Monitoring and evaluation of lymphatic filariasis interventions

Lymphatic filariasis is caused by three closely related nematode parasites: Wuchereria bancrofti, Brugia malayi and Brugia timori. Accurate detection of W. bancrofti microfilaria is essential to measure the impact of community treatment programs. PCR-based assays are specific, highly sensitive tools allowing the detection of W. bancrofti DNA in human blood samples. The purpose of this review was to monitor and evaluate lymphatic filariasis interventions based on various PCR protocols designed to enhance its sensitivity and usefulness for population-based studies. These species have many ecological variants that differ in several aspects of their biology such as mosquito vector species, host range, periodicity, and morphology. Although the genome of B. malayi (the first genome sequenced from a parasitic nematode) has been available for more than 5 years, very little is known about genetic variability among the filariae within the lymphatic system. The genetic diversity among these worms is not only interesting from a biological perspective, but it may have important practical implications for the Global Program to Eliminate Lymphatic Filariasis, as the parasites may respond differently to diagnostic tests and/or medical interventions. Therefore, better information on their genetic variability is urgently needed. Improved information on filarial genetic diversity may increase the chances of success for lymphatic filariasis elimination programs.