Reduced Loa loa microfilaria count ten to twelve months after a single dose of ivermectin.

The action of a single dose of ivermectin (200 micrograms/kg) on 71 Gabonese patients with Loa loa microfilariae in the peripheral blood, and living in areas highly endemic for loiasis, has been evaluated. Ten to 12 months after treatment, 43 patients (63%) had no circulating microfilaria and the geometric mean peripheral blood microfilaria count had decreased by 88.6% (P < 0.02). Thus, a single annual dose of ivermectin can markedly reduce loiasis transmission.