Filariasis: new drugs and new opportunities for lymphatic filariasis and onchocerciasis.

PURPOSE OF REVIEW: Chemotherapy against onchocerciasis and lymphatic filariasis has been discussed mainly within the framework of mass drug administration with diethylcarbamazine, ivermectin and albendazole. Although strong reductions in infection prevalence were achieved, the regimes for these drugs do not fully cover needs of individual patients who seek treatment because of symptoms. Chemotherapy against filarial Wolbachia endosymbionts with doxycycline showed higher antiparasitic efficacy in onchocerciasis and lymphatic filariasis and also improved disease. This review details the recent indications for this new treatment, focussing on regimes for individual drug administration.

RECENT FINDINGS: A regimen of 6-week/100 mg doxycycline per day sterilized adult female Onchocerca volvulus. Two hundred milligrams doxycycline per day for 4 or 6 weeks revealed 50 and 60% macrofilaricidal effects, respectively. Reduction of 80-90% of adult worms was observed in bancroftian filariasis with 200 mg/day doxycycline for 4 or 6 weeks. The latter regimen showed reduction of lymph vessel dilation and of hydrocele. Lymphoedema progression was halted and reversed in early stages.

SUMMARY: Different options for antiwolbachial individual drug administration are summarized here. With improving health systems in endemic countries, individuals will demand best-possible treatment and accelerate a shift from mass drug administration-only approaches to integrated approaches combining both mass drug administration and individual drug administration. Treatment may be further improved by new antibiotics detected in high-throughput settings.