Consequences of polyparasitism on anaemia among primary school children in Zimbabwe.
ABSTRACT The effect of concomitant infection with schistosomes, Plasmodium falciparum and soil transmitted helminths (STHs) on anaemia was determined in 609 Zimbabwean primary school children. P. falciparum, haemoglobin levels and serum ferritin were determined from venous blood. Kato Katz, formal ether concentration and urine filtration techniques were used to assess prevalence of Schistosoma mansoni, STHs and Schistosoma haematobium infections. The prevalence of S. haematobium, S. mansoni, P. falciparum, hookworm, Trichuris trichiura and Ascaris lumbricoides were 52.3%, 22.7%, 27.9%, 23.7%, 2.3% and 2.1%, respectively. The overall prevalence of anaemia and iron deficiency anaemia (IDA) were 48.4% (277/572) and 38.1% (181/475). Haemoglobin levels among children who had P. falciparum, S. haematobium and hookworm were lower than negative individuals, p<0.001, p<0.001 and p=0.030, respectively. The prevalence of anaemia and IDA in co-infections was almost double that in single infection. Children with P. falciparum/STHs/schistosome and schistosomes/P. falciparum co-infections recorded higher prevalence of anaemia and IDA (80.8% and 57.4%, respectively) than other combinations, p<0.001. Logistic regression revealed that, age group > or = 14 years, P. falciparum, S. haematobium light and heavy infections, and S. mansoni moderate and heavy infection, hookworm light infection were predictors of anaemia. This study suggests that integrated school based de-worming and malaria control have the potential to reduce the burden of anaemia.
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ABSTRACT: This study compared five methods for detecting the eggs of the human parasitic geohelminths Ascaris, Trichuris, and hookworm in infant stool, and describes the epidemiology of infection in infants from a parasite-endemic area. A total of 424 infants 5-11 months old were enrolled from three villages on Pemba Island, Zanzibar. Methods used included the Kato-Katz technique, formol ethyl acetate sedimentation, modified formol ethyl acetate sedimentation, modified Wisconsin floatation, and simple gravity sedimentation. Of methods used alone, Wisconsin floatation and simple gravity sedimentation each provided the highest sensitivity for detecting eggs of these three geohelminths (89.6%). Of methods used in combination, the Kato-Katz technique/simple gravity sedimentation and Wisconsin floatation/simple gravity sedimentation each provided the highest sensitivity (99.0%). Prevalence of geohelminth infection was 26.5%. Between five and nine months of age the mean prevalence was 9.4%, while at 10 and 11 months of age the mean prevalence was 43.4%. Village prevalence varied from 3.6% to 43.8%. Infant geohelminth infection can occur at a high prevalence, and what method is best depends on research specifics.The American journal of tropical medicine and hygiene 04/2007; 76(4):725-31. · 2.53 Impact Factor
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ABSTRACT: Malaria is a major cause of morbidity and mortality in early childhood, yet its consequences for health and education during the school-age years remain poorly understood. We examined the effect of intermittent preventive treatment (IPT) in reducing anaemia and improving classroom attention and educational achievement in semi-immune schoolchildren in an area of high perennial transmission. A stratified, cluster-randomised, double-blind, placebo-controlled trial of IPT was done in 30 primary schools in western Kenya. Schools were randomly assigned to treatment (sulfadoxine-pyrimethamine in combination with amodiaquine or dual placebo) by use of a computer-generated list. Children aged 5-18 years received three treatments at 4-month intervals (IPT n=3535, placebo n=3223). The primary endpoint was the prevalence of anaemia, defined as a haemoglobin concentration below 110 g/L. This outcome was assessed through cross-sectional surveys 12 months post-intervention. Analysis was by both intention to treat, excluding children with missing data, and per protocol. This study is registered with ClinicalTrials.gov, number NCT00142246. 2604 children in the IPT group and 2302 in the placebo group were included in the intention-to-treat analysis of the primary outcome; the main reason for exclusion was loss to follow-up. Prevalence of anaemia at 12 months averaged 6.3% in the IPT group and 12.6% in the placebo group (adjusted risk ratio 0.52, 95% CI 0.29-0.93; p=0.028). Significant improvements were also seen in two of the class-based tests of sustained attention, with a mean increase in code transmission test score of 6.05 (95% CI 2.83-9.27; p=0.0007) and counting sounds test score of 1.80 (0.19-3.41; p=0.03), compared with controls. No effect was shown for inattentive or hyperactive-compulsive behaviours or on educational achievement. The per-protocol analysis yielded similar results. 23 serious adverse events were reported within 28 days of any treatment (19 in the IPT group and four in the placebo group); the main side-effects were problems of balance, dizziness, feeling faint, nausea, and/or vomiting shortly after treatment. IPT of malaria improves the health and cognitive ability of semi-immune schoolchildren. Effective malaria interventions could be a valuable addition to school health programmes.The Lancet 08/2008; 372(9633):127-38. · 39.06 Impact Factor
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ABSTRACT: The impact of albendazole (400 mg) and praziquantel (40 mg/kg body weight) treatment of schoolchildren was compared with placebo according to the presence of anaemia (haemoglobin concentration < 11. 0 g/dl) and heavy (> 5000 epg) or light (< 5000 epg) hookworm egg load. The study was conducted in rural Tanga. Medication was administered in September 1994 and children were followed-up in January 1995. Overall, anthelminthic treatment reduced the fall in haemoglobin concentration compared with that observed in the placebo group (- 0.11 g/dl vs. - 0.35 g/dl; P = 0.02). Anthelminthic treatment was of greatest benefit to the 9% of children with both anaemia and heavy hookworm egg load (+ 0.67 g/dl vs. - 0.67 g/dl) and was also of significant benefit to the 38% of children with anaemia and light hookworm egg load (+ 0.07 g/dl vs. - 0.21 g/dl). It was of no significant benefit to children who were not anaemic. This study suggests that single-dose anthelminthic treatment distributed in schools in this area achieves haematological benefits in nearly half of children infected with S. haematobium and geohelminths (37% of total population).Tropical Medicine & International Health 12/1999; 4(11):744-50. · 2.94 Impact Factor