Influence of birth weight on mortality from infectious diseases: a case-control study.

The association between birth weight and infant mortality from infectious diseases was investigated in a population-based case-control study in two urban areas in southern Brazil. All deaths of children, seven to 364 days of age, occurring in a year were studied and the parents of the 357 infants dying of an infectious cause were interviewed, as were the parents of two neighborhood control infants for each case. Low birth weight infants (less than 2,500 g) were found, after allowing for confounding factors, to be 2.3 (90% confidence interval = 1.6 to 3.4) times more likely to die of an infection than those of higher birth weight. The odds ratios were 2.0 (1.1 to 3.6) for deaths due to diarrhea, 1.9 (1.0 to 3.6) for respiratory infections, and 5.0 (1.3 to 18.6) for other infections. These estimates of the risks associated with low birth weight are considerably lower than those from studies in developed countries.

Water supply, sanitation and housing in relation to the risk of infant mortality from diarrhoea.

In a population-based case-control study in the metropolitan areas of Porto Alegre and Pelotas in southern Brazil children dying in infancy from diarrhoea were compared to neighbourhood controls in terms of several social and environmental variables. Factors found to be significantly associated with an increased risk of death from diarrhoea included the non-availability of piped water, the absence of a flush toilet, residence in a poorly built house and household overcrowding. When adjustment was made for confounding variables and the mutual confounding effect of the environmental variables on each other, the only association that remained statistically significant was that with the availability of piped water. The association with poor housing was almost significant (p = 0.052). Compared to those with water piped to their house, those without easy access to piped water were found to be 4.8 times more likely to suffer infant death from diarrhoea (95% confidence interval 1.7 to 13.8) and those with water piped to their plot but not to their house had a 1.5 times greater risk (95% confidence interval 0.8 to 3.0).

Deaths due to dysentery, acute and persistent diarrhoea among Brazilian infants.

In a population-based study, all infant deaths occurring in a one-year period in the metropolitan areas of Porto Alegre and Pelotas, in southern Brazil, were studied. There were 227 infants who presented diarrhoea during the fatal illness, and in 75% of these diarrhoea was considered to be the underlying cause of death. Acute diarrhoea (< 14 days' duration) accounted for 28% of the deaths, persistent diarrhoea for 62% and dysentery for a further 10%. Approximately one-half of the children with persistent diarrhoea were admitted to a hospital in the first two weeks of the episode. Hospital-acquired infections were likely to have contributed to one- to two-thirds of deaths due to dysentery and persistent diarrhoea. A comparison with neighbourhood controls showed that breast milk provided substantial protection against deaths due to either acute or persistent diarrhoea.

[Female mortality in Brazil: the weaker sex or stronger sex?]. / Mortalidade feminina no Brasil: sexo frágil ou sexo forte?

Population ageing in Brazil has been more rapid and more intense among women. This phenomenon is well described in developed countries where mortality rates are higher for men than women. In this regard, the analysis of mortality patterns by cause contributes to elucidate the determinant factors of the present situation in Brazil and provides indications of some future trends in female mortality. This is especially important due to the fact that in Brazil the social role of women has experienced great changes. This study presents data on mortality from ten capital cities in 1985, showing age-standardized overall and cause-specific mortality rates for five of the main groups of causes by sex. Ratios and differences effect estimators were used. The results revealed that regional patterns are associated with the urban and industrial processes with greater differences by sex in more developed regions. External causes and cardiovascular diseases are the main factors responsible for higher mortality among men with special emphasis on violent deaths. It is inferred that the present trend will be maintained, though it is possible that mortality differences by sex could decrease in the near future. The authors discuss that longer survival among women in Brazil does not reveal better life conditions.

[Evaluation of the quality of information on the basic cause of death of infants in Rio Grande do Sul (Brazil)]. / Avaliação da qualidade da informação sobre a causa básica de óbitos infantis no Rio Grande do Sul (Brasil).

The validity of the official information on the cause of infant deaths was studied in the Brazilian cities of Porto Alegre and Pelotas in 1985. Using data collected for a population-based case-control study of infant mortality due to infectious diseases or malnutrition, a comparison was made between the causes of death reported on the death certificates and those obtained after a careful review of case-notes and a medical interview with the parents of the decreased infants. Official death certificates showed an excess of deaths attribute to bronchopneumonia (ICD 485X) and septicemia (ICD 038.9), and an underestimation of the number of deaths due to diarrheal diseases (ICD 009.1) and of sudden infant deaths (ICD 798.0). The overall rate of agreement between official and revised certificates, in terms of groups of causes of death, was only 27.9%. Lower respiratory infections, which were the leading infectious cause of infant death according to official statistics, were superseded by diarrheal diseases after this revision.

Falling diarrhoea mortality in Northeastern Brazil: did ORT play a role?

The impact of oral rehydration therapy (ORT) on the recent decline in diarrhoea mortality in the northeast of Brazil was studied. Proportionate infant mortality fell from 32% in 1980 to 17% in 1989 and infant deaths attributed to diarrhoea dropped from 41% to 25%, resulting in an overall reduction of 57%. Similar decreases were observed for children aged 1-4 years. Diarrhoea admissions also fell from 57% of infant hospitalizations in 1980 to 30% in 1990. None of the other major causes of death or admissions showed such decline. ORT was introduced in the early 1980s, being used in 35% of all episodes in 1991 and in 62% of those regarded as severe by the mother. Other changes included a worsening of socioeconomic conditions and increases in water supply, vaccine coverage, breastfeeding duration and nutritional status. A simulation model estimated that changes in factors other than ORT would lead to a 21% reduction in infant diarrhoea mortality, or about one-third of the actual decline. Finally, an ecological analysis showed that ORT use rates were inversely correlated to infant diarrhoea mortality (r=-0.61; p=0.04). Despite the shortcomings of the available data, these findings suggest an important impact of ORT on diarrhoea mortality.

PIP: Proportionate infant mortality in the northeast of Brazil fell from 32% in 1980 to 17% in 1989, with infant deaths attributed to diarrhea falling from 41% to 25%; these declines comprise an overall reduction of 57%. Similar decreases were observed for children aged 1-4 years. Diarrhea admissions also fell from 57% of infant hospitalizations in 1980 to 30% in 1990. No such decline was observed in any of the other major causes of death or admissions. The authors explored the impact of oral rehydration therapy (ORT) upon this recent decline in diarrhea mortality in the region. ORT was introduced in the early 1980s, being used in 35% of all episodes in 1991 and in 62% of those regarded as severe by the mother. Socioeconomic conditions worsened during the 1980s, but the levels of water supply, vaccine coverage, breastfeeding duration, and nutritional status increased. A simulation model estimated that changes in factors other than ORT would lead to a 21% reduction in infant diarrhea mortality, or approximately one third of the actual decline. An ecological analysis found ORT use rates to be inversely correlated with infant diarrhea mortality. These findings suggest that the introduction and use of ORT in northeastern Brazil had an important impact upon diarrhea mortality.

Infant feeding and deaths due to diarrhea. A case-control study.

The association between infant feeding habits and infant mortality from diarrhea was investigated in a population-based case-control study in two urban areas in southern Brazil during 1985. Each of 170 infants who died due to diarrhea was compared with two neighborhood controls. After allowance was made for confounding variables, infants who received powdered milk or cow's milk, in addition to breast milk, were at 4.2 times (95% confidence interval (CI) 1.7-10.1) the risk of death from diarrhea compared with infants who did not receive artificial milk, while the risk for infants who did not receive any breast milk was 14.2 times higher (95% CI 5.9-34.1). Similar results were obtained when infants who died from diarrhea were compared with infants who died from diseases that were presumed to be due to noninfectious causes. Each additional daily breast feed reduced the risk of diarrhea death by 20% (95% CI 2-34%), but the increase in risk associated with each bottle feed was not significant after allowance was made for the number of breast feeds. The only other consumption variable associated with diarrhea mortality was the frequency with which tea, water, or juice were drunk with each feed (increase in risk, 42% (95% CI 4-93%]. The odds ratios associated with nonbreast milk were highest in the first two months of life. Possible biases were investigated, including the interruption of breast-feeding as an early consequence of the terminal illness, but the strong protective effect of breast-feeding persisted after these adjustments.

Evidence for protection by breast-feeding against infant deaths from infectious diseases in Brazil.

In a population-based case-control study of infant mortality in two urban areas of southern Brazil, the type of milk in an infant's diet was found to be an important risk factor for deaths from diarrhoeal and respiratory infections. Compared with infants who were breast-fed with no milk supplements, and after adjusting for confounding variables, those completely weaned had 14.2 and 3.6 times the risk of death from diarrhoea and respiratory infections, respectively. Part-weaning was associated with corresponding relative risks (RR) of 4.2 and 1.6. The risk of death from infections other than diarrhoea or respiratory infection was less clearly associated with breast-feeding (completely weaned, RR = 2.5; partly weaned, RR = 0.4). Cow's and formula milk seemed to be equally hazardous. For deaths due to diarrhoea the increased risk associated with not breast-feeding was greatest in the first two months of life (RR for completely weaned vs breast-fed without supplementary milk = 23.3).

PIP: In a population-based case-control study of infant mortality in 2 urban areas of southern Brazil, the type of milk in an infant's diet was found to be an important risk factor for deaths from diarrheal and respiratory infections. Compared with infants who were breastfed with no milk supplements, and after adjusting for confounding variables, those completely weaned had 14.2 and 3.6 times the risk of death from diarrhea and respiratory infections, respectively. Part-weaning was associated with corresponding relative risks (RR) of 4.2 and 1.6. The risk of death from infections other than diarrhea or respiratory infection was less clearly associated with breastfeeding (completely weaned, RR=2.5; partly weaned, RR=0.4). Cow's and formula milk seemed to be equally hazardous. For deaths due to diarrhea the increased risk associated with not breastfeeding was greatest in the 1st 2 months of life (RR for completely weaned vs. breastfed without supplementary milk =23.3). (author's modified).