Update on Pandemic H1N1 2009: Oman

Transcription

1 Update on Pandemic H1N1 2009: Oman Dr Shyam Bawikar, Ministry of Health Websites: who.int, ecdc.europa.eu, cdc.gov, moh.gov.om

2 Past Influenza Pandemics H2N2 H2N2 H1N1 H1N1 H3N8 H3N2 Pandemic H1N Russian Flu H2N Old Hong Kong Flu H3N Spanish Flu H1N Asian Flu H2N Hong Kong Flu H3N Pandemic Flu H1N1 Recorded new avian influenzas H H9 * H

3 213 countries reported cases with at least deaths

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5 *The reported number of fatal cases (1018) is an under representation of the actual numbers as many deaths are never tested or recognized as influenza related.

6 Pandemic & Seasonal Flu A: 5 Oct-24 Dec 2009 Result # Negative 4070 H1N Flu A 710 H1N1+Flu A 2 Inconclusive 18 Total 8941 Province FluA positive Muscat 293 Dhofar 57 N Batinah 95 S Batinah 22 Dakhliyah 48 N Sharqiyah 24 S Sharqiyah 97 Dhahira 63 Buraimi 3 Musandam 5 Al Wustah 0 Blanks 5 Total 712 n = 8941 Negative H1N1 Flu A H1N1+Flu A Inconclusive 8% 46% 46%

7 H1N1 Lab-confirmed Cases Week # 44,47,48,50,52,53 (2009) Cases per Wilayat (Administrative unit) No cases < 5 cases 5-9 cases cases 50+ cases The decline of the second wave

8 H1N1 Lab-confirmed Cases Week # (2010) Cases per Wilayat (Administrative unit) No cases < 5 cases 5-9 cases cases 50+ cases The decline of the second wave

9 What probably can be assumed! Known knowns Modes of transmission (droplet, direct and indirect contact) Broad incubation period and serial interval At what stage a person is infectious Broad clinical presentation The general effectiveness of personal hygiene measures (frequent hand washing, using tissues properly, staying at home when you get ill) In temperate zones transmission will be lower in the spring and summer than in the autumn and winter

10 What cannot be assumed! Known unknowns Antigenic type and phenotype Susceptibility/resistance to antivirals Age-groups and clinical groups most affected and with most transmission Clinical attack rates Pathogenicity (case-fatality rates)/ Severity of the pandemic Precise parameters needed for modelling and forecasting (serial interval, Ro) Precise clinical case definition The duration, shape, number and tempo of the waves of infection Will new virus dominate over seasonal type A influenza? Complicating conditions (super-infections) The effectiveness of interventions and counter-measures The safety of pharmaceutical interventions

11 PoE Surveillance (Containment) Muscat/Salalah International Airports On entry selfdeclaration form Airport clinic: Doctor on duty Containment failed

12 Reduction of influenza transmission Mitigation No interventions Objectives Delay/flatten epidemic curve Reduce peak burden on health system Reduce total cases Buy time for preparedness Daily cases With interventions Infection control Vaccination Days since first case

13 Cases of Influenza Like Illnesses (ILI) Weekly Reported Cases of ILI, SARI Inpatients, Lab-Confirmed H1N1 Cases, H1N1 Associated Deaths: Week First cluster SARI Admissions Influenza-like Illnesses Lab-confirmed Cases Deaths associated with H1N1 Private Schools Open Restricted Testing Government Schools Open H1N1 Vaccination Restricted Testing SARI admissions & Lab-confirmed Cases June July August September October November December Note: For surveillance purpose Severe Acute Respiratory Illnesses (SARI) have been defined as admitted cases of acute febrile respiratory illness and the data are compiled manually from daily reports of 14 sentinel hospitals in the country. Similarly data on ILI are compiled by certain grouping of 'J' codes (ICD 10) amongst outpatient cases with respiratory illness. ILI data are retrieved nationally from patients' records available in computerized health care institutions in the country. For non-computerized institutions data are collected manually and merged with the dataset. Deaths associated with H1N1 are recorded according to date of death. Note: Laboratory testing was restricted on two occasions. Once during the surge of cases in the first wave (week 32-33) which coincided with the tourist season (Khareef) in Dhofar and opening of private expatriate schools. Overwhelming cases were reported. Another occasion was in week #44-47 after the opening of Government Omani schools with outbreaks and subsequent increase in number of cases leading to the second wave.

14 Cases of Influenza Like Illnesses (ILI) Weekly Reported Cases of ILI, SARI Inpatients, Lab-Confirmed H1N1 Cases, H1N1 Associated Deaths: Week (2009) & (2010) Peak of 2nd Wave (47) SARI Admissions Influenza-like Illnesses Lab-confirmed Cases Deaths associated with H1N1 Govt. schools open (44-47) Total 6344 Lab-confirmed Cases and 32 Deaths SARI admissions & Lab-confirmed Cases November December January February March April Note: For surveillance purpose Severe Acute Respiratory Illnesses (SARI) have been defined as admitted cases of acute febrile respiratory illness and the data are compiled manually from daily reports of 14 sentinel hospitals in the country. Similarly data on ILI are compiled by certain grouping of 'J' codes (ICD 10) amongst outpatient cases with respiratory illness. ILI data are retrieved nationally from patients' records available in computerized health care institutions in the country. For non-computerized institutions data are collected manually and merged with the dataset. Deaths associated with H1N1 are recorded according to date of death. Note: Laboratory testing was restricted on two occasions. Once during the surge of cases in the first wave (week 32-33) which coincided with the tourist season (Khareef) in Dhofar and opening of private expatriate schools. Overwhelming cases were reported. Another occasion was in week #44-47 after the opening of Government Omani schools with outbreaks and subsequent increase in number of cases leading to the second wave.

15 ILI Cases Dhofar Governorate (ILI, SARI, H1N1 cases, Deaths: Week #23-45) SARI Admissions Influenza-like Illnesses Lab-confirmed Cases Restricted Testing Deaths associated with H1N SARI admissions & Lab-confirmed Cases Week Week Week Week Week Week Week Week Week Week Week Week Week Week Week Week Week Week Week Week Week Week Week June July August September October

16 Regional Waves of H1N1 in 2009: Lab-confirmed cases Muscat Dhofar North Batinah South Batinah Dakhliyah North Sharqiyah South Sharqiyah Dhahira Buraimi Musandam Al Wustah

17 #34 #35 #36 #37 #38 #39 #40 #41 #42 #43 #44 #45 #46 #47 #48 #49 #50 #51 #52 #53 #01 #02 #03 #04 #05 #06 H1N1 Associated deaths: End of Week # n = 32 Omani 87% Indian 13% 0 <12 yrs yrs yrs yrs 60 & above H1N1 associated death trend: Week #34-53 (2009); (2010) Females 53% Male 47%

18 H1N1 Associated deaths: End of Week #06 Co-morbidity 44% None 28% Risk factors # None 9 Pregnancy 4 Smoker 3 Obesity 2 Co-morbidity 14 Total 32 Co-morbidity # DM 6 Transplant 2 Malignancy 1 Congenital 3 Others 2 Obesity 6% Smoker 9% Pregnancy 13% Muscat Dhofar N Batinah S Batinah Death rate/100,000 population 2.9 Dakhliyah 0.6 N Sharqiyah 0.6 S Sharqiyah 1.5 n = 32 Dhahira Buraimi Musandam Al Wustah National average death rate 1.1/100,000 population

19 Oseltamivir resistance Total 264 Oseltamivir resistant pandemic influenza A (H1N1) 2009 viruses were reported globally (10 th Mar). All have the H275Y substitution and are assumed to remain sensitive to Zanamivir.

20 Pandemic Vaccines The dilemma To be OR not to be VACCINATED Your decision will not only influence you but also your family and people around you We present the facts and you make your own Informed decision

21 Vaccines Influenza vaccines Pandemic H1N1 vaccines are now available globally Seasonal flu vaccine [Influenza A(H3N2); A(H1N1) & B] Preference to high-risk groups Pilgrims HCWs Essential services Pregnancy Age group: < 5yr Co-morbidity Obesity BMI>40 Attenuated/Inactivated Adjuvanted/Non-adjuvanted Injectable/Intranasal Monodose/Multidose Single/Two doses Egg-based/Cell cultured Vaccine efficacy in <10yr Adverse events

22 Global vaccine availability 65-70% of global vaccine production located in Europe Source: EVM Press Release 30 April 2004 H1N1 vaccine: Timeline

23 Novartis: Focetria Virus: A/California/7/2009 (H1N1)v like strain (X-179A) Vaccine type: Split virion, inactivated, adjuvanted Antigen: 7.5 µg Preservative: Thiomersal (47.5 µg/dose) Adjuvant: Squalene-based, MF mg/dose Presentation: Multi-dose vial (10 doses per vial) Storage Temperature: 2 0 to 8 0 C Reconstitution: Liquid vaccine. No reconstitution Recommended doses: > 6 m single dose of 0.5 ml MDVP policy: Use vaccine for 7 days Contraindication: H/o Allergy to eggs H/o allergic reaction to seasonal flu vaccine Children < 6 months of age

24 GSK: Arepanrix Virus: A/California/7/2009 (H1N1)v like strain (X-179A) Vaccine type: Split virion, inactivated, adjuvanted Antigen: 3.75 µg Preservative: Thiomersal (5 µg/0.5ml dose) Adjuvant: Squalene based AS03, mg/dose Presentation: Multi-dose vial (10 doses per vial) Storage Temperature: 2 0 to 8 0 C Reconstitution: Liquid antigen & adjuvant Recommended doses: 6 m-<10 yr: Single dose of 0.25 ml >10 years: single dose of 0.5 ml MDVP policy: Use reconstituted vaccine within 6 hours or end of immunization session Contraindication: H/o Allergy to eggs H/o allergic reaction to seasonal flu vaccine Children < 6 months of age

25 WHO Recommendations (SAGE): 30 th Oct 2009 Single dose adequate (above 10 yrs) Limited data on immune response in >6m to 10 yrs Co-administration of seasonal flu & pandemic vaccine Vaccine in pregnancy: No evidence of direct or indirect effect on fertility, pregnancy, development of the embryo or foetus, birth, or post-natal development after use of attenuated/inactivated or adjuvanted/non-adjuvanted Adverse effects: minimal, no unusual incidence Post-marketing surveillance should continue

26 Concern-1: Inadequate Safety Testing Strategic Advisory Group of Experts (SAGE) on Immunization Advises WHO on policies and strategies for vaccines and immunization National Regulatory Authority (NRA): EMEA, FDA, Canadian Agency (country of production) Approval essential before vaccine can be used Other National Agencies: NITAG Pandemic vaccines have been approved under exceptional circumstances Vaccine is the only effective tool for mitigation Pandemic has spread rapidly globally hence we do not have time Same techniques of vaccine production as seasonal flu shot

27 WHO report on H1N1 Vaccine Safety (18 th Dec 2009) Conclusions 1. Ten weeks into the worldwide immunization campaign against pandemic (H1N1) 2009 influenza, the GACVS reviewed the safety of pandemic (H1N1) 2009 vaccines currently in use. To date, the safety data are reassuring. 2. Most of the adverse events that have been reported after immunization have not been serious. To date, no unexpected safety concerns have been identified. 3. Reporting mechanisms have been enhanced. Ongoing vaccine safety monitoring (pharmacovigilance) is critical, including regular information sharing with WHO by national regulatory and health authorities. Most of the safety information to date is from passive surveillance. Data from active surveillance will be assessed as they become available.

28 Concern-2: Use of adjuvant - Squalene Adjuvants: are added to stimulate the immune system and increase response to vaccine antigen sparing Squalene: natural organic compound obtained originally from shark liver oil. All higher animals produce squalene including humans Gulf War Syndrome : a study showed association with squalene in Anthrax vaccine but later disproved Used as adjuvant in flu shots since 1997 in Europe (22 million vaccinated). No adverse events observed

29 Concern-3: Preservative - Thiomersal Preservative in multi-dose vials: Organic mercury compound used as antiseptic and antifungal (HepB, DTP, DT, Td, TT) (also in immunoglobulins, skin test antigens, antivenoms, ophthalmic and nasal products, tattoo inks) Pandemic vaccines: 5 50 µgm (mercury content µgm) per dose Clearance: Organic mercury (ethyl) has half life of 3.7 days Autism: No convincing scientific evidence available in favour of causal association

30 Concern-4: Rare adverse events- GBS Guillian-Barré Syndrome (GBS) autoimmune disease causing acute muscle weakness and paralysis Many known precipitating causes In 60-70% cases no identifiable causal factor Baseline incidence of GBS (12-19/million) Flu precipitates GBS (1%) 30% of GBS with no identifiable cause had H/o Influenza Like Illness Studies have shown that the Flu-associated GBS is rare but the risk is higher than after vaccination

31 Concern-5: The Conspiracy Theory CIA, KGB, MI5 plotting for world domination Biological weapons to cause impotency or sterility of masses Al Jazeera is the best informed TV channel in the world, they interview the top experts and they are the most honest channel safeguarding and protecting interest of all the ignorant people on this Earth And many more.

32 Carry home messages Neither be complacent nor panic There are NO travel restrictions Follow personal hygiene & respiratory etiquettes especially wash hands frequently Use antivirals with discretion Know the evolution of the pandemic in the world & the changing knowledge Get vaccinated and promote vaccination

33 Questions? Questions?