The newly released HHS Pandemic Influenza Plan is now available at: www.hhs.gov/pandemicflu/plan. The Plan has useful planning advice for clinicians in health care facilities and out-patient care settings, with supplements on clinical management, inflection control, and lab testing. We are currently in a “Pandemic Alert Period” for the avian influenza A (H5N1) virus. A summary of surveillance, testing, and initial management recommendations for human cases of avian influenza A at this time (H5N1) follows. Information will be updated as necessary.

Testing for avian influenza A (H5N1) is indicated for hospitalized patients with:

For a regularly updated listing of H5N1-affected countries, see the World Organization for Animal Health [OIE] website at www.oie.int/eng/en_index.htm and the WHO website at www.who.int/en).

When a patient meets both clinical and epidemiologic criteria for a suspected case of novel influenza:

• Implement infection control precautions: Patients should be placed on Droplet Precautions for a minimum of 14 days, unless there is full resolution of illness or another etiology has been identified before that period has elapsed. Healthcare personnel should wear surgical or procedure masks on entering a patient’s room, as per Droplet Precautions, as well as gloves and gowns, when indicated for Standard Precautions. Patients should be admitted to a single-patient room, and patient movement and transport within the hospital should be limited.
  
  
• Notify Public Health: Report each patient who meets the clinical and epidemiologic criteria for a suspected case of novel influenza as quickly as possible to facilitate initiation of public health measures.
  
  
• Obtain clinical specimens for testing by the Washington State Public Health Laboratory (WA PHL): If feasible, all of the following specimens should be collected for novel influenza A virus testing: throat swab, nasopharyngeal swab; nasal swab, wash, or aspirate; and tracheal aspirate (for intubated patients). Store specimens at 4°C in viral transport media. Acute (within 7 days of onset) & convalescent serum specimens (2–3 weeks after the acute specimen and >3 weeks after onset) should be obtained & refrigerated at 4°C or frozen at minus 20–80°C.

NOTE: Avian influenza can be identified by RT-PCR at the WA PHL ONLY after reporting the case to Public Health at 206-296-4774.  WA PHL will not accept specimens for testing without prior approval from Public Health – Seattle & King County. 

Although some commercial laboratories may offer testing for novel influenza viruses, at this time results from these laboratories will not be interpretable without confirmatory testing at the WA PHL.  For this reason, Public Health does not recommend specimens be submitted to commercial laboratories for novel influenza virus testing.

Viral culture of specimens from suspected novel influenza cases can be attempted only in laboratories that meet the biocontainment conditions for BSL-3 with enhancements or higher (CDC) and should not be attempted in clinical laborotories.

Rapid influenza diagnostic tests and immunofluorescence (IF) tests may be used to detect seasonal influenza, but should not be used to confirm or exclude novel influenza during the Pandemic Alert Period. Rapid influenza tests have relatively low sensitivity for detecting seasonal influenza, and their ability to detect novel influenza subtypes is unknown. Such tests cannot distinguish between infection with seasonal and novel influenza A viruses. A negative rapid influenza test result does not necessarily exclude infection with either seasonal or novel influenza A viruses, and a positive rapid influenza test result could be a false positive or represent infection with either seasonal or novel influenza A viruses. Therefore, both negative and positive rapid influenza test and IF results should be interpreted with caution.  Acute and convalescent serum samples and other available clinical specimens (respiratory, blood, and stool) should be saved and refrigerated or frozen for additional testing until a specific diagnosis is made.

• Evaluate alternative diagnoses.  If an alternate etiology is identified, the possibility of co-infection with a novel influenza virus may still be considered if there is a strong epidemiologic link to exposure to novel influenza.
  
  
• Decide on inpatient or outpatient management. The decision to hospitalize a suspected novel influenza case will be based on the clinical assessment, assessment of risk, and whether adequate precautions can be taken at home to prevent the potential spread of infection. Patients cared for at home should be separated from other household members as much as possible. All household members should carefully follow recommendations for hand hygiene, and tissues used by the ill patient should be placed in a bag and disposed with other household waste. Consult with Public Health before discharging any patient with suspected avian influenza A (H5N1).
  
  
• Initiate antiviral treatment as soon as possible, even if laboratory results are not yet available. Clinical trials have shown that these drugs can decrease the illness due to seasonal influenza duration by several days when they are initiated within 48 hours of illness onset. The clinical effectiveness of antiviral drugs for treatment of novel influenza is unknown, but it is likely that the earlier treatment is initiated, the greater the likelihood of benefit.

For additional information, including a CLINICAL FLOW CHART and links to the HHS Pandemic Plan, see Public Health’s Pandemic Flu Web Page: at www.metrokc.gov/health/pandemicflu

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