TO: Physicians, Infection Control Coordinators
FROM: Jason Eberhart-Phillips, MD, MPH, - Public Health Officer
SUBJECT: Public Health Alert: Novel H3N2 Influenza A
DATE: December 21, 2011
Dear Colleagues:
The emergence of a novel H3N2 influenza A virus (currently referred to as Swine-Origin triple reassortant H3N2 or S-Otr-H3N2) has been
reported in five states since July, including Pennsylvania, Indiana, Maine, Iowa and West Virginia. Of the 11 reported cases, six had
either direct or indirect exposure to swine, while investigation of the other five cases has suggested transmission by person-to-person
contact. Almost all cases have occurred in children. Although three cases with underlying chronic medical illnesses have required
hospitalization, every patient has fully recovered.
All 11 cases were identified by routine influenza surveillance conducted at public health laboratories, with further characterization
conducted by the Centers for Disease Control and Prevention (CDC). The California Department of Public Health has requested that local
health jurisdictions, including ours in Marin County, increase surveillance testing for influenza, particularly in children <18 years of age
with influenza-like illness (ILI). The primary objective of this testing is to identify how widely the novel H3N2 influenza (S-OtrH3N2) virus
has spread and to gather information on its transmission potential.
Infection control recommendations for the influenza season remain unchanged
Follow standard respiratory precautions when working with patents with ILI illness. Be prepared to screen patients for signs and
symptoms of febrile respiratory illness at entry to your facility. If feasible, use separate waiting and exam rooms for possible flu patients,
plan to offer surgical masks to symptomatic patients who are able to wear them, provide facial tissues and receptacles for their disposal,
and provide hand hygiene products in waiting areas and examination rooms.
Vaccination
Current recommendations are to continue vaccination efforts for your patients and staff through the end of March. All medical personnel
are strongly urged to be vaccinated against the flu this year and every year. Although S-OtrH3N2 is not specifically included in this year’s
flu vaccine, it is unknown whether or not immunization with this season’s vaccine or exposure to vaccines or flu viruses from past years
will provide any level of protection from S-OtrH3N2.
Treatment
S-OtrH3N2, like 2009 H1N1, is sensitive to neuraminidase inhibitors (oseltamivir and zanamivir), but is resistant to
adamantanes. Therefore the current recommendations for treatment of influenza remain unchanged.
Please see the following websites for more information:
CDC-Have You Heard December 9, 2011:
http://www.cdc.gov/media/haveyouheard/s ... uenza.htmlCDC-Seasonal Flu Information for Health Professionals:
http://www.cdc.gov/flu/professionals/index.htmI will keep you informed as we learn more. Updates on this strain, and all flu activity reported locally, in California and in the United
States, will be included in the Marin County Influenza Surveillance report that you are receiving weekly by email throughout the flu
season.
Jason Eberhart-Phillips, MD, MPH
Public Health Officer
County of Marin
899 Northgate Drive, Suite 104