Infectious agents in acute and chronic diarrhea of chilhood

Abstract

Even today acute diarrheal disease is thought of by many laymen as well as by some medical professionals in developing countries as being a syndrome of alimentary origin. Despite recognition of shigellosis, cholera, salmonellosis, giardiasis, amebiasis, and other enteric infectious diseases, there has been much difficulty in accepting the fact that most of the "nonspecific" diarrheas in the general population were also of an infectious nature. The frequent appearance of diarrhea after onset of weaning in many animal species and in man (1) and the systematic failure in the past to find pathogenic agents in a majority of the diarrheas tended to rule out a microbial etiology. Epidemiologists, pediatricians, and microbiologists suspected that the nonspecific diarrheas of childhood were also of microbial or viral origin (2) because of their characteristics in poor urban and rural settings. First, in such ecosystems, diarrhea prevails if sanitation and personal hygiene are deficient. Second, infants and preschool children are more frequently and more severely affected than school children, adolescents, and adults, which stiggests the acquisition of immunity and host resistance. Third, acute diarrhea in the community follows a pattern similar to that of other infectious diseases in that secondary cases develop after contact with the index case, eventually resulting in self-limiting to extensive outbreaks or even epidemics of great magnitude. It is clear that if personal hygiene and environmental sanitation are deficient, diarrhea is prevalent. This explains the similarity in diarrhea morbidity and mortality between some contemporary developing nations and New York City at the turn of the century, when environmental conditions in New York were as deficient as they are today in some developing nations.