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. 2016 Dec 6;10(12):e0005161.
doi: 10.1371/journal.pntd.0005161. eCollection 2016 Dec.

Contribution of Wastewater Irrigation to Soil Transmitted Helminths Infection among Vegetable Farmers in Kumasi, Ghana

Isaac Dennis Amoah  1   2 , Amina Abubakari  2 , Thor Axel Stenström  1 , Robert Clement Abaidoo  2 , Razak Seidu  3
Affiliations

Contribution of Wastewater Irrigation to Soil Transmitted Helminths Infection among Vegetable Farmers in Kumasi, Ghana

Isaac Dennis Amoah et al. PLoS Negl Trop Dis. .

Abstract

Wastewater irrigation is associated with several benefits but can also lead to significant health risks. The health risk for contracting infections from Soil Transmitted Helminths (STHs) among farmers has mainly been assessed indirectly through measured quantities in the wastewater or on the crops alone and only on a limited scale through epidemiological assessments. In this study we broadened the concept of infection risks in the exposure assessments by measurements of the concentration of STHs both in wastewater used for irrigation and the soil, as well as the actual load of STHs ova in the stool of farmers and their family members (165 and 127 in the wet and dry seasons respectively) and a control group of non-farmers (100 and 52 in the wet and dry seasons, respectively). Odds ratios were calculated for exposure and non-exposure to wastewater irrigation. The results obtained indicate positive correlation between STH concentrations in irrigation water/soil and STHs ova as measured in the stool of the exposed farmer population. The correlations are based on reinfection during a 3 months period after prior confirmed deworming. Farmers and family members exposed to irrigation water were three times more likely as compared to the control group of non-farmers to be infected with Ascaris (OR = 3.9, 95% CI, 1.15-13.86) and hookworm (OR = 3.07, 95% CI, 0.87-10.82). This study therefore contributes to the evidence-based conclusion that wastewater irrigation contributes to a higher incidence of STHs infection for farmers exposed annually, with higher odds of infection in the wet season.

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Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1. A map of Kumasi showing the location of the wastewater farms and homes of the farmers and control (courtesy Google Maps).
Fig 2
Fig 2. Distribution of Ascaris spp and hookworm ova in irrigation water in the dry (n = 71) and wet (n = 107) seasons.
Fig 3
Fig 3. Distribution of Ascaris spp and hookworm ova in farm soil in the dry (n = 71) and wet (n = 107) seasons.
Fig 4
Fig 4. Distribution of Ascaris spp for farmers and non-farmers in both seasons.
Fig 5
Fig 5. Distribution of hookworm infection intensity for farmers and non-farmers in both seasons.
See this image and copyright information in PMC

References

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