Published Date: 2012-03-07 02:45:29
Subject: PRO/AH> Angiostrongylus cantonensis - Australia: (NS) canine
Archive Number: 20120307.1063168
ANGIOSTRONGYLUS CANTONENSIS - AUSTRALIA: (NEW SOUTH WALES) CANINE
A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
Date: Mon 5 Mar 12
Source: The Manly Daily [edited]
Rare illness strikes dog in North Narrabeen
A North Narrabeen [New South Wales] woman is warning dog owners about a serious infection dogs can get from slugs.
And the nematode that causes the infection can also affect humans -- in 2010 a 21 year old man fell ill after he ate a slug for a dare. The parasitic nematode _Angiostrongylus cantonensis_ can cause meningitis and normally lives in the arteries of rats, leading to its common name, rat lungworm.
The infection it causes, called angiostrongyliasis, can lead to death or brain and nerve damage though it can't be passed from person to person. [The woman] said her 14 week old cavalier King Charles spaniel initially showed flu-like symptoms and was prescribed antibiotics. But when the dog's condition worsened, she returned Zumby to the vet.
"After a series of painful tests, Zumby was kept in the vet all weekend and has now been placed on steroid treatment," she said. "Treatment can be lengthy but we are optimistic that, as we caught it early, Zumby will not have any problems in the future once he has recovered." But she said she had been told another dog in Powder Works Rd had also contracted the infection and fears children might also get infected if they touch a slug and then put their finger in their mouth.
"The only place Zumby could have got it is in Powder Works Rd and it's really concerning that it's happened twice in our street," she said. She said the wet conditions in recent months could be responsible to an increase in the number of slugs in peninsula back yards and gardens.
[byline: John Morcombe]
[This disease is not a new disease, and likely is not an emerging disease, however, it may be a re-emerging disease in the age of electronic media.
Canine neural angiostrongyliasis (CNA) is caused by the obligatory neural migration of _Angiostrongylus cantonensis_ larvae in dogs. Characteristically, cases are juvenile dogs with progressive central nervous system dysfunction characterized by hyperesthesia and often associated with eosinophilic pleocytosis of the CSF (cerebrospinal fluid).
Until the recent (2001) establishment of _A. cantonensis_ in North America, Australia was the only developed region endemic for this parasite. Almost 50 years ago the life cycle was elucidated there, in the city of Brisbane, and the 1st human infections probably occurred in 1959. From the 1970s, increasing numbers of autochthonous infections have been reported along the central east coast of the continent (south east Queensland and northern New South Wales), involving humans, rats, dogs, horses, flying foxes, and marsupials.
Ten years ago (1991), the parasite was discovered in Sydney, almost 1000 km [about 600 mi] to the south, in dogs. In that city, it has since been diagnosed as a cause of neurological disease in increasing numbers of dogs, flying foxes, marsupials, and zoo primates. Presumably, these infections resulted from the ingestion of snails or slugs, and it seems that virtually all species of native and exotic terrestrial molluscs can serve as intermediate hosts. It is not known how the parasite was introduced to Australia, or how it has spread over such an extensive territory, although eventually its range could encompass the entire east coast of Australia, and potentially other regions. It is also not known if the almost identical, native species, _A. mackerrasae_, is able to infect people (or other non rodent hosts). All worms recovered to date, from one fatal human case, and from many animal infections, have been confirmed as _A. cantonensis_.
In Australia, most cases of CNA occur between March and June. The rat lungworm, _A. cantonensis_ was first described by Chen in 1935 in Canton, China. While initially called _Pulmonema cantonensis_ the parasite was later reclassified as _A. cantonensis_.
A disease diagnosed as eosinophilic meningoencephalitis was first described in 1944 in Taiwan. The same disease was reported in 1948 in the East Caroline Islands (Micronesia) but it was not until 1961 that _A. cantonensis_ was confirmed as the etiological agent when a patient in a Hawaiian mental institution, who had died of eosinophilic meningoencephalitis, had _A. cantonensis_ larvae recovered from the brain and spinal cord.
The 1st reports of animals infected with _A. cantonensis_ were made by Mason in 1976 when he described a syndrome occurring in puppies in the Brisbane area, characterized by urinary incontinence, hind limb paresis and hyperesthesia, often associated with eosinophilic pleocytosis of the CSF.
The major differential diagnosis for CNA is neosporosis. Other differential diagnoses include idiopathic eosinophilic meningoencephalitis, parasitic infections including _Toxoplasma gondii_, _Taenia solium_, _Gnathostoma spinigerum_, visceral larval migrans (_Toxocara canis_), and schistosomiasis, fungal, bacterial, viral, and rickettsial infections as well as neoplasia, trauma, drug reactions, and toxicities. Treatment of CNA has been limited to glucocorticoids, however there may be adjunct therapies including anthelmintics, cyclosporine, and matrix metalloproteinase inhibitors.
In dogs, treatment with anthelmintics may be contraindicated as it is likely to exacerbate the clinical signs. This is not necessarily true in other species and the mechanism of its occurrence in dogs is not understood.
Routine heartworm and intestinal parasite prophylaxis appears to have no influence on the occurrence of CNA.
Portions of this comment have been extracted from http://www.tm.mahidol.ac.th/seameo/2001-32-suppl-2/25-126.pdf and from http://ses.library.usyd.edu.au/handle/2123/2077.
Narrabeen, New South Wales, Australia, may be found on the HealthMap/ProMED-mail interactive map at http://healthmap.org/r/1WWI. - Mod.TG]