Incidence of infection by Helicobacter pylori in a cohort of infants from the State of Morelos.

Objective. To study the incidence of Helicobocter pylori infection in infan ts from the State of Morelos, Mexico. Material and methods. A cohort of I I O healthy infants was studied between 1997 and 1999. Serum samples were col lected from mothers and their infants at 2, 6, 18, and 24 months of life. A ll serum samples were tested for antibodies against Helicobacter pylori wit h the ELISA test, A questionnaire was used to collect socio-economic and cl inical data. Associations among selected variables and Helicobocter pylori infection were determined using Fisher's exact test. Results. Two thirds of mothers and six (5.5%) infants tested positive. Two of the six positive in fants were born to positive mothers; both of them became negative before ag e two. The other four infants remained positive. Although not statistically significant, a vaginal birth and more than five people living in the house hold are possible risk factors for infant H. pylori infection. Conclusions. Despite the previously reported high prevalence of infection by H, pylori in Mexican children, in this population we found a low incidence of infecti on in infants up to two years of age. The English version of this paper is available at: http://www.insp.mx/salud/index.html.