Some morphological aspects of Wuchereria bancrofti uterus after treatment with diethylcarbamazine

Confocal and EM analyses revealed that some female Wuchereria bancrofti, obtained from volunteers that received recommended diethylcarbamazine dose regimens, showed few or no embryos. Furthermore, inside the gravid uterus of female W. bancrofti treated with DEC we observed a finely granular, electron-dense material organised as strings of pearls, ∼70 nm in maximal length surrounding intra-uterine microfilariae and apparently secreted by the embryo. Over the eggshells a similar material was also observed, possibly secreted by the uterine wall. The surface of intra-uterine microfilariae presented a material with identical electron-density to the scattered structures observed inside the egg. Similarly, the sheath of blood microfilariae of W. bancrofti also showed electron-dense projections, with shape and size similar to that observed inside the uterus.