Status of onchocerciasis in Teppi area, Southwestern Ethiopia, after four years of annual community-directed treatment with ivermectin

Abstract

Abstract Background: Information on the impact of annual community-directed treatment with ivermectin (CDTI) on the prevalence and intensity of onchocerciasis as well as its transmission following years of repeated ivermectin distribution is vital to monitor the impact of the control efforts. Objective: To determine the status of the prevalence and intensity of onchocerciasis after four years of ivermectin distribution in Teppi area. Methods: Skin snips were obtained from 390 study participants and kept in physiological saline at room temperature for 24 hours. The emerged microfilariae were counted under 10x microscope objective. The skin snips were weighed and the microfilarial load was expressed as the arithmetic mean of two skin snips per mg of skin snip. Results: Out of the total 390 examined subjects, 87 (22.3%) were found to be positive for microfilaridermia. Significant differences in the prevalence and microfilarial load of the disease were not found among untreated and treated subjects (p > 0.05). Significant reductions of the prevalence (25.5%) and intensity of infection (0.08 – 8mf, mean 1.3) were found compared to prevalence (81%) and intensity of infection ( 0-855, mean 33 ± 5.6) reported before the initiation of the CDTI programme in the study area. Conclusion: The overall results of the study showed a high reduction both in the prevalence and intensity of infection compared to prevalence and intensity of the disease before the initiation of the CDTI programme in the study area. Nevertheless, continued assessment of the long-term impact of repeated annual CDTI programme on onchocerciasis and identification of factors that could affect the sustainability of the programme in various CDTI areas of Ethiopia, could contribute towards the effective control of the programme. [Ethiop. J. Health Dev. 2010;24(1):51-56]