Gnathostomiasis
Gnathostomiasis | |
---|---|
Other names | Gnathostoma, Larva migrans profundus, Nodular migratory eosinophilic panniculitis, Spiruroid larva migrans, Wandering swelling, Yangtze edema[1] |
Specialty | Infectious diseases, helminthology |
Gnathostomiasis, also known as larva migrans profundus,[2]: 436 is the human infection caused by the nematode Gnathostoma spinigerum and/or Gnathostoma hispidum, which infects vertebrates.
Symptoms and signs
A few days after ingestion epigastric pain,
Causes
Human gnathostomiasis is infection by the migrating third-stage larvae of any of five species of Gnathostoma. The most common cause in Asia is G. spinigerum, and the most common cause in the Americas is G. binucleatum. G. hispidium and G. doloresi occur in East and Southeast Asia; the former has also been found in Eastern Europe. G. nipponicum occurs only in Japan and China.[5][6][7] There is one unconfirmed report of G. malaysiae causing disease in humans.[8]
Transmission
Gnathostomiasis is transmitted by the ingestion of raw or insufficiently cooked definitive hosts such as fresh water fish, poultry, or frogs.[citation needed]
In Thailand and Vietnam, the most common cause appears to be consumption of undercooked Asian swamp eels (
Hosts
Intermediate host
The primary
Definitive host
The definitive hosts for gnathostomiasis include cats, dogs, tigers, leopards, lions, mink, opossums, raccoons, poultry, frogs, freshwater fish, snakes or birds.[1]
Incubation period
The incubation period for gnathostomiasis is 3–4 weeks when the larvae begin to migrate through the subcutaneous tissue of the body.[15]
Morphology
The adult parasite is reddish-brown in color and has a globular cephalic dome that is separated from the rest of the body by constriction.
Life cycle
Life cycle in definitive hosts
Adult worms are found in a tumor located in the gastric wall of the definitive hosts and release eggs into the host's digestive tract. The eggs are then released with
Life cycle in humans
Infection of humans by gnathostomiasis is accidental because humans are not one of the definitive hosts of the parasite and do not allow the parasite to complete its life cycle. Infection in humans follows ingestion of raw or insufficiently cooked infected intermediate hosts.[14] The ingested third stage larva migrates from the gastric wall and its migration results in the symptoms associated with infection by gnathostomiasis.[3] The third stage larvae don't return to the gastric wall preventing it from maturing into adult worms, leaving the life cycle incomplete. Instead the larvae continue to migrate unpredictably unable to develop into adults, so eggs are seldom found in diagnostic tests.[1] This also means the number of worms present in humans is a reflection of the number of third stage larvae ingested.[citation needed]
Diagnosis
Diagnosis of gnathostomiasis is possible (with microscopy) after removal of the worm.
The primary form of diagnosis of gnathostomiasis is the identification of larva in the tissue.
Prevention
The best strategies for preventing accidental infection of humans is to educate those living in endemic areas to only consume fully cooked meat. The inability of the parasite to complete its life cycle within humans means that transmission can easily be contained by adequate preparation of meat from intermediate hosts. This is especially useful because of the difficulty and lack of feasibility inherent in eliminating all intermediate hosts of gnathostomiasis. So instead, individuals in endemic areas should avoid eating raw and undercooked meat in endemic areas, but this may be difficult in these areas.[citation needed]
The dish ceviche is native to Peru and a favorite of Mexico. It consists of onion, cubed fish, lime or lemon juice and Andean spices including salt and chili. The ingredients are mixed together and they are allowed to marinate several hours before being served at room temperature. Then in endemic areas in Southeast Asia there are traditional dishes associated with these areas that also include raw uncooked fish, such as koipla in Thailand, goi ca song in Vietnam, sashimi and sushi in Japan.[16]
Acknowledging these cultural traditions, individuals in these cultural can be educated on methods of adapting their food preparation activities in order to remove the larvae without greatly altering these traditional dishes. For instance, meat should be marinated in vinegar for six hours or in soy sauce for 12 hours in order to successfully kill the larvae. In areas with reliable electricity, meat can be frozen at -20 degrees Celsius for 3–5 days to achieve the same results of killing the larvae present.[14]
Treatment
Surgical removal or treatment with albendazole or ivermectin is recommended. The most prescribed treatment for gnathostomiasis is surgical removal of the larvae but this is only effective when the worms are located in an accessible location.[1] In addition to surgical excision, albendazole and ivermectin have been noted in their ability to eliminate the parasite.[3] Albendazole is recommended to be administered at 400 mg daily for 21 days as an adjunct to surgical excision, while ivermectin is better tolerated as a single dose.[1] Ivermectin can also serve as a replacement for those that can't handle albendazole 200 ug/kg p.o. as a single dose.[1] However, ivermectin has been shown to be less effective than albendazole.[19]
Epidemiology
Endemic areas include Asia, Mexico, India and parts of South Africa.[3] Originally believed to be confined to Asia, in the 1970s gnathostomiasis was discovered in Mexico,[3] and found in Australia in 2011.[20][21] Even though it is endemic in areas of Southeast Asia and Latin America, it is an uncommon disease. However, researchers have noticed recently an increase in incidence. This disease is most common in both Thailand and Japan, but in Thailand it is responsible for most of the observed parasitic CNS infection.[14] It has long been recognised in China, but reports have only recently appeared in the English literature.[22]
History
The first case of Gnathostoma infection was identified by Sir
See also
- List of parasites (human)
- List of migrating cutaneous conditions
References
- ^ a b c d e f g h i Gideon; Gnathostomiasis
- ISBN 0-7216-2921-0.
- ^ ISBN 978-0-7216-4793-7.
- PMID 17901651.
- ^ "CDC - DPDx - Gnathostomiasis". www.cdc.gov. 2019-05-07. Retrieved 2019-08-14.
- ^ PMID 21762569.
- PMID 19597010.
- PMID 11023048.
- PMID 1822890.
- PMID 9139388.
- S2CID 24447639.
- S2CID 23748298.
- .
- ^ a b c d e f Robert W. Tolan Jr. (January 2009). "Gnathostomiasis". Medscape. Retrieved July 8, 2011.
- ^ PMID 5392612.
- ^ ISBN 978-1-4419-4392-7.
- ^ "CDC Life Cycle of Gnathostomiasis". Archived from the original on 2013-02-15. Retrieved 2009-02-26.
- PMID 8158995.
- PMID 34578113.
- S2CID 37139535.
- Yahoo. July 5, 2011. Retrieved July 8, 2011.
- PMID 19190210.
- ^ Yangtse Oedema (Gnathostomiasis) Patient UK
- PMID 16124431.
External links
- Gnathostomiasis Archived 2013-02-15 at the Wayback Machine at CDC
- Gnathostomiasis at eMedicine