Schistosoma mekongi

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Schistosoma mekongi
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Platyhelminthes
Class: Trematoda
Order: Diplostomida
Family: Schistosomatidae
Genus: Schistosoma
Species:
S. mekongi
Binomial name
Schistosoma mekongi
Voge, Bruckner & Bruce, 1978

Schistosoma mekongi is a species of trematodes, also known as flukes. 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

intermediate host for Schistosoma mekongi.[1]

History

Schistosomiasis was first reported in the

helminth infections was developed and endorsed by the Cambodian MoH in 2009. This served as the backbone of future helminth control. A specific national schistosomiasis elimination action plan for the period 2016–2020 has been developed as a guidance for the National Control Program. This plan is supported by a Technical Taskforce at the central, provincial and district levels, and the task-force members are experts from the ministries, which are already involved by the National Committee for NTD Control.[3]

Characteristics

Schistosoma 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 and produce on average 250 per day. N. aperta infected release on 42 cercaria per day, far lower than other Schistosomes.[4]

Epidemiology

Endemic region

Schistosoma mekongi is found in the Lower Mekong river basin region, from

Reservoir hosts also play a big role in keeping the disease around, although the number of reservoir hosts for the Mekong species is less than that of other species. With the use of stool examinations, only about 1500 people are shown to be infected, but it is projected that more than 10 times this number is more accurate.[3] In 1989, a universal mass treatment with praziquantel of the people of Khong Island 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.[2]

Attempting to control the

intermediate host with a molluscicides also had no long-term effect.[2]

Life cycle/etiology

Schistosoma mekongi infections are caused by the penetration of the skin by the cercariae stage of the parasite. Eggs are released into the water in urine or fecal matter. These eggs hatch and release miracidia, which penetrate and infect the intermediate host, the snail Neotricula aperta. Sporocysts are then released in the water by either successive generations of snails or by predatory birds in the area eating infected snails and defecating the sporocysts in the water. The sporocysts then mature into cercariae that penetrate the skin and develop into schistosomulae. The schistosomulae circulate in the host blood and turn into adults. Adult worms release eggs into the bloodstream that lodge in the small capillaries of the intestine or bladder, penetrate the wall, and are released in feces or urine, respectively. The cycle then repeats itself. Schistosoma mekongi is much like Schistosoma japonicum in that adults more frequently in the superior mesenteric veins, but can be found in the central nervous system.[5]

Treatment and prevention

Treatment for all types of schistosomiasis are the same, but first step to treatment is always to see a physician. They will likely treat you with praziquantel for 1–2 days to treat all schistosomiasis infections. To prevent yourself from getting the parasite you should boil all drinking water and try to restrain from swimming in areas of slow current or evidence of rotting wood in the dry season.[6]

Reservoir hosts

The

reservoir hosts
for Schistosoma mekongi are dogs and pigs. It is believed that S. mekongi is unable to use cattle, such as water buffalo, as an effective reservoir host, unlike its close cousin S. japonicum.

References

  1. ^
    PMID 18350111
    .
  2. ^ .
  3. ^ a b Virak Khieu;Somphou Sayasone; Siuon Muth; Masashi Kirinoki; Sakhone Laymanivong; Hiroshi Ohmae; Rekol Huy; Thipphavanh Chanthapaseuth; Aya Yajima; Rattanaxay Phetsouvanh; Robert Bergquist; Peter Odermatt(2019/02/7) "Elimination of Schistosomiasis Mekongi from Endemic Areas in Cambodia and the Lao People's Democratic Republic: Current Status and Plans". Nation Center for Parasitology
  4. ^ Hebner, Rebecca. "Schistosoma mekongi". Parasites and Pestilence. Stanford University. Retrieved 2017-04-24.
  5. ^ CDC DPDx. Accessed: 2020/4/25. Last updated: 2019/8/14. https://www.cdc.gov/dpdx/schistosomiasis/index.html
  6. ^ CDC (2018/12/18)

External links