Avian Influenza / Pandemic Influenza Neyla Gargouri Darwaza, M.D. Surveillance Department Directorate of Disease Control Ministry of Health, Jordan

Outline Influenza virus Avian influenza Influenza pandemic

Influenza viruses Orthomyxoviruses Influenza virus A, B, C –A: birds, pigs, humans –B & C: humans

Influenza virus type A 16 different HA and 9 NA All subtypes found in birds Only H5 and H7 caused severe disease in birds Human disease caused by H1, H2, H3, N1, N2 Hemagglutinin (HA) Neuraminidase (NA)

Influenza virus type A 24–48 hours or hard non porous surfaces 8–12 hours on cloth, paper, tissue 5 min on hands 4 days in water 22ºC 30 days at 0ºC 30 min at 60ºC Inactivated by 70% alcohol, chlorine and disinfectants

Genetic reassortment

Migratory water birds Pandemic influenza strain

Understanding pandemic influenza Pandemics * occur when a novel influenza strain emerges that has the following features: –readily transmitted between humans –genetically unique (i.e., lack of preexisting immunity in the human population) –increased virulence * Very widespread epidemic that affects a whole region, a continent or the world.

Previous pandemics Death million StrainFluYear 50H1N1Spanish1918 2H2N2Asian1957 1H3N2Hong Kong 1968

Avian influenza H5N1 Since mid-2003, H5N1 virus has caused the largest and most severe outbreaks in poultry on record.

H5N1 among poultry or wild birds Cambodia China Croatia Indonesia Japan Kazakhstan Laos Malaysia Mongolia Romania Russia South Korea Turkey Thailand Ukraine Vietnam

Global risk of avian influenza outbreaks EpidemicPandemic riskEndemic High RiskAt-Risk Category 1Category 2Category 3Category 4

Why is H5N1 very dangerous? Present in healthy waterfowl (e.g. ducks), shed in feces Very lethal to poultry and other animals including humans Big impact on trade and economics Crossed species barrier in 1997 in Hong Kong, caused 18 human cases & 6 deaths

Cumulative Number of Confirmed Human Cases of Avian Influenza A/(H5N1) Reported to WHO

10 January 2006 Total number of cases includes number of deaths. WHO reports only laboratory-confirmed cases.

Pandemic alert H5N1 currently lacks ability for efficient spread among humans But, continual H5N1 transmission in animals (and humans): –increases viruses in environment and chances of humans being infected –increases chances of mutations/reassortments to create pandemic virus

Present situation InterpandemicPandemic alertPandemic Phase 1:Phase 2:Phase 3:Phase 4:Phase 5:Phase 6: No new virus in humans Animal viruses low risk to humans No new virus in humans Animal viruses high risk to humans New virus in humans Little/no spread among humans Small clusters, localized limited spread among humans Larger cluster, localized limited spread among humans Increased and sustained spread in general human population Current status of H5N1 ?

Influenza pandemic “Once a fully contagious virus emerges, its global spread is inevitable” “Given the speed and volume of international travel today, the disease could reach all continents in less than 3 months” 2 waves of 6 weeks each

Influenza pandemic Worldwide –30-50% human population –2 to 7.4 million deaths (conservative estimates, based on 1957 pandemic) In Jordan –1.75 million cases (AR * 35%) –10,000 deaths (CFR † 0.6%) * Attack rate † Case fatality rate

Influenza pandemic Recent studies 1,2 suggest that 1918 H1N1 and H5N1 are similar –macrophage activities with high levels of cytokine production maybe a factor in the lung and other organ damage (cytokine storm) 1 Kobasa et al; Nature 2004;431:703 2 Peiris et al; Lancet 2004;363:617

If influenza pandemic takes place… It will take several months before any vaccine becomes available Vaccines, antiviral agents and antibiotics will be in short supply & unequally distributed Medical facilities will be overwhelmed It will affect essential community services It will cause social and political disruption and considerable economic losses

Can a pandemic be prevented? Theory: –antiviral drugs can contain/eliminate pandemic virus –soon after it develops ability to spread human to human –WHO antiviral stockpiles for rapid deployment in initially affected countries

Can a pandemic be prevented? Requirements: –good surveillance and rapid reporting –rapid response teams –stockpile of antiviral drugs, PPE *, etc. * Personal protective equipment

Can a pandemic be prevented? Challenges: –limited money –limited staff and training –limited planning, coordination, cooperation within government and with other countries

Which antiviral? M2 protein inhibitor: amantadine, rimantadine –up to 30% resistance, one passage in cell culture –not effective against H5N1 Neuraminidase inhibitors: oseltamivir *, zanamivir † –multiple passages in cell culture required to produce resistance –effective against H5N1 Susceptibility or resistance to antivirals of the new strain of influenza virus??? * Tamiflu, † Relenza

Suspected case of H5N1 Symptoms: –Flu illness or respiratory illness AND History within 10 days of onset : –Travel to a country with documented H5N1 in poultry or humans, and/or –Contact with poultry or domestic birds, or known or suspected patient with influenza H5N1

How to reduce risk of infection? Thorough cooking of all foods from poultry, including eggs Avoiding contact with poultry and any surfaces that may have been contaminated by poultry or their feces/secretions

How to reduce risk of infection? Frequent hand washing with soap & water –after touching birds –after cooking food involving poultry or eggs Simple etiquette like covering nose & mouth when sneezing & coughing

Conclusion “The next pandemic is just a matter of time” “For the first time in human history we have a chance to prepare ourselves for a pandemic before it arrives” Pray, plan and practice

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