Comparison of ranging behaviour in a multi-species complex of free-ranging hosts of bovine tuberculosis in relation to their use as disease sentinels.

Sentinel species are increasingly used by disease managers to detect and monitor the prevalence of zoonotic diseases in wildlife populations. Characterizing home-range movements of sentinel hosts is thus important for developing improved disease surveillance methods, especially in systems where multiple host species co-exist. We studied ranging activity of major hosts of bovine tuberculosis (TB) in an upland habitat of New Zealand: we compared home-range coverage by ferrets (Mustela furo), wild deer (Cervus elaphus), feral pigs (Sus scrofa), brushtail possums (Trichosurus vulpecula) and free-ranging farmed cattle (Bos taurus). We also report in detail the proportional utilization of a seasonal (4-monthly) range area for the latter four species. Possums covered the smallest home range (<30 ha), ferrets covered ~100 ha, pigs ~4 km(2), deer and cattle both >30 km2. For any given weekly period, cattle, deer and pigs were shown to utilize 37­45% of their estimated 4-month range, while possums utilized 62% during any weekly period and 85% during any monthly period of their estimated 4-month range. We suggest that present means for estimating TB detection kernels, based on long-term range size estimates for possums and sentinel species, probably overstate the true local surveillance coverage per individual.

Micronutrient dietary supplements--a new fourth approach.

Currently the three main widely used strategies to control micronutrient deficiencies are food diversification, fortification, and consumption of medicinal supplements. In Tanzania a fourth strategy has been evaluated in school children, and is to be studied in pregnant and lactating women. The dietary supplement comes in the form of a powder used to prepare a fruit flavored drink. Children consumed for six months 25 grams per school day attended, the powder being added to 200 ml of water. The dietary supplement provides between 40 and 100 percent of the RDA of 10 micronutrients, which includes iron, vitamin A and iodine. Unlike medicinal supplements it provides the multiple vitamins and minerals in physiologic, not megadoses. In a well conducted randomized double blind placebo controlled trial, a dietary supplement in the form of a fortified powder fruit drink produced statistically significant differences not only in vitamin A and iron status, but also in the growth of young school age children.

Unnecessary water supplementation for babies: grandmothers blame clinics.

UNLABELLED: This study was designed to obtain policy-and programme-relevant data on exclusive breastfeeding in Lesotho at a time when global recommendations for exclusive breastfeeding were new. During both phases of field research, conducted in 1991 and 1992, qualitative information was obtained through focus groups and individual interviews with mothers, grandmothers and nurses. This was complemented during the second phase with quantitative data collected through a clinic-based survey of mothers. The qualitative and the quantitative findings consistently converged, illustrating a culture of infant feeding in which breastfeeding was central, but exclusive breastfeeding was an unknown concept and not practised. Grandmothers seemed to be more in tune with the ideal of exclusive breastfeeding as they had given their young infants thin gruel only occasionally. Contemporary mothers, in contrast, were regularly giving their young infants water. Mothers and grandmothers frequently cited nurses as the source of advice for giving water. Grandmothers were adamant in pointing out that they had never given water to their own young infants and asserted that they avoided giving it to their grandchildren as they considered it unnecessary and harmful. According to the grandmothers, water supplementation was a new practice that had been introduced through the clinics. CONCLUSION: Efforts to discourage water supplementation and encourage exclusive breastfeeding in this setting need to be directed both at mothers and health providers.

Malnutrition and parasitic helminth infections.

The Global Burden of Disease caused by the 3 major intestinal nematodes is an estimated 22.1 million disability-adjusted life-years (DALYs) lost for hookworm, 10.5 million for Ascaris lumbricoides, 6.4 million for Trichuris trichiura, and 39.0 million for the three infections combined (as compared with malaria at 35.7 million) (World Bank, 1993; Chan et al. 1994); these figures illustrate why some scarce health care resources must be used for their control. Strongyloides stercoralis is the fourth most important intestinal worm infection; its nutritional implications are discussed, and the fact that its geographic distribution needs further study is emphasized. Mechanisms underlying the malnutrition induced by intestinal helminths are described. Anorexia, which can decrease intake of all nutrients in tropical populations on marginal diets, is likely to be the most important in terms of magnitude and the probable major mechanism by which intestinal nematodes inhibit growth and development. We present a revised and expanded conceptual framework for how parasites cause/aggravate malnutrition and retard development in endemic areas. Specific negative effects that a wide variety of parasites may have on gastrointestinal physiology are presented. The synergism between Trichuris and Campylobacter, intestinal inflammation and growth failure, and new studies showing that hookworm inhibits growth and promotes anaemia in preschool (as well as school-age) children are presented. We conclude by presenting rationales and evidence to justify ensuring the widest possible coverage for preschool-age children and girls and women of childbearing age in intestinal parasite control programmes, in order to prevent morbidity and mortality in general and specifically to help decrease the vicious intergenerational cycle of growth failure (of low-birth-weight/intrauterine growth retardation and stunting) that entraps infants, children and girls and women of reproductive age in developing areas.

Global malnutrition.

The four most important forms of malnutrition worldwide (protein-energy malnutrition, iron deficiency and anaemias (IDA), vitamin A deficiency (VAD), and iodine deficiency disorders (IDD)) are examined below in terms of their global and regional prevalences, the age and gender groups most affected, their clinical and public health consequences, and, especially, the recent progress in country and regional quantitation and control. Zinc deficiency, with its accompanying diminished host resistance and increased susceptibility to infections, is also reviewed. WHO estimates that malnutrition (underweight) was associated with over half of all child deaths in developing countries in 1995. The prevalence of stunting in developing countries is expected to decline from 36% in 1995 to 32.5% in 2000; the numbers of children affected (excluding China) are expected to decrease from 196.59 millions to 181.92 millions. Stunting affects 48% of children in South Central Asia, 48% in Eastern Africa, 38% in South Eastern Asia, and 13-24% in Latin America. IDA affects about 43% of women and 34% of men in developing countries and usually is most serious in pregnant women and children, though non-pregnant women, the elderly, and men in hookworm-endemic areas also comprise groups at risk. Clinical VAD affects at least 2.80 million preschool children in over 60 countries, and subclinical VAD is considered a problem for at least 251 millions; school-age children and pregnant women are also affected. Globally about 740 million people are affected by goitre, and over two billions are considered at risk of IDD. However, mandatory salt iodisation in the last decade in many regions has decreased dramatically the percentage of the population at risk. Two recent major advances in understanding the global importance of malnutrition are (1) the data of 53 countries that links protein-energy malnutrition (assessed by underweight) directly to increased child mortality rates, and (2) the outcome in 6 of 8 large vitamin A supplementation trials showing decreases of 20-50% in child mortality.

Dietary vitamin A intakes of preschool-age children in South India.

The vitamin A intake of children aged 1-3 y (n = 683) was assessed using a quantitative food-frequency questionnaire in a vitamin A intervention study in South India. Trained field workers interviewed mothers about their children's usual consumption of common sources of vitamin A and collected information on portion sizes using standard cups. Mothers were asked to state the number of months in a year during which specific seasonal foods were available. Information about current breast-feeding was also obtained. Vitamin A intakes from nonbreast milk sources were extremely low at all ages. The median intake of total vitamin A, beta-carotene and retinol was 121, 100 and 21 retinol equivalents (RE), respectively. Maternal education and socioeconomic status (SES) were positively associated with total vitamin A and retinol intakes. Girls had significantly lower intakes than boys even after adjusting for differences in age, maternal education, SES and breast-feeding status. Breast-feeding was common, but declined to 60% by 24 mo and to 15% by 36 mo. Vitamin A intakes from nonbreast milk sources increased with age only for currently breast-fed children, who tended to be of lower SES. After taking into account the potential contribution of breast milk by using published estimates, nonbreast-fed children met only 60% of the Indian recommended dietary allowance (RDA; 250 RE/d), whereas breast-fed children met approximately 90% of the RDA during y 2 of life.

Grandma ahead of her time: traditional ways of diarrhoea management in Lesotho.

The study was aimed at learning about home management of infant and young child diarrhoea in Lesotho. Focus groups and individual interviews were conducted with mothers, grandmothers and nurses during two phases of field work in three geographically different locations. It was found that home management of diarrhoea traditionally had emphasised feeding. While medical advice in the past recommended that, except for breast feeding, food should be withheld during diarrhoea, mothers, grandmothers and even nurses had been reluctant to follow this advice. Mothers and grandmothers saw feeding during diarrhoea as so essential that they would make special efforts to feed a child with diarrhoea. Since most foods contain protein and carbohydrates which stimulate intestinal fluid absorption, feeding during diarrhoea, besides maintaining nutrition, will help maintain hydration. When such beneficial feeding practices are protected and supported there is less need to promote new practices and less risk of producing harmful effects.

Vitamin A supplementation and morbidity among preschool children in south India.

A randomized, double-blind, placebo-controlled trial was conducted in an ongoing Growth Monitoring Research project in TamilNadu, India, to assess the impact of high-dose vitamin A supplementation on morbidity among mildly to moderately malnourished children aged < 3 y. Every 4 mo, the treatment group received 60 mg vitamin A (200,000 IU) whereas the control group received a placebo. Cases of xerophthalmia and severe malnutrition were excluded. Anthropometric measurements and serum retinol determinations were made at baseline and at the end of 1 y. Morbidity data were collected by trained village-level workers throughout the study period by using the weekly recall method. The two groups had similar nutritional status, serum retinol concentrations, age-sex composition, and other sociodemographic indicators at baseline. The mean number of episodes per child-year was 2.62 +/- 2.95 and 2.56 +/- 2.5 for respiratory illness and 1.9 +/- 2.2 and 1.77 +/- 1.77 for diarrhea for the vitamin A (n = 309) and placebo (n = 274) groups, respectively. The differences in respiratory and diarrheal morbidity between the two groups were not statistically significant and these findings remained unaltered after multivariate analysis in which the effects of age, sex, socioeconomic status, sanitation, etc, were considered. These findings are similar to other recent findings and indicate that vitamin A supplementation does not reduce common morbidity in children with mild-to-moderate vitamin A deficiency in areas where access to health care and immunization are good.

Rational home management of diarrhoea.

PIP: During the 1960s-1970s, treatment of dehydration caused by diarrhea shifted from intravenous (IV) fluid replacement to use of oral rehydration salts (ORS). During diarrhea, glucose through a sodium-coupled transport mechanism and water (ORS solution) improves the ability of the small intestine to absorb fluid. Initially, the international health community ignored the potential usefulness of food, especially carbohydrates and proteins, in preventing and treating dehydration. The leading obstacle to acceptance of allowing food intake during diarrhea was variations in composition of local food staples. Food was almost always excluded during conventional clinical management of diarrhea (i.e., IV therapy). Health workers were advised to withhold food, including breast milk, during the first rehydration phase (first 24 hours). Despite the advice to withhold feeding, mothers in many developing countries continued to feed and breast feed their children during diarrhea with no ill effects. The mothers tended to use cereal-based solutions or breast feed during diarrheal episodes. In the beginning, health personnel were most concerned about access to ORS rather than acceptance. They assumed that oral rehydration therapy (ORT) was relatively easy to use. Experience showed that neither ORS nor home-prepared sugar and salt solutions (SSS) were easy to prepare correctly. In fact, mothers/caretakers often prepared SSS with unsafe high concentrations of sodium. In 1987, WHO developed a guide to help Control of Diarrheal Diseases program managers select home-based fluids that were as ORS-like as possible. Diarrhea cases in hospitals tend to be more severe than those at home. Almost all hospital cases need treatment, while those at home tend to be less severe and only need simple measures to prevent dehydration. Yet, international health specialists designed home-treatment to be like hospital-treatment. This is a restrictive approach. More rational guidelines for ORS have since emerged due to ORS failures at home.^ieng

Prolonged breastfeeding without the introduction of supplementary feeding.

A study on the determinants of nutritional marasmus (NM) and kwashiorkor (K) was conducted using Sudanese children aged 6-36 months. The hypotheses tested were related to the specific circumstances leading to the development of NM and K. Subjects consisted of 55 children with NM and 55 with K, admitted to the Children's Emergency Hospital in Khartoum. This paper presents the results of the association between NM and prolonged breastfeeding without introduction of supplementary feeding between the ages of 6 and 24 months. Mothers were interviewed in hospital, and information on duration of breastfeeding, age at introduction of supplementary foods, and weaning foods was obtained. Observations were made in 20 per cent of homes of study children. The results suggest a positive association between prolonged breastfeeding without introduction of supplementary feeding between the ages of 6 and 24 months, and NM. Using multivariate analysis the data show that late introduction of supplementary foods produces an increase of 1.4-fold the odds of developing nutritional marasmus, rather than kwashiorkor. In contrast the odds ratio is 1.9 for the two conditions in terms of age of cessation of breastfeeding, the kwashiorkor children breastfeeding for fewer months. Results suggest strategies to reduce the prevalence of NM and K, plus mild and moderate PEM.

Vitamin A supplementation does not improve growth of preschool children: a randomized, double-blind field trial in south India.

A randomized, double-blind, placebo-controlled trial was conducted in an ongoing growth monitoring research project in TamilNadu, India, to assess the role of high dose vitamin A supplementation on the growth of mild to moderately malnourished children < 3 y old. The treatment group received 60 mg of vitamin A and the control group received a placebo every 4 mo. Infants 6-11 mo of age received only 30 mg of vitamin A Cases of xerophthalmia and severe malnutrition were excluded. Anthropometric measurements and serum retinol determinations were made at baseline and at the end of 1 y. The two groups were similar at baseline in nutritional status, serum retinol, age-sex composition and other socio-demographic indicators. The mean height increments were 9.20 +/- 3.51 and 9.01 +/- 3.41 cm/y for the vitamin A-treated (n = 310) and placebo (n = 282) groups, respectively, and the mean weight increments were 2.02 +/- 0.83 and 1.99 +/- 0.81 kg/y, respectively. The differences in growth increments between the two groups were not statistically significant. These findings remain unaltered following multivariate analysis and suggest the lack of an effect of vitamin A supplementation on growth in young children where access to health care and immunization are good.

Physical activity and growth of Kenyan school children with hookworm, Trichuris trichiura and Ascaris lumbricoides infections are improved after treatment with albendazole.

Growth, activity, appetite and intestinal helminth infections were compared for 55 Kenyan primary school children with hookworm (93% prevalence), T. trichiura (84% prevalence) and A. lumbricoides (29% prevalence) before and 9 wk after treatment with three 400-mg doses of albendazole (Zentel) or placebo. Fecal samples were examined for helminth eggs using a modified Kato technique. Activity was measured during free-play with motion recorders on the dominant thigh. Children rated their appetites on a 5-point scale. After baseline measurements, children were randomly allocated to the albendazole-treated (n = 28) and placebo (n = 27) groups, treated, and re-examined 9 wk later. At follow-up, egg counts were significantly lower than at baseline in the albendazole-treated group (P < or = 0.002), and gains in activity, reported appetite and most indices of growth were significantly greater for the albendazole-treated group than for the placebo group. We conclude that treatment of undernourished school children for intestinal helminth infections with albendazole may improve growth and appetite and increase spontaneous physical activity.

Iron supplementation improves appetite and growth in anemic Kenyan primary school children.

A randomized, double-blind, placebo-controlled iron supplementation trial was conducted in Kenya to examine the effect of iron supplements on appetite and growth in 87 primary school children. Sustained-release ferrous sulfate (150 mg) or placebo tablets were provided daily at school for 14 wk. Prior to tablet administration, baseline anthropometry, iron nutritional status (hemoglobin and serum ferritin), parasitic infections and clinical indicators of morbidity were measured. A baseline appetite test was conducted twice on each child by quantitatively measuring the ad libitum consumption of a midmorning snack. In addition, each child was asked for a subjective assessment of his or her appetite. Follow-up exams and appetite tests were identical to those at baseline. Findings indicated that provision of iron supplements resulted in improved growth and improved appetite (in terms of both energy intake of the snack and child report of appetite) as compared with children receiving the placebo. The increased energy intake from the snack was 10% of the daily estimated energy intake for children of this same age group living elsewhere in Kenya. Further research into the underlying physiological mechanisms may shed light on the relationship between iron nutritional status and appetite.

Evaluation of effectiveness of good growth monitoring in south Indian villages.

We conducted a community intervention trial in 12 villages in Tamil Nadu, India to evaluate the benefits of growth monitoring. The villages were divided into 6 "growth-monitoring package" of intervention villages (GMP) and 6 "non-growth-monitoring package" of intervention villages (NGM). A functioning primary health care system was in place in all 12 villages implemented a set of interventions including health and nutritional education. About 550 children under the age of 60 months were studied over 4 years in GMP villages and a similar number of children in NGM villages. The interventions were identical in the two sets of villages except for the use of growth charts in education in the 6 GMP villages. The nutrition worker in the NGM villages had the same contact time as in the GMP villages but advised mothers without the benefit of growth charts. The research team, independently of the nutrition worker, did anthropometric studies on children in all villages every 4 to 5 months. Comparisons were done by calculating monthly gains in stature, and weight, and the significance of differences observed was adjusted for age and sex. After 30 months of interventions, similar improvements in growth were seen in GMP and NGM children. The interventions seemed to have improved the nutritional status of young children in both groups of villages. In view of the lack of additional benefit from growth monitoring over other educational interventions, we question its use as part of child survival programmes in India.