Febrile status, malarial parasitaemia and gastro-intestinal helminthiases in schoolchildren resident at different altitudes, in south–western Cameroon

Abstract

In the many areas where human malaria and helminthiases are co-endemic, schoolchildren often harbour the heaviest infections and suffer much of the associated morbidity, especially when co-infected. In one such area, the Buea district, in south-western Cameroon, two cross-sectional surveys, together covering 263 apparently healthy schoolchildren aged 4-12 years, were recently conducted. The prevalences of fever, malarial parasitaemia and intestinal helminth infections, the seroprevalences of anti-Plasmodium falciparum IgG and IgE and anti-glycosylphosphatidylinositol (anti-GPI) IgG, plasma concentrations of total IgE, and the incidence of anaemia were all investigated. The mean (S.D.) age of the study children was 7.56 (1.82) years. Overall, 156 (59.3%) of the children were found parasitaemic, with a geometric mean parasitaemia of 565 parasites/microl. Parasitaemia and fever were significantly associated (P=0.042). The children who lived at low altitude, attending schools that lay 400-650 m above sea level, had significantly higher parasitaemias than their high-altitude counterparts (P<0.01). At low altitude, the children attending government schools had significantly higher parasitaemias than their mission-school counterparts (P=0.010). Of the 31 children (11.9%) found anaemic, 22 (70.4%) had mild anaemia and none had severe anaemia. A significant negative correlation (r=-0.224; P=0.005) was observed between haemoglobin concentration and level of parasitaemia. Infection with Plasmodium appeared to reduce erythrocyte counts (P=0.045), a condition that was exacerbated by co-infection with helminths (P=0.035). Plasma concentrations of total IgE were higher in the children found to be excreting helminth eggs than in those who appeared helminth-free, while levels of anti-P. falciparum IgE were higher in the children with low-grade parasitaemias than in those with more intense parasitaemias. Levels of anti-GPI IgG increased with age and were relatively high in the children who lived at low altitude and in those who were aparasitaemic. The survey results confirm that asymptomatic malarial parasitaemia frequently co-exists with helminth infections in schoolchildren and indicate links with fever, altitude and school type. Immunoglobulin E may play a role in immune protection against helminthiasis whereas anti-GPI antibodies may be important in the development of antimalarial immunity in such children. In Cameroon, as in other areas with endemic malaria, control programmes to reduce the prevalences of infections with intestinal helminths and malarial parasites in schoolchildren, which may effectively reduce the incidence of anaemia, are clearly needed.

Malaria and soil-transmitted intestinal helminth co-infection and its effect on anemia: a meta-analysis

“…STH in this case) in children has been associated with their particularly poor hygiene (at home) and recreational or other activities that regularly bring them close to areas contaminated with human feces. 15,33 Based on available data, we found the positive association between malaria and hookworm was pronounced in pregnant mothers; a stream of bioimmunological mechanisms appeared to be involved in such interactions. Not all of these interactions are mutually exclusive and some are worthy of special mention.…”

“…Among school-aged children, the pooled analysis of three studies (n¼476) 32,33,49 showed that there was comparable mean Hb levels in the two groups (MD: 0.47; 95% CI:20.1 to 1.03). The pooled estimates of two studies 43,51 gave a higher risk of anemia in those co-infected with A. lumbricoides (summary OR: 2.72; 95% CI: 1.11-6.7; I 2 : 0%).…”

“…35,36,46 Twelve studies 8,26,28,32,33,35,41,43,46,[49][50][51] assessed the impact of co-infection on anemia, using various measurements. Five studies 26,28,32,33,49 quantitatively reported anemia with the mean Hb level in various age groups and pregnant women. One study reported anemia with the Hb cut-off level.…”

Co-Infections of Asymptomatic Malaria and Soil-Transmitted Helminths in School Children in Localities with Different Levels of Urbanization in the Mount Cameroon Region

“…School-aged children have been reported to be at the highest risk of co-infections of both malaria and STHs and consequently anaemia [12,13]. Although a number of studies have been carried out on malaria and STHs coinfections [13][14][15] in the Mount Cameroon region, none has specifically focused on the influence of urbanization on coinfections in school children. This study was therefore aimed at finding out if the level of urbanization influences the prevalence and intensity of co-infections of malaria and STHs in school children in the Mount Cameroon Region.…”

Prevalence of malaria and soil-transmitted helminth infections and their association with undernutrition in schoolchildren residing in Mfou health district in Cameroon

“…Infections by intestinal helminths have been shown to result in abdominal pain, diarrhea, anaemia, malnutrition, ulcers, intellectual retardation, cognitive and educational deficits, intestinal obstruction and, in severe chronic and untreated infections, could even lead to death (Crampton and Nesheim, 2002;Hotez et al, 2008;Hall et al, 2008;Brooker et al, 2010). In the context of continuous exposure to Anopheles mosquitoes, these conditions are further exacerbated with asymptomatic malaria parasites, often resulting in co-infections with Plasmodium, and thus, putting these children at enhanced risk of clinical disease (Mwangi et al, 2006;Nkuo-Akenji et al, 2006;Achidi et al, 2008).…”