Diarrheal diseases of infancy in Cali, Colombia: study design and summary report on isolated disease agents.

For public health reasons, it is important that the etiologic agents of early childhood diarrhea be isolated and identified, and that their routes of transmission be defined. This is especially true in tropical and subtropical developing countries, where childhood patterns of exposure to diarrheal disease agents usually differ from those in developed countries, and where diarrheal illness is a frequent harbinger of death among children under five years of age. This artical describes a study designed to identify diarrheal disease agents and transmission patterns in Cali, a large city of western Colombia's fertile Cauca River Valley. The study area, composed of five working-class districts with a total population of some 40,000, appeared to provide an environment fairly similar to those of many other "average" working-class communities in Latin America. Beginning in July 1962, a cohort of 296 children being born in these districts was studied, the period of investigation starting with the date of birth and continuing until each child's second birthday or its premature withdrawal from the study. Weekly home visits were made to establish defecation patterns, feeding practices, and anthropometry. The resulting data were then analyzed in terms of defecation frequencies, occurrence of liquid stools, and the presence of blood, mucus, or pus in the stools. Differences were noted in male and female defecation patterns and in the defecation frequencies of different age groups. Stool specimens for bacteriologic, virologic, and parasitologic examination were collected monthly on a regular basis and weekly when diarrhea occurred. Numerically, viruses were isolated and identified more often than other agents. The most commonly isolated parasite species and viral and bacterial serotypes were G. lamblia (from 222 subjects), echovirus 11 (from 166 subjects), and enteropathogenic Escherichia coli 026:B6 (from 138 subjects). Compared with the findings of several studies in other countries, isolations of shigellae were relatively rare.

The serological assessment of a tetanus toxoid field trial.

To determine the effectiveness of a method for controlling tetanus neonatorum, a double-blind controlled trial involving 1 618 women was conducted between 1961 and 1966. Women in the study were given 1-3 injections (1 ml) of aluminium-phosphate-adsorbed tetanus toxoid or a placebo (influenza vaccine). At the conclusion of the trial, 5-ml samples of blood were obtained from 299 women. Sera were titrated for anti-tetanus antibodies by two methods.A comparison of the clinical and laboratory results showed a close relationship. It is suggested that the level of protection may be lower than is at present accepted. Antitoxin levels were inversely related to age and directly to the interval between injections. Two widely spaced injections (8 months or more) may be about as effective as 3 injections. One injection of specially prepared toxoid with a high immunizing potency might give significant protection.

The use of toxoid for the prevention of tetanus neonatorum. Final report of a double-blind controlled field trial.

With a view to determining the effectiveness of a method for the control of tetanus neonatorum which would be independent of medical examination or care, a double-blind field trial covering 1618 women was conducted between 1961 and 1966 in a rural area of Colombia with an estimated existing tetanus neonatorum death rate of 11.6 per 100 births. The study group was given 1-3 injections of 1 ml of an aluminium-phosphate-adsorbed tetanus toxoid more than 6 weeks apart, and the control group a similar number of injections of an influenza-virus vaccine.There was no statistically significant difference between those in the two groups given one injection. Those in the control group given 2 or 3 injections had a tetanus neonatorum death rate of 7.8 deaths per 100 births, and the corresponding subjects in the study group had none. This difference is unlikely to have occurred by chance.