RESUMEN
In the Bolivian Chaco, south-east of Bolivia, studies conducted over the past three decades reported hepatitis A virus (HAV) and Helicobacter pylori seroprevalences above 90% and 60%, respectively. Hepatitis E virus (HEV) prevalence was previously found to be 6-7% but is probably an underestimate because of the poor sensitivity of the assays used. In November 2013, we conducted a cross-sectional study of 263 healthy volunteers from two rural communities of the Bolivian Chaco, aiming to reassess HAV, HEV, and H. pylori seroprevalence 10-20 years following the previous surveys. Hepatitis A virus seroprevalence was 95%, with universal exposure after the first decade of life; HEV seroprevalence was considerably higher (31-35%) than that previously reported; H. pylori seroprevalence was 59%, with an age-dependent distribution. The high prevalence of these infections suggests that major efforts are still needed to reduce fecal-oral transmission and to improve human health in the Bolivian Chaco.