Avian Influenza"bird flu"

• Contagious disease of animals caused by viruses that normally infect only birds and pigs

• H5N1 can infect people (very rarely)• First outbreak in 1997 in Hong Kong• 70% chance of dying when infected• Incubation period usually 3-7 days

Why is Avian Influenza so dangerous?

• Antigenic “Drift”

• Antigenic “Shift”

• No immunity in human population

• No effective vaccine available

Testing for influenza A when:

Hospitalized

Eye infections(Viral)pneumoniaAcute respiratory

distressContact with poultry

Case to case

Documented temp > 38

influenza-like symptoms cough, sore throat, muscle aches, shortness of breath

Contact with poultry

diagnostic

• Identification of influenza A, H5N1 virus is possible in humans.

• Diagnostic tests:– Serology test ( 2 wks)

– Viral culture test ( 3-10 days)

– PCR ( 24 hours)

– Directigen© kit for detection of any influenza A virus internal antigen ( <30 minutes)

• Searching for a fast diagnostic test, that has a high sentivity and specificity

Outbreaks

• Hong Kong, 1997 • China and Hong Kong, 1999• Virginia, 2002• China and Hong Kong, 2003• Netherlands, 2003• Hong Kong, 2003• New York, 2003• Thailand and Vietnam, 2003• Canada, 2004• Thailand and Vietnam, 2004

Treatment

• M2 inhibitors (amantadine* and rimantadine) and the neuraminidase inhibitors (oseltamivir and zanimivir)

• New trail for new drugs like oseltamivi (H5N1)

*mutations and resistance

Prevention and intervention

• Banning imports• Culling of birds• Protective clothing• Decontamination• Anti viral drugs for

high-risk groups

• Travelers should avoid risk areas and monitor their health

• Quarantine measurements

• Traffic control

Present

• Since mid-December 2003 a growing number of Asian countries have reported outbreaks of highly pathogenic avian influenza in chickens and ducks

• Great concern for human health as well as for agriculture

• EU and WHO experts discussed influenza pandemic preparedness on 2 and 3 March

Pandemic

• Rapid spread (global trafficking)• High death rates and mortality• Short supply of vaccines and antibiotics• Medical facilities overwhelmed• Great social disruption and shortage of

personnel• Economic consequences• Obliged reporting of new cases of avian

influenza

Preparing for a pandemic

1. Preparing for an emergency2. Surveillance3. Case investigation and treatment4. Preventing spread of the disease in the community5. Maintaining essential services6. Research and evaluation7. Implementation, testing and revision of the

national plan

Negative Socio-Economic effects:

• Human Casualties• Discontinued imports of poultry by non-effected countries,

leading to reduced export by effected countries• Tourism affected (in Thailand)• Culling of poultry,

o Impact on livelihood for poultry ownerso Smallholders hardest hit and least able to recover from

crisis