Infectious Disease Compendium

Schistosoma

Microbiology

A blood fluke, five infect humans. S. mansoni, S. japonicum, S. mekongi, S. haematobium, and S. intercalatum.

Look in a first morning urine for the eggs.

Epidemiologic Risks

Spread by wading in water containing the host snails, disease can be caused by cercariae (itch), mature worms (Katayama fever), and eggs (late findings).

Also, humans can be the accidental host of avian schistosomes (Great Lake Area) and get a way bad self limited itch. There is a new strain causing swimmers itch in the SF bay area (PubMed).

And if someone from an endemic area is pissing in your drinking water, you can acquire it as well. Ick (PubMed).

S. mansoni: Arabia, Africa, Caribbean, South America.

S. japonicum: China, Philippines.

S. mekongi: Southeast Asia.

S. haematobium: Africa, Middle East. And Corsica (PubMed). No doubt it will be spreading north in Europe as the world warms and people do a Patty Smith (pissing in a river (Pubmed), for those who do not know the work of the greatest female rocker of all time).

Syndromes

They can all cause swimmers itch.

- Schistosoma mansoni. Katayama fever, chills, sweating, headache, and cough, hepatosplenomegaly, lymphadenopathy and eosinophilia. Chronic disease due to eggs in the intestines or liver and subsequent immune response to the organism hepatosplenomegaly and varices. LFT's are normal.

- Schistosoma japonicum. Katayama fever, chills, sweating, headache, and cough, hepatosplenomegaly, lymphadenopathy and eosinophilia. Chronic disease due to eggs in the intestines or liver and subsequent immune response to the organism hepatosplenomegaly and varices. LFT's are normal.

- Schistosoma mekongi. Chronic disease due to eggs in the intestines or liver and subsequent immune response to the organism with hepatosplenomegaly and varices. LFT's are normal.

- Schistosoma haematobium. Involves the bladder with hematuria and can be associated with Salmonella carriage in bladder and bladder cancer.

-Schistosoma intercalatum. It lives in the mesenteric veins; abdominal pain and bloody stool.

Treatment

S. mansoni or S. haematobium. Praziquantel two doses in one day of 20 mg/kg or 40 mg/kg x 1 (PubMed). The widespread use of praziquantel is leading to failures (Pubmed).

Also, mefloquine-artesunate is very effective against S. haematobium (PubMed).

Combination therapy does not increase efficacy (PubMed).

S. japonicum or S. mekongi. Praziquantel 20 mg/kg three times in 1 day or 40 mg/kg x 1 (PubMed).

Notes

They have found eggs in 6000 year old pelvis (PubMed).