Effect of water supply and sanitation on the prevalence and intensity of Ascaris lumbricoides among pre-school-age children in Ajebandele and Ifewara, Osun State, Nigeria

Abstract

The relationship between Ascaris lumbricoides infection and provisions for safe water supply and excreta disposal was investigated in Ajebandele and Ifewara, 2 peri-urban communities near Ile-Ife, Osun State, Nigeria, from September 1998 to December 1999. Although there were more facilities for safe water supply (pipe-borne and shallow wells) and sanitation (flush toilets and pit latrines) in Ajebandele than in Ifewara, they were not evenly distributed and only a few families, mainly in Ajebandele, were well provided for. Our results indicated that the prevalence of A. lumbricoides was significantly higher in Ifewara (21.2%) than in Ajebandele (13.1%), and within villages was much lower in houses with tap water and flush toilets. However, the mean intensity of infection was unexpectedly higher in Ajebandele (166.5 +/- 692.0) than in Ifewara (153.1 +/- 485.8) suggesting that the present level of investment in Ajebandele is probably not sufficient to reduce morbidity. These findings confirm suggestions that there is a threshold level of investment below which interventions on water supply and sanitation may not significantly improve human health. Sustainable ascariasis control in the study communities will require significant improvements to existing water supplies and sanitation facilities and any future interventions should incorporate a programme of health education to ensure that the facilities provided are properly used and hygienically maintained.

Judgment under uncertainty; a probabilistic evaluation framework for decision-making about sanitation systems in low-income countries

“…Similar results on failure of improved water supply and sanitation to combat disease infection are also reported from Bangladesh, Lesotho and Guatemala (Asaolu et al, 2002). Asaolu et al, 2002) suggest that these variations in results show that the outcome of such interventions is largely dependent on the coverage and the general socioeconomic conditions of the society. A more recent study by Ferrer et al (2008) confirms this idea.…”

“…However the results from such studies are not always coherent and sometimes even contradicting. For instance, a study in per-urban communities in Nigeria indicates that while improved water supply and sanitation facilities may reduce the prevalence of ascariasis, the morbidity problems linger, with infection intensity being unexpectedly higher among the ones who had access to improved sanitation (Asaolu et al, 2002). Similar results on failure of improved water supply and sanitation to combat disease infection are also reported from Bangladesh, Lesotho and Guatemala (Asaolu et al, 2002).…”

“…For instance, a study in per-urban communities in Nigeria indicates that while improved water supply and sanitation facilities may reduce the prevalence of ascariasis, the morbidity problems linger, with infection intensity being unexpectedly higher among the ones who had access to improved sanitation (Asaolu et al, 2002). Similar results on failure of improved water supply and sanitation to combat disease infection are also reported from Bangladesh, Lesotho and Guatemala (Asaolu et al, 2002). Asaolu et al, 2002) suggest that these variations in results show that the outcome of such interventions is largely dependent on the coverage and the general socioeconomic conditions of the society.…”

Effects of Annual Mass Treatment with Ivermectin for Onchocerciasis on the Prevalence of Intestinal Helminths

“…Other studies have found improved sanitation alone to be an insufficient control measure for intestinal helminth infections, but have not noted a differential effect with different intestinal parasites. 40,41 Reported use of shoes was not associated with a lower prevalence of hookworm infection; although this has previously been reported to be protective against hookworm infection. 42 However, so few children reported shoe use that this finding is probably not noteworthy.…”

Environmental interventions and the pattern of geohelminth infections in Salvador, Brazil

“…It does not always follow that use of toilets will reduce transmission of intestinal helminths (Gross et al 1989 ;Asaolu et al 2002), but community sanitation infrastructure may have more impact, by preventing contamination of the public environment with worm eggs, than the facilities enjoyed by individual households .…”