Elephantiasis on the decline in Cameroon
Lymphatic filariasis—a parasitic infection commonly known as elephantiasis—is among the 10 neglected tropical diseases that the World Health Organization (WHO) is aiming to eliminate by 2020. In Cameroon, large-scale annual mass drug administration efforts are successfully curbing rates of LF, researchers now report in PLOS Neglected Tropical Diseases.
In 2000, more than 120 million people were infected with LF, and 40 million were disfigured and incapacitated by the disease. The WHO has proposed a strategy to eliminate LF which includes mass drug administrations and disability prevention programs. In Cameroon, annual drug administrations of ivermectin and albendazole began in 2008.
In the new work, Joseph Kamgno, of the University of Yaoundé, Cameroon, and colleagues studied 5,292 children aged 5-8 from 97 communities in five health districts in Cameroon that achieved at least 65% drug coverage in six annual mass drug campaigns. The communities were assigned into three evaluation units based on WHO criteria. A blood sample from each child was tested for LF.
In the three evaluation units, 2, 8, and 11 cases of LF were detected, giving rates of 0.13%, 0.57%, and 0.45%. These rates were below WHO critical cut-off thresholds—which would be 18 cases in each evaluation unit—for stopping treatment.
"These results support the cessation of mass drug administration in these implementation units, but this decision needs further thinking," the researchers say. It is possible for disease transmission to continue even when prevalence is very low, they add. "Post-mass drug administration surveillance activities should be organized to evaluate whether recrudescence can occur."