A.M. Greenwood

Mortality and morbidity from malaria among children in a rural area of The Gambia, West Africa

Mortality and morbidity from malaria were measured among 3000 children under the age of 7 years in a rural area of The Gambia, West Africa. Using a post-mortem questionnaire technique, malaria was identified as the probable cause of 4% of infant deaths and of 25% of deaths in children aged 1 to 4 years. The malaria mortality rate was 6.3 per 1000 per year in infants and 10.7 per 1000 per year in children aged 1 to 4 years. Morbidity surveys suggested that children under the age of 7 years experienced about one clinical episode of malaria per year. Calculation of attributable fractions showed that malaria may be responsible for about 40% of episodes of fever in children. Although the overall level of parasitaemia showed little seasonal variation, the clinical impact of malaria was highly seasonal; all malaria deaths and a high proportion of febrile episodes were recorded during a limited period at the end of the rainy season.

Changes in the pattern of infant and childhood mortality in upper river division, The Gambia, from 1989 to 1993.

A surveillance system was used to detect births and deaths in children in a large, rural, West African population from 1989 to 1993. Cause of death was investigated using post‐mortem questionnaires. Overall infant (age 0–11 months) and child (age 1–4 years) mortality rates of 80.1 and 18.8 per 1000 per year were recorded. These were reasonably consistent over the period of surveillance. The most frequent cause of death in infants was acute respiratory infection (ARI), whereas in children it was malaria: these two conditions accounted for 41% of the deaths in children under 5 years old. Other leading causes of death were acute gastroenteritis, malnutrition, and septicaemia. Deaths attributed to ARI decreased over the 5‐year period, but mortality rates from other causes were either unchanged or increased slightly. Mortality from all causes peaked in the rainy season and was slightly higher in villages which were part of a primary health care programme than in those which were not. There were also no differences between male and female mortality rates beyond one year of age. Despite the introduction of a number of health interventions, there has been no major change in the overall pattern of mortality in children in a rural area of The Gambia. Malaria and ARI remain the main causes of death.

Deaths in infancy and early childhood in a well-vaccinated, rural, West African population.

A survey of deaths in children under the age of 7 years was made over a 1-year period in a rural area of The Gambia with few facilities for curative medicine but with a good record of infant immunizations. One hundred and eighty-four deaths were investigated. Only 12% of deaths occurred in a hospital or health centre but an attempt was made to establish a cause of death by interviewing the family of each dead child and by examining any health records that were available. The infant mortality rate was 142 per 1000 live births and the child mortality rate (death in children aged 1-4 years) 43 per 1000 per year. Acute respiratory infections, malaria and chronic diarrhoea with marasmus were the most frequent causes of death after the 1st month of life. Few children died of diseases that could have been prevented by routine immunizations. An effective immunization programme has probably had some effect on deaths in infancy and early childhood but it will be necessary to find ways of preventing deaths from malaria, acute respiratory infections and chronic diarrhoea/marasmus at the primary health care level if infant and childhood mortality are to be reduced further in rural areas of The Gambia.

Malaria chemoprophylaxis, birth weight and child survival.

Study of the effects of malaria chemoprophylaxis given during pregnancy on birthweight and investigation of the influence of birthweight on child survival suggest that, in a rural area of The Gambia, chemoprophylaxis given during pregnancy might reduce infant mortality by about one-fifth in the children of primigravidae but by less than 5% in the children of multigravidae. In malaria endemic areas, primigravidae should be protected against malaria not only for their own sake but also for that of their infants.

Malaria in a peri-urban area of The Gambia

A clinical and entomological survey of malaria was carried out in Bakau, a peri-urban coastal settlement in The Gambia, from June 1988-May 1989. Only 41 of a cohort of 560 children, aged from three months to nine-years-old, experienced a clinical episode of malaria during the observation period. The majority of cases were identified at clinics and not by regular community surveillance. In Bakau Old Town episodes of malaria were more common on the periphery of the settlement, adjacent to typical anopheline breeding sites, than in the centre. Overall malaria cases were not significantly clustered in space and time, although three pairs of cases among children sleeping in the same room at the same time were identified. A cross-sectional survey in November, at the end of the rainy season, revealed a point prevalence parasitaemia of 2.0% and a spleen rate of 0.3%. All malariometric parameters measured were much lower than any found in comparable studies undertaken in rural areas of the country, reflecting the low number of malaria vectors, Anopheles gambiae complex mosquitoes, found in Bakau. Chloroquine consumption, sleeping under bednets, houses with ceilings, the use of insecticide aerosols and burning traditional mosquito repellents may all have contributed to the low prevalence of malaria in the study area.

Ethnic differences in the prevalence of splenomegaly and malaria in The Gambia.

Significant variations in the prevalence of splenomegaly were found among members of the three main ethnic groups resident in North Bank Division, The Gambia. Among young children splenomegaly and malaria were less prevalent in Mandinkas than in Wollofs or Fulas, suggesting that some genetic or environmental factors protect Mandinka children from this infection. Among older children and adults splenomegaly was found most frequently in Fulas. Six of 22 adults with very large spleens had a high serum IgM level and probably had the hyperreactive malarial splenomegaly (tropical splenomegaly) syndrome. Four of these six subjects were Fulas. This finding, together with the results of a previous study in Nigeria, suggest that Fulas have a predisposition to this condition.

NEONATAL MORTALITY IN A RURAL AREA OF THE GAMBIA

Childhood mortality in Upper River Division, The Gambia is high, 99 per 1000 mid-year population, and 27% of deaths occur is the neonatal period. The aims of the present study were to describe patterns of neonatal death and to identify risk factors. Cause of death was investigated using a neonatal post-mortem questionnaire, and a population-based, matched case-control study was conducted to identify potential risk factors. The neonatal mortality rate in Upper River Division was 39 per 1000 live births (95% CI 36.8-41.2). The rates in the early and late neonatal periods were 21.0 (19.4-22.6) and 18.0 (16.5-19.5), respectively. Infection accounted for 57% of all deaths. In the early neonatal period, 30% of deaths were due to prematurity. Only 55% of babies who died presented for treatment and 84% died at home. Risk factors for neonatal death were primiparity (OR 2.18), previous stillbirth (OR 3.19), prolonged labour (OR 2.80) and pre-lacteal feeding (OR 3.38). A protective effect was seen in association with delivery by a trained traditional birth attendant (OR 0.34) and the application of shea nut butter, a traditional medicine, to the cord stump (OR 0.07). This study has identified the need to understand the reasons underlying the widespread use of pre-lacteal feeds and the barriers to health service use in this community in order to plan effective interventions.

Factors influencing susceptibility to meningococcal disease during an epidemic in The Gambia, West Africa.

A study was made of factors that influenced susceptibility to group A meningococcal disease during an epidemic that affected The Gambia, West Africa during the dry season of 1982-83. No explanations were found for the distribution of cases between villages or within affected villages. Socio-economic status, crowding, nutrition and previous exposure to meningococcal disease all appeared to be unimportant. Examination of serum samples obtained before the outbreak from a few children who subsequently became patients and from an equal number of age-matched controls from the same village showed a higher mean serum IgA value in children who became patients than in controls. There were not, however, any significant differences found in the concentrations of IgG, IgM, complement or meningococcal antibody between the two groups. Four children who developed culture-proven group A meningococcal disease had raised titres of bactericidal antibody to the epidemic strain 2-3 months before their illnesses. Our findings suggest that some important risk factors for group A meningococcal disease remain to be identified.

The pattern of infant and childhood mortality in Upper River Division The Gambia.

A system has been established to document births and deaths in children in a large, rural, West African population, using community reporters. Causes of death in children under the age of 5 years were investigated using post-mortem questionnaires completed by field assistants. There was a marked seasonal incidence of all major causes of death with peak rates in the rainy season. Acute lower respiratory infections (ALRI) were the most frequent cause of death in children under 5 years of age. Other major causes of death were malaria, acute gastro-enteritis and chronic diarrhoea with malnutrition. Mortality from all the major causes of death decreased with increasing village size. Our findings have implications for interventions against childhood mortality.

The distribution of birth weights in Gambian women who received malaria chemoprophylaxis during their first pregnancy and in control women

The distribution of birth weights among the infants of 172 Gambian primigravidae who had received chemoprophylaxis with Maloprim (pyrimethamine+dapsone) during pregnancy was compared with that of the infants of 149 primigravidae who had received placebo. Administration of chemoprophylaxis led to a reduction in the prevalence of low birth weight babies and to an increase in the median birth weight. However, these changes were not accompanied by a comparable increase in the prevalence of high birth weight babies. The perinatal mortality rate was lower, although not significantly so, among the babies of women who had received chemoprophylaxis. Thus, no evidence was found to support the view that administration of chemoprophylaxis might increase the risks of delivery by causing cephalo/pelvic disproportion.