Dietary fibre, exercise and serum lipids and lipoprotein cholesterols in 12 to 15 year olds.

Serum lipid and lipoprotein cholesterol levels track from childhood and are associated with risk of coronary heart disease. There is some evidence that these are influenced by dietary intake and exercise. Serum lipid and lipoprotein cholesterols were measured in a cohort of 119 British children aged 12-15 y who completed a dietary assessment and exercise questionnaire. The ratio of total- to high-density lipoprotein cholesterol fell with increasing fibre intake, but after adjustment for age, body mass index, sex and other dietary factors, this was not statistically significant. Children exercising at least once a day had significantly lower serum total cholesterol and low density lipoprotein cholesterol levels than those exercising less frequently, even after adjustment for the above factors and dietary fibre intake. No dietary factor was significantly associated with any lipid measure after adjustment for the above factors. The challenge is how to optimize exercise level in adolescent children.

Population distribution of Trichuris trichiura in a community of Jamaican children.

The Trichuris trichiura worm burdens of 23 children living in a Place-of-Safety in Kingston, Jamaica, were assessed by stool collection for more than five days after treatment with mebendazole. This procedure was repeated after a seven-month period of natural re-infection. For both collections the maximum rate of worm expulsion was achieved on the fourth day after starting treatment. The worm population distributions were overdispersed and well described by the negative binomial probability model (k = 0.29) in each case. For any one individual, the number of worms passed on the first expulsion was unrelated, absolutely or relatively, to the number passed on the second. These data suggest that: knowledge of the time dependency of helminth expulsion is essential for the accurate estimation of worm burdens by this method; populations of Trichuris are more highly aggregated than those of Ascaris and may thus be more susceptible to control by selective rather than random chemotherapy; and the inherent predisposition of hosts to infection may be of minor importance in determining the distribution of worms in the population-heavily infected hosts appear no more or less likely to acquire large worm burdens on subsequent exposures.

Immediate hypersensitivity, IgE and asthma.

Twenty-one asthmatic and twenty-two non-asthmatic children and nine asthmatic adults from two different rural areas of Tanzania, and eight asthmatic children from Dar-es-Salaam were surveyed by questionnaires, skin testing and the measurement of serum IgE. Asthma was significantly commoner in female rural children (four males, fifteen females). The rural asthmatic children apparently had less skin reactivity (in seven of nine tests) and lower specific (in two of four tests) and total serum IgE than age-, sex- and village-matched controls. This pattern of asthma in rural children in the tropics represents a different type of asthma from that found in temperate zones. In contrast, the adult rural asthmatics and the urban children seemed to have the pattern of increased skin reactivity and serum IgE found in asthmatic patients from temperate climates.

Nutritional status, globulin titers, and parasitic infections of two populations of Tanzanian school children.

Two schools in rural Tanzania were surveyed regarding the pupils' nutrition (weight and height), serum immunoglobulins (IgA, IgG, IgM, and IgE), autoantibodies, malaria antibodies, hepatitis B antigenemia, and fecal and urinary parasites. The survey attempted to quantify the relative importance of undernutrition and parasitic infestation in determining the serological abnormalities found. Of all the children surveyed 69% were undernourished (less than 80% of expected weight for age); 63% had fecal parasites and 38% had urinary schistosomiasis. Serum IgG and IgM concentrations were raised and the serum IgE concentration was strikingly raised (mean 4990IU/ml). Elevated serum IgE was associated with ascariasis. Autoantibodies were common but no autoimmune disease was detected. Notably there was a 35% prevalence of reticulin antibody. This reticulin antibody positivity correlated with increased malaria antibody concentrations. Reduced malaria antibody concentration was significantly associated with hepatitis B antigenemia. The study illustrates that parasites, notably malaria, are important determinants of the serum antibodies of children in the tropics and suggests that mild undernutrition has little effect.

A preliminary survey of malnutrition and helminthiasis among schoolchildren in one mountain and one lowland ujamaa village in Northern Tanzania.

The nutritional status, parasite prevalence and immediate skin hypersensitivity to Ascaris and Schistosoma antigens were determined for 185 schoolchildren living in two ujamaa villages in Northern Tanzania. In the lowland village of Kwamsisi the parasite ova found were Schistosoma haematobium (53.8%), Ascaris (26.0%) and hookworm (24.7%). 57.5% of the children examined were regarded as malnourished, being less than 80% of their expected weight for age. In the mountain village of Ubiri the parasite prevalence rates were 15.2% for Schistosoma haematobium, 1.6% for S. mansoni, 65.2% Ascaris and 24.1% hookworm. Malnutrition was found in 81.9% of the boys and in 41.2% of the girls. This sex difference is considered to be due to the physiological effects of living in a hilly environment. Correlation between malnutrition and multiple infections of Ascaris, hookworm and Schistosoma gave a chi-square value of 5.972 (p = 0.02). All other statistical comparisons between parasite prevalence and nutritional status were insignificant. Immediate skin hypersensitivity tests proved unreliable with 23.3% false negatives (negative skin test with parasite ova found). The serum IgE levels were extremely high with a mean of 3174 units per ml suggesting that the immune mechanisms were not retarded by undernutrition.

Breast-feeding and atopic disease.

PIP: The value of prolonged breast-feeding in the prophylaxis of atopic disease was confirmed by Dr. Saarin and colleagues, and Matthew et al. have suggested that antigen avoidance by prolonged breast-feeding could help prevent asthma. Prolonged breast-feeding is more prevalent in rural Africa, but supplementation, often with cow's milk is frequently introduced before the age of 6 months. In Belize, the Maya Indians commonly feed their infants from birth until 12-18 months exclusively on breast milk. Asthma and hypersensitivity reactions to cow's milk and housedust mite in Maya children in Southern Belize and in a control group of Mestizo children from an urban area was studied. All the children aged 5-9 years attending the 2 schools in the study and control areas were studied. No child in the Maya village school admitted to or was known by the nurse or teachers to have asthma, whereas 2 of 39 children in the control group were known to be affected. The results of the prick tests show that the Maya children had significantly fewer positive reactions to both housedust mite and cow's milk. Reactivity to the 2 antigents was significantly correlated. Both tests were positive in 19 cases, both negative in 52, while only 7 were dust mite positive and cow's milk negative and only 2 were dust mite negative and milk positive. The housedust mite is widely prevalent, so the low incidence of positive reactions and the associated absence of asthma may be related to the traditional feeding pattern in Africa.^ieng

Zinc and immunocompetence in protein-energy malnutrition.

Malnourished children have thymic atrophy which is reversed by zinc supplementation. To see if their defect in cell-mediated immunity was also associated with zinc deficiency ten children were skin-tested with Candida antigen on both arms. One test site was covered with local zinc sulphate and the other with placebo ointment. There was a highly significant increase in the typical delayed-hypersensitivity reaction at the site covered with zinc. The magnitude of the difference between the supplemented and unsupplemented arms correlated negatively with the plasma-zinc concentration. These data show that zinc deficiency is a cause of the immunoincompetence seen in malnutrition. The normal reactions of the zinc-supplemented side indicate that, of the many nutritional deficits of malnourished children, zinc deficiency specifically impairs the cell-mediated immune system. Local skin-testing with and without zinc may provide a measure of zinc status. Local application of zinc may enhance the reliability of tests to diagnose diseases such as tuberculosis in malnourished patients.

IgE, parasites and asthma in Tanzanian children.

Two rural Tanzanian primary schools were surveyed to test the hypothesis that parasitic infestation prevents the development of asthma. 242 pupils were interviewed to determine the prevalence of pupils with recurrent episodes of wheezing. The nineteen pupils so discovered had more exercise-induced bronchial lability than equivalently exercised controls. More girls (12.8%) than boys (3.3%) had asthma. In one school, 77% of the controls had faecal parasites, mainly Ascaris spp., and in the other school 55% of the controls had Schistosoma haematobium in their urine. Parasites were found in similar proportions in the asthmatics. The mean serum IgE for the whole population was 3174 u/ml with no demonstrable difference between the asthmatics and controls. There was no difference in immediate cutaneous hypersensitivity to twenty-two allergens between the asthmatics and controls. These findings suggest that parasitic infestation does not prevent the development of asthma.

The viral etiology of acute respiratory infections in children in Uganda.

The role of viruses in respiratory diseases of young children in Uganda was studied. A viral etiology was established in 36% of the infections investigated. The most important pathogens were found to be respiratory syncytial virus and parainfluenza viruses, which were responsible for 26% of infections investigated. They caused both upper and lower respiratory tract diseases. There was little or no seasonal variation in the etiology of these infections. Adenoviruses were found to be less important and were etiologically related to only 4% of respiratory disease cases. Influenza viruses and enteroviruses were also found to be associated with respiratory infections. However, they were less frequent and their role was insignificant. The role of multiple virus infections was also insignificant.

Parasites and asthma in Tanzanian children.

It has been claimed that parasitic infestation suppresses the development of asthma. Eight Tanzanian schoolchildren in whom asthma was confirmed by the demonstration of exercise-induced bronchospasm were found in an ascaris-endemic area of rural Tanzania. Faecal parasites were found equally commonly in the children with asthma and the ninety-seven non-asthmatic controls. The prevalence of asthma (3.3%) in the school under study was comparable with that found in developed countries.