Magnified 125X, this photomicrograph revealed the presence of a fertile Ascaris sp. egg that was found in an unstained formalin-preserved stool sample. See PHIL 411 for an example of an unfertilized Ascaris lumbricoides egg.Geographic Distribution:The most common human helminthic infection, Ascaris sp. have a worldwide distribution. Their highest prevalence is in tropical and subtropical regions, and areas with inadequate sanitation. Ascariasis occurs in rural areas of the southeastern United States.Created: 1973
Depicted in this 1960 photograph were two Ascaris lumbricoides nematods, i.e., roundworms. The larger of the two was the female of the species, while the normally smaller male was on the right. Adult female worms can grow over 12 inches in length.Created: 1960
This 2007 photograph depicted Center for Disease Control/ NCZVED/DPD laboratory technician, Henry Bishop holding a mass of Ascaris lumbricoides worms, which had been passed by a child in Kenya, Africa. This nematode parasitizes the human small intestine, and is spread from human to human by the fecal-oral route. Children seem to be infected more often than adults, and though the organisms depicted here originated in Africa, the disease can be acquired in the southeastern United States.Created: 2007
