Systematic Literature Review of Role of Noroviruses in Sporadic Gastroenteritis.

A systematic review was conducted of studies that used RT–PCR to diagnose norovirus (NoV) infections in patients with mild or moderate (outpatient) and severe (hospitalized) diarrhea. We estimate that each year NoVs cause 64,000 episodes of diarrhea requiring hospitalization and 900,000 clinic visits among children in industrialized countries, and up to 200,000 deaths of children <5 years of age in developing countries. Future efforts should focus on developing targeted strategies, possibly even vaccines, for preventing NoV disease and better documenting their impact among children living in developing countries, where >95% of the deaths from diarrhea occur. Since the application of molecular assays, NoVs have been well-documented as the leading cause of epidemic gastroenteritis in all age groups, causing >90% of nonbacterial and ?50% of all-cause epidemic gastroenteritis worldwide. Recent studies that used improved diagnostics have demonstrated that NoVs may also fill in the diagnostic gap in severe sporadic gastroenteritis among all age groups worldwide. However, because these novel assays are not typically available outside of reference laboratories, the true global prevalence and potential economic impact of NoV disease remain unrecognized. To further understand the etiologic role of NoVs in sporadic diarrhea, we conducted a systematic review to identify studies that used similar inclusion criteria and molecular assays based on RT-PCR to detect NoVs in fecal specimens from patients with diarrhea. Emerg Infect Dis [serial on the Internet]. 2008 Aug [date cited]. Available from http://www.cdc.gov/EID/content/14/8/1224.htm