Schistosoma mekongi

Schistosoma mekongi
Scientific classification
Kingdom:	Animalia
Phylum:	Platyhelminthes
Class:	Trematoda
Subclass:	Digenea
Order:	Strigeidida
Genus:	Schistosoma
Species:	S. mekongi
Binomial name
Schistosoma mekongi Voge, Bruckner & Bruce, 1978

Schistosoma mekongi is a trematode, also known as a flatworm or fluke. It is one of the five major schistosomes that account for all human infections, the other four being S. haematobium, S. mansoni, S. japonicum, and S. intercalatum. This trematode causes schistosomiasis in humans.

Freshwater snail Neotricula aperta serves as an intermediate host for Schistosoma mekongi.

Schistosomiasis was first reported in the Mekong river basin region in 1957.  It was believed that the cause of these cases was Schistosoma japonicum until 1978, when Neotricula aperta was discovered and it was determined that the Schistosome was a unique species, Schistosoma mekongi.

S. mekongi shares many general characteristics with other schistosomes, particularly S. japonicum, but it does have crucial differences.  S. mekongi eggs are 30-55 μm and have a diminutive spine, and only 95 per mating pair are produced per day, whereas S. japonicum eggs are larger, have no spine, and produce on average 250 per day.  N. aperta infected release on 42 cercaria per day, far lower than other Schistosomes.

S. mekongi is found in the Mekong river basin region, from Kratie province, Cambodia, to Khong Island, Laos.

In 1989 a universal mass treatment with praziqauntel of the people of Khong Island, Laos was performed.  In 1995 a similar treatment was performed in Cambodia.  In some areas this treatment was highly effective, eliminating S. mekongi. In other regions, particularly Khong Island, there was little effect.

Attempting to control the intermediate host with a molluscicides also had no long-term effectiveness.

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Wikipedia