsI SNIDmOPV

#duration

15513 mon

47912 mon

2119m+

RoundsAfter last

5 NIDs+SNID

2 SNIDs

Poliovirus Importation (RTAG) when a case is known to have been infected in

one country and then moves to another country, the case should be listed in the country where infection took place (genomic sequencing data would help in identifying the most probable source of infection).

The regional office should therefore revise the records with respect to the above mentioned case recorded currently under Saudi Arabia.

Polio-free countries which receive confirmed cases of wild poliovirus from other countries during the period of communicability should timely implement appropriate immunization and surveillance response.

LESSONS LEARNED1. Cessation of SIAs in situation of low routine → wide

immunity gap

2. Surveillance staff should expect polio as possibility among AFP cases

3. Delayed reaction to appearance of polio in neighbouring countries → loss of preventive effect

4. Immediate response before extensive spread is essential to ensure rapid cessation of circulation

LESSONS LEARNED(CONT’D)

5. Importance of studying population movement between and within countries and anticipate importation & spread

6. Avoid limited responses7. The main factor that prevents secondary

spread is high routine immunization8. Two well prepared and implemented

rounds using the appropriate monovalent vaccine are capable of knocking down the epidemic

LESSONS LEARNED(CONT’D)

9. In case of secondary spread we expect about 8-10 months programme of work

10. Having pockets of insufficiently immunized children due to refusals or inaccessibility, will be capable of maintaining some low grade transmission and few sporadic cases

11. Outbreaks can be explosive but are controllable12. Finishing the job efficiently is essential to avoid

conversion of the situation to endemicity13. Preparedness plans should be put in effect