Schistosoma-Induced Chronic Kidney Disease

Schistosomiasis is a tropical disease, reported to occur in more than 70 countries, mainly in Africa, East Mediterranean and the Caribbean. From an estimated total of 200 million infected people – 85% of whom live in sub-Saharan Africa - approximately 120 million develop symptoms, 20 million have severe disease and 100,000 of them die each year.

Schistosomiasis is a parasitic disease caused by trematode worms of the genus Schistosoma. The five species that causes human schistosomiasis are Schistosoma haematobium, Schistosoma intercalatum, Schistosoma japonicum, Schistosoma mansoni and Schistosoma mekongi[1].

The parasites are released from infected freshwater snails. The disease is spread by contact with fresh water contaminated with the parasites.

The worms migrate to the veins around the bladder and ureters, leading to abdominal pain, diarrhea, bloody stool or blood in the urine. The late phase (chronic form) begins from the 6th month after infection and can last for several years. Over time, fibrosis can lead to obstruction of the urinary tract, hydronephrosis (swelling of a kidney due to a build-up of urine) and kidney failure.

Some studies show that renal lesions are irreversible because many cases have delayed diagnosis[2]. However, specific antiparasitic treatment can alter the renal disease development or progression when instituted in the initial phases. Patients with proliferative forms do not respond to antiparasitic treatment nor to immunosuppression, suggesting that this type of glomerular involvement has a progressive pattern.

We would like to suggest to call this particular variant: Schistosoma-Induced Chronic Kidney Disease

[1] Bezerra da Silva et al: Schistosomiasis-associated kidney disease: A review in Asian Pacific Journal of Tropical Disease – 2013. See here. 
[2] Martinelli et al: Envolvimento glomerular na esquistossomose mansônica in Jornal Brasileiro de Nefrologia – 1996