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HOT TOPIC: Swine Flu. H1N1. A,B,C of Flu. Human FLU Deaths worldwide Seasonal flu : mainly A + B (C rare) 500,000 / yr. Influenza A virus pandemics: H1N1 : Spanish Flu 1918 50 million H2N2 : Asian Flu 1957 2 million H3N2 : Hong-Kong Flu 1968 1 million H5N1 : Bird Flu.
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HOT TOPIC: Swine Flu H1N1
A,B,C of Flu Human FLUDeaths worldwide • Seasonal flu: mainly A + B (C rare) 500,000 / yr Influenza A virus pandemics: • H1N1: Spanish Flu 1918 50 million • H2N2: Asian Flu 1957 2 million • H3N2: Hong-Kong Flu 1968 1 million • H5N1: Bird Flu
Swine Flu • New influenza A(H1N1) virus • Unrelated to seasonal flu • Respiratory disease of pigs, birds, poultry, horses & humans “Quadruple reassortant" virus • Bird-Flu gene • Pig-flu gene • 2 genes: Europe & Asia • Human-gene
Pandemic H1N1 2009 • Never before circulated in humans • WHO Phase 6 = Pandemic • > 300,000 cases in over 200 countries
Symptoms • Fever (> 38°C / 100.4°F) Plus 2 or more of: • Tiredness • Headache • Runny nose • Sore throat • SOB /cough • Loss of appetite • Aching muscles • D&V
Who Is At Risk? Chronic Disease: • Lung • Heart • Kidney • Liver • Neurological • Immunosuppressed • Diabetes • Asthma (Rx past 3 y) Also: • Pregnant women • Elderly ≥ 65 y • Children <5 y
UK 2009 Timeline • March: first confirmed cases (US & Mexico) • April: confirmed in UK • June: first death in UK, Glasgow • July: 1st death with no underlying medical probs • Containment to Treatment Phase • Diagnose on symptoms NOT testing • All contact tracing stopped • Exposure does not = antiviral drugs • Sept: Rising new cases
Predictions Infected = 18.3m Deaths • 18-64,050 Hospital • 366,000 Complications • 2.74m Mild • 15m
Public Messages • Catch it, bin it, kill it • Cover mouth / tissues / basic hygiene • Hard surfaces e.g. Door handles, keyboards, phones • Stay at Home • If symptoms (5-7d) • Flu friends • Face mask unnecessary • Contact • GP / NHS 24 • National Pandemic Flu Service
DOH: General Advice • Children • Attend schools unless flu symptoms • Avoid “flu-parties” • See Doctor if < 1 yr • Pregnant • Routine avoidance measures • Safe to breastfeed if anti-virals • Teachers advised to attend school • Travel: • Unrestricted unless symptomatic • Avoid Mecca Pilgrimages if high-risk group
Headlines • “Swine flu jabs rushed through safety tests” • “GPs demand more money for swine flu jabs” TIMES ONLINE • “NHS staff don’t want swine flu jab” • “Up to half of GPs and one in three nurses ... because of concerns over safety.” Telegraph • “Vaccine risk outweighs risk of virus” Irish-Times • “Swine flu over-diagnosed” • “Swine-flu under-reported”
HCP Advice • Triage suspected cases • Avoid in surgery if possible • Declutter waiting rooms • Use of PPE • Gloves • Mask • Glasses • Gown
Antivirals • May lessen severity by reducing: • Length of illness (~ 1 day) • Symptoms, and • ? Serious complications risk • Maximum benefit • Adults: Within 48 hrs of symptoms onset • Children: Within 36 hrs of symptoms onset • Preparation: • TAMIFLU (Oseltamivir) & RELENZA (Zanamivir) • neuraminidase enzyme inhibitors
Action • Block viral enzyme • Prevent shedding Safety • Relatively new • report via the MHRA’s ‘Swine Flu ADR Portal’
Tamiflu • Age 1 and over • Caps: 30/45/75mg • Susp: 12mg/ml solution SEs • 676 suspected ADRs since April • nausea, vomiting, diarrhoea, abdo pain, headache, mild allergic • ??seizures/delirium Caution • Severe renal impairment • AVOID dialysis (CrCl ≤ 10ml/min) • ?methotrexate ?probenecid • ?? warfarin Dose: • Age 1-12 • BW ≤ 15kg: 30mg • BW ≤ 23kg: 45mg • BW ≤ 40kg: 60mg • Age 13+/>40kg: 75mg Duration: • Treat = bd for 5 days • Prev = od for 10 days NB • Best with food
Relenza • Age 5 and over • Inhaled (Diskhaler): 5mg dose • Use: pregnancy, renal disorders SEs: • 22 suspected ADRs since April • V rare: 1 in 10,000 • allergy, bronchospasm Caution: • persistent asthma/severe COPD • AVOID severe asthma • Use bronchodilator before taking AVOID: • allergy to lactose/milk protein Dose: • 2 inhalations (2 blisters) = 10mg Duration: • Treat = bd for 5 days • Prev = od for 10 or 28 days* * Longer duration if community outbreak
Vaccination • First batches expected October • Once licensed by European Medicines Agency (EMEA) • Safety concerns (medical / case reports Guillain-Barre 1970’s) • Prioritised by risk Grp • 2 doses, 3 weeks apart • Annual flu vaccination also required • “Previous Swine-flu” does not reduce risk • Even if received anti-virals • Exception is lab (swab) +ve cases
1st Stage Contact SCOTLAND ENGLAND • High Risk: age > 6m – 65 y 640,700 5 m • Pregnant 60,000 0.5 m • House contacts immunosuppr53,000 0.5 m • High-Risk: age > 65 y 428,250 3.5 m • Frontline Health Professionals 250,000 2 m _______ __ ________ TOTAL = 1.4 million 11 million
Complications NEJM 2009 • Most common severe complications • Respiratory Distress • Pneumonia • Youth Shift: Age 5-59 • 87% of total Deaths (exp ~ 17%) • 71% of Severe pneumonia (exp~32%) • Selective Antivirals (WHO Aug 2009) • High risk groups • Serious / deteriorating cases = • SOB / Resp distress / cyanosis / haemoptysis / chest pain / fever >3d / confusion / low BP
Is it coming back? Week until 14/9/9: Sentinel GP practice data • New cases in Scotland • Higher now than start of August • Past week 6181 • Prev week 3336 • Consultation rates • Tayside > Scottish average • Increasing age < 65 • Decreasing age > 65 • Complications • Hospitalised 13 cases (1 ICU) • Deaths 8 cases • 2nd wave likely coincide with seasonal flu
Summary • High Risk • “Young people” • Pregnancy • Chronic Disease / immuno-suppressed • esp < 5y & >65y • Course • Most mild self-care • Mortality ~0.3% (= seasonal flu) • Second-wave • Anti-virals • Best evidence severe cases / high-risk • Treat based on risk groups • ? Emerging resistance • Vaccination • Late-October • Normal flu-risk group 6m – 65y Extra: • Frontline health-care workers
The End • www.direct.gov.uk • www.nhs24.com • www.scotland.gov.uk • www.rcgp.org.uk/pandemic • www.hpa.org.uk • www.bma.org.uk/health_promotion_ethics/influenza • www.documents.hps.scot.nhs.uk/respiratory/swine-influenza/situation-reports/weekly-h1n1v