Public health implications of soil contaminated with helminth eggs in the metropolis of Kaduna, Nigeria.

Environmental and socio-cultural variables influencing the distribution of helminth eggs in 608 soil samples were studied in 14 playgrounds that differ in socio-economic status in Kaduna metropolis, Nigeria, using a modified sieving method and a sucrose flotation medium of specific gravity 1.27. Helminth eggs were found in 62% of the soil samples and the distribution was as follows: Toxocara spp. 50.4%, Taenia spp./Echinococcus spp. 36.9%, Dipylidium caninum 26.3%, Ancylostoma spp. 9.0%, Ascaris spp. 7.2%, Trichuris spp. 3.7% and Ascaridia spp. 1.9%. A higher prevalence (68.1%) was recorded during the dry harmattan period while in the rainy period the rate was 58.1%. Mean egg densities ranged from 1.11 +/- 0.32 to 3.92 +/- 2.47 in areas moderately rated. Samples from site 14, which was highly rated, were more contaminated (78.1%) than those collected from other sites, while the intensity of contamination (14.0%) was more in moderately rated site 4 than in the rest of the sites. There were significant associations between the prevalence of helminth eggs and rainy period of the study (odds ratio (OR) = 0.38; 95% confidence interval (CI) on OR: 0.20 0.05). This study shows that the period of study, the presence of dogs and vegetation influence the prevalence of helminth eggs in soil in Kaduna metropolis.