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The effect of nutrition intervention programs in developing countries is likely to vary with the degree to which the program can be successfully targeted at the most vulnerable. In Honduras, the existence of a recent census of the height of first-grade children makes it possible to assess a priori the effect of different targeting strategies, holding constant other features of a hypothetical program. We simulate a nutrition intervention with 20% national coverage and uniform gains of 0.5 Z-scores for all beneficiaries, with a number of different approaches to targeting. The VIIth National Census of First-Graders' Heights provides the baseline scenario and permits identification of priority departments, municipalities, schools and individuals, for a total of six alternative targeting mechanisms. Effect is assessed on the basis of changes in the prevalence of stunting (less than -2 Z-scores) and in two different measures of the severity of stunting adapted from the economics literature (the malnutrition gap and the quadratic malnutrition gap). We find that the simulated program has the potential to substantially improve the severity, but not the prevalence of stunting in Honduras. Household targeting with an imperfect indicator of vulnerability could reduce the malnutrition gap by >20% and the quadratic malnutrition gap by >30%, but would be very expensive to implement. "Broad stroke" geographic targeting could reduce the same measures by 15 and 20%, respectively, and would be much less expensive to implement. We conclude that geographic targeting has the potential to substantially enhance the effect of nutrition programs on the severity of stunting in Honduras.

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Low birthweight (LBW) occurs in 17% of births in developing countries and many of them are full term. The subsequent development of LBW term infants is poorer than higher birthweight children and more likely to be affected by poor social circumstances. We investigated the effects of morbidity and breastfeeding on the development of these LBW term infants. Two parallel cohorts (n = 131 + 131) of LBW term (1500-2499 g) and higher birthweight (3000-3499 g) infants were recruited from six maternity centers in northeast Brazil. The longitudinal prevalence of morbidity and the frequency of breastfeeding over the first 6 mo of life were assessed. The infants' development was assessed on the Bayley Scales at 6 and 12 mo, and we previously reported that the low birthweight group had lower scores than the higher birthweight group. Hospitalizations in the first 6 mo were negatively associated with 6-mo and 12-mo Bayley scores in both groups. Among LBW infants, but not higher birthweight infants, there were significant associations between the prevalence of diarrhea and mental and motor development at 6 mo and mental development at 12 mo. Breastfeeding frequency in the first 4 wk of life was positively associated with mental development in both birthweight groups at 6 mo but not at 12 mo. Breastfeeding beyond 4 wk was not associated with the children's development. We conclude that low birthweight infants are especially vulnerable to the effects of diarrhea, and the greater frequency and differential effect of diarrhea partly explains their poorer development.

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BACKGROUND: Women in developing countries often continue their agricultural work during late pregnancy. Whether this adversely affects birthweight is not clear from previous studies as few controlled for confounding factors. This study seeks to clarify this issue. METHODS: This retrospective cohort study investigated 958 low-income women and their singleton newborn babies residing in a region of Northeast Brazil dependent on sugar-cane production. Women were recruited at maternity centres, when attending for delivery, and were allocated to one of two groups according to their exposure to heavy agricultural labour for at least 3 months during the second and third trimesters of pregnancy (n = 250), or to household activities only (n = 708). RESULTS: The mean birthweight of infants born to women who worked in agriculture during 9 months of pregnancy was 190 g lower than that of the non-exposed group (P = 0.02). After controlling for confounding factors, the adjusted effect was 117 g (P = 0.05). Heavy agricultural work for 6, 7 or 8 months had no significant effect. CONCLUSIONS: These findings suggest that working throughout pregnancy significantly reduces birthweight in this low-income population.

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BACKGROUND: Previous research has suggested that there may be significant within-subject variability, both site-to-site and over time, in hemoglobin concentrations in capillary blood. OBJECTIVE: This study examined the reliability of the portable hemoglobinometer (PHM) system with use of capillary blood and the implications of errors of the magnitude found for the classification of anemia status in individuals and population groups. The precision and accuracy of the method with use of venous blood were also tested. DESIGN: Three empirical data sets were used to measure reliability, precision, and accuracy of the PHM system [2 from Honduras (n = 87 and 141); 1 from Bangladesh (n = 73)]. Simulation data were used to assess the implications of errors for screening individuals for anemia and to estimate anemia prevalence. RESULTS: High within-subject variability (unreliability) was identified when capillary blood from the left hand was compared with that from the right hand (CV: 6.3%) and when measurements were taken on 4 consecutive days (CV: 7.0%). Reliability was only 69% and 50%, respectively. Precision and accuracy, however, were very high (concordance coefficients of 0.99 and 0.98 and CV < 1%). CONCLUSIONS: The simulation data showed that errors of the magnitude found due to unreliability can lead to misclassification of anemia status in individuals and small biases in anemia prevalence estimates. We recommend replicate sampling to reduce the influence of unreliability in the use of the PHM system with capillary blood.

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The authors studied the impact of a rural development project on household food security and nutrition. A quasi-experimental study design was used to compare the experience of members of thirteen Honduran small-holder farmers groups which had already received a year of credit and technical assistance, with another thirteen groups which had just joined the project, and thirteen control communities. All these communities were followed-up for one year (March/April 1997-March/April 1998). Farmers participating in the project showed a greater increase in maize stores than farmers in the control communities (p = 0.01), but did not increase their dietary energy consumption. There was, however, a small improvement in their dietary diversity (p = 0.01). The impact of the project on the nutritional status of under 5's was complex. The study underlined the importance of monitoring the impact of programs which may affect food and nutrition.

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OBJECTIVE: To evaluate the impact of large-dose vitamin A supplementation given to infants > 6 months old (200000 IU) and to preschool children aged 1-4 years (400000 IU) during a pneumonia episode, on their subsequent morbidity and severe morbidity. METHOD: In a randomized, double-blind, placebo controlled trial, the children were followed-up with 2-weekly visits at home for 16 weeks, with the first visit 2 weeks after treatment for pneumonia was initiated. The field workers asked about the presence of morbidity on the day of the visit and in the previous two weeks and about the occurrence and number of clinic attendances and hospital admissions since the last visit. They also measured the patients respiratory rate and temperature and assessed the children for the presence of cyanosis, chest indrawing and wheezing. RESULTS: Except for the prevalence of diet refusal which was higher in the vitamin A group, no differences between the study groups were observed, either in the prevalence of morbidity or in the incidence of clinic attendances and hospital admissions. CONCLUSION: No evidence was found for a beneficial effect of vitamin A given during acute pneumonia on the subsequent morbidity and severe morbidity of children in a population with marginal vitamin A deficiency.

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In Brazil, the highest incidence of low birth weight (LBW) occurs in the northeast, and diarrhea and respiratory infections are the main causes of infant mortality and morbidity. We hypothesized that LBW infants may be zinc deficient, and that this might be adversely affecting their immune function, morbidity, and postnatal growth. We therefore examined the effect of zinc supplementation on these outcomes during the first 6 mo of life. LBW full-term infants (mean birth weight 2337 g) were given daily for 8 wk either 5 mg Zn (n = 71), 1 mg Zn (n = 68), or a placebo (n = 66). Morbidity was determined prospectively through daily home visits (except on Sunday) during weeks 0-8, then twice weekly in weeks 9-26. Anthropometric measurements were made at 0, 4, 8, 17, and 26 wk. Immune function was assessed at 8 wk by the phytohemagglutinin skin test. Supplementation (5 mg Zn) was associated with a 28% reduction in diarrhea prevalence over the 6-mo period [after adjustment for confounders (P = 0.043)], and a 33% reduction in the prevalence of cough (NS, adjusted prevalence P = 0.073). All infants had a positive immune response at 8 wk. Although supplementation had no significant effect on weight and length gains from 0 to 26 wk, infants given 5 mg Zn gained more weight than infants given placebo during weeks 17-26 (P = 0.024, analysis of variance). There was no effect on any outcome with 1 mg Zn. We conclude that 5 mg Zn/d is of benefit to LBW, full-term infants who only have a modest weight deficit.

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The current international growth reference, the National Center for Health Statistics (NCHS) reference, is widely used to compare the nutritional status of populations and to assess the growth of individual children throughout the world. Recently, concerns were raised regarding the adequacy of this reference for assessing the growth of breast-fed infants. We used the NCHS reference to evaluate infant growth in one of the most developed areas of Brazil. Infants who were exclusively or predominantly breast-fed for the first 4-6 mo, and partially breast-fed thereafter, grew more rapidly than the NCHS reference in weight and length during the first 3 mo, but appeared to falter thereafter. The average growth of all infants, regardless of feeding pattern, was faster than the NCHS reference until approximately 6 mo, after which their growth became slower than that of the NCHS sample. To substantiate this finding, the NCHS growth curves were then compared with growth data of breast-fed infants in developed countries from pooled published studies, formula-fed North American and European infants and predominantly bottle-fed U.S. infants monitored by the Centers for Disease Control and Prevention (CDC) Pediatric Surveillance System. In all three cases, weights showed the same pattern as the Brazilian infants-higher than NCHS in the early months but an apparent decline thereafter. The pattern for length gain was similar but less marked. Breast-fed infants showed more pronounced declines than those who were predominantly bottle-fed. These findings suggest that the infancy portion of the NCHS reference does not adequately reflect the growth of either breast-fed or artificially fed infants. This probably results from characteristics of the original sample and from inadequate curve-fitting procedures. The development of an improved international growth reference that reflects the normal infant growth pattern is indicated.

PIP: The National Center for Health Statistics (NCHS) reference is the international standard widely used to compare the nutritional status of populations and to assess the growth of individual children around the world. There has, however, recently been concern over the adequacy of this reference for assessing the growth of breast-fed infants. Findings are presented from an evaluation of infant growth using the NCHS reference in the city of Pelotas, Brazil, one of the most developed areas of the country. The 5304 children enrolled in the study comprised all but 0.3% of all hospital births occurring in the city in 1993. Infants who were either exclusively or mainly breast-fed for the first 4-6 months, and partially breast-fed thereafter, grew faster than the NCHS reference in weight and length during the first 3 months, but appeared to falter thereafter. The average growth of all infants, regardless of feeding pattern, was faster than the NCHS reference until approximately age 6 months, after which they grew slower than did the NCHS sample. A comparison of NCHS growth curves with growth data on breast-fed infants in developed countries from pooled published studies, formula-fed North American and European infants, and mainly bottle-fed US infants monitored by the Centers for Disease Control and Prevention (CDC) Pediatric Surveillance System found infant weights in all cases to exhibit the same pattern as that of the Brazilian infants. The pattern for length gain was similar, but less marked. Breast-fed infants showed more pronounced declines than those who were mainly bottle-fed. An improved international growth reference should be developed and used.

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Longitudinal prevalence, the proportion of all days of observation that a given individual manifests symptoms of illness, is a measure of disease frequency that is easy to generate from daily morbidity data and has been shown to be strongly related to subsequent health outcome. It is hypothesized that this measure could be derived using a representative sample of days of observation rather than continuous surveillance. The authors use 1990-1991 data from a Brazilian supplementation trial comprising a year's daily records of the occurrence of diarrhea, fever, and cough in 906 children under 5 years of age to examine how many days of morbidity data need to be observed to rank subjects into quintiles of illness frequency. Systematic samples of the full data set, based on every 2nd, 3rd, 5th, 10th, 15th, 20th, and 30th day of data, are compared with the continuous record. For diarrhea and fever, estimates based on less than 72 days of observation result in over one fourth of individuals who should have been in the extreme quintiles of the morbidity distribution being misclassified, and over one fifth of all subjects appear (falsely) to suffer no morbidity. Estimates of longitudinal prevalence should be based on at least 72 days of observation.

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BACKGROUND: Low birthweight infants suffer greater mortality and neonatal morbidity, grow less well in infancy and show poorer psycho-motor development. However, this simple categorization may obscure important differences in aetiology and prognosis between infants born stunted, thin, or both. METHODS: In 1993, all births in Pelotas, Brazil, were enrolled into a prospective study of health and development in infancy. Of 5249 live births, 5160 had length and weight measures at birth, and were classified into tertiles of length and ponderal index. All deaths and hospitalizations were monitored, and suspected developmental delay and attained growth at 12 months were assessed on a subsample of 1364 infants. Logistic regression was used to control for gestational age and socioeconomic status. RESULTS: There was no association between birth length and ponderal index tertiles. After adjusting for gestational age, infants in the lower tertiles of both length and ponderal index presented a 3.8-times higher risk of mortality from day 8 to day 365, and a 2.5-times higher risk of hospitalization compared to infants with greater birth lengths and/or ponderal indices. Suspected developmental delay was associated with length and, less strongly, with ponderal index, but there was no synergism between the two. Infants in the middle and upper tertiles of ponderal index at birth became thinner. CONCLUSIONS: Birth length was strongly associated with development at 12 months, but only infants born both short and thin were at increased risk of mortality and hospitalizations. The combination of the two measures provides a useful classification of the anthropometric status of the newborn.

PIP: A prospective study of all 5249 live births in Pelotas, Brazil, in 1993 examined interactions between health and development in infancy. The 5160 infants who had length and weight measurements taken at birth were classified into tertiles of length-for-age Z score and ponderal index--a measure of soft tissue growth. There was no association between these two measures. After adjustments for gestational age, infants in the lower tertiles of both length and ponderal index had a 3.8 times greater risk of mortality from day 8 to 365 and a 2.5 times higher risk of hospitalization than infants in the high tertile. However, infants born short but not thin, or thin but not short, were not at increased risk of either mortality or hospitalization. Suspected developmental delay at 12 months was associated with shorter stature at birth and, less strongly, with a lower ponderal index, but there was no synergism between the two measures. Infants in the middle and upper tertiles of ponderal index at birth became markedly thinner in the first year of life, while length changes were less strongly associated with initial status. Overall, these findings suggest that the combination of length and ponderal index at birth may provide a functionally relevant means of classifying the newborn's anthropometric status since the two measures are relatively independent of each other at the level of the individual and appear to affect different aspects of the infant's subsequent health and development.

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