Novel H1N1 Influenza A Current Knowledge and Recommendations June

Idaho situation Currently: Currently: A total of 16 confirmed or probable cases in the state A total of 16 confirmed or probable cases in the state 5 under investigation 5 under investigation Over 485 negative samples tested Over 485 negative samples tested Reports and samples coming in daily Reports and samples coming in daily

What criteria need to be met to cause a pandemic? According to CDC, a pandemic is an epidemic: affecting a very wide area (several countries or continents at once) affecting a very wide area (several countries or continents at once)AND affecting a larger proportion of the population than a typical epidemic affecting a larger proportion of the population than a typical epidemic Additionally, there must be: Additionally, there must be: Ability to infect humans resulting in high mortality Ability to infect humans resulting in high mortality Global immunologically naïve human population Global immunologically naïve human population Efficient human-to-human transmission Efficient human-to-human transmission

Who declares a pandemic? WHO does! Their criteria are: Phase 4 verified human-to-human transmission of an animal or human-animal influenza reassortant virus able to cause community-level outbreaks. Phase 4 verified human-to-human transmission of an animal or human-animal influenza reassortant virus able to cause community-level outbreaks. Phase 5: human-to-human spread of the virus into at least two countries in one WHO region. Phase 5: human-to-human spread of the virus into at least two countries in one WHO region. Phase 6, the pandemic phase, is characterized by community level outbreaks in at least one other country in a different WHO region in addition to the criteria defined in Phase 5. Designation of this phase will indicate that a global pandemic is under way. Phase 6, the pandemic phase, is characterized by community level outbreaks in at least one other country in a different WHO region in addition to the criteria defined in Phase 5. Designation of this phase will indicate that a global pandemic is under way.

Potential Sources of New Viruses Infecting Humans Human virus virus Reassortantvirus Diagram source: Ben Schwartz; National Vaccine Program

Belshe, R. B. N Engl J Med 2005;353: The Two Mechanisms whereby Pandemic Influenza Originates

The new virus Has genes from: Has genes from: North American swine influenza North American swine influenza avian influenza avian influenza human influenza human influenza Asian/European swine influenza Asian/European swine influenza Never been seen before in swine or humans Never been seen before in swine or humans Different from the 1976 swine flu outbreak virus Different from the 1976 swine flu outbreak virus Apparently no cross-protection from the seasonal vaccine Apparently no cross-protection from the seasonal vaccine

Clinical features so far Incubation period about 2-7 days Incubation period about 2-7 days Symptoms similar to seasonal influenza Symptoms similar to seasonal influenza Complications not clear yet, with so few cases– assume the same potential as seasonal influenza Complications not clear yet, with so few cases– assume the same potential as seasonal influenza High-risk groups have not yet been identified, so presume usual groups are at high risk for now (eg elderly, pregnant women) High-risk groups have not yet been identified, so presume usual groups are at high risk for now (eg elderly, pregnant women)

Infectiousness and viral shedding Infected persons should be assumed to be contagious for at least 7 days from illness onset or longer, if still ill. Infected persons should be assumed to be contagious for at least 7 days from illness onset or longer, if still ill. Some persons who are infected might potentially shed virus and be contagious for longer periods (e.g. young infants, immunosuppressed, and immunocompromised persons). Some persons who are infected might potentially shed virus and be contagious for longer periods (e.g. young infants, immunosuppressed, and immunocompromised persons).

Antiviral medications CDC shipped antiviral medications from the Strategic National Stockpile CDC shipped antiviral medications from the Strategic National Stockpile Idaho received these May 1 Idaho received these May 1 Tamiflu and Relenza are antiviral influenza drugs that can make your illness milder and may help you feel better, sooner; and may prevent serious influenza complications Tamiflu and Relenza are antiviral influenza drugs that can make your illness milder and may help you feel better, sooner; and may prevent serious influenza complications

What is happening: vaccine CDC has begun working with vaccine manufacturers CDC has begun working with vaccine manufacturers Vaccine production is meeting designated timelines and may be ready by about October Vaccine production is meeting designated timelines and may be ready by about October Not certain if vaccine will ever be recommended– depends on the course of this outbreak Not certain if vaccine will ever be recommended– depends on the course of this outbreak

Recommendations to the public Usual respiratory etiquette recommendations Usual respiratory etiquette recommendations Cover nose and mouth with a tissue when coughing or sneezing, properly dispose of that tissue Cover nose and mouth with a tissue when coughing or sneezing, properly dispose of that tissue Wash your hands often with soap and water; alcohol based hand cleaners are also effective Wash your hands often with soap and water; alcohol based hand cleaners are also effective Avoid touching your eyes, nose, mouth. Germs spread this way Avoid touching your eyes, nose, mouth. Germs spread this way Avoid contact with sick people Avoid contact with sick people Stay home if you are sick for 7 days after your symptoms begin or until you have been symptom- free for 24 hours, whichever is longer. Stay home if you are sick for 7 days after your symptoms begin or until you have been symptom- free for 24 hours, whichever is longer.

Questions??