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.

The use of changes in hair root morphology in the assessment of protein-calorie malnutrition.

A study was carried out to evaluate the use of changes in hair root morphology in the assessment of protein-calorie malnutrition (PCM) among a group of Black West Indian children. Significant differences in mean shaft diameter, mean % anagen, and mean % telogen were found only between the well-nourished and the severely malnourished groups. No significant differences in mean % atrophy, and in mean diameter of anagen bulbs were found among well-nourished children, children with mild-moderate PCM, severely malnourished children, and children hospitalized for conditions with a secondary effect on nutritional status. The method was found to be time consuming; it can be used only for differentiating well-nourished from severely malnourished children; and it cannot be used for determining the prevalence of the different degrees of PCM. For these reasons, the method is not recommended for use in the field assessment of PCM.

Anemia of pregnancy in Liberia, West Africa: a therapeutic trial.

Research was conducted in Liberia, West Africa to ascertain which hematinics produce the best Hb response in women during the 3rd trimester of pregnancy. After obtaining background information, each of the 621 subjects was randomly assigned to one of four treatment groups. Group 1 was given 60 mg iron once daily, group 2 was given 60 mg iron 3 times daily, group 3 was given 60 mg iron 3 times daily plus a 5-mg folic acid tablet once daily, and group 4 was given the same treatment as group 3 but also a weekly antimalarial prophylactic. For comparison, 58 untreated women in their 3rd trimester were also studied. Before therapy the five groups were similar with respect to selected socioeconomic status, health, and dietary variables. Hb response to therapy was measured at 4-wk intervals from the 24th wk of gestation until term. The Hb rises in all four treatment groups were significantly (p less than 0.001) higher than the base-line values at 4, 8, and 12 wk after the interventions. The percentage of anemic women was reduced from 78 to 45% over the 12 wk of supplementation. Hb rises in groups 3 and 4 were not significantly different from those in groups receiving iron alone. It is concluded that iron deficiency is the main cause of anemia in this population.

Lactose malabsorption among Masai children of East Africa.

There is much disagreement about milk and its use in feeding programs both in the United States and internationally. A few authors suggest that milk consumption should not be encouraged in lactose intolerant populations due to adverse symptoms. Others suggest, however, that small or modest quantities of milk can be tolerated and can be nutritionally useful to such groups. Data are presented in this paper that show that 1) the Masai regularly drink considerable quantities of milk without apparent symptoms, 2) milk is an important constituent of the Masai diet, and 3) 62% of 21 Masai examined were malabsorbers of lactose as measured by the lactose tolerance test. This finding of lactose malabsorption in a nomadic cattle raising and milk drinking people is interesting and is contrary to the views often expressed by anthropologists and others. An ability to drink nutritionally useful quantities of milk does not, however, necessarily mean that milk production or imports should be encouraged in the Lesser Developed Countries.

Rapid and portable methods of lactose tolerance test administration.

Abbreviated, portable methods of lactose tolerance test administration were investigated. Results obtained with the Ames Reflectance Meter/Dextrostix system for blood glucose determination during lactose tolerance testing were compared with those obtained from a standard method, the AutoAnalyzer. Subjects who had maximum blood glucose rises below 20 mg/100 ml were considered to have a flat lactose tolerance curve and were designated lactose nondigesters. Results of the two methods were very similar for determination of maximum rise in blood sugar over fasting level, for obtaining values of individual blood sugar determinations, and for diagnosis of lactose nondigesters. The effect of omission of the final blood sample on tolerance test results was examined. It was found that maximum rises in blood glucose occurred before the final sample in 31 of 35 cases on the AutoAnalyzer and in 26 of 27 cases on the Reflectance Meter. In no case did omission of the final sample change the results of the lactose tolerance test.

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.

An evaluation of strategies to control vitamin A deficiency in the Philippines.

Xerophthalmia has been found to be an important cause of blindness in the Philippines. An earlier study had investigated its prevalence and epidemiology on the island of Cebu. The research now presented consists of an evaluation of the relative effectiveness of three different intervention strategies to control vitamin A deficiency in Cebu. These interventions were 1) a public health and horticulture intervention, 2) the provision of 200,000 IU of vitamin A to children every 6 months (the "capsule intervention"), and 3) the fortification of monosodium glutamate with vitamin A. A total of 12 areas or barangays were included. Each intervention was monitored in four different barangays, two urban and two rural, for almost 2 years. Similar examinations were performed before and after the interventions. The monosodium glutamate fortification was the only intervention that resulted both in a significant reduction in clinical signs of xerophthalmia and in a significant rise in serum vitamin A levels. Fortification is now being planned in three Philippine provinces.

The prevalence and the etiology of the nutritional anemias in Guyana.

A survey was carried out in Guyana to determine the prevalence and the etiology of the nutritional anemias among both sexes, in various age groups, and in pregnant and lactating women. The sample consisted of 590 subjects drawn from 103 households selected by multistage cluster sampling. Anthropometric and hematological measurements and stool investigations for intestinal parasites were carried out in each subject. Socioeconomic and other demographic data were obtained for each household. High prevalences of anemia, although of a relatively mild degree, were found among all age groups especially among pregnant and lactating women. The major factors related to Hb levels were found to be inadequate consumption of food rich in the erythropoietic nutrients, iron deficiency, age, sex, pregnancy, household income, and percentage of household income spent on food. A number of socioeconomic and other demographic variables were associated with anemia. More anemia was found in urban than in rural areas.

An evaluation of the use of changes in hair root morphology in the assessment of protein-calorie malnutrition.

A study was carried out to evaluate the use of changes in hair root morphology in the assessment of protein-calorie malnutrition (PCM) among a group of black West Indian children. The following five hair root characteristics were measured: percentage of anagen (the growing phase), percentage of telogen (the resting phase), percentage of atrophy, diameter of anagen bulbs, and shaft diameter. Significant differences in shaft diameter, percentage of anagen, and percentage of telogen were found only between well-nourished and severely malnourished children. Significant correlation coefficients were obtained between both bulb diameter and percentage of atrophy and muscle circumference. No significant differences in any of the hair root characteristics were obtained between children with nutritional marasmus and those with kwashiorkor. The method was found to be time-consuming; it can be used for differentiating well-nourished children only from those with severe PCM; and it is unsuitable for determining the prevalence of the three degrees of PCM. For these reasons, the method is not recommended for use in the field assessment of protein-calorie malnutrition.

Symptom response to lactose-reduced milk in lactose-intolerant adults.

The possible usefulness of low-lactose milk for those lactose-intolerant subjects who develop symptoms from milk consumption was investigated. In the first part of the study, 16 intolerant subjects (blood glucose rise less than 25 mg/100 ml) received low-lactose skim milk containing 15 g lactose (2.5 cups) and 7.5 g lactose (2.5 cups), regular skim milk containing 30 g lactose (2.5 cups), and all three milks plus a small breakfast. The low lactose milks produced significantly fewer symptoms. The food given with the milk had no significant effect on symptomatic response. The second group of 17 subjects received 25 g lactose in water (250 ml), skim milk (500 ml) and whole milk (500 ml); 10 g lactose in lactose-reduced skim (500 ml) and whole milk (500 ml) and whole milk (500 ml); and a placebo (250 ml). There was a significant positive relationship between amount of lactose consumed and symptom response. The form in which the lactose was administered (e.g., whole versus skim milk) was not significantly related to symptoms. It is concluded that in a symptomatic subjects a significantly greater quantity of low-lactose milk than regular milks can be consumed.

Vitamin A deficiency in the Philippines: a study of xerophthalmia in Cebu.

An investigation of xerophthalmia was undertaken in four ecological zones in Cebu in the Philippines. One thousand seven hundred fifteen children aged 1 to 16 years were examined in 12 barrios. Clinical, biochemical and anthropometric data were collected from the children. Dietary and socioeconomic information was obtained from the households. Multivariate statistical techniques were used to examine factors possibly associated with xerophthalmia. Of children 47% had deficient or low serum vitamin A levels and 4.5% had clinical signs of xerophthalmia. Approximately 2% had both low serum vitamin A levels and clinical eye signs and were then defined as having active xerophthalmia. Vitamin A deficiency was more prevalent in males than females. Xerophthalmia was most common in the 4 to 6 year old age group. Diarrhea, roundworm infestation and measles were not positively correlated with xerophthalmia but whooping cough and tuberculosis were. Low intakes of carotene and vitamin A were associated with xerophthalmia but protein and fat intakes were not. A higher incidence of xerophthalmia occurred in children of working than nonworking mothers. Data on home production and use of vegetables and fruits are presented. The results of this study are being used to introduce three alternate intervention strategies to control xerophthalmia.

Worker productivity and the nutritional status of Kenyan road construction laborers.

The effects of energy supplementation (group I received 200 kcal/day and group II received 1000/kcal day) were examined on road workers in Kenya. Anthropometric, dietary, worker productivity, clinical hematology, and parasitology data were collected from 224 workers of both sexes or, subsamples of these workers at base-line, midpoint, and final measurement periods. Sixty-seven percent of the work force was less than 85% of weight for height. Females tended to be better nourished than males. Multiple regression analysis showed that increases in arm circumference and Hb levels were associated with significant productivity gains of about 4%. At the midpoint, group II males gained 1.10 kg (p less than 0.0003) while group I males showed no change. Weight loss during the latter part of the study resulted in no significant final weight change for males. "Successful" supplementation was weakly associated with a productivity increase for group II workers of 12.5% (p less than 0.10).

Relationships between Ascaris infection and growth of malnourished preschool children in Kenya.

A longitudinal study in Ascaris-infected and noninfected children was conducted in two Kenyan villages. Anthropometric, clinical, and stool exams were performed three times at 14-week intervals. All children received an anthelmintic drug (levamisole) at the second examination. In the 14 weeks before deworming, children with Ascaris (n = 61) did not differ from controls (n = 125) in percentage expected weight gain. In the 14 weeks after deworming, previously infected children showed higher percentage expected weight gain than controls. Before deworming, there was a statistically significant (P less than 0.0005) decrease in triceps skinfold thickness in Ascaris-infected children versus controls. After deworming, skinfold increased significantly (P less than 0.0005) in previously infected children versus controls. Multiple regression analysis showed that Ascaris infection was by far the most important variable of those studied explaining decrease in skinfold thickness before and increase after deworming. It appears that even light Ascaris infections might adversely influence nutritional status, and deworming might enhance growth.

Use of positive-negative deviant analyses to improve programme targeting and services: example from the TamilNadu Integrated Nutrition Project.

This paper describes the characteristics of southern rural Indian children who grow best (positive deviants) and worst (negative deviants) as compared to median growers. A 100 each of positive and negative deviants and 120 median growers were selected after analysing the 12-month growth patterns (weight-for-age) of 2954 children enrolled in the TamilNadu Integrated Nutrition Project (TINP), a major health and nutrition intervention project covering nearly one million children in rural south India. The determinants of poor growth that have been left unaddressed by 6 years of TINP exposure are delineated to address the question of what more needs to be done. Further, the rationale for differential targeting of services to negative deviants and to median growers is discussed, as are the implications for programme evaluation. Data indicate that the next generation of projects targeted at the most needy (negative deviants) should address the issues of gender discrimination in childcare, of breastfeeding, of diarrhoeal disease, and of maternal empowerment. Such interventions will, however, not improve the growth of median growers in the direction of positive deviance. Instead, programmes targeted at the median growers need to support the hygienic use of nonbreast milk supplements. Improving family wealth will also improve the nutritional status of the median growers, but less so than for the negative deviants.

Single dose metrifonate or praziquantel treatment in Kenyan children. I. Effects on Schistosoma haematobium, hookworm, hemoglobin levels, splenomegaly, and hepatomegaly.

The relationships between S. haematobium, hookworm, malaria, hemoglobin level, splenomegaly, and hepatomegaly before and 8 months after treatment with a single dose of metrifonate or praziquantel were studied in Kenyan primary schoolchildren in an area where anemia, S. haematobium, and hookworm are common and malaria is holoendemic. Children with light to moderate S. haematobium infection were examined (Exam 1), assigned at random to groups receiving placebo (PL, n = 104), metrifonate (MT, n = 103, dose 10 mg/kg body weight) or praziquantel (PR, n = 105, dose 40 mg/kg body weight), treated, and examined 8 months later (Exam 2). At Exam 2, 62% of the MT group still passed S. haematobium eggs vs. 13% in the PR group. Egg reduction rates were substantial in both groups, but greater in the PR group; geometric mean egg counts in both groups were very low. Prevalence and intensity in the PL group had not changed between exams. Hookworm egg counts were significantly reduced in the MT group (59% egg reduction rate); malarial infection had increased in all 3 groups, presumably due to the long rainy season between exams. Hookworm egg count was the most significant predictor of initial hemoglobin level, followed by S. haematobium egg count and presence of malarial infection. Treatment with a single dose of MT or PR can produce substantial decreases in S. haematobium infection 8 months later.

Single dose metrifonate or praziquantel treatment in Kenyan children. II. Effects on growth in relation to Schistosoma haematobium and hookworm egg counts.

We studied the growth of comparable groups of children with light to moderate Schistosoma haematobium infections who received a single dose of metrifonate (MT, 10 mg/kg), praziquantel (PR, 40 mg/kg), or a placebo (PL). Children were re-examined 8 months later. The MT and PR groups gained significantly more than the placebo group in weight, percent weight for age, percent weight for height, arm circumference, and in triceps and subscapular skinfold thicknesses. The MT and PR groups did not differ significantly from each other. The placebo group showed statistically significant decreases or no change between exams in percent weight for age, percent weight for height, percent arm circumference, and both skinfold thicknesses; the MT and PR groups exhibited highly significant increases in these parameters (P less than 0.0002). The intensity of S. haematobium infection had decreased significantly in both the MT and PR groups, but especially in the PR group. Multiple regression analyses showed that a decrease in the intensity of S. haematobium infection was by far the most important predictor of growth rate after treatment for all 5 anthropometric measures tested; decreases in the intensity of hookworm infection was also significant for 2 of the 5 measures.

Sensitivity and specificity of reagent strips in screening of Kenyan children for Schistosoma haematobium infection.

The reliability of using urinalysis reagent strips, which semi-quantitatively measure hematuria and proteinuria, to correctly select urine specimens found by microscopy to have Schistosoma haematobium eggs was studied in 359 previously unscreened Kenyan primary school children. The presence of and degree of hematuria and proteinuria were highly correlated with the presence of S. haematobium eggs and with egg counts in urine specimens. Hematuria was more strongly correlated with S. haematobium egg counts than was proteinuria. The ability of presence of hematuria or proteinuria, or both, to select all microscopically positive cases of urinary schistosomiasis for treatment was tested using sensitivity (ST) and specificity (SP) analysis. Selection of cases using 1) presence of hematuria alone, and 2) presence of either hematuria or proteinuria had the highest combined ST and SP (88% ST, 97% SP; 91% ST, 92% SP, respectively). Most of the few cases detected by microscopy but not by reagent strips had low egg counts. The presence of hematuria alone failed to detect only 12% of S. haematobium-positive cases (mostly low egg counts), and only 3% of S. haematobium-negative persons had urinary blood and would have received unnecessary treatment. Preliminary studies on the use of reagent strips to screen previously infected children 6 months after treatment, and the effects of seasonal variations in temperature and humidity on urine specimen volume, egg counts, and reagent strip results are also presented. The practical field use and cost of reagent strips in S. haematobium control programs are discussed.

Regression of splenomegaly and hepatomegaly in children treated for Schistosoma haematobium infection.

During a study in Kenya of the relationships between Schistosoma haematobium infection and anemia and growth, evidence was found to suggest that this infection was associated with splenomegaly in children, and that both splenomegaly and hepatomegaly regressed in children treated for urinary schistosomiasis, compared with a placebo group. These results imply that S. haematobium is partially responsible for the splenomegaly and hepatomegaly found in this malarious area, and that treatment for S. haematobium may cause a significant regression of splenomegaly and hepatomegaly in children.

The effectiveness of metrifonate in reducing hookworm infection in Kenyan school children.

The reduction in hookworm egg counts was determined in children treated with 1 and 2 doses of metrifonate. Kenyan primary school children were allocated to receive either 10.0 mg (n = 53) or 7.5 mg (n = 53) of metrifonate per kg of body weight (mg/kg) or a placebo (n = 26). Two doses of 10.0 mg/kg reduced hookworm egg counts (from arithmetic means of 4,177 to 438 eggs per gram of feces [epg]) more than did 2 doses of 7.5 mg/kg (from 4,329 to 1,392 epg; P less than 0.01). Two doses of metrifonate reduced egg counts more than did 1 dose (P less than 0.0001). The placebo group did not show a significant change in egg counts. The single dose of 10.0 mg/kg led to a 78% reduction in hookworm egg counts (from 4,177 to 918 epg), a level unlikely to cause iron deficiency anemia. This was as effective as 2 doses of 7.5 mg/kg, and was more easily administered than 2 or 3 doses. The further reduction after a second dose of 10.0 mg/kg (to 438 epg) is probably not of practical importance. This study shows that metrifonate, even in a single dose for treatment of S. haematobium, is also useful in reducing hookworm egg counts.

Treatment with a single dose of albendazole improves growth of Kenyan schoolchildren with hookworm, Trichuris trichiura, and Ascaris lumbricoides infections.

We studied the growth of primary schoolchildren with hookworm (87%), T. trichiura (97%), and A. lumbricoides (49%) who received a single 400 mg dose of albendazole or an identical placebo. Children were allocated at random to placebo (PL, n = 72) or albendazole (A, n = 78) groups, treated, and re-examined 6 months later. The A group gained significantly more than the PL group in weight (1.3 kg), percent weight for age (4.5% age points), percent height for age (0.5% age points), percent weight for height (4.3% age points), percent arm circumference (2.9% age points), and in triceps and subscapular skinfold thicknesses (1.2 mm). The PL group showed significant decreases between exams in percent weight for age, percent height for age, percent weight for height, percent arm circumference for age, and skinfold thicknesses for age. The A group had highly significant increases (P less than 0.0002) in all of these parameters except height for age. From Exam 1 to 2, the A group exhibited decreases (P less than 0.0002) in geometric means eggs per gram of feces (epg): for hookworm, means = 1,183 epg at Exam 1 vs. 136 epg at Exam 2 (67% egg reduction); for T. trichiura, means = 2,857 epg at Exam 1 vs. 1,061 epg at Exam 2 (28% egg reduction); and for A. lumbricoides, means = 86 epg at Exam 1 vs. 2 epg at Exam 2 (91% egg reduction). The PL group had a borderline increase in geometric means hookworm egg count, no significant change in T. trichiura egg count, and a small but significant decrease in A. lumbricoides egg count. Decreases in intensities of all infections were significant predictors of growth improvement. Hookworm egg count entered the equations for all 6 measurements, and A. lumbricoides and T. trichiura entered 4/6 equations. Single dose treatment with albendazole, despite continual exposure to infection, can permit improved growth rates in areas where intestinal helminths and protein-energy malnutrition are highly prevalent.