Epidemiology Of Leishmania Infection And Insecticide Treated Bed Net Use In Three Communities Of Oti Region, Ghana

Abstract

ABSTRACT Background: Leishmaniasis is a neglected tropical disease caused by parasites of the genus Leishmania and is transmitted by various species of female sand flies. In Ghana, the DNA of Leishmania parasites has been identified in skin lesions from some patients suspected to have cutaneous leishmaniasis (CL) and also from some female sand flies sampled from the Ho municipality of the Volta Region. Systematic reviews have demonstrated that the application of insecticides against sand fly vectors is effective in reducing incidence of leishmaniasis. Methods: Using a community-based cross-sectional study design, the prevalence of Leishmania infection, insecticide treated bed (ITN) use, and the occurrence of sand flies in three communities of the Oti region of Ghana were investigated. Awareness about CL, CL experience, and CL related knowledge among household heads were also investigated. Results: A total of 3,440 participants from 587 households comprising 189 (32.2%), 200 (34.1%), and 198 (33.7%) households from Ashiabre, Keri, and Sibi Hilltop respectively, participated in this study. Leishmanin skin test (LST) results for 1091, 848, and 1132 participants from Ashiabre, Keri, and Sibi Hilltop, indicated an overall prevalence of Leishmania infection of 41.8% and individual community prevalence of 39.4%, 55.1%, and 34.2% respectively. An overall prevalence of 31.9% and individual community prevalence of 23.2%, 29.8%, and 36.8% for CL in Ashiabre, Keri, and Sibi Hilltop respectively was observed. Being male (AOR=1.27; CI: 1.09, 1.49), and living in Keri (AOR=1.83; CI: 1.43, 2.34) were associated with an increase in the odds of exposure to Leishmania infection using LST. Being 5-15 years old (AOR=1.49; CI: 1.31, 1.98), 16-45 years old (AOR=3.31; CI: 2.44, 4.47), and >45 years old (AOR=4.85; CI: 3.29, 7.15) were also significantly associated with increased odds of being exposed to Leishmania infection. Nonuse of ITN was not significantly associated with Leishmania infection. The proportion of all study households that owned at least one ITN was 97.1%. 97.4% of households in Sibi Hilltop and 97.0% of households in both Ashiabre and Keri owned at least one ITN. Cumulatively, the number of households having at least one ITN for every two members was 386 (65.8%) while 63.5%, 68.0%, and 65.7% of households in Ashiabre, Keri, and Sibi Hilltop owned at least one ITN for every two household members. Of the 3639 de facto household population comprising 1116, 864, and 1179 in Ashiabre, Keri, and Sibi Hilltop, the overall population with access to ITN was 3159 (86.8%) while 87.3%, 87.9%, and 85.6% of the household populations in Ashiabre, Keri, and Sibi Hilltop respectively, had access to ITN. The overall household population that slept in ITN the night before this survey was 2370 (65.1%) while in Ashiabre, Keri, and Sibi Hilltop, it was 66.4%, 65.1%, and 64.0% respectively. Of 2181 population in households with ITN access, 1581 (72.5%) persons slept in ITN the night before the survey. Lack of household access to ITN (AOR=1.80; CI: 1.31, 2.47), having a family size of more than 10 members (AOR=2.53; CI: 1.20, 4.24), having more than 10 rooms for sleeping in a household (AOR=10.18; CI: 1.28, 81.00), having 2-4 screened windows (AOR=1.49; CI: 1.00, 2.20), and having 8-10 screened windows (AOR=3.57; CI: 1.25, 10.17) were significantly associated with increased odds of not sleeping in ITN the night before the survey. All household heads were aware of CL with 243 (41.4%) of them demonstrating good knowledge about it. A total of 45.3% of household heads (57.1%, 35.0%, and 44.4% in Ashiabre, Keri, and Sibi Hilltop) indicated that at least one member of their household had experienced CL two years prior to this study. A total of 193 female sand flies were trapped from various locations within the study communities. Conclusions: This study demonstrated exposure to Leishmania infection in the study communities and confirmed CL which suggests an active cycle of transmission of Leishmania infection. Being male, living in Keri and being five years or older were associated with Leishmania infection. The non-use of ITNs was not significantly associated with Leishmania infection. Household ITN access of 65.8% and usage by 65.1% of the study population suggests a need for strategies to improve both access to ITN and its usage. Factors associated with nonuse of ITN were Lack of household access to ITN, having a family size of more than 10 members, having more than 10 rooms for sleeping, and having 2-4 or 8-10 screened windows. The occurrence of sand flies was confirmed and suggests a need for investigation of the sand fly species and their possible role in Leishmania transmission. Demonstration of good knowledge about CL by less than half of household heads calls for strategies to improve knowledge about CL.