Sindew Mekasha Feleke
Ethiopian Public Health Institute, Ethiopia
Title: Evidence for possible interruption of onchocerciasis transmission in metema focus, north gondar, ethiopia
Biography
Biography: Sindew Mekasha Feleke
Abstract
Background: Onchocerciasis is a neglected tropical parasitic disease (NTD) caused by a filarial nematode worm called onchocerca volvulus and transmitted by the bites of simulium flies. Since 2001, Ethiopia has been committed to implementation of the National Onchocerciasis Control Programme, which was revised during 2012 to undertake elimination through interruption of transmission until 2020. This strategy uses annual or semiannual community-based treatment using the drug Ivermectin.
Objective: This study was aimed at assessing whether the goal of focal transmission interruption attained or not in one of the areas receiving annual community based Ivermectin for more than a decade.
Methods: A community-based cross sectional study was conducted in selected communities of Metema focus during 2014 and 2015 in North Gondar, Ethiopia. High endemicity before intervention, proximity to the breeding sites and representativeness of the focus within 20-30 km distance between sites was used for selection. The study participants were community residents above the age of 5 years for skin microfilariae survey and children’s born during the period of mass treatment with age below 10 years for Ov-16 IgG4 antibody exposure test. Skinsnip sample collected from left and right iliac crest of 2,986 individuals with sterilized biopsy punch and examined under a microscope after 24 hours’ incubation. Whereas, finger prick samples collected from 3,136 children and dried blood spot (DBS) prepared for Ov-16 ELISA laboratory analysis.
Results: From microscopic examination, no skin snip found positive for microfilaria. ELISA showed 0.25% (8 of 3,136) antibody positive. But molecular assay of skin snip using PCR demonstrated no infective parasite for those 8 sero-reactive children.
Conclusion: The skin microfilarial survey results revealed absence of Onchocerca volvulus in the community and the serology results implied that children born during the period of the intervention are protected from acquiring infection. An entomological assessment appears important to confirm absence of infectious flies in the focus and interruption of focal transmission.