who views on emerging pathogens - ipfa.nl 2011/02 padilla.pdf · who views on emerging pathogens...

IPFADublin2011-QSMAP

WHO views on Emerging Pathogens

Ana PadillaAna Padilla Blood Products and related BiologicalsBlood Products and related Biologicals

Quality Assurance and and Safety: Medicines Quality Assurance and and Safety: Medicines World Health OrganizationWorld Health Organization


● "Emerging infectious diseases can be defined as infections that have newly appeared in a population or have existed but are rapidly increasing in incidence or geographic range. "

S.S. Morse. Factor in Emergence of infectious diseases. EID 1996.

Emerging Infectious Diseases: a definition


Assessment criteria considered Assessment criteria considered

● Global health concern regarding the disease agent

● Incidence rapidly increasing; risks to increase in future

● Adaptability to unplanned urbanized environment

● Adequate surveillance or not to allow recognition

● Possibility of impact in health sectors and blood supply

● Infectious agent with actual or potential risk of transfusion transmission (asymptomatic blood phase)

● WHO collected information on prevalence and outbreaks available


Dengue Fever Global Situation


Dengue Virus

● Most rapidly spreading mosquito-borne viral disease

● Transmitted by Aedes mosquitoes

● Four virus serotypes (DEN-1, 2, 3, 4)

● Each serotype induces specific lifetime immunity

● All serotypes can cause severe and fatal disease

● Secondary infection with a different serotype increases the risk of more severe disease


Average number of Dengue cases reported

to WHO per year

908 15497

122174

295554

479848

925896

1279668

1451083

0

200000

400000

600000

800000

1000000

1200000

1400000

1600000

55-59 60-69 70-79 80-89 90-99 00-07 2008 2009

Period or year

Nu

mb

er

of

ca

se

s

IPFADublin2011-QSMAP N Engl J Med 2007;356:769-771

Aedes albopictus (Asian Tiger mosquito(


● Up to 3.0 billion people live under threat of dengue

● with 50 million new infections

● and 24,000 deaths reported annually

● in over 100 countries

DENGUE IS GROSSLY UNDER REPORTED

Estimates of Dengue Disease Burden

*Asymptomatic infection increases risk of more severe disease with subsequent infection


High number of cases unreported

“Iceberg” phenomenon: how much of it is visible?

UNREPORTED

REPORTED


DENGUEDENGUE

VirusVirus

●More than one circulating virus serotype

●No effective ant-viral drug or vaccine

Vector

• High adaptability to unplanned urbanised environment

• Seasonal, temperature & vapour pressure influence

• Viability of desiccated eggs upon rehydration

Host

●Population density

●Population mobility

●Health- seeking behaviour

●Rate of sub-clinical infection

●Herd immunity

Dengue: a Multifactorial Disease


Drivers of epidemic dengue

●Demographic Changes● Population growth

● Urbanization

●Modern Transportation● Increased movement of people and goods

●Changes in Public Health Policy ● Lack of Vector control

●Microbial Adaptation


Human outbreak

0

10

20

30

40

50

60

70

80

90

-20 -15 -10 -5 0 5 10 15 20 25 30 35 40

Nu

mb

er o

f C

ases

TIME

Dengue fever outbreak alert and response

Humanoutbreak

NB: Yellow areas represent cases that can be prevented with control operationsMosquito population

ForecastingReadiness

Early Detection

Rapid Response

Control Opportunity


Coordination● Activate established multisectoral dengue action committee

● Activate formalized emergency response plan with all stakeholders from local government (blood national programmes should be involved), public and private sectors, professional and community representatives

● Partnership with media and information to the community and professional groups about the control procedures used by the responsible authorities in their jurisdiction

Social mobilization

● Promote practices that lead to source reduction, personal protection and health care seeking behaviour

● Restrict practices that promote transmission and source of infection

1: Strategy to CONTROL dengue outbreak


Health Care● Ensure appropriate triage, patient care and infection control at all

levels of the health sector- (blood programmes should be involved)● Establish active surveillance system

Identify new cases and follow-up clinical complications Stop human source of infection and link with entomological

surveillance

Vector control● Implement appropriate vector control program based on

entomological surveys to reduce ongoing transmission in outbreak areas, prevent transmission in dengue free areas and stop transmission in areas with sporadic cases

2. Strategy to CONTROL Dengue outbreak


Dengue Guidelines 2009

http://www.who.int/denguecontrol/en


Diagnostic tests according their accessibility and their confidence


Chagas Disease Global Situation


Migration Flows from Latin America Chagas Disease

Schm

unis G; M

em Inst O

swaldo C

ruz , 2007


Update of the world map: Chagas disease (Trypanosoma cruzi)W

HO

NT

D R

eport 2010


0 10 20 30

WHO 1960

WHO 1976

WHO 1981

PAHO 1984

Walsh 1984

WHO 1985

WHO 1990

Schmunis 1998

World Bank/DCPP 2006

PAHO 1994

millions

Chagas diseaseEstimated prevalence by year


AcuteAcutephasephase

Chronic cardiac Chronic cardiac formform

Chronic phaseChronic phaseInitial indeterminate formInitial indeterminate form

Severe cardiopathySevere cardiopathyMild cardiopathyMild cardiopathy

Permanent Permanent indeterminateindeterminate

formform

90%

60%30%

Clinical evolution of Chagas disease

15%15%

Digestive formDigestive form

10%


Epidemiological information update - Europe

Distribution of cases of T. cruzi infection in Europe by country, and reported transmission among the European population

(data reported to WHO as of Dec 2009)


Stop transmission: blood transfusion,

organ transplantation,…

Patient care: diagnosis & treatment

of vertical transmission, acute and chronic

cases

Reduction of Chagas disease

burden

The two-pillar strategy

Global epidemiological

surveillance

Reporting in the next 65 WHA (2 years period)

Chagas disease: control and elimination (WHAResolution 63.20, May 2010)


WHO International Biological Reference Preparations

for Chagas Disease Diagnostic Tests

• To provide a tool for comparison of results between different assays (biological measurement)

• To support development of improved diagnostic and blood screening tests and convergence of international regulations


WHO event risk management flow chartWHO event risk management flow chartIdentify, Assess, Assist, InformIdentify, Assess, Assist, Inform

States PartiesWHO and UN

Others sources

Event risk assessment

Di ssemi nate

i nf or mati on

Verification

Initial screenin

g & triage

Informal/Unofficial

information

Formal reports

Other partners

Assist Respond

other technical partners

and

Initial sources of

information - EBS


http://www.who.int/neglected_diseases/en/





Early warning systemsEarly warning systems Event-based surveillance (EBS)Event-based surveillance (EBS)

A process for all hazards: Organised and rapid capture of information about events that are a potential risk to public health Events related to the occurrence of disease in humans as

recognised by health professionals and other key informants in the country (including the media) Unusual disease patterns (clusters or atypical cases)

Unexpected deaths

Events related to potential exposure for humans Events related to disease and deaths in animals,

contaminated/adulterated food, environmental hazards including chemical and radionuclear events

[email protected]@who.int


EBS for blood safety issues?EBS for blood safety issues?

● What would be useful signal events?

● Are there any key words that could be used for EBS?

● Any new or emerging diseases – to be assessed for blood safety implications?



Thanks to my colleagues in WHO:

Dengue Haemorrhagic fever

Dr Raman VelayudhanDr Raman VelayudhanControl of Neglected Tropical DiseasesControl of Neglected Tropical Diseases http://www.who.int/neglected_diseases/en/http://www.who.int/neglected_diseases/en/

Dr Renu Drager-DayalDr Renu Drager-DayalGlobal Alert and ResponseGlobal Alert and Response

http://www.who.int/csr/en/ http://www.who.int/csr/en/

Chagas Disease Dr Pedro Albajar ViñasDr Pedro Albajar Viñas Control of Neglected Tropical DiseasesControl of Neglected Tropical Diseases http://www.who.int/neglected_diseases/en/http://www.who.int/neglected_diseases/en/

Events based surveillance Dr Angela MerianosDr Angela MerianosAlert and Response OperationsAlert and Response OperationsGlobal Alert and ResponseGlobal Alert and Response


who views on emerging pathogens - ipfa.nl 2011/02 padilla.pdf · who views on emerging pathogens...

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