Micronutrients and HIV infection: a review.
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Publications and source records attributed to H Friis.
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As part of a cross-sectional study among 156 primary school children (median age 13 years, range 10-18) in Western Kenya, geophagy was assessed through interviews. 114 (73.1%) of these children reported eating soil daily. Haemoglobin levels were determined in all 156 children and serum ferritin concentrations in 135. The mean haemoglobin (Hb) concentration was 12.7 g/dl, and median ferritin concentration 27.2 microg/l. Both the proportion of anaemic (Hb < 11.0 g/dl) and of iron-depleted (ferritin < 12 microg/l) children was significantly higher among the geophageous children than among the nongeophageous (9.6% vs. 0% anaemia; P = 0.037; 18.4% vs. 5.4% iron depletion; P = 0.046). Serum ferritin and haemoglobin concentrations were not correlated (r = 0. 13 5; P = 0. 100). Multiple regression analysis showed that geophagy, hookworm eggs per gram faeces and malaria parasite counts per microl blood were independent predictors of serum ferritin, when controlling for other helminth infections, age and sex, and socio-economic and educational background of the children's families and family size (y = 36.038-11.247(geophagy) -- 0.010(hookworm epg) + 0.001(malaria parasite counts); R2 = 0.17). Multiple regression analysis with haemoglobin as dependent variable and the same independent variables did not reveal any significant predictors. Analysis of the soil eaten by the children revealed a mean HCl-extractable iron content of 168.9 mg/kg (SD 44.9). Based on the data on the amounts eaten daily and this mean iron content, soil could provide on average 4.7 mg iron to a geophageous child (interquartile range 2.1-7.1 mg), which is equivalent to 32% of the Recommended Nutrient Intake (RNI) for girls (interquartile range 14-48%) or 42% of the RNI for boys (interquartile range 19-63%). Iron depletion and anaemia are associated with geophagy, but only serum ferritin concentrations were shown to be dependent upon geophagy in the regression model. From the cross-sectional data no inference about causality can be made. To clarify the possible causal relationships involved, longitudinal studies and iron-supplementation intervention studies are needed.
OBJECTIVES: To assess the effect of zinc supplementation on growth and body composition among schoolchildren. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING AND SUBJECTS: 313 rural Zimbabwean schoolchildren (144 boys and 169 girls, 11-17 y). INTERVENTIONS: Supplementation with zinc (30 or 50 mg) or placebo on schooldays for 12 months. Due to drought, a food programme was in operation during the last eight months of the study. VARIABLES: Weight, height, upper arm circumference, triceps skinfold thickness, and weight-for-age, height-for-age, weight-for-height, arm muscle-area-for-age and arm fat-area-for-age Z-scores. RESULTS: Significant effects on weight gain (0.51 vs 0.14 kg, P = 0.01), weight-for-age Z (-0.08 vs -0.14, P = 0.01) and arm muscle area-for-age Z-score (0.10 vs 0.01, P = 0.03) were seen over the first three months, whereas no effects were seen over the full 12 months. CONCLUSIONS: Zinc deficiency impairing lean body mass and weight gain was documented. However, the effect of zinc seen over the first three months vanished during the last nine months when the food programme was in operation. Zinc deficiency may have persisted, but another nutrient may have become growth limiting during the last nine months.
OBJECTIVES: To assess the effect of zinc supplementation on susceptibility to S. mansoni reinfections among schoolchildren. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING AND SUBJECTS: 313 rural Zimbabwean schoolchildren (144 boys and 169 girls), 11-17 y). INTERVENTIONS: Supplementation with zinc (30 or 50 mg) or placebo on schooldays for 12 months. Due to drought, a food programme was in operation during the last eight months of the study. OUTCOME MEASURES: S. mansoni and S. haematobium reinfection rates and intensities. RESULTS: There was no difference in reinfection rates between the zinc and placebo groups (25 vs 29%, P = 0.46). However, the median intensity of S. mansoni reinfection, although low in both groups, was significantly lower in the zinc than in the placebo group (7 vs 13 eggs per gram of faeces, P = 0.048). No difference in either S. haematobium reinfection rates or intensities were seen. CONCLUSIONS: Zinc supplementation reduced the intensity of S. mansoni reinfections. Although the intensities of reinfection were very low, the finding probably reflects a biological effect of zinc that could be of public health importance in settings with higher transmission.
A cross-sectional study was conducted among 285 school children aged 5-18 years in Nyanza Province, Western Kenya, to determine the prevalence of geophagy and the types and amounts of soil eaten. Stool samples were taken from a subsample of 53 (19%) and their silica content determined to compare the results with the reported geophagy. Geophagy was practised by 73% of the children. The prevalence decreased with age for both sexes up to age 15, then remained stable for girls between 15 and 18 years but continued to decrease for boys in that age range. Most children ate soil from the surface of termitaria; others preferred the edges of paths and gullies, material from the wall of huts, and a chalk-like, soft stone commonly found in the area. The soil was eaten dry and was occasionally ground, but not processed in other ways. All but 4 of the children practising geophagy reported to eat soil at least once daily. The median amount reported eaten was 28 g daily, ranging from 8 to 108 g. The reported amount of soil eaten daily was significantly correlated to the results of the stool silica determinations. Using the median of 1% silica of faecal wet weight as a cut-off point to distinguish geophageous children from non-geophageous, the examination of a single stool sample had a sensitivity of 76% and a specificity of 80% to detect a geophageous child compared to the interview method. The cultural context of geophagy and its potential health impact in terms of infection and nutrition need to be further investigated, and it is suggested that more school and community-based studies on geophagy in different societies should be undertaken.
Parasitic determinants of serum retinol concentrations were studied in 159 preschool (0.25-5.1 y) and 695 primary school (9.2-17 y) children in western Kenya. Mean serum retinol was 0.63 micromol/L in preschool and 0.94 micromol/L in primary school children; 62% and 24%, respectively, had serum retinol < 0.70 micromol/L. Serum retinol was lower in boys than in girls among both preschool (P = 0.04) and primary school children (P = 0.0001). Schistosoma mansoni, Ascaris lumbricoides, hookworm, and Trichuris trichiura egg output and malarial parasitemia were determined and their relation with serum retinol assessed. Among preschool children, sex, elevated serum concentrations of C-reactive protein, and malarial parasitemia were significant predictors of serum retinol. Among the 63 children from whom stool samples were available, none of the helminth infections were significant predictors of serum retinol. For primary school children, age, sex, and S. mansoni egg output were predictors of serum retinol. Malarial parasitemia among nonimmune preschool children may contribute to low serum retinol, whereas malarial parasitemia did not have any effects in semiimmune primary school children. In contrast, the inverse relation between S. mansoni and serum retinol found in primary school children could be due to an effect of infection on serum retinol or an increased susceptibility to infection among children with low serum retinol. Although parasitic infections may contribute to poor vitamin A status in children, they do not explain the age and sex differences.
The clinical manifestations and epidemiological data of 11 patients infected with Vibrio vulnificus found in Denmark during the unusually warm summer of 1994 are reported. All patients had been exposed to seawater prior to illness, but none had consumed seafood. Nine patients, including four with bacteraemia, developed skin manifestations of various degrees of severity. One patient died of septic shock despite surgery and treatment with relevant antibiotics. Four patients contracted the disease while fishing. High seawater temperature increases the risk of V. vulnificus infections even in temperate climates such as the Danish. Exposure to seawater, including handling of fresh seafood, during warm periods carries a risk of infection with V. vulnificus.
METHODS: The effect of zinc supplementation on antipyrine clearance was evaluated in 14 outpatients with stable alcoholic liver disease, of whom nine had biopsy proven alcoholic cirrhosis. RESULTS: There was no change in antipyrine clearance after 14 days of zinc supplementation (median 12.5 vs 12.9 ml.min-1). However, a significant increase in P-prothrombin-proconvertin was found. There was a positive correlation between S-zinc and antipyrine clearance at inclusion (rs = 0.76) as well as after zinc supplementation (rs = 0.72). CONCLUSION: No effect of zinc supplementation on antipyrine clearance was found. The positive correlation between S-zinc and antipyrine clearance could be due to the confounding effect of alcoholic liver disease.
The effect of zinc deficiency on the response of CBA mice to infection with the intestinal trematode Echinostoma caproni was examined. Young CBA mice were allocated to one of three dietary groups: a group fed a zinc deficient diet ad libitum, a control group pair fed a zinc sufficient diet and a control group fed a zinc sufficient diet ad libitum. The mice on the zinc deficient diet gained significantly less weight than the pair fed controls. In primary infections with six E. caproni metacercariae followed over a period of 128 days, zinc deficiency delayed worm expulsion. In addition, zinc deficiency resulted in a prolonged IgM response, a delayed IgG response and an increased IgA response towards the end of the experiment. Resistance to challenge infection day 21 following a primary infection with 25 E. caproni metacercariae was slightly, but not significantly, affected by zinc deficiency.
Attempts have been made to develop a staging system of sonographic Schistosoma mansoni morbidity for use in epidemiological studies and for evaluation of control programmes. Therefore, normal dimensions of livers and spleens in children in countries with endemic S. mansoni infections need to be established. Normal dimensions of livers and spleens are presented, based on examination of 144 Zimbabwean children between 8 and 16 years of age found to be S. mansoni egg negative 12 months after treatment with praziquantel. Based on the liver and spleen measurements, an index of liver size and the spleen volume were calculated. Height was employed as the independent variable in all multiple regression models. The organometric data are presented as prediction plots, with observed values and fitted regression line with 95% confidence and prediction intervals. The mean spleen volume was 30% larger for boys than for girls, whereas there was no consistent difference in liver size. No effect of growth Z-scores was seen. The measurements were compared with normal dimensions of livers of German children. For a given height, the mean index of liver size was lower in Zimbabwean than in German children, but inter-observer variation could be a possible explanation for this difference.
A simplified version of the magnetic bead antigen-capture enzyme-linked immunoassay (MBAC-EIA) was used to detect circulating anodic antigen (CAA) in individuals of different age groups with Schistosoma haematobium infection only in an endemic area of Zimbabwe. An overall positive correlation between S. haematobium egg excretion and CAA levels was demonstrated. The age profile for CAA levels was generally comparable with the age profile of S. haematobium prevalence and intensity of infection. The CAA levels were higher in younger (5-14 years of age) individuals than in older (greater than 14 years of age) ones. Since the sensitivity of the MBAC-EIA in the diagnosis of S. haematobium infection was found to be 97%, CAA levels appear to be a useful indicator of worm burden in an endemic area.
Ultrasound examinations for Schistosoma haematobium - and S. mansoni-related morbidity were done in 174 schoolchildren from a subsistence farming community in southern Zimbabwe. The examinations were done according to the standardized protocol elaborated by the Cairo Working Group (the Cairo classification) and the Managil classification. Forty-six percent of the children had grade I periportal thickening (PPT) on ultrasound according to the Cairo classification, but none had grade II or higher. The significance of grade I PPT in the Cairo classification is questionable, since there were no differences between those without and those with grade I PPT with respect to intensity of S. mansoni infection or liver size. The prevalence of grade I PPT according to the Managil classification was 10%, and no association between the two classifications was seen. In multiple regression analysis, S. mansoni egg output was found to be a significant predictor of liver size, when controlling for height and sex. An interaction between S. haematobium and S. mansoni infection is suggested because the positive relationship between S. mansoni and liver size was seen in the presence but not in the absence of S. haematobium infection.
OBJECTIVE: To study the relation between indicators of infection and Schistosoma mansoni and S. haematobium infection, and serum concentrations of zinc, ferritin and retinol. DESIGN: Cross-sectional. SETTING AND SUBJECTS: 313 rural Zimbabwean schoolchildren (144 boys and 169 girls, 11-17 years). VARIABLES: S. mansoni and S. haematobium egg output, concentration of C-reactive protein, neutrophil count, questionnaire data on fever and diarrhoea, and serum concentrations of retinol, ferritin and zinc. RESULTS: Age, elevated CRP, fever and S. mansoni egg output were significant predictors of the concentration of retinol. The regression coefficient for age was positive, and negative for elevated CRP, fever and S. mansoni egg output. As S. mansoni, but not S. haematobium, was of significance, it is unlikely that low retinol level increased susceptibility to infection. The effect of S. mansoni on retinol level was 0.03 mumol/l (95% CI: 0.002-0.06, P = 0.03) for each 100 eggs/g increase in egg output. Neither indicators of infection nor age and sex were predictors of concentration of zinc and log10 concentration of ferritin. CONCLUSION: S. mansoni infection reduced retinol level, when indicators of infection and age were controlled for. High intensities of S. mansoni infection may induce vitamin A deficiency among children with marginal vitamin A status. The study emphasizes the importance of controlling for age and metabolic response to concurrent infections in studies using serum retinol as a measure of vitamin A status.
In the present study, simplification and adaptation of the Magnetic Bead Antigen Capture Enzyme Immuno Assay (MBAC-EIA) technique for detection of circulating anodic antigens (CAA) under field conditions was achieved. It was shown that the assay could be performed successfully within the broad temperature range of 18-37 degrees C. The slightly lower sensitivity observed at low temperatures could be adjusted for by prolonging the incubation period. Shaking the plate by hand was as good as automatic mechanical shaking, aspiration of the supernatant before the addition of conjugate was not necessary, and the use of whole blood and serum offered similar assay sensitivity. Furthermore incubation times could be considerably shortened without loss of sensitivity. A major advantage of the MBAC-EIA was that the beads, after elution of bound components, were found to be reusable. The study also showed that the sensitivity of the MBAC-EIA technique in diagnosis of schistosomiasis in a Zimbabwean community endemic for both urinary and intestinal schistosomiasis, was 94%.
The results of studies of the effect of simethicone on abdominal gas-related symptoms have been contradictory. In a randomized, double-blind, cross-over study, ten healthy volunteers were given 30 g lactulose and 600 mg simethicone or placebo. End-expiratory breath samples were collected and analyzed for H2, and gastrointestinal symptoms registered. There were no differences in biochemical parameters or symptom score between simethicone and placebo. In contrast to previous studies, we used a sufficiently large dose of lactulose to produce gastrointestinal symptoms, a higher dose of simethicone and placebo tablets containing the same additives as the simethicone tablets. There was no demonstrable effect of simethicone on symptoms or intestinal gas production caused by carbohydrate malabsorption.
As part of a programme for improving hospital infection control in Mauritius a nationwide survey, including a prevalence study, was carried out in order to identify characteristics of the hospitals, the population, and the infections. Community-acquired infections were three times more prevalent than nosocomial infections: 15.0% and 4.9%, respectively. Surgical wound infection was by far the most common nosocomial infection, with a prevalence rate of 8.2 per 100 operations, followed by urinary tract infection with a low rate of 0.8 per 100 admissions. The survey showed that these hospitals in Mauritius housed mainly a young population (mean of 36.8 years for females and 39.4 years for males) with few risk factors for acquiring nosocomial infection. Although diabetes mellitus is prevalent in Mauritius the diagnosis of diabetes was not associated with nosocomial infection. The spectrum of operations offered was limited, and Caesarean section was the most prevalent operation. The amount and types of antibiotics used in hospitalized patients were recorded. More than one third of the patients received antibiotic treatment at the time of the survey, which is comparable to figures reported from large teaching hospitals in Western Europe. The information gathered from the survey, the interviews and the inspection were used to establish priorities for a collaborative programme for improved infection control. It included the draft of a set of custom-made guidelines, which were eventually studied by staff members from hospitals in Mauritius during a training period in Denmark. We believe that a prevalence survey is useful for initiating infection control programmes in hospitals in developing countries.
OBJECTIVE: To examine the effect of a reduction on the reimbursement of drugs on the use of antibiotics by general practitioners in Denmark. DESIGN: A prospective study using a questionnaire comparing the results with a similar study 3 years before, a period with normal reimbursement. PARTICIPANTS: 553 general practitioners prescribed antibiotics for 5765 patients. MAIN OUTCOME MEASURE: Number of treated patients and choice of antibiotics. RESULTS: 7607 patients were treated in 1987 compared with 5765 in 1990, the relative number of patients treated for sinusitis, other upper respiratory tract infections, acute bronchitis, pneumonia and upper gynaecological infections was significantly less in 1990 than in 1987. Other infections, particularly those that are often diagnosed by culture or microscopy by the general practitioners themselves, increased significantly. They included tonsillitis and urinary tract infections. CONCLUSION: Reimbursement can be a very powerful tool controlling the use of antibiotics by general practitioners.
The use of antibiotics is increasing with increasing ecological and economic problems as a consequence. In Denmark, antibiotics are prescribed by doctors and in order to intervene, it is important to know details about prescription habits. Danish patients are referred to specialists by their general practitioner when further investigation or treatment is needed. In one week in 1988, 180 specialists (60%) participated in a study registering all prescriptions made by these specialists. Only 3.2 patients per specialist were treated with antibiotics. The infections were mainly of the upper respiratory tract, the skin, or gynecological. The prescribed daily dosages (PDD) did not differ from those given by the general practitioners, but the specialists used significantly less penicillin and significantly more erythromycin, tetracycline or local antibiotics. Compared with the general practitioners the specialists in Denmark only prescribed approximately 10% of the total amount of antibiotics used outside the hospitals. Their contribution to the potential ecological and economic problems caused by antibiotics in Denmark is limited.