Worms usually appear in the anterior chamber and vitreous and can sometimes be removed surgically. Incubation period
The incubation period in humans is usually from 1 week to 1 month after infection, and can be as long as 47 days. This interval varies, since humans are accidental hosts and the life cycle does not continue predictably as it would in a rat. Cause
Transmission
Transmission of the parasite is usually from eating raw or undercooked snails or other vectors. Infection is also frequent from ingestion of contaminated water or unwashed salad that may contain small snails and slugs, or have been contaminated by them. Reservoirs
Rats are the definitive host and the main reservoir for A. cantonensis, though other small mammals may also become infected. While Angiostrongylus can infect humans, humans do not act as reservoirs since the worm cannot reproduce in humans and therefore humans cannot contribute to their life cycle. Vectors
Angiostrongylus cantonensis has many vectors among invertebrates, with the most common being several species of snails, including the giant African land snail (Achatina) in the Pacific islands and apple snails of the genus Pila in Thailand and Malaysia. The golden apple snail, Pomacea canaliculata, is the most important vector in areas of China. Freshwater prawns, crabs, or other paratenic, or transport, hosts can also act as vectors. Organism
Morphology
A. cantonensis is a nematode roundworm with 3 outer protective collagen layers, and a simple stomal opening or mouth with no lips or buccal cavity leading to a fully developed gastrointestinal tract. Males have a small copulatory bursa at the posterior.
The infection is now endemic in wildlife and a few human cases have also been reported in areas where the parasite was not originally endemic, such as New Orleans and Egypt. The disease has also arrived in Brazil, where there were 34 confirmed cases from 2006 to 2014, including one death. The giant African land snail, which can be a vector of the parasite, has been introduced to Brazil as an invasive species and is spreading the disease. There may be more undiagnosed cases, as Brazilian physicians are not familiar with the eosinophilic meningitis associated to angiostrongyliasis and misdiagnose it as bacterial or viral.The parasite is rarely seen outside of endemic areas, and in these cases patients generally have a history of travel to an endemic area. See also
Schistosomiasis, a parasitic disease also spread by snails
List of unusual deaths – lists Australian man Sam Ballard as dying from Angiostrongyliasis in 2018, as a result of eating a garden slug eight years earlier on a dare

References
Further reading
"Parasites - Angiostrongyliasis (also known as Angiostrongylus Infection)". CDC. 2015-12-28. Retrieved 2017-04-04. "DPDx - Angiostrongyliasis". CDC. 2016-10-17. Retrieved 2017-04-04. Tabs for Parasite Biology, Image Gallery, Laboratory Diagnosis, and Treatment Information. == External links ==