Acute Helicobacter pylori infection is followed by an increase in diarrheal disease among Peruvian children

Background. Cohort and case-crossover studies were conducted to evaluate wh ether new Helicobacter pylori infections are followed by increased diarrhea . Methods. Participants were 6-month-old to 12-year-old shantytown residents living near Lima, Peru. Baseline data were collected from community househo lds. Health interviews were completed daily, and sera, drawn every 4 months , were tested for H pylori immunoglobulin G. Diarrhea rates among newly H p ylori-infected (seroconverting) children were compared with rates among per sistently uninfected and infected children using cohort and case-crossover analyses. Results. Sera were obtained from 345 children from January 1, 1995, through September 1, 1997. H pylori incidence was 12% per year (36 H pylori infect ions in 109 866 seronegative days). In adjusted cohort analyses, seroconver ters had more diarrhea days (rate ratio: 2.0; 95% confidence interval: 1.6- 2.4), episodes, and sick days in the year after infection than did uninfect ed children; and more diarrhea days and sick days than did persistently inf ected children. This effect was strongest in the first 2 months. Case-cross over analyses supported these findings. Conclusion. Preventing H pylori infection may help reduce pediatric diarrhe al disease.