When it comes to the diagnosis and treatment of influenza, pay special attention to patients at high risk for flu hospitalization, such as pregnant women and the extremely obese, begin treatment as soon as possible, and use the newest testing methods, the Infectious Diseases Society of America (IDSA) said.
High-risk populations should receive antiviral treatment immediately — even if it has been more than two days since flu symptoms began, according to updated guidelines authored by Timothy M. Uyeki, MD, of the CDC, and colleagues.
Moreover, rapid molecular testing, such as nucleic acid testing, should be used to diagnose influenza in outpatients as opposed to rapid-influenza diagnostic tests (RIDT), which tend to have a higher false negative rate, according to the guidelines published in Clinical Infectious Diseases.
The authors noted that this was the first time these guidelines have been updated since they were published just prior to the 2009 pandemic influenza season.
Patients at high risk for hospitalization from the flu include:
- Pregnant and postpartum women
- Adults with a BMI ≥40
- Children age <2
- Immunocompromised patients
“High-risk individuals who are hospitalized with flu complications are at an increased risk for serious bacterial infections and infectious diseases, physicians’ expertise is critical to ensuring they receive the best care,” said Andrew T. Pavia, MD, FIDSA co-chair of the guidelines committee and chief of pediatric infectious diseases at the University of Utah in Salt Lake City, in a statement. “ID doctors also can provide guidance when a patient who has the flu is not responding to antiviral treatment or is getting worse.”
In fact, the authors recommended that healthcare providers consult with infectious disease doctors if patients in these high risk categories become seriously ill with influenza.
“Annual influenza vaccination is the best way to prevent influenza, but it is not 100% effective. Those at high risk need to be encouraged to seek medical care right away if they develop influenza symptoms during influenza season,” Uyeki said.
They also addressed methods of testing, stating that the newer and highly accurate molecular tests deliver results in 15-60 minutes, while RIDT produces a false negative in at least 30% of outpatients with influenza.
Other recommendations about diagnosis and testing of influenza included:
- Testing patients for influenza who present with acute onset of respiratory symptoms
- Testing all patients admitted to the hospital for acute respiratory illness, including pneumonia, with or without fever
- Testing any patient with acute worsening of chronic cardiopulmonary disease
- Using reverse-transcription polymerase (RT-PCR) or other molecular assays for influenza testing in the hospital
The authors added that antivirals are recommended for anyone hospitalized with influenza or outpatients with “severe, progressive illness,” regardless of duration, as well as adults ages ≥65, immunocompromised patients, and those with chronic medical conditions. They said that treatment should begin as soon as possible, and “irrespective of influenza vaccination history.” Recommended treatment is “a single neuraminidase inhibitor (NAI) (either oral oseltamivir, inhaled zanamivir, or intravenous peramivir).”
The guidelines do not address use of the non-NAI flu drug baloxavir (Xofluza), which was approved after the update was written.
These guidelines were supported by the Infectious Diseases Society of America.
Uyeki disclosed no conflicts of interest.
Pavia disclosed support from the National Institute of Allergy and Infectious Diseases (NIAID)/NIH, NIAID/Biofire, the CDC, Antimicrobial Therapy Inc, WebMD, and Johnson & Johnson.
Other co-authors disclosed support from the New York State Department of Health, Current Opinion in Pediatrics, Shire Human Genetic Therapies, the Harvard School of Public Health, the American Academy of Pediatrics (AAP, Sanofi Pasteur, Gilead, the Bill & Melinda Gates Foundation, Chimerix, Novavax, Alios/Janssen, MedImmune, bioMérieux, Curetis AG, GlaxoSmithKline, Melinta, Meji Seika Pharma Co, Merck & Co, MotifBio, Nabriva, Paratek, Shionogi, Seqirus, Pfizer, Longevoron, Janssen, the Gerontological Society of America, the NIH, CDC, the World Health Organization, the University of Alabama Antiviral Drug Discovery and Development Consortium, the University of Virginia, Celltrion, GSK, and Vaccitech, PREP Biopharm, CoCrystal, Farmak, Genentech/Roche, Medivector/FujiFilm, Regeneron, resTORbio, SAB Biotherapeutics, Vir, and Visterra), Global Blood Therapeutics, Fogarty International Center, the Health Resources and Services Administration, the Centers for Medicare and Medicaid, the Maryland Institute of Emergency Medical System Services, Emergent BioSolutions, Celltrion, VirBio, Alios, Biota, Crucell, NexBio, the Canadian Institutes of Health Research (CIHR), the Public Health Agency of Canada, the Ontario Workplace Safety Insurance Board, UpToDate, and Johns Hopkins University.
One co-author disclosed being a member of the Advisory Committee on Immunization Practices at CDC; is an ex-officio member of the Committee on Infectious Diseases at AAP; and is an editor of the Red Book Online at AAP.
One co-author disclosed being a speaker for the American College of Obstetricians and Gynecologists.