CDC warning: Prepare for a strong flu season
ATLANTA - The Centers for Disease Control and Prevention put America on high alert Monday, noting that influenza activity is increasing across the country and that the agency has received reports of severe influenza illness.
Clinicians are reminded to treat suspected influenza in high-risk outpatients, those with progressive disease and all hospitalized patients with antiviral medications as soon as possible, regardless of negative rapid influenza diagnostic test results and without waiting for RT-PCR testing results.
Since October 2015, CDC has detected co-circulation of influenza A(H3N2), A(H1N1)pdm09, and influenza B viruses. However, H1N1pdm09 viruses have predominated in recent weeks. CDC has received recent reports of severe respiratory illness among young- to middle-aged adults with H1N1pdm09 virus infection, some of whom required intensive care unit admission; fatalities have been reported.
Some of these patients reportedly tested negative for influenza by RIDT; their influenza diagnosis was made later with molecular assays. Most of these patients were reportedly unvaccinated. H1N1pdm09 virus infection in the past has caused severe illness in some children and young- and middle-aged adults.
Clinicians should continue efforts to vaccinate patients this season for as long as influenza viruses are circulating, and promptly start antiviral treatment of severely ill and high-risk patients if influenza is suspected or confirmed, the CDC stated.
The CDC recommends:
Clinicians should encourage all patients who have not yet received an influenza vaccine this season to be vaccinated against influenza. This recommendation is for patients 6 months of age and older. There are several influenza vaccine options for the 2015-2016 influenza season, and all available vaccine formulations this season contain A(H3N2), A(H1N1)pdm09, and B virus strains. CDC does not recommend one influenza vaccine formulation over another;
Clinicians should 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; and
Decisions about starting antiviral treatment should not wait for laboratory confirmation of influenza. Clinicians using RIDTs to inform treatment decisions should use caution in interpreting negative RIDT results. These tests, defined here as rapid antigen detection tests using immunoassays or immunofluorescence assays, have a high potential for false negative results. Antiviral treatment should not be withheld from patients with suspected influenza, even if they test negative by RIDT.
Treatment with an appropriate neuraminidase inhibitor antiviral drugs (oral oseltamivir, inhaled zanamivir or intravenous peramivir) is recommended as early as possible for any patient with confirmed or suspected influenza who is hospitalized; has severe, complicated or progressive illness; or is at higher risk for influenza complications.
The spectrum of illness observed thus far during the 2015-2016 season has ranged from mild to severe and is consistent with that of other influenza seasons. Although influenza activity nationally is low compared to this time last season, it is increasing; and some localized areas of the United States are already experiencing high activity. Further increases are expected in the coming weeks.