1. Infectious Disease Epidemiology Section Office of Public Health Louisiana Department of Health and Hospitals www.infectiousdisease.dhh.louisiana.gov

2. I have no financial interests or other relationship with manufacturers of commercial products, suppliers of commercial services, or commercial supporters. My presentation will not include any discussion of the unlabeled use of a product or a product under investigational use. 2

3.  Human infections with influenza A virus subtypes that are different from the currently circulating human subtypes (A/H1 and A/H3)  Human infections with Novel influenza A viruses transmissible from person to person may signal the beginning of an influenza pandemic  Swine influenza virus infection in humans is a novel influenza A virus infection 3

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5.  Goal of novel influenza reporting: to facilitate prompt investigation and accelerate the implementation of effective public health responses  June, 2007 - CSTE added novel influenza A infections to the National Notifiable Diseases Surveillance System (NNDSS) 5

6. Increased Diagnostic Capability at Public Health Labs New Reporting Requirements Identification of Human Swine Influenza Infections 6

7. Human Triple Reassortant Swine Influenza Infections N=12 Occurred: 12/2005 – 1/2009 Median Age: 12 years, range 1-49 years Symptoms: Mild ILI to critically ill Incubation Period: 2-4 days, range 1-10 days Exposure: 5 direct exposure to pigs 6 indirect exposure 1 unknown Symptomatic Pigs: 8 yes, 1 no, 3 unknown Fully Investigated:8 cases 7

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10.  Between April 15-17, 2009  2 cases of febrile respiratory illness  Residents of adjacent counties in southern California  Swine Influenza A (H1N1) virus  Both viruses are genetically closely related to each other  Resistant to amantadine and rimantadine  Contain a unique combination of gene segments previously not recognized among swine or human influenza viruses in the United States  Neither child had contact with pigs 10

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12. April 151 st novel H1N1 in the US confirmed by CDC April 172 nd case confirmed April 22CDC EOC activated April 26U.S. government declared a public health emergency June 3All 50 states were reporting cases of novel H1N1 June 11WHO declared a pandemic July 8 WHO reports three H1N1 viruses in Denmark, Japan and China are resistant to Tamiflu Sept 1919,161 Hospitalizations, 936 Deaths 12

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15.  Person to person  Respiratory droplets  5 virions sufficient to cause infection if aerosol reaches lower respiratory tract  Airborne transmission  Acheson 1952: factory outbreak in Arkansas – risk of transmission not related to proximity  Moser 1979: airline outbreak in Alaska – 72% of passengers that sat in plane 4 hours without ventilation became infected  Animal models  Large droplets on oropharynx (500)  Contact, fomites 15

16. A droplet ofWill fall in 100 µm10 seconds 40 µm1 minute 20 µm4 minutes 10 µm20 minutes 5-10 µm30-45 minutes Droplets above 10 µm are trapped in the nose and usually do not make it to the bronchi 16

17.  Cough  1 good cough produces465 DN  After 30 minutes228 DN (49%)  Speech  Count from 1 to 1001764 DN  After 30 minutes106 DN (6%) 17

18.  Artificial aerosols differ from natural aerosols generated by coughing:  Mean artificial aerosols 8µ  Natural coughing produces >99.9% particles >8µ  Therefore, natural coughing may produce particles of the correct size to remain suspended in air, but most particles are too large and fall to the ground (Branktson, 2007) 18

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21. Incubation 1-5 days Disease 3-8 days TRANSMISSIBLE Does Shedding = Infectious??? Asymptomatic cases ??? Infectious Period 1 day before symptom onset Peak shedding 1 st day of symptoms Adults shed 4-6 days Infants and children may shed longer Immunocompromised 21

22. Leekha S.,2007. Duration of Influenza A Virus Shedding in Hospitalized Patients and Implications for Infection Control 22

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27.  Conference call with CDC on April 23  7 cases : 5 in California, 2 in Texas  Human-to-human spread  All cases have resolved  Enhanced surveillance: Sentinel Providers  Specimens collected on all ILI  Daily ILI reports 27

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29. 12 Clusters involving 82 cases Cluster size ranged from 3 to 23 cases 29

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33.  2,396 confirmed cases  Real case count near 292,000  Distribution of cases by gender is similar to the population distribution by gender  68 % of outpatient cases in the 5-24 year age group  62% of inpatient cases between 5-49 years of age  71% of cases had typical influenza-like illness  736 Hospitalizations  53 deaths * as of April 17, 2010 33

34.  Pediatric Mortality  Pregnancy  Hemorrhagic Pneumonitis  Hospitalization Case Series  Death Case Series  Vaccine Failures  Repeat Infections  Tamiflu Resistance * as of April 17, 2010 34

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