Avian Influenza Pandemic Influenza Neyla Gargouri Darwaza M

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 Neuraminidase (NA) Hemagglutinin (HA) • 16 different HA and 9 NA • All subtypes found in birds • Only H 5 and H 7 caused severe disease in birds • Human disease caused by H 1, H 2, H 3, N 1, N 2

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

Pandemic influenza strain Migratory water birds

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 Year Flu Strain 1918 Spanish H 1 N 1 Death million 50 1957 Asian H 2 N 2 2 1968 Hong Kong H 3 N 2 1

Avian influenza H 5 N 1 • Since mid-2003, H 5 N 1 virus has caused the largest and most severe outbreaks in poultry on record.

H 5 N 1 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 Category 1 Category 2 Endemic Epidemic Category 3 High Risk Category 4 At-Risk Pandemic risk

Why is H 5 N 1 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/(H 5 N 1) Reported to WHO

Cumulative Number of Confirmed Human Cases of Avian Influenza A/(H 5 N 1) Reported to WHO 10 January 2006 Total number of cases includes number of deaths. WHO reports only laboratory-confirmed cases.

Pandemic alert • H 5 N 1 currently lacks ability for efficient spread among humans • But, continual H 5 N 1 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 Interpandemic Pandemic alert Pandemic Phase 1: Phase 2: Phase 3: Phase 4: Phase 5: Phase 6: No new virus in humans New virus in humans Small clusters, localized Larger cluster, localized Animal viruses low risk to humans Animal viruses high risk to humans Little/no spread among humans limited spread among humans ? Current status of H 5 N 1 Increased and sustained spread in general human population

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 H 1 N 1 and H 5 N 1 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? • M 2 protein inhibitor: amantadine, rimantadine – up to 30% resistance, one passage in cell culture – not effective against H 5 N 1 • Neuraminidase inhibitors: oseltamivir*, zanamivir† – multiple passages in cell culture required to produce resistance – effective against H 5 N 1 • Susceptibility or resistance to antivirals of the new strain of influenza virus? ? ? * Tamiflu, † Relenza

Suspected case of H 5 N 1 • Symptoms: – Flu illness or respiratory illness AND • History within 10 days of onset : – Travel to a country with documented H 5 N 1 in poultry or humans, and/or – Contact with poultry or domestic birds, or known or suspected patient with influenza H 5 N 1

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

References • http: //www. who. int/csr/disease/avian_influenza/ en/index. html • http//: www. cdc. gov/flu/avian/outbreaks/asia. htm

Contact • MOH/ Disease Control – Tel 5607144 – Fax 5686965 – epijor@wanadoo. jo – neylagd@yahoo. com • MOH – Tel 5200230 • MOA/ Hotline – Tel 5657756