Molecular techniques to identify gastrointestinal infections

Abstract

In a retrospective, nested, case-control study of acute gastroenteritis (AGE) in American Indian infants ≤ 9 months of age performed in placebo recipients during a rotavirus vaccine trial, investigators used molecular techniques to identify 5 viruses (astrovirus, group F adenovirus, norovirus, group A rotavirus, and sapovirus) in stool specimens acquired under the study's protocol. The crude incidence of AGE among infants studied was 183 episodes per 100 child-years. In 65% of cases of AGE, at least one virus was detected compared with 38% of controls. Norovirus was detected most frequently (32%), followed by rotavirus (28%). In cases compared with controls, detection of any virus, norovirus, or rotavirus was significantly associated with AGE (OR 3.22, 2.0 and 2.69, respectively). The study report further describes virus-specific severity of diarrhea, seasonality, care-seeking behavior, and protection by human milk. This study clarifies the importance of use of molecular techniques in understanding the epidemiology of enteric viruses and defining burden of infection. It also suggests pitfalls in ascribing AGE to certain viruses detected, thus limiting usefulness of broad molecular testing for diagnosis. Article page 110▶