Vector control and entomological capacity for onchocerciasis elimination. Issue 7 (July 2022)

• Record Type: Journal Article
• Authors: Tirados, Iñaki; Thomsen, Edward; Worrall, Eve; Koala, Lassane; Melachio, Tito T.; Basáñez, María-Gloria
• Is Part Of: Trends in parasitology. Volume 38:Issue 7(2022)
• Page Start: 591
• Page End: 604
• Publication Date: 2022-07
• Subjects: onchocerciasis -- loiasis -- Simulium -- Chrysops -- vector control -- elimination; Parasitology -- Periodicals; Parasitology -- Periodicals; Biology -- Periodicals; Parasitology; Biology; Parasitologie -- Périodiques; Online resources; 571.999
• DOI: 10.1016/j.pt.2022.03.003
• Languages: English
• ISSNs: 1471-4922

Abstract

Abstract : Mass drug administration (MDA) of ivermectin is currently the main strategy to achieve elimination of transmission (EoT) of onchocerciasis. Modelling suggests that EoT may not be reached in all endemic foci using annual MDA alone. Onchocerciasis and loiasis are coendemic in forest areas of Central Africa where ivermectin treatment can lead to severe adverse events in individuals with heavy loiasis load, rendering MDA inappropriate. Vector control has been proposed as a complementary intervention strategy. Here, we discuss (i) achievements and pitfalls of previous interventions; (ii) epidemiological impact, feasibility, and combination with MDA to accelerate and/or protect EoT; (iii) role of modelling; (iv) opportunities for innovative methods of vector monitoring and control; and (v) strengthening entomological capacity in endemic countries. Highlights: Modelling studies have suggested that elimination of transmission (EoT) of onchocerciasis may not be achieved by relying solely on mass drug administration (MDA) of ivermectin, particularly in hyperendemic areas and in those areas where onchocerciasis and loiasis are coendemic. In onchocerciasis-loiasis coendemic areas, vector control methods could provide complementary strategies to accelerate elimination. Study of host-seeking behaviour could inform the development of new control/monitoring tools against vectors. These new tools could be used against vectors of onchocerciasis, vectors of loiasis, or both. Control and monitoring tools, exploiting the natural attraction of hosts, could be implemented by communities and enhance country ownership. To ensure vector control capacity, well-trained, motivated, and appropriately funded local entomologists are essential to lead vector research and entomological operations.