Soil transmitted helminthes in free-range chickens and domestic herbivores: potential reservoirs for human infections in a Rwandan village

Abstract

Background: A disproportionate burden of soil transmitted helminthes (STH) in human populations occurs in marginalized, low-income, and resource-constrained regions of the world, with approximately two billion people infected worldwide. Infections are widely distributed in tropical and subtropical areas, with the greatest numbers occurring in sub-Saharan Africa, South America, China and East Asia. The control of STH infections in developing countries is of considerable public health importance. Infections with most STH are known to be closely linked with conditions of poverty, unsafe water, sanitation and hygiene. The possible contribution of domestic animals in the transmission of these parasites, if any, is largely unknown. Objective: The objective of this study was to investigate the prevalence of STH infection in domestic free-range chickens and herbivores in a rural Rwandan village, as a potential source of transmission of infection from these animals to humans, and vice-versa Significance of the study: This study will help in the understanding of the role that domestic free-range chickens and herbivores play in the transmission of human STH, in a rural Rwandan village Methodology Design: This was a community based cross-sectional study and used both qualitative and quantitative research designs. Study area: This study was conducted in Nyarubuye village, a rural village in eastern province with about 750 households. Data collection: Chickens droppings and stool of herbivores were screened for STH eggs and larvae and a standard questionnaire was used for demographic data collection. Study population: The study population comprised of households keeping domestic free-range chickens and herbivores in the particular village. Only adult members of the households were enrolled for the study. Sample size: The study used simple random sampling to select 75 homesteads; this was equivalent to 10% of the entire village population based on 2007 survey of homesteads. Data analysis and presentation: Collected data were analyzed using SPSS and presented through frequencies and percentages. xi Results and conclusions Majority of the domestic animals were cows at 38% followed by goats at 35%. Free-range chickens formed 24% of the animals and the least group was sheep at 3%.The animals had eggs of hookworm, Trichuris trichiura, Trichostrongylus spp. and Taenia spp. in their faeces. The study found out that hookworm eggs were present in all herbivorous animals studied. Eggs of hookworm, Trichuris trichuris, Trichostrongylus spp. and Taenia spp. were also found in chickens‟ droppings. Majority of the households, domestic animals grazed in open areas with only a small proportion of the population doing closed grazing. This practice may have been responsible for exposing the domestic animals to human STH. Majority of the households had toilets (97.3%), about 72% were located outside their compounds and it is thus possible that they were not being used all the time, especially by young children who may not be able to walk the long distance out of the compounds. The presence of human STH in the stool of domestic animals may be attributed to the community not utilizing the toilets. Based on these findings the use of pit latrines by the villagers is recommended to minimize the spread of STH infections. The study also calls for community education on soil STH infections to equip the community with basic knowledge for better prevention. One of the limitations of the study is that it is not clear whether the eggs found in the faeces of domestic herbivores and free-range chickens are actually eggs of human STH and not of animals. This calls for more laboratory tests for confirmation. In addition, the sample size was small and a larger study is needed to confirm the findings.