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Novel Influenza A (H1N1) Virus - Data and Statistics

Reported Cases of Novel Influenza A (H1N1) Virus Infections in California
(as of June 25, 2009)

1519 cases (1294 confirmed, 225 probable) from 43 of 61 local health jurisdictions

  • Provisional Data Table - Reported confirmed and probable cases, hospitalizations, and deaths, by local health jurisdiction
  • Provisional Map - Reported cases by local health jurisdiction
  • Note: Data is posted on a weekly basis on Thursday afternoons.  All data is considered provisional until published and is subject to change.  Local Health Jurisdictions include the 58 California county health departments and 3 city health departments (Berkeley, Long Beach, and Pasadena).  The city health department jurisdiction data are not included in the county jurisdiction totals. 

    For additional data and information, see the CDPH enhanced surveillance for novel influenza A (H1N1) virus webpage.

    Surveillance System

    The reported number of cases of H1N1 (swine flu) in California do not reflect how many actual cases there may be in the state because individuals in outpatient settings are no longer being tested for the presence of the virus and many cases go undetected due to the mild nature of disease among most people.  Laboratory testing is limited to individuals with serious H1N1 illness, including hospitalized patients, and those at high risk for complications.  An update of the number of cases is published on a weekly basis to provide an estimate of H1N1 frequency among those patients being tested.