H1N1 virus -update

1. Dr Anna Sharma MBBS MSc MRCP(paeds) FRCPCH Consultant paediatrician Immunisation clinical lead-Hillingdon PCT H1N1 virus -update

2. H=haemaglutinin N=neuraminidase Family of orthomyxoviridae RNA viruses Infect humans pigs birds and horses Structure of Influenza virus

3. H1N1 virus -epidemiology

4. Flu pandemics Name   Year   Deaths (millions)   Subtype   • Russian Flu1889-90 1 possibly H2N2 • Spanish Flu1918-20 40 (?) H1N1 • Asian Flu1957-58 1-1.5 H2N2 • Hong Kong Flu1968-69 0.75 H3N2 • New Jersey Flu 1976 H1N1 • Swine Flu2009 - H1N1

5. What is a pandemic? • Greek-pan=all,demos=people • WHO definition • Emergence of a new infectious disease • Agents infect humans causing serious illness • Agents spread easily and sustainably among humans

6. Pandemic phases-WHO definitions

8. The 1918 pandemic • 1918- a severe haemmorhagic disease • Deaths by secondary infection- mainly pneumonia • ‘Cytokine storm’ overwhelms healthy immune sytems • Severe forms spread widely due to transport of infected soldiers in crowded trains to field hospitals

9. 1918-19 epidemic-comparision of age profile with 1917 seasonal flu age profile

15. Rate per 100,000 of new cases of pandemic influenza in England by week and age group (17/09/09-HPA)

16. Antiviral prescriptions as of 17/09/09 (HPA)

19. ‘Spanish flu’ 1918-19 H1N1 Infected a third of the worlds population Killed 50 million in 6 months 200,000 died in UK 2-3% mortality ‘Asian flu’ 1956-57 H2N2 Mainly young children Clinical attack rate 30% Mortality<0.2% Previous flu pandemics

22. UK mortality 1918figure taken from Center for Disease Control and Prevention USA

23. Started in one military installation in US Weakened population at end of war Affected mainly young adults More serious cases often travelled in crowded trains and in field hospitals- spreading infection Very rapid spread throughout the world Began to subside when doctors started to treat pneumonia with antibiotics Started in multiple generational community in Mexico Antivirals available before vaccine Heightened emergency preparedness due to alerts on anthrax/bioterrorism in 9/11 Open and prompt monitoring of cases Recognised rating system to declare a pandemic Digital media communications Containment of cases early on Only milder cases tend to travel and spread infection Milder infection Pandemic of 1918 and now-comparision

24. Fever >38 C or a history of fever AND Influenza like illness-TWO or more of Cough Sore throat Rhinorrhoea Joint /limb pains Headache Vomiting Diarrhoea OR Fever >38C AND Severe and/or life threatening illness suggestive of an infection Case Definition/Diagnostic criteria

31. Antivirals • Tamiflu (Oseltamivir) • Relenza (nasal-more suitable for pregnant women) • Not suitable for • Pregnant women • Children under 1 • Those in risk groups • Prophylaxis • Hot Line

32. Dose to prescribe antivirals in children • Over 1 year • Oseltamivir capsules • <15 kg =30mg bd 5/7 • 15-23 kg=45mg bd 5/7 • 23-40 kg=60mg bd 5/7 • >40 kg =75mg bd 5/7 • Renal impairment • Possibly zanamivir

33. Prescribe made up solution 15 mg in 1 ml (Bitter taste)-syringe graduated in ml Can get Tamiflu suspension 12 mg in 1 ml -syringe graduated in mg 2mg/kg bd 5/7 Not licensed Potential neurotoxicity/ Encephalopathy Could be ineffective in <4 weeks old RCPCH consensus statement So weigh up risks and benefits Under 1 year

34. Side effects of oral antivirals • Gastroenterological • Nausea • Abdominal pain • diarrhoea • Neuropsychiatric • Irritability • Reduced concentration • Bad dreams • delusions

35. H1N1 virus -vaccines

36. Introducing a new vaccine • Burden of disease • Availability of timely and safe treatment for disease • Availability and efficacy of vaccine • Safety profile of vaccine • Disease profile (age/clinical groups) • Acceptability • Cost/effectiveness

46. Vaccine characteristics

47. Vaccine characteristics

48. Vaccine characteristics