LSTM Home > LSTM Research > LSTM Online Archive

Does Increasing Treatment Frequency Address Sub-optimal Responses to Ivermectin for the Control and Elimination of River Blindness?

Frempong, Kwadwo K., Walker, Martin, Cheke, Robert A., Tettevi, Edward Jenner, Gyan, Ernest Tawiah, Owusu, Ebenezer O., Wilson, Michael D., Boakye, Daniel A., Taylor, Mark ORCID:, Biritwum, Nana-Kwadwo, Osei-Atweneboana, Mike and Basáñez, María-Gloria (2016) 'Does Increasing Treatment Frequency Address Sub-optimal Responses to Ivermectin for the Control and Elimination of River Blindness?'. Clinical Infectious Diseases, Vol 62, Issue 11, pp. 1338-1347.

Full text not available from this repository.


Several African countries have adopted a biannual ivermectin distribution strategy in some foci to control and eliminate onchocerciasis. In 2010, the Ghana Health Service started biannual distribution to combat transmission hotspots and sub-optimal responses to treatment. We assessed the epidemiological impact of the first 3 years of this strategy and quantified responses to ivermectin over two consecutive rounds of treatment in 10 sentinel communities.

We evaluated Onchocerca volvulus microfilarial intensity and prevalence in those aged ≥20 years before the first, second and fifth (or sixth) biannual treatment rounds using skin snip data from 956 participants. We used longitudinal regression modelling to estimate rates of microfilarial repopulation of the skin in a cohort of 217 participants who were followed-up over the first two rounds of biannual treatment.

Biannual treatment has had a positive impact, with substantial reductions in infection intensity after 4 or 5 rounds in most communities. We identified three communities—all having been previously recognised as responding sub-optimally to ivermectin—with statistically significantly high microfilarial repopulation rates. We did not find any clear association between microfilarial repopulation rate and the number of years of prior intervention, coverage, or the community level of infection.

The strategy of biannual ivermectin treatment in Ghana has reduced O. volvulus microfilarial intensity and prevalence, but sub-optimal responses to treatment remain evident in a number of previously and consistently implicated communities. Whether increasing the frequency of treatment will be sufficient to meet the World Health Organization's 2020 elimination goals remains uncertain.

Item Type: Article
Subjects: QX Parasitology > Helminths. Annelida > QX 301 Filarioidea
WA Public Health > WA 105 Epidemiology
WA Public Health > Preventive Medicine > WA 110 Prevention and control of communicable diseases. Transmission of infectious diseases
WW Ophthalmology > Diseases. Color Perception > WW 160 Eye infections. Hypersensitivity diseases (General or not elsewhere classified)
Faculty: Department: Biological Sciences > Department of Tropical Disease Biology
Digital Object Identifer (DOI):
Depositing User: Jessica Jones
Date Deposited: 29 Mar 2016 14:37
Last Modified: 16 Sep 2019 09:01


View details

Actions (login required)

Edit Item Edit Item