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Swine origin influenza virus H1N1 Case Report Ibrahim D’Andrea. OVERVIEW. What we already know Genetic history of SOI-V Our role as Emergency physicians. PHASE 1- no animal influenza virus infecting humans. PHASE 2- virus in animals has caused infection in humans.
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Swine origin influenza virus H1N1 Case Report Ibrahim D’Andrea
OVERVIEW • What we already know • Genetic history of SOI-V • Our role as Emergency physicians
PHASE 1- no animal influenza virus infecting humans PHASE 2- virus in animals has caused infection in humans PHASE 3-animal virus has caused clusters of human infection. No human to human PHASE 4- human to human transmission capable of sustained community outbreak PHASE 5- same virus causing 2 or more sustained community outbreaks in 2 countries in one WHO region PHASE 6-phase 5 plus one sustained outbreak in another who region
CLINICAL PICTURE • Influenza – like • Severe acute respiratory infection • Severe illness
Influenza - like • Temp > 38 and any of the following • Sore throat • Rhinorrhoea/blocked nose/cough • Myalgia • Diarrhoea
Severe Acute Respiratory Infection • 2 days to 3 months • Any child with sepsis or LRTI • 3 months to 5 years • Any child with LRTI( bronchiolitis , pneumonia, bronchitis , pleural effusion) • >5 • Sudden onset fever>38 PLUS • Cough and sore throat • Shortness of breath with or without xray changes
Severe Illness • Child -cough and difficulty breathing PLUS -danger signs:-can’t drink -vomiting -lethargy -unconscious -indrawing/stridor in calm child • Adult -respiratory distress -dyspnoea -hypotension -hypoxia
TESTING • SARI if: -testing will assist diagnosis - no other cause is found - influenza is part of the differential • Comorbid disease and at risk and symptomatic • Clusters of outbreak • Any death from H1N1
Who is high risk? • Underlying medical condition • Immunosuppressed • Any disease which would compromise respiratory function • >65 years • Patients on long-term aspirin therapy-Reye’s • Nursing home residents • Pregnant women
What to do • Mild cases - avoid aspirin - high risk for treatment at discretion of physician when therapy can be started in 48 hours of infection • SARI or severe infection - treat with oseltamivir or zanamivir
DRUGS OSELTAMIVIR • Adults 75mg bd • Children <15kg 30 mg bd 15-23 kg 45mg bd 24-40 kg 60mg bd >40 kg 75 bd For 5 days ZANAMIVIR • Adults 10mg bd • Children 10 mg bd • Only for >12 years old • For 5 days
Prophylaxis • For high risk close contacts of suspected or confirmed cases. • Daily dose instead of bd
Swine Origin Influenza Virus genetic composition 1998 H1N1 triple reassortment 1918H1N1 1968H3N2 1979 H1NI Eurasia
1918 Spanish flu H1N1 Pandemic Started in Europe Came South for the winter Returned to Europe with a vengeance 40 – 50 000 000 dead within 1 year Genetic material appears to originate from birds
H1N1 Swine flu From the humans pigs got the flu. Before 1918 flu was unknown in swine Sep 30 to Oct 5 1918 at Cedar Rapids Swine show influenza entered swine history This became known as the North American Classic Swine flu and is endemic in swine today.
1957 H2N2 PANDEMIC 3 Avian segments 5 Human segments Human H1N1 became extinct at the onset of H2N2 BUT in 1977 it was reintroduced into society from what is believed to be a lab leakage H2N2 subsequently became extinct as well
1967 H3N2 Pandemic Two new genes from avian pool
H3N2 1998-2009 triple reassortment H1N2 Avian origin H1N1 Swine
1979 Eurasian H1N1 Swine flu Introduced from birds into European pigs
Eurasian H1N1 SOI-V H1N1 Triple reassortment
EMERGENCY MEDICINE Who are we? Why do we exist? What is our role in a pandemic??
REVOLUTION A revolution (from the Latinrevolutio, "a turn around") is a fundamental change in power or organizational structures that takes place in a relatively short period of time. Aristotle described two types of political revolution: Complete change from one constitution to another Modification of an existing constitution.[1]
PIONEER —v.t.1. to be the first to open or prepare (a way, settlement, etc.). 2. to take part in the beginnings of; initiate: to pioneer an aid program.3. to lead the way for (a group); guide.
References • Historical perspective – emergence of H1N1 virussesNEngl J Med 2009;361:279-85. • The origins of pandemic influenza- lessons from 1918 pandemic n engl j med 353;21 www.nejm.org november 24, 2005 • 3. Revised health workers handbook on pandemic influenza A(H1N1) 2009 “swine flu” • 4. www.nicd.ac.za • 5.www.doh.gov.za/swineflu/swineflu-f.html • 6.www.cdc.gov/h1n1flu/ • 7. www.who.int/csr/disease/swineflu/en/