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Health Advisory

Date: December 20, 2011

To: Health Care Providers
From: Mark Netherda, MD, Interim Health Officer
Disease Control Unit, Public Health (707)565-4567 / Fax: (707)565-4565

Novel H3N2 Influenza Health Advisory

PLEASE SHARE WITH ALL MEDICAL STAFF

The emergence of a novel H3N2 influenza A virus (currently referred to as Swine-Origin triple resortment H3N2 or S-Otr-H3N2) has been reported in five states (Pennsylvania, Indiana, Maine, Iowa and West Virginia). Of the eleven reported cases, six had either direct or indirect exposure to swine, while investigation of another five cases has suggested transmission by person-to-person contact. Although three cases with underlying chronic medical illnesses were hospitalized, all cases have recovered. All eleven 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 requests that California Local Health Jurisdictions increase surveillance testing for influenza, including subtyping, in children under 18 years of age with influenza-like illness (ILI). The primary objective of this testing is to indentify how widely the novel H3N2 influenza (S-OtrH3N2) has spread and to gather information on the transmission potential of this virus.

Actions requested of all clinicians during this period of active surveillance:

Be alert to Influenza-like infections (ILI), especially in children under 18 years of age.

Test ILI cases under 18 years of age - send naso-pharyngeal swab specimens to Sonoma County Public Health Lab. This surveillance testing is offered at no charge to your patients. Specimens will be tested in batches with results reported out weekly. Please do not wait for test results when making clinical or treatment decisions for a specific patient. Public Health lab specimen collection instructions.

Infection Control

Continue/initiate respiratory hygiene measures. 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 (adult and pediatric sizes should be available), provide facial tissues, receptacles for their disposal, and provide hand hygiene products in waiting areas and examination rooms.

Follow standard respiratory precautions when working with patients with ILI, including using N-95 or higher respirators.

Vaccination

Current recommendations are to continue vaccination efforts for your patients through the end of March. All medical personnel are strongly urged to be vaccinated against the flu this 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.