Risks of parasitic helminth disease outbreaks and influence of physico-chemical factors in flood prone areas of Yaoundé, Cameroon

Abstract

Background

Urbanization coupled with poverty has promoted the exploitation of risk zones like flood-prone areas in the city of Yaoundé. The overcrowding and poor hygiene observed in these areas are responsible for the unsmiling variations in environmental cleanliness, exploitation of river water for domestic purposes thus putting them at risk for parasitic disease transmissions. This study was conducted in order to assess the risks of human helminthiases outbreaks in relation to water physico-chemical factors in the city of Yaoundé.

Method

Water samples were collected monthly from January to June 2022 in 12 stations from 4 rivers (Biyeme, Ebogo, Olezoa and Tongolo) situated in flood plains in the town of Yaoundé. Intestinal parasite resistant forms were identified using the basic sedimentation technique, while water parameters were assessed using standard procedures.

Results

Results indicated that rivers in flood-prone areas are highly contaminated with a 75 % prevalence rate. In all, resistant forms of nine parasite species were recorded with the genus Toxocara being the most diversified with two species. Strongyloides stercoralis was the most prevalent (33.3 %) and most abundant (1269) species followed by Toxocara canis (26.4 %), Ascaris lumbricoides (25 %), Toxocara leonina (20.8 %), Hookworm (15.3 %), Trichostrongylus sp. (11.1 %), Diphyllobothrium latum (8.3 %), Trichuris trichiura (2.8 %) and Schistosoma intercalatum (1.4 %). The least abundant species was Trichuris trichiura (33). Higher densities of parasite resistant forms were observed during the dry season. River Tongolo was the most contaminated with pathogenic forms. Water pH, orthophosphate, organic matter and alkalinity revealed negative corelations with the occurrence of Diphyllobotrium latum (r = −0.375, −0.253, −462, −0.448 respectively) while organic matter and pH showed positive correlations with the occurrence of Strongyloides stercoralis (r = 0.378) and Trichostrongylus sp. (r = 0.238) respectively.

Conclusion

Flood areas constitute a potential risk zone for the maintenance and spread of human helminthiases. Maintaining proper personal cleanliness, environmental sanitation through the building of functional and accessible faecal disposal facilities and drainages and abstaining from using the rivers as waste dumps are essential in this area to prevent parasitic helminth disease outbreaks.