Occasionally, invasion of the female genital tract with vulvovaginitis and pelvic or peritoneal granulomas can occur. The most typical symptom is perianal pruritus, especially at night, which may lead to excoriations and bacterial superinfection. vermicularis occurs worldwide, with infections occurring most frequently in school- or preschool-children and in crowded conditions.Įnterobiasis is frequently asymptomatic. vermicularis, although occasional infections have been reported in captive chimpanzees. Humans are considered the only host for E. Oxyurid nematodes (pinworms) generally exhibit high host specificity. Retroinfection, or the migration of newly hatched larvae from the anal skin back into the rectum, may occur but the frequency with which this happens is unknown. Rarely, eggs may become airborne and be inhaled and swallowed. The larvae contained inside the eggs develop (the eggs become infective) in 4 to 6 hours under optimal conditions. Gravid females migrate nocturnally outside the anus and oviposit while crawling on the skin of the perianal area. At full maturity adult females measure 8 to 13 mm, and adult males 2 to 5 mm the adult life span is about two months. The time interval from ingestion of infective eggs to oviposition by the adult females is about one month. Following ingestion of infective eggs, the larvae hatch in the small intestine and the adults establish themselves in the colon, usually in the cecum. contaminated surfaces, clothes, bed linens, etc.). Infection occurs via self-inoculation (transferring eggs to the mouth with hands that have scratched the perianal area) or through exposure to eggs in the environment (e.g. Gravid adult female Enterobius vermicularis deposit eggs on perianal folds.
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