including active surveillance for new illness cases. e.g., use of antivirals empirically for treatment or for chemoprophylaxis of influenza, changes in infection control practices (isolation or cohorting of ill, quarantine of exposed), changes in admission or staffing policies, or changes in social distancing recommendations, etc. In an outbreak setting, because of the low sensitivity of RIDTs, use of the tests on specimens from more than one ill person is recommended. The presence of any influenza positives among persons with clinically compatible illnesses is supportive of influenza as the probable cause of the outbreak. Confirmation of RIDT results by more specific influenza testing is indicated. Figure 3: Algorithm to assist in the interpretation of RIDT results and clinical decision-making during periods when influenza viruses are circulating in the community 1 In Figure 3, if the RIDT is POSITIVE for one of the following: Influenza A, Influenza B, or Influenza A and B (A/B) then the interpretation is Influenza virus infection likely . 1,2 Actions are to initiate antiviral treatment for influenza if clinically indicated. Consider additional influenza virus testing to confirm RIDT results, for subtyping of influenza A virus, to distinguish between influenza A and B viruses, or for more specific analyses, if indicated. Consider additional diagnostic testing for other pathogens and/or empiric antibiotic therapy for bacterial co-infection, in indicated 3 . In Figure 3, if the RIDT is NEGATIVE for one or more of the following: Influenza A, Influenza B, or Influenza A and B (A/B) then the interpretation is