Swine Flu


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Swine Flu

  1. 1. Influenza A (H1N1) Swine Flu <br />Dr Muhammad Khurram<br /> FCPS, FRCP<br />Assistant Professor- Medicine<br />Rawalpindi Medical College, Rawalpindi<br />
  2. 2. <ul><li>RNA, enveloped
  3. 3. Viral family: Orthomyxoviridae
  4. 4. Size: </li></ul>80-200nm or .08 – 0.12 μm (micron) in diameter<br /><ul><li>Three types
  5. 5. A, B, C
  6. 6. Surface antigens
  7. 7. H (haemaglutinin)
  8. 8. N (neuraminidase)</li></ul>Virus<br />Credit: L. Stammard, 1995<br />
  9. 9. InfluenzaVirus - Types<br />
  10. 10.
  11. 11. Influenza: Normal Burden of Disease<br />Seasonal Influenza<br />Globally: 250,000 to 500,000 deaths per year<br />In the US (per year)<br />~35,000 deaths (mainly among people 65 years or older)<br />>200,000 Hospitalizations<br />$37.5 billion in economic cost (influenza & pneumonia)<br />>$10 billion in lost productivity<br />Pandemic Influenza<br />An ever present threat<br />
  12. 12. Definitions<br />Epidemic – a located cluster of cases<br />Pandemic – worldwide epidemic<br />Antigenic drift<br />Changes in proteins by genetic point mutation & selection <br />Ongoing and basis for change in vaccine each year<br />Antigenic shift<br />Changes in proteins through genetic reassortment<br />Produces different viruses not covered by annual vaccine<br />
  13. 13. Swine Flu<br />Swine Influenza (swine flu) is a respiratory disease of pigs caused by type A influenza that regularly cause outbreaks of influenza among pigs<br />
  14. 14. Human Virus<br />Avian Virus<br />Avian/Human<br />Reassorted Virus<br />Swine Virus<br />Transmission Through Species<br />Reassortment in Pigs<br />
  15. 15. Transmission to Humans<br />Through contact with infected pigs or environments contaminated with swine flu viruses<br />Through contact with a person with swine flu <br />Human-to-human spread of swine flu has been documented also and is thought to occur in the same way as seasonal flu, through coughing or sneezing of infected people<br />
  16. 16. Status Update<br />GLOBALLY: March 1-December 06 <br />At least 9,596 Deaths<br />Africa Region (AFRO): 109<br />Americas Region (AMRO): <br /> 6,131 <br />Eastern Mediterranean Region (EMRO): 452<br />Europe Region (EURO) : <br /> 1,242<br />South-East Asia Region (SEARO): 814 <br />Western Pacific Region (WPRO) : 848<br />Source: WHO<br />
  17. 17. Swine Influenza A(H1N1)Global Confirmed Deaths, by Week<br />As of December 18, 2009<br />n=10,863<br />* Increase in number of deaths in week 43 due to aggregate reporting of fatal cases from Brazil (week 37-40) & due to batch report of US fatal cases since August 1, 2009<br />Source: ECDC<br />
  18. 18. North-East & South Asia Confirmed Deaths<br />As of December 18, 2009<br />n=1,356<br />Source: ECDC<br />
  19. 19. Level of Threat<br />The WHO raises the alert level to Phase 6<br />WHO’s alert system was revised after Avian influenza began to spread in 2004 – Alert Level raised to Phase 3<br />In Late April 2009 WHO announced the emergence of a novel influenza A virus <br />April 27, 2009: Alert Level raised to Phase 4<br />April 29, 2009: Alert Level raised to Phase 5<br />June 11, 2008: Alert Level raised to Phase 6<br />Source: WHO<br />
  20. 20. Pathogenesis<br />
  21. 21. Features<br />Short incubation period, usually 1-4 days. <br />Spread by respiratory droplets<br />Person to person,<br />Direct contact, rare aerosol<br />Highly contagious<br />infectious period:<br /><ul><li>Adults: 1 day prior to symptoms & 5 days post illness
  22. 22. Children: >10 days
  23. 23. Immune compromised shed virus for weeks to months</li></ul>Virus is detectable just before symptom onset.<br />Usually not detectable after 5-10 days<br />
  24. 24. The illness<br />
  25. 25. Symptoms<br />Source: CDC. http://www.cdc.gov/h1niflu/surveillanceqa.htm<br />
  26. 26. Signs and Complications<br />
  27. 27. Signs of progressive illness<br /><ul><li>Persistent high fever beyond 3 days
  28. 28. Dyspnea, cyanosis
  29. 29. Bloody or coloured sputum, chest pain or low blood pressure
  30. 30. Dyspnea, tachypnea in children
  31. 31. Drowsiness, confusion or severe weakness
  32. 32. Dehydration, which can cause dizziness, decreased urine output or lethargy.
  33. 33. Diagnostic testing to confirm the pandemic virus should be prioritized for patients at higher risk for severe illness.</li></li></ul><li>Attention<br />Children younger than 2 years <br />Persons aged 65 years or older <br />Pregnant females <br />Persons of any age with chronic medical or immunosuppressive conditions <br />Persons younger than 19 years who are on chronic aspirin therapy.<br />
  34. 34. Radiological Findings in Severe Disease<br />
  35. 35. Indications for H1N1 Testing<br />a. Radiographically confirmed pneumonia, acute respiratory distress syndrome, or other severe respiratory illness for which an alternate diagnosis has not been established, <br />AND<br />b. Stay or history of travel within 10 days of symptom onset to a place with documented influenza in animal and/or humans<br />
  36. 36. Case Definitions<br />A Case under Investigation<br />Individual presenting with <br /><ul><li>A). High fever >38°C, </li></ul>AND <br /><ul><li>B). One or more of the respiratory symptoms</li></ul>AND <br /><ul><li>C). One or more of the following:
  37. 37. Close contact with a person diagnosed as Influenza A/H1N1 OR
  38. 38. Recent travel to an area reporting cases of confirmed Influenza A/H1N1 </li></li></ul><li>Case Definitions (cont)<br />Probable Case<br />Defined as a suspected case, with an influenza test that is <br />positive for influenza A<br />Confirmed Case<br />Laboratory confirmed Influenza A/H1N1 virus infection by <br /><ul><li>Real-time RT-PCR
  39. 39. Viral culture
  40. 40. 4-fold rise in H1N1 virus specific neutralizing antibodies</li></li></ul><li>Available Diagnostic Tests1<br />Source: CDC<br />
  41. 41. How Severe It is…..????<br />Initial estimates of mortality rates from H1N1 infection in Mexico ranged as high as 8%. This is a remarkably high mortality rate when viewed in the context of the 2% mortality rate during the 1918 Spanish Flu pandemic. <br />Subsequent data from the United States and WHO indicated that the mortality rate from H1N1 infection was probably even lower than the mortality rate expected from seasonal flu.<br />Data over the ensuing months have confirmed that overall mortality from H1N1 infection is less than 1% and may be less than 0.1%<br />
  42. 42. Management<br />Don’t get panic….Treat as simple RTI<br />Bed rest, hydration, analgesic, cough suppressants<br />Antivirals<br />Neuraminidase inhibitors<br />Oseltamivir (Tamiflu)<br />Zanamivir (Relenza)<br />Peramivir <br />Adamantanes (Not used because of resistance)<br />Amantadine<br />Rimantadine<br />
  43. 43. Antiviral Treatment<br />There are two flu antiviral drugs recommended<br />Oseltamivir or Zanamivir<br />Use of anti-virals can make illness milder and recovery faster <br />They may also prevent serious flu complications<br />For treatment, antiviral drugs work best if started soon after getting sick (within 2 days of symptoms)<br />Warning! Do NOT give aspirin (acetylsalicylic acid) or aspirin-containing products (e.g. bismuth subsalicylate – Bismol) to children or teenagers (up to 18 years old) who are confirmed or suspected ill case of swine influenza A (H1N1) virus infection; this can cause a rare but serious Reye’s syndrome. For relief of fever, other anti-pyretic medicationsare recommended such as acetaminophen or non steroidal anti-inflammatory drugs.<br />Treatment is recommended for: <br />All hospitalized patients with confirmed, probable or suspected H1N1 cases. <br />Patients who are at higher risk for seasonal influenza complications<br />If patient is not in a high-risk group or is not hospitalized, healthcare providers should use clinical judgment to guide treatment decisions<br />Source: CDC<br />
  44. 44. Treatment Priority Groups<br />Treatment is recommended for all outpatients with confirmed or <br />suspected influenza if they belong to groups known to be at higher <br />risk. These groups include:<br />Children younger than 2 years; <br />Persons aged 65 years or older; <br />Pregnant females; <br />Persons of any age with chronic medical or immunosuppressive conditions; and <br />Persons younger than 19 years who are on chronic aspirin therapy. <br />
  45. 45. Chemoprophylaxis<br /><ul><li>Antiviral Chemoprophylaxis
  46. 46. Post-exposure: can be considered in:
  47. 47. Close contacts of cases (confirmed, probable, or suspected)
  48. 48. Health care personnel, public health workers, or first responders who have had a recognized, unprotected close contact exposure to a person (confirmed, probable, or suspected) during that person’s infectious period.
  49. 49. Pre-exposure: Antivirals should only be used in limited circumstances, and in consultation with local medical or public health authorities.</li></ul>Source: CDC<br />
  50. 50. Antiviral Protection<br />Dosing recommendations for antiviral treatment of children younger than 1 year using oseltamivir. Recommended treatment dose for 5 days. <3 months: 12 mg twice daily; 3-5 months: 20 mg twice daily; 6-11 months: 25 mg twice daily<br />Dosing recommendations for antiviral chemoprophylaxis of children younger than 1 year using oseltamivir. Recommended prophylaxis dose for 10 days. <3 months: Not recommended unless situation judged critical due to limited data on use in this age group; 3-5 months: 20 mg once daily; 6-11 months: 25 mg once daily<br />Source: CDC<br />
  51. 51. Management Issues<br />ICU care<br />Oseltamivir resistance has been an issue with seasonal influenza A infection and is beginning to emerge in pandemic H1N1. <br />Zanamivir and asthma <br />In Extracorporeal membrane oxygenation (ECMO) the patient's large vessels are cannulated, blood pumped through the a membrane that removes CO2 and adds O2, and then returned to the patient. ECMO has traditionally been used in neonates. <br />
  52. 52. Vaccine Protection<br />H1N1 vaccine available for since Mid-September<br />H1N1 vaccine is not intended to replace the seasonal flu vaccine – it is intended to be used along-side seasonal flu vaccine<br />Vaccines:<br />Inactivated influenza virus vaccines<br />CSL Ltd. of Australia <br />Novartis Vaccines of Switzerland <br />Sanofi Pasteur of France GlaxoSmithKline (GSK) of UK<br />Sinovac Biotech of China<br />Live-attenuated virus vaccine<br />MedImmune LLC of US (nasal-spray)<br />
  53. 53. Vaccine Protection<br />Pregnant women because they are at higher risk of complications and can potentially provide protection to infants who cannot be vaccinated; <br />Household contacts and caregivers for children younger than 6 months of age because younger infants are at higher risk of influenza-related complications and cannot be vaccinated. Vaccination of those in close contact with infants less than 6 months old might help protect infants by “cocooning” them from the virus; <br />Healthcare and emergency medical services personnel because infections among healthcare workers have been reported and this can be a potential source of infection for vulnerable patients. Also, increased absenteeism in this population could reduce healthcare system capacity; <br />All people from 6 months through 24 years of age<br />Children from 6 months through 18 years of age because many cases of H1N1 influenza in children and they are in close contact with each other in school and day care settings, which increases the likelihood of disease spread, and <br />Young adults 19 through 24 years of age because we have seen many cases of novel H1N1 influenza in these healthy young adults and they often live, work, and study in close proximity, and they are a frequently mobile population; and, <br />Persons aged 25 through 64 years who have health conditions associated with higher risk of medical complications from influenza.<br />Source: CDC<br />
  54. 54. Other Preventive Steps<br />
  55. 55. Survival of Influenza Virus Surfaces and Affect of Humidity & Temperature*<br />Hard non-porous surfaces 24-48 hours<br />Plastic, stainless steel<br />Recoverable for > 24 hours<br />Transferable to hands up to 24 hours<br />Cloth, paper & tissue<br />Recoverable for 8-12 hours<br />Transferable to hands 15 minutes<br />Viable on hands <5 minutes only at high viral titers<br />Potential for indirect contact transmission<br />*Humidity 35-40%, Temperature 28C (82F)<br />Source: Bean B, et al. JID 1982;146:47-51<br />
  56. 56. Biosafety Guidelines <br />Precautions include:<br />Respiratory protection - fit-tested N95 respirator or higher level of protection<br />Shoe covers<br />Closed-front gown<br />Double gloves<br />Eye protection (goggles or face shields)<br />Waste<br />All waste disposal procedures should be followed as outlined <br /> in your facility standard laboratory operating procedures<br />Appropriate disinfectants<br />70 per cent ethanol<br />5 per cent Lysol<br />10 per cent bleach<br />Source: CDC<br />
  57. 57. N95 Mask is effective but must be tight-fitting <br />
  58. 58.
  59. 59. All personnel should self monitor for fever and any symptoms. Symptoms of swine influenza infection include diarrhea, headache, runny nose, and muscle aches <br />Any illness should be reported immediately<br />For personnel who had unprotected exposure or a known breach in personal protective equipment to clinical material or live virus from a confirmed case of swine influenza A (H1N1), antiviral chemoprophylaxis with zanamivir or oseltamivir for 7 days after exposure can be considered <br />
  60. 60. Infection Control in ill admitted Persons<br />Patients with suspected or confirmed case-status should be placed in a single-patient room with the door kept closed.  If available, an airborne infection isolation room (AIIR) with negative pressure air handling with 6 to 12 air changes per hour can be used. Air can be exhausted directly outside or be recirculated after filtration by a high efficiency particulate air (HEPA) filter. For suctioning, bronchoscopy, or intubation, use a procedure room with negative pressure air handling.<br />The ill person should wear a surgical mask when outside of the patient room, and should be encouraged to wash hands frequently and follow respiratory hygiene practices. Cups and other utensils used by the ill person should be washed with soap and water before use by other persons.<br />Source: CDC<br />
  61. 61. Infection Control in ill admitted Persons<br />Standard, Droplet and Contact precautions should be used for all patient care activities, and maintained for 7 days after illness onset or until symptoms have resolved.  Maintain adherence to hand hygiene by washing with soap and water or using hand sanitizerimmediately after removing gloves and other equipment and after any contact with respiratory secretions.<br />Personnel providing care to or collecting clinical specimens from suspected or confirmed cases should wear disposable non-sterile gloves, gowns, and eye protection (e.g., goggles) to prevent conjunctival exposure.<br />Source: CDC<br />
  62. 62. Guidelines for General Population<br />Covering nose and mouth with a tissue when coughing or sneezing<br />Dispose the tissue in the trash after use. <br />Handwashing with soap and water<br />Especially after coughing or sneezing. <br />Cleaning hands with alcohol-based hand cleaners <br />Avoiding close contact with sick people<br />Avoiding touching eyes, nose or mouth with unwashed hands<br />If sick with influenza, staying home from work or school and limit contact with others to keep from infecting them<br />
  63. 63. Household Cleaning, Laundry, and Waste Disposal<br /><ul><li>Throw away tissues and other disposable items used by the sick person in the trash. Wash your hands after touching used tissues and similar waste.
  64. 64. Keep surfaces (esp bedside tables, surfaces in the bathroom, children’s toys, phone handles, doorknobs) clean by wiping them down with a household disinfectant .
  65. 65. Linens, eating utensils, and dishes belonging to those who are sick do not need to be cleaned separately, but importantly these items should not be shared without washing thoroughly first.
  66. 66. Wash linens (such as bed sheets and towels) by using household laundry soap and tumble dry on a hot setting. Avoid “hugging” laundry prior to washing it to prevent contaminating yourself. Clean your hands with soap and water or alcohol-based hand rub right after handling dirty laundry.
  67. 67. Eating utensils should be washed either in a dishwasher or by hand with water and soap. </li></li></ul><li>Summary<br /><ul><li>WHO raised the alert level to Phase 6 on June 11, 2009
  68. 68. As of December 6, 2009, worldwide more than 208 countries and overseas territories or communities have reported laboratory confirmed cases of pandemic influenza H1N1 2009, including at least 9,596 deaths
  69. 69. Influenza transmission remains active in much of western and central Asia and there is evidence of pandemic virus circulation in most regions of Africa
  70. 70. The overall global case-fatality is ~1%
  71. 71. Symptoms mimic seasonal flu
  72. 72. 1:1 Male:Female Ratio
  73. 73. Globally
  74. 74. Number of deaths being reported is rising
  75. 75. Vaccine
  76. 76. Total Adverse Events: 5.4% (0.3% fatal)
  77. 77. Sanofi Pasteur vaccine recalled due to potency issues
  78. 78. Anti-virals (oseltamivir and zanamivir)
  79. 79. Oseltamivir resistance reported recently in immunocompromised patents</li></li></ul><li>Panic and Fear are much dangerous than Swine Flu<br />