Brief SummaryRead full entry
Mansonella ozzardi is one of the eight parasitic nematode (roundworm) species that account for most cases of filariasis in humans, although it is responsible for less morbidity than are many of the other seven species (notably, Wuchereria bancrofti and Brugia malayi, which cause lymphatic filariasis, and Onchocerca volvulus, which causes onchocerciasis (river blindness)). Mansonella ozzardi occurs only in the New World. (Centers for Disease Control Parasites and Health website). It is found in Central and South America (Hoerauf 2009).
During a blood meal, an infected arthropod (a Culicoides midge or Simulium blackfly) introduces third-stage filarial larvae onto the skin of the human host, where they penetrate into the bite wound. They develop into adults that commonly reside in subcutaneous tissues. Adult worms are rarely found in humans. The size range for females worms is 65 to 81 mm in length and 0.21 to 0.25 mm in diameter but unknown for males. Adults worms recovered from experimentally infected Patas monkeys (Erythrocebus patas) measured 24 to 28 mm in length and 70 to 80 μm in diameter (males) and 32 to 62 mm in length and 0.13 to 0.16 mm in diameter (females). Adults produce unsheathed and non-periodic microfilariae that reach the blood stream. The fly ingests microfilariae during a blood meal. After ingestion, the microfilariae migrate from the fly's midgut through the hemocoel to the thoracic muscles. There the microfilariae develop into first-stage larvae and subsequently into third-stage infective larvae. The third-stage infective larvae migrate to the fly's proboscis and can infect another human when it takes a blood meal. (Centers for Disease Control Parasites and Health website)