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United States Department of Agriculture

Agricultural Research Service

Research Project: POSTHARVEST TREATMENT OF TROPICAL COMMODITIES FOR QUARANTINE SECURITY, QUALITY MAINTENANCE, AND VALUE ENHANCEMENT

Location: Tropical Crop and Commodity Protection Research

Title: Apple Snails As Disease Vectors

Authors
item Hollingsworth, Robert
item Cowie, Robert - UNIV. HAWAII (MANOA)

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: September 22, 2005
Publication Date: November 14, 2006
Citation: Hollingsworth, R.G. and R.H. Cowie. 2006. Apple snails as disease vectors. In R. C. Joshi & L. S. Sebastian, Eds. Global Advances in Ecology and Management of Golden Apple Snails. Nueva Ecija: Philippine Rice Research Institute. pp 121-132.

Interpretive Summary: Apple snails (in the family Ampullariidae) carry parasites causing at least three diseases in humans: “swimmer’s itch” (cercarial dermatitis) caused by a type of schistosome, intestinal disease, caused by a different type of schistosome in the genus Echinostoma, and rat lungworm disease (eosinophilic meningitis) caused by the nematode Angiostrongylus cantonensis. The rat lungworm disease is the most important of these diseases. Experiments show that apple snails do not become infected with the A. cantonensis nematode as easily as certain other molluscs, and the natural parasite load of individual apple snails is generally much lower than in large species of land molluscs, such as the giant African snail (Achatina fulica) and veronicellid slugs. Nevertheless, apple snails are important carriers of A. cantonensis nematodes because of their widespread use as a human food item and because individual slugs or snails sometimes carry unusually high numbers of nematodes within their bodies. Rat lungworm disease caused by apple snails results primarily from consumption of raw or undercooked snail meat but contact with the debris associated with preparation of the snails for eating may also cause infection. As pest species of apple snails continue to be spread, it is expected that A. cantonensis nematodes will also spread into new regions, increasing the number of cases of rat lungworm worldwide.

Technical Abstract: Apple snails (Ampullariidae) are intermediate hosts of parasites causing at least three diseases in humans: cercarial dermatitis (“swimmer’s itch”) caused by trematode cercaria, intestinal problems caused by flukes in the genus Echinostoma, and eosinophilic meningitis caused by the nematode Angiostrongylus cantonensis. Angiostrongyliasis is the most important of these diseases. Experiments show that apple snails do not acquire A. cantonensis as easily as certain other molluscs, and the natural parasite load of individual apple snails is generally much lower than in large species of land molluscs, such as the giant African snail (Achatina fulica) and veronicellid slugs. Nevertheless, apple snails are important carriers of A. cantonensis because of their widespread use as a human food resource and high intra-specific variation in parasite load. Angiostrongyliasis caused by apple snails results primarily from consumption of raw or undercooked snail meat but contact with the debris associated with preparation of the snails for eating may also cause infection. As pest species of apple snails continue to be spread there is the potential for the concomitant spread of A. cantonensis into new regions, increasing the number of cases of angiostrongyliasis worldwide.

Last Modified: 7/28/2014
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