October 1st 2003
ABSTRACT: When influenza is present in the community, clinical symptoms are as accurate as rapid point-of-care tests for making the diagnosis; in this setting, the combination of cough and fever (temperature, 37.7°C [100°F] or higher) of acute onset has a positive predictive value of 77% to 79%. Accurate diagnosis ensures timely administration of antiviral agents and prevents unnecessary antibiotic use. In elderly persons, vaccination reduces illness severity, incidence of complications, and mortality. An intranasal vaccine is a new option for persons aged 5 to 49 years who are at risk for complications and refuse injection. Chemoprophylaxis with amantadine, rimantadine, or a neuraminidase inhibitor is a useful adjunct to vaccination in certain groups, such as nursing-home residents. Antiviral therapy started within 24 to 48 hours of symptom onset can reduce the duration of illness by 1 to 1.5 days and ameliorate symptoms in patients with uncomplicated influenza. However, treatment is expensive and does not prevent complications.