The Health Department has started influenza surveillance for the 2017-2018 season. We depend on healthcare providers and facilities to report cases of influenza for this surveillance. While it is still early in the influenza season, we have received positive influenza tests in hospitalized patients and from people seen in outpatient settings.
Please report the following to Tacoma-Pierce County Health Department by calling (253) 798-6534 or (253) 798-6410:
- Laboratory-confirmed influenza deaths in persons of all ages (within three days).
- Suspect cases of novel or unsubtypable influenza virus (immediately).
- Outbreaks of influenza-like illness or laboratory positive influenza in an institutional setting (e.g., long-term care facility) (immediately).
Rapid diagnostic testing for influenza can help clinical decision-making. However, sensitivity of rapid tests is low, ranging from 50–70%. Rapid test may not detect novel or variant influenza viruses. Therefore, a negative rapid test does not rule out influenza.
Positive and negative predictive values vary considerably depending upon influenza activity in the community.
- False-positive influenza test results are more likely to occur when influenza activity is low, which is generally at the beginning and end of an influenza season.
- False-negative influenza test results are more likely to occur when influenza activity is high, which is typically at the height of an influenza season.
See more on diagnosis at www.cdc.gov/flu/professionals/diagnosis/clinician_guidance_ridt.htm
When influenza is circulating and regardless of rapid test results, treat a person who has symptoms suggesting influenza and is at high risk for complications with a neuraminidase inhibitor antiviral medication. People at high risk for flu complications include children less than five years of age (especially those under age two) and age 65 and older, pregnant women, or people with diabetes, asthma, heart disease, morbid obesity, or other chronic health conditions.
Early treatment with a neuraminidase inhibitor can shorten the duration of fever and illness symptoms and may reduce the risk of complications from influenza (e.g., otitis media in young children, pneumonia, and respiratory failure).
Early treatment of hospitalized patients can shorten the duration of hospitalization and improve survival. Neuraminidase inhibitors work best when given within 48 hours of flu onset. Because of the high prevalence of resistance, you should not use adamantanes (amandine, rimantadine) to treat influenza. For complete information on antiviral medications, see www.cdc.gov/flu/professionals/antivirals/summary-clinicians.htm.
The Health Department will continue its seasonal influenza surveillance through April. We post weekly or biweekly influenza surveillance updates on our website at providerresources.tpchd.org/health-advisories-and-alerts. If you would like to receive surveillance updates by email, please sign up at www.tpchd.org/email, and check “Health Alerts and Advisories.”