The pattern of childhood hepatitis B infection in two Gambian villages.

Serologic markers of hepatitis B virus (HBV) infection were measured in children from Manduar and Keneba, two adjacent villages in The Gambia, in 1980 and in 1984. The rate of HBV infection over the 4 years differed markedly: in Manduar 71% of children who were less than 5 years of age in 1980 became infected, whereas in Keneba only 37% became infected. Male children were more frequent carriers of either HBs or e antigen than were female children. Marked clustering of hepatitis B surface antigen (HBsAg) antigenemia within sibling relationships was shown in both villages. The chance of the youngest child in a household being a carrier of HBsAg was strongly related to the number of antigen-positive siblings. Four years later, 53% of children who were initially positive for HBsAg and 33% who were positive for hepatitis B e antigen still carried these antigens. Jaundice was not observed.

Evaluation of a primary health care programme in The Gambia. II. Its impact on mortality and morbidity in young children.

Mortality and morbidity in children under 5 years of age were measured in 41 villages and hamlets in a rural area of The Gambia for a 1-year period before and for a 3-year period after the introduction of a primary health care (PHC) programme into 15 of the larger villages in the area. Both infant mortality and child mortality rates fell during the post-intervention period but declines were similar in PHC and in non-PHC villages suggesting that factors such as an up-grading of the Farafenni dispensary, improvements in transport and the survey itself may have played an important part in bringing about these changes. Measurements of morbidity showed a lower prevalence of diarrhoea, vomiting or severe cough in PHC villages after the introduction of the PHC programme. Introduction of the PHC programme had no significant effect on nutritional status or on vaccine coverage. Significant improvements in the health of children in the Farafenni study area have taken place during the past 5 years but the PHC programme is probably only one of the factors that have brought about these changes.

Evaluation of a primary health care programme in The Gambia. I. The impact of trained traditional birth attendants on the outcome of pregnancy.

In 1983 a primary health care (PHC) programme was introduced into the Farafenni area of The Gambia; an important component of this programme was the identification and training of a traditional birth attendant (TBA) in each village with a population of 400 or greater. The outcome of pregnancy has been documented among women resident in 15 villages which joined the PHC programme and in 26 which were too small to do so, for 1 year before and for 3 years after the start of the programme. In PHC villages 65% of women were assisted at delivery by a trained TBA during the post-implementation period and the proportion of women who delivered in a hospital or health centre increased. Both maternal and neonatal death rates fell in PHC villages during the post-intervention period, declining to about half the levels recorded during pre-intervention surveys during the last year of the study. In non-PHC villages there was also a fall in the maternal death rate but little change in the neonatal death rate. Trained traditional birth attendants probably played some part in improving the outcome of pregnancy in the Farafenni area but other factors, such as improvements in transport, may also have contributed.

A comparative study of Lapudrine (chlorproguanil) and Maloprim (pyrimethamine and dapsone) as chemoprophylactics against malaria in Gambian children.

A comparison has been made of Lapudrine (chlorproguanil) and Maloprim (pyrimethamine +dapsone) as malaria chemoprophylactics when given every two weeks for 3 years to Gambian children under the age of 5 years. Both drugs produced falls in spleen and malaria parasite rates and an increase in packed cell volume. Maloprim, but not chlorproguanil, significantly reduced the incidence of episodes of fever accompanied by malaria parasitaemia. Children who received Maloprim, but not those who received chlorproguanil, grew better than children in the placebo group. This finding suggests that brief clinical episodes of malaria are more important in impairing growth than more prolonged periods of asymptomatic parasitaemia. No serious side-effect attributable to either drug was observed. After chemoprophylaxis had been given for 3 malaria transmission seasons the level of resistance of Plasmodium falciparum to pyrimethamine and to chlorproguanil was about 10%.

The effects of antimalarials and folate supplements on haematological indices and red cell folate levels in Gambian children.

Haematological indices and red cell folate levels (RCF) were measured during two annual surveys in a group of Gambian children aged 3 months-5 years who were participating in a trial of malaria chemoprophylaxis with Maloprim or chlorproguanil given with or without folate supplements. Chlorproguanil was given in an adult dose of 20 mg, Maloprim as one quarter or one half of the adult dose of 25 mg pyrimethamine and 100 mg dapsone. Antimalarials and folate supplements were given fortnightly. About 20% of children had low RCF levels (less than 100 ng/ml). Among children who did not receive supplementation with folate there were no significant differences in mean RCF levels between children who received Maloprim, chlorproguanil or placebo. Among children who received folate supplements, the mean RCF was significantly lower among those receiving chlorproguanil than among the controls. Mean RCF values were similar in children who received Maloprim or placebo. If chlorproguanil is used for malaria chemoprophylaxis in young children an age-related dose should be used.

Comparison of two strategies for control of malaria within a primary health care programme in the Gambia.

Two drug strategies for the control of malaria in children aged 3-59 months have been compared in a rural area of The Gambia--treatment of presumptive episodes of clinical malaria with chloroquine by village health workers, and treatment combined with fortnightly chemoprophylaxis with 'Maloprim' (pyrimethamine/dapsone) which was also given by village health workers. Treatment alone did not have any significant effect on mortality or morbidity from malaria. In contrast, treatment and chemoprophylaxis reduced overall mortality in children aged 1-4 years, mortality from probable malaria, and episodes of fever associated with malaria parasitaemia. A high level of compliance with chemoprophylaxis was obtained and no harmful consequences of chemoprophylaxis were observed.

Sequelae of epidemic meningococcal meningitis in Africa.

Audiological and other long-term neurological sequelae were determined in 157 cases and their controls matched for age, sex and village 6 to 12 months after an epidemic of group A meningococcal meningitis in rural West Africa. 19 cases (12.1%) and 3 controls (1.9%) had moderate or severe neurological sequelae of any type (P less than 0.001); 6 cases (3.9%) and no controls had severe or profound sensorineural hearing loss (P = 0.03). There was no difference in conductive hearing loss between cases and controls. Other cranial nerve sequelae (except visual defects) and generalized neurological and motor and co-ordination sequelae were also significantly increased in cases. Sensorineural hearing loss and other cranial nerve sequelae occurred significantly more frequently in males than in females, and co-ordination sequelae more frequently in cases aged 10 years or more than in younger cases. Sensorineural hearing loss and loss of visual acuity were found significantly more frequently in cases whose treatment was delayed for 4 d or more, compared with those who received treatment sooner.

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.

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.

PIP: Mortality under seven years of age in a rural population in the Gambia in 1982-1983 is analyzed. The population examined is one with a high level of infant immunization but poor access to health facilities. An infant mortality rate of 142 per 1,000 live births and a mortality rate for children aged 1-4 years of 43 per 1,000 are observed. Acute respiratory infections, malaria, and chronic diarrhea with marasmus are shown to be the major causes of death after the first month of life. The authors conclude that very little impact could be made on these rates by expanded immunization efforts.

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.

A prospective survey of the outcome of pregnancy in a rural area of the Gambia.

PIP: Pregnancy outcome was studied in 672 women over a 1-year period in a rural area of Gambia where medical resources were very limited, prior to the introduction of a primary health care program. Maternal mortality was quite high (22/1000), primarily the result of postpartum hemorrhage and infections. Stillbirth and neonatal death rates were also very high (35 and 65/1000); prematurity and infections were the primary causes of neonatal deaths. First or late pregnancies, either prior to age 20 or after age 40, and multiple pregnancies were all associated with a poor pregnancy outcome. Women in these groups should therefore be encouraged by traditional birth attendants and by the staff of rural antenatal clinics to deliver at a health center or hospital.^ieng

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.

Mortality from meningococcal disease during an epidemic in The Gambia, West Africa.

Mortality from meningococcal disease was determined during an epidemic in a rural area of The Gambia with few medical resources, but where a system of registration of births and deaths had been established before the introduction of a primary health care programme. 33 deaths were recorded among 127 patients, a case mortality rate of 26%. 84% of deaths occurred within the first 24 h of illness and many patients died before they could reach any source of treatment. Previous studies, based on regional statistics or on hospital series, may have underestimated mortality from epidemic meningitis in Africa. Mortality from this infection will be reduced only if treatment can be made readily accessible to patients early in the course of their illness.

Malumfashi Endemic Diseases Research Project XXI. Some aspects of the collection of demographic data.

This paper considers some of the procedures used and problems encountered in the collection of demographic data for a large-scale medical project: the Endemic Diseases Research Project at Malumfashi in northern Nigeria, 1974-1979. 43,216 people were enumerated and a subset of 26,100 were visited monthly for one year for the purpose of registration of vital events. The majority of problems encountered are relevant to similar studies in developing countries. Some difficulties cannot be avoided, but it is considered helpful to identify them. Other situations, however, deserve particular attention, such as the development of adequate on-site data-checking mechanisms, as these are areas in which future programmes could benefit from the experience of the demographic studies in Malumfashi. More effort still needs to be put into the improvement of data collection methods themselves.

Seasonal variations in the nutritional status of urban Gambian children.

1. Children aged 6-35 months in an urban community in The Gambia, West Africa, were weighed and their lengths measured at four surveys over an 18-month period, twice towards the end of the rains, and twice during the dry season. 2. Relative to international standards, height-for-age deteriorated steadily with age, while weight-for-age fell sharply in the second-half of infancy but showed no further deterioration from 12 to 35 months of age. 3. Height-for-age showed little seasonal variation, but weight-for-age and weight-for-height were lower at the end of the rains than during the dry season. Weight and height velocities were much lower during the rains than in the dry season, with more than 20% of the children losing weight during the rains. Possible reasons for these seasonal variations are discussed. Compensatory weight gain in the dry season exceeded the velocity expected from the standards in children aged 12 months or more, but height velocity fell below the standards all year. 4. The results are compared with previous findings from Keneba, a rural Gambian village. Weight velocity during the dry season was similar in the two communities, but the village children experienced a sharper decline in weight gain during the rains. 5. These results suggest that seasonal ecological factors may seriously influence the nutritional status of children living in an urban environment with adequate availability of food.

The immune response to vaccination in undernourished and well-nourished Nigerian children.

The immune response of young Nigerian children to a full course of infant immunizations was studied in relation to their nutritional state at the time of vaccination. No significant correlations were found between anthropometric measurements made at the time of vaccination and the antibody response to triple, polio, measles, meningococcal and typhoid vaccines. Significant correlations were found between serum pre-albumin levels and the response to group A meningococcal polysaccharide vaccine and between serum albumin levels and the response to group C meningococcal polysaccharide vaccine. These correlations may reflect the depressive effect of malaria both on serum albumin and pre-albumin levels and on immune responsiveness to meningococcal polysaccharides. No significant correlations were found between nutritional state at the time of BCG vaccination and the development of a positive tuberculin reaction five weeks later. We conclude that under-nutrition has little or no effect on the immune response to vaccines used in routine infant immunization programmes.

Bed-nets (mosquito-nets) and morbidity from malaria.

A study was undertaken in the Farafenni area of The Gambia to determine the relation between morbidity from malaria in children and the use of bed-nets (mosquito-nets). From comparisons of parasite and spleen rates in bed-net users and in non-users it seemed that bed-nets had a strong protective effect. However, the prevalence of malaria in the study population was also influenced by ethnic group and place of residence, and the association of bed-net use with these two confounding factors accounted for some of the differences observed between bed-net users and non-users. Nevertheless, a significant inverse correlation between splenomegaly and the use of bed-nets remained. This suggests that bed-nets give Gambian children some protection against malaria and that the use of bed-nets, either untreated or treated with an insecticide such as permethrin, should be investigated further as a means of malaria control in Africa.