General Information

COMMON NAMES: Acaris GLOBAL DISTRIBUTION: NATIVE global COOK ISLANDS STATUS: Introduced - Recent, Naturalised; Land, parasite on people SIGNIFICANCE LIST: ; Disease causing - moderate KEY FEATURES: Large cylindrical worms to 350mmTL and 6mmØ. Live in the small intestine feeding on the gut contents. Sexes separate. Pale yellow to brown with whitish stripes. Females can lay 200,000 eggs a day. Eggs pass with faeces and develop in water for about 3 months, and then if swallowed the infective larvae hatch in the small intestine and burrow into the blood stream. The juveniles live in teh blood stream and burrow into various organs, finally they burrow into the lungs and move up the windpipe (often assisted by coughing). They are swallowed a second time and can then grow into adults in the small intestine. Throughout the body the juveniles cause vaarious symptoms and infammatory reactions, while a heavy infestation of adults can cause malnutrition.

Cook Islands Distribution

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Southern Group: Present    Makatea: Present
RR	MG	AT	MK	MT	AK	PL	TK	MN

Northern Group: Present
TN	MH	RK	PK	NS	SW

Ascaris lumbricoides Linnaeus, 1758
TAXONOMY: ANIMALIA; NEMATODA; SECERNENTEA (=Phasmidia); Ascaridida; ASCARIDIDAE

GENERAL NOTE: Notes for diagram of life-cycle (McGill University): Adult worms1 live in the lumen of the small intestine. A female may produce up to 240,000 eggs per day, which are passed with the feces 2. Fertile eggs embryonate and become infective after 18 days to several weeks 3, depending on the environmental conditions optimum: moist, warm, shaded soil). After infective eggs are swallowed 4, the larvae hatch 5, invade the intestinal mucosa, and are carried via the portal, then systemic circulation to the lungs 6 . The larvae mature further in the lungs (10 to 14 days), penetrate the alveolar walls, ascend the bronchial tree to the throat, and are swallowed 7. Upon reaching the small intestine, they develop into adult worms 1. Between 2 and 3 months are required from ingestion of the infective eggs to oviposition by the adult female. Adult worms can live 1 to 2 years. (CDC 1999)

Vouchers:
Pukapuka: reported by Dr Steve Kennier, 1980s, as common.

References:
None recorded.

Data Update History (information):
zTX, zB02, zM05a

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