Comparative analysis of a chemotherapy effect on the cuticular surface of Wuchereria bancrofti adult worms in vivo

Wuchereria bancrofti is the main species responsible for human lymphatic filariasis and remains a major public health problem in tropical countries around the world. Diethylcarbamazine (DEC) has been used for decades in control programs as an effective microfilaricide, although its efficacy in killing adult worms is only around 50% and its direct mode of action is unclear. Recently, in an attempt to control and eliminate lymphatic filariasis, WHO has recommended albendazole (ALB), a broad-spectrum anthelminthic combined with DEC or ivermectin for mass treatment. Some studies have shown that DEC alone blocks oogenesis, fertilization in adult worms, and loss of the microfilarial sheath of several filarial species, whereas ALB is thought to target nematode tubulin. So far, the direct effect of ALB in combination with DEC has not been described in W. bancrofti adult worms. Therefore, the purpose of this study is to investigate by scanning electron microscopy if DEC coadministered with ALB can induce in vivo morphological alterations of the W. bancrofti adult worm surface obtained from a patient in whom the adult worm remained alive, checked serially by ultrasonography for 2 months after antifilarial treatment. Our analysis demonstrates that worms presented morphologic alterations in some regions suggesting cuticular surface damage. On the other hand, adult worms that were recovered from a patient treated with DEC alone after a single dose did not show such any abnormalities.