Schistosomiases are acute or chronic visceral parasitic diseases due to 5 species of trematodes (schistosomes). The three main species infecting humans are Schistosoma haematobium, Schistosoma mansoni and Schistosoma japonicum. Schistosoma mekongi and Schistosoma intercalatum have a more limited distribution.
Humans are infected while wading/bathing in fresh water infested with schistosome larvae. Symptoms occurring during the phases of parasite invasion (transient localized itching as larvae penetrate the skin) and migration (allergic manifestations and gastrointestinal symptoms during migration of schistosomules) are frequently overlooked. In general, schistosomiasis is suspected when symptoms of established infection become evident. Each species gives rise to a specific clinical form: genito-urinary schistosomiasis due to S. haematobium, intestinal schistosomiasis due S. mansoni, S. japonicum, S. mekongi and S. intercalatum.
The severity of the disease depends on the parasite load. Heavily infected patients are prone to visceral lesions with potentially irreversible sequelae. Children aged 5 to 15 years are particularly at risk: prevalence and parasite load are highest in this age group.
An antiparasitic treatment should be administered to reduce the risk of severe lesions, even if there is a likelihood of re-infection.
Clinical features
|
Parasite/Epidemiology
a
Citation
a.
For more information on geographic distribution of schistosomiasis: |
Clinical features/Diagnosis |
---|---|---|
Genito-urinary schistosomiasis |
S. haematobium |
|
Intestinal schistosomiasis |
S. mansoni S. japonicum S. mekongi S. intercalatum |
|
Treatment
praziquantel PO
[1]
Citation
1.
Treatment Guidelines from The Medical Letter. Vol. 11 (Suppl). Drugs for Parasitic Infections. 2013.
https://www.uab.edu/medicine/gorgas/images/docs/syllabus/2015/03_Parasites/RxParasitesMedicalLetter2013.pdf [Accessed 25 May 2020]
[2]
Citation
2.
Centers for Disease Control and Prevention (CDC). Schistosomiasis. Resources for Health Professionals. 2018.
https://www.cdc.gov/parasites/schistosomiasis/health_professionals/index.html#tx [Accessed 25 May 2020]
Children 4 years and over and adults
b
Citation
b.
For the treatment of schistosomiasis, praziquantel may me administered to pregnant women.
:
- S. haematobium, S. mansoni, S. intercalatum: 40 mg/kg single dose or 2 doses of 20 mg/kg administered 4 hours apart
- S. japonicum, S. mekongi: 2 doses of 30 mg/kg or 3 doses of 20 mg/kg administered 4 hours apart
- (a)For more information on geographic distribution of schistosomiasis:
https://www.who.int/schistosomiasis/Schistosomiasis_2012-01.png?ua=1 - (b)For the treatment of schistosomiasis, praziquantel may me administered to pregnant women.
- 1.Treatment Guidelines from The Medical Letter. Vol. 11 (Suppl). Drugs for Parasitic Infections. 2013.
https://www.uab.edu/medicine/gorgas/images/docs/syllabus/2015/03_Parasites/RxParasitesMedicalLetter2013.pdf [Accessed 25 May 2020] - 2.Centers for Disease Control and Prevention (CDC). Schistosomiasis. Resources for Health Professionals. 2018.
https://www.cdc.gov/parasites/schistosomiasis/health_professionals/index.html#tx [Accessed 25 May 2020]