Incidence of Acute Gastroenteritis and Role of Norovirus, Georgia, USA, 2004-2005

TLDR

Approximately 179 million cases of acute gastroenteritis occur annually in the United States, yet routine clinical testing for viruses is lacking, limiting understanding of viral contributions. The study analyzed fecal specimens from a Georgia health maintenance organization, applying molecular diagnostics for norovirus, rotavirus, astrovirus, sapovirus, and adenovirus, and estimated incidence using national health‑care utilization rates. Routine diagnostics identified a pathogen in 7.3 % of 572 specimens, but adding molecular viral testing raised detection to 15.7 %, and the estimated community incidence was 41,000 cases per 100,000 person‑years, with norovirus accounting for 16 % of community and 12 % of outpatient AGE episodes, confirming it as the leading cause among patients seeking care.

Abstract

Approximately 179 million cases of acute gastroenteritis (AGE) occur annually in the United States. However, lack of routine clinical testing for viruses limits understanding of their role among persons seeking medical care. Fecal specimens submitted for routine bacterial culture through a health maintenance organization in Georgia, USA, were tested with molecular diagnostic assays for norovirus, rotavirus, astrovirus, sapovirus, and adenovirus. Incidence was estimated by using national health care utilization rates. Routine clinical diagnostics identified a pathogen in 42 (7.3%) of 572 specimens; inclusion of molecular viral testing increased pathogen detection to 15.7%. Community AGE incidence was 41,000 cases/100,000 person-years and outpatient incidence was 5,400/100,000 person-years. Norovirus was the most common pathogen, accounting for 6,500 (16%) and 640 (12%) per 100,000 person-years of community and outpatient AGE episodes, respectively. This study demonstrates that noroviruses are leading causes of AGE among persons seeking medical care.