Recent Alerts Concerning pH1N1 Influenza
From the California Health Alert Network — January 3, 2014
This health alert provides summaries of recent advisories on influenza from the Centers for Disease Control and Prevention (CDC) and the California Department of Public Health (CDPH), summarizes current influenza activity in San Diego County, and provides links to useful influenza resources.
On December 24, CDC issued a Health Alert Network (HAN) advisory discussing recent reports from several states of severe infection associated with influenza A (H1N1) pdm09 (pH1N1) virus infection. The advisory described critically-ill young and middle-aged adults infected with influenza, with complications of severe pneumonia requiring hospitalization, intensive care unit (ICU) admission, need for mechanical ventilation, extra corporeal membrane oxygenation (ECMO), and death. CDC warned that if pH1N1 virus continues to circulate widely this season, illness that disproportionately affects young and middle-aged adults may occur. The advisory summarized current recommendations on vaccination and the use of antivirals for influenza.
CDPH issued a Health Advisory on December 31 noting that while it is early in the influenza season, pH1N1 has been the predominant circulating virus so far both nationwide and in California. The advisory reiterated the recommendation for annual influenza immunization for everyone 6 months and older. In addition, it stated that anyone not yet vaccinated this season should get the vaccine now; particularly persons at higher risk for severe influenza such as pregnant women and obese persons. The advisory also discussed the general and specific recommendations for influenza antiviral medication use. Recommendations were provided for treatment of critically-ill influenza-infected patients, handling specimens collected from those patients, and reporting cases.
San Diego Summary
In San Diego, 357 influenza cases have been reported this season through the week ending December 28 (week #52). Of these, 342 were Influenza A, and among the 64 cases in which subtyping was performed, 84% were pH1N1. There have been no influenza-related reported fatalities in the county, however 11 San Diegans have required intensive care due to their illnesses. Nine of these cases were under age 65, with ages ranging from 2 months to 64 years. Most had pre-existing health conditions. Detailed information about influenza surveillance in San Diego is available here.
Recommendations:
- Encourage all patients 6 months of age and older who have not yet received an influenza vaccine this season to be vaccinated against influenza using one of the available vaccine options for the 2013–14 flu season. All available vaccine formulations this season contain a pH1N1 component.
- Encourage all persons with influenza-like illness who are at high risk for influenza complications to seek care promptly to determine if treatment with influenza antiviral medications is warranted.
- Provide antiviral treatment as soon as possible to any patient with confirmed or suspected influenza who is hopspitalized; has severe or progressive illness; or is at risk for influenza complications. Oseltamivir is an oral medication approved for treatment of persons 2 weeks and older. Zanamivir is administered through oral inhalation and is approved for treatment of persons aged 7 years and older.
- Register for Influenza Watch, a weekly update on influenza surveillance in San Diego by contacting (619) 692-8499, or email EpiDiv.HHSA@sdcounty.ca.gov. The reports can also be viewed at the County website.
- Report any laboratory positive influenza detections to the County’s Epidemiology Program by FAX to (858) 715-6458 using a Case Report Form and/or a printed laboratory result. If known, indicate if patient was admitted to ICU or died.
- Use the updated Public Health Laboratory (PHL) PCR Test Request Form to submit specimens to PHL as needed. Questions may be directed to (619) 692- 8500.
For more information: