|Community-Based Longitudinal Nutrition and Health Studies : Classical Examples from Guatemala, Haiti and Mexico (International Nutrition Foundation for Developing Countries - INFDC, 1995, 184 pages)|
|2. The Santa María Cauqué study: Health and survival of Mayan Indians under deprivation, Guatemala|
Interventions were minimized during the study, to the extent compatible with ethical principles. Medical services in the clinic conformed with government policies but were better than in most Guatemalan villages. Three programs were implemented in the village: a) improvement of medical care and hygiene during the three-village study (1959-1963) and the Cauqué, study described in this chapter (1964-1972); b) and subsequently improvement of the diet through maize fortification (19721976); and c) improvement of housing and income after the 1976 earthquake (1976-1980).
Improvement of Medical Care and Hygiene (1959-1972)2
Prior to the study described in this chapter, Santa María Canqué was the village that received enhanced medical care and some hygiene measures as part of the "three-village study" described in Chapter 1. During the present study, treatment in the clinic was continued and extended to the homes. The quality of the central water supply was improved but not its distribution.
Traditional village infusions and intravenous fluid therapy were used for dehydration from diarrhea, although many mothers refused the latter. Breast-feeding was encouraged for all infants and children still at the breast, even when they were suffering from infectious diseases, especially with dehydration. Invasive diarrhea was treated with broad-spectrum antibiotics. Penicillin was used for complicated bronchitis, pneumonia, and other bacterial infections. Personal hygiene improved somewhat, although it continued to be deficient. The latrine program was stagnant during the study, but usage improved considerably to reach 54% of the families at the end of the study period. In summary, slow progress was evident at the end in personal hygiene, water supply, sanitation, education, and literacy (Mate, 1978a), along with some reduction in mortality.
Improvement of the Diet (1972-1976)
The Cauqué, study officially ended on May 29,1972, in its eighth year. At that time there was still controversy with respect to the relative value of food supplementation versus infection control, despite the fact that the Canqué study had demonstrated a strong deleterious effect of infection on host nutrition and growth. There was considerable international interest in the implementation of nutrition programs in developing countries, even though they had shown only limited or negligible impact. The experience gained in field work during the Canqué study justified an intervention consisting of adding a supplement to maize, the staple food, to correct most of its nutrient deficiencies, and "make it like beef" The improved maize supposedly should significantly improve the nutrition of pregnant women, infants, and preschool children, enhance resistance and response to infection, and raise the overall level of health.
The maize fortification study began in June of 1972 and continued for almost four years (Mate, 1971). The fortifying mixture, developed in INCAP by Ricardo Bressani, contained 97.5% soybean flour, 1.5% Llysine, thiamine, riboflavin, niacinamide, vitamin A, and ferric orthophosphate. When nixtamal (maize kernels cooked with lime) was fortified with 8% of this mixture by weight and fed to healthy rats and to children who had recovered from malnutrition, normal nitrogen balances and adequate growth were achieved (Bressani et al., 1976).
Meetings with leaders and villagers were held to discuss the convenience and scope of the intervention. A scale and a set of tin cups were installed in each of the two mills to measure the nixtamal and the supplement. The supplement was added at the time of milling to produce the fortified dough for tortillas. Grinding was done almost exclusively at the mills. A literate youngster from the village, posted at each mill, added the supplement in proportion to the amount taken by the women. The operation began as soon as the mills opened early in the morning, to closing time at dawn, every day the mills operated during the study period. The amounts of nixtamal and of the fortifying mixture were recorded for each family each time maize was milled.
For the first two days, 95% of the people accepted the supplement. Shortly thereafter, the taste and odor of soy flour led to self-distribution of the families into three groups: a) 40% accepted supplementation at the higher fortification index (FI)3 of 40-100 (this group contributed 504 newborns to the study); b) 10% accepted a lower FI of 20-39 (43 newborns); c) 50% refused the mixture entirely or allowed an FI no greater than 19 (255 newborns) (Mate et al., 1973; Urrutia et al., 1976).
Fortification was monitored in random samples of tortillas for dietary and chemical analysis, and in random samples of women's urine for riboflavin. Intake was monitored by individual dietary studies. The variables measured and the methods and personnel were those of the Canqué study (Mate, 1978a). The study of infection and colonization of the intestine could not be repeated. The intervention lasted 45 months, during which there were intermittent problems of acceptance of fortified tortillas, related to odor and taste of soy, previously unknown to the villagers. The perishability of fortified tortillas also was a problem.
At the end of the intervention, no significant changes were noted in mean birth weight and gestational age from previous values of the Cauqué, study (Urrutia et al., 1976; Mata 1978a). The supplement which did not affect calorie consumption had no apparent effect on mean weight at six months of age. At 18 months supplemented children actually weighed less. No differences were noted in the mean weight of children when siblings were paired for comparison, in which one sibling was offered the supplement and the other was not (Urrutia et al., 1976; Mata 1978a). The supplement did not influence growth velocity or the development of ossification centers of the hand (Urrutia et al., 1976).
There were no differences in the rates of infectious diseases among the three groups by FI, but the total number of days ill was larger for children with the lowest FI (Urrutia et al., 1976). Also, infant mortality was lower for children in the group with the highest FI. There was no effect on infant mortality, and an actual increase in one- to four-year-old mortality for the village as a whole during the intervention (Urrutia et al., 1976; Mata 1978a). A plausible explanation for the lower morbidity rates in families with high FI is that acceptance of the supplement by families reflected cooperation with the study personnel. Families with the strongest ties with the clinic would also be likely to have better social development and a greater tendency to seek medical treatment as well as to use the food supplement. Families with a higher risk of infection and malnutrition might have had poorer relations with the staff and have been more likely to reject the supplement.
The Principal Investigator (Leonardo Mata) left Guatemala one year before termination of the maize fortification study, and the Field Director Juan Urrutia) left two years after its termination. New duties and lack of enthusiasm for publishing negative findings of this intervention delayed release of these data.
Improvement of Housing and Income
At 3:05 a.m. on February 4, 1976, an earthquake (40 seconds, 7 Richter) destroyed homes, mill houses, granaries, mud walls and other structures of the village. Only the clinic, the school, the municipal building, the slaughterhouse, and one private house were left standing, because they had been built with concrete, iron frames, and more adequate materials. The leveled houses had walls made of layers of adobe blocks without supporting frames, with roofs placed on top without enough binding. The structures collapsed while villagers were sleeping. There were 78 deaths (5% of the population), mainly of children and old people (Glass et al., 1977); this number was replaced within 18 months by the 3.6% population growth estimated for 1970-1972.
Immediately after the earthquake, the clinic staff shifted the maize fortification study to full-time relief activities. In any case, the maize fortification study could not have been continued because the houses, the mills, and the warehouse storing the fortification mixture were destroyed. The local people rapidly rebuilt the village with the aid of national and international organizations. Ulike their former houses, most of the new ones had separate sleeping quarters and improved sanitation. Water toilets became popular and latrines were used more often. A cooperative was organized, widening the opportunities for diversified agriculture, more commerce, and more income. Water quantity and quality increased notably, although the village remained deficient in basic needs. Health services suffered a prolonged attrition and were reduced to sporadic visits by a physician of the Ministry of Health and the services of one or two resident auxiliary nurses.
Infant mortality rate which had been decreasing leveled off or increased after the earthquake. Nevertheless, one-year semilongitudinal data collected 15 years after the Cauqué, study (1986-1987) showed moderate increments in maternal body size, breast milk output, and child growth (Delgado et al., 1988). Since no documentation of infectious morbidity and of microbial entities was done on that occasion, no judgment can be made of the force of infection in comparison with the period of the Cauqué, study. Nevertheless, it is fair to assume that infections had decreased in the intervening 15 years, consequent to greater availability and usage of latrines, flush toilets, and drinking water. Also, education, communication, personal hygiene, and income had increased in the intervening period.