In the past. we thought there were differences hetween tropica! and temperate zones in the etiology of intestinal diseases. Recent observations indicate that such differences do not exist. Infectious agents are ubiquitous. ...

Shigella infections are very common in Central America, except in Costa Rica and Panama where prevalence rates are low. Shigellosis is the most serious among all the specific diarrhoeas, due to its invasive character, systemic ...

Costa Rica has a rather humble ancestry of tribal aborigines blended with poor and mostly illiterate colonizing Spaniards, and with a later and very modest immigration of other Europeans. A rural agricultural society ...