The DOLF project has supported two community studies and one clinical trial to assess the impact of semiannual treatment with albendazole alone—i.e. without ivermectin—for elimination of lymphatic filariasis (LF). Albendazole is known to be safe in persons with Loa loa infections, but its efficacy for eliminating LF was unknown when we started our studies.

Use of Semiannual Albendazole to Eliminate LF in Central Africa

Ivermectin, one of two drugs most commonly used in mass treatment programs in Africa cannot be safely used for widespread treatment in many areas in Central Africa. It sometimes causes serious adverse events including coma and death in persons with heavy Loa loa infections, a different filarial parasite that is also common in that region.

Community Studies in the Republic of Congo

Results show that semiannual albendazole alone is not only successful to reducing LF, but also for reducing STH, especially hookworm infection (Pion et al. 2015, Pion et al. 2017). Data from a parallel study in the Democratic Republic of Congo is currently being analyzed.  Additional surveys are planned for the Republic of Congo and Democratic Republic of Congo to evaluate the long-term effects of treatment on prevalence and intensity for both LF and soil transmitted helminths.

Community Studies in the Democratic Republic of Congo

Community trials were performed in Mandingo District and in Kwilu Province, both in the Democratic Republic of the Congo, to determine whether semiannual MDA with Albendazole alone can eliminate LF in Central Africa where the standard MDA regimen (Ivermectin plus Albendazole) cannot be used because of coendemic loiasis. Semiannual albendazole dramatically reduced infection rates to below 1% over a period of years in both study areas, and the community treatments greatly reduced rates of intestinal worm infections in these areas. Furthermore we studied the risk factors for LF in the study villages (Chesnais et al. 2019).

Clinial Trial in Côte d’Ivoire

A clinical trial was conducted in Côte d’Ivoire to compare the impact of three years of semiannual (i.e. twice annual) albendazole with three annual doses of ivermectin with albendazole. While the combination treatment reduced infection rates faster than albendazole alone, three years of semiannual albendazole was as effective as three annual treatments with ivermectin + albendazole for clearing filarial parasites from the blood of study participants. Taken together, these studies provide strong support for the World Health Organization’s recent endorsement of semiannual albendazole together with integrated vector management to eliminate lymphatic filariasis in areas of Central Africa where ivermectin cannot be safely used for mass treatment programs.


Chesnais CB, Awaca-Uvon NP, Vlaminck J, Tambwe JP, Weil, GJ, Pion SD, Boussinesq M. Risk factors for lymphatic filariasis in two villages of the Democratic Republic of the Congo.
Parasites Vectors. 2019;12:162

Pion SDS, Chesnais CB, Weil GJ, Fischer PU, Missamou F, Boussinesq M. Effect of 3 years of biannual mass drug administration with albendazole on lymphatic filariasis and soil-transmitted helminth infections: a community-based study in Republic of the Congo. Lancet Infect Dis. 2017;17:763-769

Pion SDS, Chesnais CB, Bopda J, Louya F, Fischer PU, Majewski AC, Weil GJ, Boussinesq M, Missamou F. The Impact of Two Semiannual Treatments with Albendazole Alone on Lymphatic Filariasis and Soil-Transmitted Helminth Infections: A Community-Based Study in the Republic of Congo.
Am J Trop Med Hyg. 2015;92(5):959-966