Miguel A. Guzmán

Nutrition and Infection Field Study in Guatemalan Villages, 1959–1964

Initially, all three study villages had poor environmental sanitation, little medical care, high mortality, and frequent malnutrition. In one village supplemental feeding of the preschool population without other intervention gave an appreciable but limited improvement in disease incidence and physical growth. A program of preventive medicine and medical care in a second village had no effect on frequency of illness and led to no improvement in physical growth; deaths were fewer. Comparison was to a control village with no added services. Collateral studies increased the usefulness of the basic study and enlarged the results. The broader contribution of the study was better definition of the general health of young children. Most usefully, the size of the problem became measurable by case incidence instead of by the usual dependence on number of deaths. Quantitative information on morbidity revealed a burden of illness on preschool children beyond most estimates; it was greatest in the second year. A publ...

Nutrition and infection field study in Guatemalan villages, 1959-1964. VII. Physical growth and development of preschool children.

This paper evaluated and compared the growth and maturation of preschool children in 3 study villages in Guatemala. Specifically this study sought to determine the extent to which the observed growth responses could be attributed to the nutrition program in the feeding village or to the program of environmental sanitation and health services in the treatment village. Sequential measurements of height weight skinfold over triceps and head circumference were made for all preschool children but those of height and weight were the ones concentrated on for the 5 years of the study. Head circumference although equal at the start of the study increased for the boys faster than for the girls in the 3 villages. Preschool children of both sexes in the feeding village had greater head circumferences than their counterparts in the treatment or control villages. However in all 3 cases these measurements were significantly smaller than for comparable groups in the US. Increase in skinfold measurements with age was similar for boys and girls in all 3 villages. For gain in height with age the general patterns in the 3 villages were similar although children in the feeding village tended to grow faster in height than those in the other 2 villages. Rates of gain in weight with age followed a similar pattern. Average age-specific gains in height and weight were less among children in the treatment and control villages than in the feeding village. The maximum growth potential was generally greater for boys than girls although differences were not significant. Estimates for maximum growth potential for both sexes do not differ among the villages. For weight gain in children under age 1 there were no significant differences between the sexes among the 3 villages in maximum growth potential or growth acceleration. Boys and girls (ages 1-4) in the feeding village have significantly higher rates of gain in height and weight. No significant relationship was found between days of illness and height or weight gain. Clearly children in the feeding village displayed superior nutritional status as seen from growth curves and data on bone maturation and head circumference. However they were still significantly retarded when compared to well-nourished children. Actually the nutritional status of children even in the feeding village was far from optimal due to the irregular consumption of the food supplement. Their better growth performance may have been due to the nutrition education program rather than the supplementary feeding. The 1st hypothesis that the nutrition in the feeding village would improve nutritional status was supported by moderate gains in height weight bone age skinfold thickness and head circumference. The 2nd hypothesis was not supported; that the introduction of environmental sanitation disease prevention and medical care would reduce frequency and severity of disease to allow for an improvement in nutritional status.

Nutrition and infection field study in Guatemalan villages, 1959-1964. IX. An evaluation of medical, social and public health benefits, with suggestions for future field study.

Initially all 3 study villages had poor environmental sanitation little medical care high mortality and frequent malnutrition. In 1 village supplemental feeding of the preschool population without other intervention gave an appreciable but limited improvement in disease incidence and physical growth. A program of preventive medicine and medical care in a 2nd village had no effect on fequency of illness and led to no improvement in physical growth; deaths were fewer in number. Comparison was made to a control village with no added services. Collateral studies increased the usefulness of the basic study and enlarged the results. The broader contribution of the study was a better definition of the general health of young children. Most useful was that the size of the problem became measurable by case incidence instead of by the usual dependence on number of deaths. Quantitative information on morbidity revealed a burden of illness on preschool children beyond most estimates; it was greatest in the 2nd year. A public health approach based on concerned action against major factors social as well as biological can be expected to give better results than measures against any 1 singly or in succession even those as important as malnutrition or infectious diseases. (authors modified)

Nutrition and infection field study in Guatemalan villages, 1959-1964. I. Study plan and experimental design.

A prospective 5-year epidemiological field study (1959-1964) of nutrition and infection in children less than 5 years old in Guatemalan villages is described. Attention is directed to the following: the background (death rates disease incidence synergism of infection and nutrition age of attack and exploratory studies of nutrition and infection); and study plan (a longitudinal investigation experimental design and study objectives). Recorded deaths from nutritional disease are few and often are absent from offical lists. This is the case despite a prevailing malnutrition at childhood ages of such an extent that as many as 85% of village children aged 1-4 years have a deficiency in weight for their age more than 10% below the mean for middle-class families. A field study of deaths among children of 4 rural Guatemalan communities showed that 2/5 of those dying at ages 1-4 years had the signs and symptoms of kwashiorkor yet only 1 death at any age up to 15 years was listed officially as due to malnutrition. As the general result is that causes of death remain highly indefinite the preferred method is the direct survey of cases and deaths using the principles and techniques of field epidemiology. A synergism frequently exists whereby infectious disease has the capacity to precipitate an acute nutritional disease in persons of borderline nutritional status; conversely persons with manifest nutritional deficiency commonly experience a severity and frequency of infection beyond ordinary expectation. In nearly all less developed countries the incidence of both infectious disease and malnutrition is greatest among children under 5 years of age. The experimental design finally adopted combines the advantages of longterm epidemiological observation of a natural population (the control) and those of a direct controlled experiment to test specific hypotheses. The formally stated objectives of this longterm prospective epidemiological study of malnutrition and infectious disease in rural Guatemalan communities were as follows: to observe and describe the interactions of malnutrition and infectious disease among infants and young children through the 5th year of life in a rural population of a developing country where both classes of disease were highly prevalent; to measure the changes in nutritional status resulting from addition of supplementary food to the diet of breastfed children; to measure the results of integrated medical services; and to identify and evaluate the relative influence of other broad ecological factors involved in the frequency and severity of infectious and nutritional diseases of early childhood in rural populations of a developing country.

Nutrition and infection field study in Guatemalan villages, 1959-1964. VIII. An epidemiological appraisal of its wisdom and errors.

The variety of problems that became evident during a 5 year-prospective field study are reviewed by the investigators. The critique focuses on the experimental design methodology operational procedures and administrative matters. The study took place from 1959-1964 in 3 highland villages in Guatemala and sought to discern the interactions of malnutrition and infectious disease among infants and children under 5 years old to measure changes in our nutritional status resulting from a supplementary food program to measure the results of an integrated medical service program and to evaluate the impact of ecological factors on nutritional and health status. The experimental design called for 1 village to be used as a control 1 to receive the supplemental food program and 1 to receive medical services combining both a curative and preventive approach. The villages were selected according to criteria to enhance internal comparability however certain biases were introduced because the entire study population was not exposed to the same external factors e.g an epidemic spread through 2 villages and not the 3rd. Alternative designs such as a random sample from a general population split village population or a switchback design were not feasible for financial or practical reasons. The addition of a 4th village receiving both interventions might have enhanced the results. Hindsight showed some operational procedures to be faulty or incomplete given the data requirements. There was no substitute in the control village for the increased social interaction which inevitably accompanied the intervention villages and which may contribute to growth and development. Information on attendance at the feeding station the age of children attending the amount of supplement consumed and the contribution of breastmilk to the regular diet was not collected. These data would have enhanced interpretation of the results. Many of the objectives of the medical service intervention could not be realized particularly in the preventive program due to cost or the selection of inappropriate personnel. For example providing water to each household was too expensive. Many of these operational problems could be diminished or avoided had a more complete pilot study been conducted. Better training for field workers would have resulted in a smoother operation. A manual containing a complete set of standard operating procedures including specific criteria for discerning the presence of diseases a syllabus for each data collection form and so on would have been beneficial for the field workers. Supervision of field personnel also could have been improved. In the feeding and control villages nonmedical personnel reported morbidity and mortality. Classification of diseases proved too broad for careful investigation and the reliability of the reports are somewhat questionable. The study also suffered to some extent from an inadequate periodic review of recorded findings. 2 administrative problems developed which are common among longterm field studies: change in key personnel which in this study included a new field director in the 4th year; and inadequate allocation of project funds for data analysis. One often unrecognized value of longterm field studies is that extensive collateral information is often obtained by alert investigators.

Early INCAP longitudinal nutrition studies at the community level.

This paper reviews the findings of early field studies of INCAP comparing the effects of vitamin B12 and animal and vegetable protein on the growth of poorly nourished schoolchildren. It also describes a 5-year community-based intervention study showing that a protein-rich supplement given to preschool children improves growth and cognition and decreases morbidity and mortality. Medical care in one village had no detectable benefits. A classical seven-year community-based detailed observational study of the infection status and growth in children from birth is also summarized.

Effect of lysine and tryptophan supplementation on nicotinic acid metabolism in pigs given raw or lime-treated corn diets

Abstract Three experiments with baby Duroc-Jersey pigs were done. The animals received either a corn or a lime-treated corn diet supplemented with all the needed vitamins except nicotinic acid and with lysine and tryptophan. When lysine was withdrawn stepwise from the diet, there was an increase in urinary N-methyl nicotinamide excretion values regardless of whether the raw or the lime-treated corn diet was fed. When tryptophan was withdrawn from the diet, there was an increase in N-methyl nicotinamide excretion values followed by a decrease to normal levels. Nitrogen balance was less affected by the with-drawal of the amino acids in the lime-treated corn than in the raw corn diet, suggesting that the former may contain a better balanced protein than the latter.

Diet and Serum Cholesterol Levels Among the "Black Caribs" of Guatemala

SERUM cholesterol levels have been found to be markedly reduced among lower socioeconomic urban groups in Guatemala,13 and the incidence and severity of atherosclerotic heart disease in these people is also very low when coml)ared with that in business and professional persons.45 The people in the rural lower socioeconomic groups in Guatenuala are predominantly Mayan Indian in racial origin while those in the upper income groups are primarily European caucasoid and mestizo. This racial difference is not considered responsible for the findings, however, since similar differences in atherosclerosis are found between racially homnogeneous persons in the upper and lower income groups in Costa Rica . 2 .5 Environmental conditions must, therefore, be responsible; among the environmental variables which have received special attention are dietary differences.

Diet and chronic diseases: INCAP studies of atherosclerosis and coronary heart disease.

This paper describes early INCAP studies showing that cholesterol and lipoprotein levels were much lower in the low-income populations of Central America than values that were just beginning to emerge from industrialized countries. These led to the collection of aortas and coronary vessels from 14,610 males and 7,906 females from serial autopsies from 12 public general hospitals in developing countries, mostly in Latin America and in New Orleans and Oslo. The severity of atherosclerotic lesions in the samples was evaluated independently by four pathologists after the samples were randomized, who determined that the severity of atherosclerosis progressed so slowly in the developing country samples that it rarely became clinically significant. The strongest correlation with the severity of lesions was the fat content of the diet.