Angiostrongylus cantonensis is a parasitic nematode (roundworm) that causes angiostrongyliasis, the most common cause of eosinophilic meningitis in Southeast Asia and the Pacific Basin. The nematode commonly resides in the pulmonary arteries of rats, giving it the common name rat lungworm. Snails are the primary intermediate hosts, where larvae develop until they are infectious. Humans are incidental hosts of this roundworm, and may become infected through ingestion of larvae in raw or undercooked snails or other vectors, or from contaminated water and vegetables. The larvae are then transported via the blood to the central nervous system, where they are the most common cause of eosinophilic meningitis, a serious condition that can lead to death or permanent brain and nerve damage. Angiostrongyliasis is an infection of increasing public health importance, as globalization contributes to the geographic spread of the disease. History
First described by the renowned Chinese parasitologist Hsin-Tao Chen (1904–1977) in 1935, after examining Cantonese rat specimens, the nematode Angiostrongylus cantonensis was identified in the cerebrospinal fluid of a patient with eosinophilic meningitis by Nomura and Lim in Taiwan in 1944. They noted that raw food eaten by the patient may have been contaminated by rats. In 1955, Mackerass and Sanders identified the lifecycle of the worm in rats, defining snails and slugs as the intermediate hosts, and noting the path of transmission through the blood, brain, and lungs in rats. Infectious agent
A. cantonensis is a helminth of the phylum Nematoda, order Strongylida, and superfamily Metastrongyloidea.
Freshwater snails: Pila spp., Pomacea canaliculata, Cipangopaludina chinensis, Bellamya aeruginosa and Bellamya quadrata
Slugs: Limax maximus, Limax flavus Deroceras laeve, Deroceras reticulatum, Laevicaulis alte, Sarasinula plebeia, Vaginulus yuxjsjs, Lehmannia valentiana, Phiolomycus bilineatus, Macrochlamys loana, Meghimatium bilineatum and probably other species of slugs.Definitive hosts of A. cantonensis include wild rodents, especially the brown rat (Rattus norvegicus) and the black rat (Rattus rattus).Paratenic hosts of A. cantonensis include the predatory land flatworm Platydemus manokwari and the amphibians, Bufo asiaticus, Rana catesbeiana, Rhacophorus leucomystax and Rana limnocharis.In 2004, a captive yellow-tailed black cockatoo (Calyptorhynchus funereus) and two free-living tawny frogmouths (Podargus strigoides) suffering neurological symptoms were shown to have the parasite. They were the first avian hosts discovered for the organism. In 2018, in Mallorca two North African hedgehogs with signs of acute neurological disease were found to have A. cantonensis in their brains, one of them with a gravid female. It was the first report of hedgehogs as hosts of Angiostrongylus.The Hawaiʻi Dept. of Health states that fresh water opihi can carry the parasite, as well as other aquatic organisms such as prawns, frogs, and water monitor lizards. House pets may interact with A. cantonensis-carrying animals yet not well studied. Cats are known to carry and spread feline lungworm in rat and snail interactions. Pathogenesis of human angiostrongylosis
The presence of parasitic worms burrowed in the neural tissue of the human central nervous system (CNS) causes complications.