Effect of Piped Water Supply on Human Water Contact Patterns in a Schistosoma haematobium-Endemic Area in Coast Province, Kenya

The effect of a piped water supply on human water contact in a Schistosoma haematobium-endemic area in Coast Province, Kenya was studied. After the construction of five community standpipes and one shower unit, there was a 35.1% reduction in the number of people observed using river water, a 44.1% reduction in the frequency of contact with river water, and a 25.4% reduction in the amount of contact. The frequency of river water contact per person also decreased significantly, but the amount of contact per person did not decrease. The total frequency of contact decreased significantly except for washing clothes by the river, washing utensils, and fishing. The frequency per person did not change for most of the activities and significantly increased for washing clothes. The frequency of river water contact in households with high piped water consumption showed a significant decrease compared with those with low piped water consumption. The volume of consumption of piped water was inversely proportional to the distance from the home to the community standpipe. These results indicate that in the study area, the effect of a piped water supply on river water contact behavior was heterologous while the total river water contact decreased significantly, and that the piped water had a beneficial effect on some villagers but very little effect on others

ケニア諸地域住民の腸管寄生原虫感染状況

1980年5月から11月の間にケニアのNaivasha，Kitui，M achakos，Taveta及びNandi Hillsの住民2,114人から採取した糞便についてホルマリン・エーテル法により腸管寄生原虫のシストの検査を行い感染状況を調査した。その結果，赤痢アメーパは31.8%， 大腸アメーパは52.3%と極めて高率を示し，その他は小形アメーパ4.8%，ヨードアメーパ8.7%，ランブル鞭毛虫8.3%，メニール鞭毛虫10.4%であった。腸トリコモナス及びEntamoeba hartmanniも少数例検出されたが，大腸パランチジウムやイソスポーラなどは検出されなかった。総陽性率(陽性総数/検査総数)は75.1%にも及び，飲料水，食物など生活環境が糞便によって高度に汚染されていることが示唆された。陽性率に男女聞の有意差は認められなかった。年齢別にみると，4歳以下の乳幼児でもすでにかなり高率に感染がみられるが，ランプノレ鞭毛虫を除き，特に30歳代から40歳代で最高値を示した。ランプル鞭毛虫は若年齢層ほど高い陽性率を示し4歳以下が最高であった。本調査は日本国際協力事業団(JICA)の医療協力「ケニア伝染病研究対策プロジェクト」の一環として行われたものであり，その撲滅対策を，戦後日本で実施され成果をあげた寄生虫予防対策事業との関連において考察した。During the period from May to November in 1980, a total of 2,114 stool specimens were collected from individuals living in Naivasha, Kitui, Machakos, Taveta and Nandi Hills areas in Kenya, and they were examined for intestinal protozoa by formol-ether concentration method followed by idoine-staining. Out of 2,114 specimens 673 (31.8%) were positive for Entamoeba histolytica, 1,105 (52.3%) for Entamoeba coli, 102 (4.8%) for Endolimax nana, 184 (8.7%) for Iodamoeba butschlii, 176 (8.3%) for Giardia lamblia, and 220 (10.4%) for Chilomastix mesnili. The total positive rate, which means the percentage of positive persons for any kinds of intestinal protozoa, was 75.1 per cent

Cryptosporidiosis: Prevalence, Genotype Analysis, and Symptoms Associated With Infections in Children in Kenya

Journal ArticleCryptosporidium parasites are leading causes of enteric disease, especially in children. A prospective survey on the prevalence of cryptosporidiosis in children less than five years of age was undertaken at six microbiology laboratories in Kenya on fecal samples submitted for routine parasite and ova investigations. Analysis of 4,899 samples over a two-year study period showed an overall prevalence of cryptosporidiosis of 4% that was highest between November to February. Investigations on the nature of enteric diseases prompting ova and cyst examination requests showed 66.4% had acute diarrhea, 9% had persistent diarrhea, and 21% had recurrent diarrhea. The main symptoms were abdominal pain (51.1%), vomiting (51.6%), and abdominal swelling (11%). The prevalence of cryptosporidiosis was highest among children 13–24 months of age (5.2%) and least among those 48–60 months of age (2%). No significant differences were observed by sex but vomiting was slightly higher in males than in females (65% males and 52% females; P _ 0.07). Cryptosporidiosis was significantly associated with persistent diarrhea (P_ 0.0001, odds ratio [OR] _ 2.193, 95% confidence interval [CI] _ 1.463–3.29), vomiting (P _ 0.0273, OR _ 1.401, 95% CI _ 1.04–1.893), and abdominal swelling (P _ 0.0311, OR _ 1.56, 95% CI _ 1.04–2.34). Genotype analysis based on polymerase chain reaction–restriction fragment length polymorphism of the 18S rRNA gene fragment showed that 87% (153 of 175) of the Cryptosporidium isolates were C. hominis, 9% (15 of 175) were C. parvum, and remaining 4% were C. canis, C. felis, C. meleagridis, and C. muris. The most common protozoa in coinfected patients were Entamoeba histolytica/E. dispar, E. coli, and Giardia intestinalis (6%, 5%, and 2%, respectively). Our results show that Cryptosporidium is among the most common protozoan parasites in children with enteric diseases and that anthroponotic species are the leading cause of human cryptosporidiosis in Kenya, which suggests that human-to-human transmission is the main mode of spread