1. Communicable Disease Surveillance and Response, WHO Avian Influenza Credit: WHO Viet Nam

2. Communicable Disease Surveillance and Response, WHO Human influenza Major signs and symptoms –Fever, cough, sore throat, headache, malaise, anorexia, photophobia, joint and muscle pains –Respiratory signs may occur but not always present Severe or fatal disease –Elderly, particularly over 65 years of age –Chronic broncho-pulmonary disease –Infants and young children –Other chronic diseases, e.g. diabetes

3. Communicable Disease Surveillance and Response, WHO Influenza pandemics 20th century A(H1N1)A(H2N2)A(H3N2) 1918: “Spanish Flu”1957: “Asian Flu”1968: “Hong Kong Flu” 20-40 million deaths1-4 million deaths Credit: US National Museum of Health and Medicine

4. Communicable Disease Surveillance and Response, WHO Influenza virus Three types –A, B, C Surface antigens –H (haemaglutinin) –N (neuraminidase) Influenza A has subtypes –H3N2, H1N1 (common human) –H7N7 (avian 2003, The Netherlands) –H5N2 (avian vaccine) –H9N2 (human case in Hong Kong, SAR China, 2003) –H5N1 (current avian strain of concern) Credit: L. Stammard, 1995

5. Communicable Disease Surveillance and Response, WHO Migratory water birds Domestic birds Source: WHO/WPRO Hong Kong, SAR China 1997, H5N1 Hong Kong, SAR China 1999, H9N2 The Netherlands 2003, H7N7 Hong Kong, SAR China 2003, H5N1 From birds to humans

6. Communicable Disease Surveillance and Response, WHO Definitions Epidemic – a located cluster of cases Pandemic – worldwide epidemic Antigenic drift –Changes in proteins by genetic point mutation & selection –Ongoing and basis for change in vaccine each year Antigenic shift –Changes in proteins through genetic reassortment –Produces different viruses not covered by annual vaccine

7. Communicable Disease Surveillance and Response, WHO Reassortment (in humans) Migratory water birds Source: WHO/WPRO

8. Communicable Disease Surveillance and Response, WHO Migratory water birds Source: WHO/WPRO Reassortment (in pigs)

9. Communicable Disease Surveillance and Response, WHO Mutation (in humans) Source: WHO/WPRO Migratory water birds

10. Communicable Disease Surveillance and Response, WHO Avian Influenza Current situation

11. Communicable Disease Surveillance and Response, WHO DecJanFebNov Thailand – reporting “chicken cholera” 12/12: Rep. of Korea – avian flu 12/1: Viet Nam – 3 human avian flu deaths confirmed 23/1: Thailand – 2 human avian flu cases confirmed 12/1: Japan – avian flu 17/3: Thailand and Viet Nam – Total: 34 cases with 23 deaths 27/1: China – avian flu 02/2: Indonesia – avian flu A(H5N1) chronology 27/1: Laos PDR – avian flu (H5) 08/1: Viet Nam – avian flu 23/1: Thailand – avian flu Mar 04

12. Communicable Disease Surveillance and Response, WHO

13. Why are we concerned? Increasing number of Countries/areas with avian influenza Human avian influenza cases Co-circulating human & avian influenza viruses High risk of genetic reassortment Emergence of pandemic strain Majority of human population would lack immunity

14. Communicable Disease Surveillance and Response, WHO Avian Influenza WHO strategy

15. Communicable Disease Surveillance and Response, WHO WHO strategy Risk reduction (avoid emergence of a new virus) –Elimination of animal reservoir (FAO, OIE) Culling, movement control, vaccine –Protection and immunization of at-risk individuals Cullers, healthcare personnel Strengthen surveillance – Animals (FAO and OIE) – Humans Diagnostic tests, national detection, global reporting Improve pandemic preparedness – A(H5N1) vaccine development – Access to antiviral drugs – Pandemic plan & self-assessment (national and international)

16. Communicable Disease Surveillance and Response, WHO WHO partnership Global Influenza Laboratory Network – Global surveillance (human and animal) – Development of vaccine strains – Development of reagents for influenza diagnostic testing – Antiviral drug susceptibility testing

17. Communicable Disease Surveillance and Response, WHO WHO partnership Global Outbreak Alert & Response Network (GOARN) –Technical partnership, coordinated by WHO, to provide rapid multi-disciplinary support for outbreak response –Field teams Viet Nam, Thailand, Cambodia, China, Indonesia –Technical support CDC, GEIS - USA; NIID - Japan; HPA - UK; EPIET, EC - EU; NCEPH, FETP - Australia; Institut Pasteur, Epicentre, InVS - France; Health Canada - Canada; RIVM - The Netherlands; WHO HQ/RO/CO

18. Communicable Disease Surveillance and Response, WHO WHO support to countries Technical guidelines (web site) –Specimen collection; laboratory diagnosis; biosafety; surveillance; clinical management; pandemic preparedness; vaccination Country support –Laboratory strengthening; case identification; patient management; infection control –Research coordination; support for safe culling; personal protective equipment –Intersectoral collaboration (health, agriculture) Resource mobilisation –Funding framework –Vaccine donations

19. Communicable Disease Surveillance and Response, WHO Avian Influenza Public health tools

20. Communicable Disease Surveillance and Response, WHO Tools for disease control Public health surveillance Epidemiological studies Clinical studies Laboratory testing Vaccine and antivirals Pandemic preparedness planning Communications Public health interventions

21. Communicable Disease Surveillance and Response, WHO Public health surveillance Epidemiological studies Clinical studies Laboratory testing Vaccine and antivirals Pandemic preparedness planning Communications Public health interventions Tools for disease control Public health surveillance and epidemiological, clinical and laboratory studies are complementary