What are the three 3 major Schistosoma species that infect man?

What are the three 3 major Schistosoma species that infect man?

Schistosomiasis (Bilharziasis) is caused by some species of blood trematodes (flukes) in the genus Schistosoma. The three main species infecting humans are Schistosoma haematobium, S. japonicum, and S. mansoni.

What is the infective stage of Schistosoma Intercalatum?

The stages in the snail include two generations of sporocysts and the production of cercariae. Upon release from the snail, the infective cercariae swim and penetrate the skin of the human host, where maturation of the worms continues.

Where is Schistosoma Intercalatum found?

Schistosoma intercalatum is a parasitic worm found in parts of western and central Africa. There are two strains: the Lower Guinea strain and the Zaire strain. S. intercalatum is one of the major agents of the rectal form of schistosomiasis, also called bilharzia.

Can you get schistosomiasis in the United States?

Parasites – Schistosomiasis Although the worms that cause schistosomiasis are not found in the United States, people are infected worldwide. In terms of impact this disease is second only to malaria as the most devastating parasitic disease. Schistosomiasis is considered one of the neglected tropical diseases (NTDs).

What disease does Schistosoma japonicum cause?

japonicum produces diffuse meningoencephalitis with fever (Katayama fever), seizures, visual loss, neck stiffness, disorientation, and stupor. Chronic disease produces seizures, focal signs, and intracranial hypertension related to the development of parenchymal brain granulomas.

What are the two major forms of schistosomiasis?

There are 2 major forms of schistosomiasis – intestinal and urogenital – caused by 5 main species of blood fluke.

When do people get Schistosoma japonicum?

The intensity and prevalence of schistosomiasis infection usually rises with age, peaking at around 15-20 years old. As people get older, although the prevalence of infection tends to stay the same, the number of parasites in the body (parasite burden) has been seen to decrease.

What does Schistosoma japonicum cause?

How long does a person live with schistosomiasis?

Schistosomes live an average of 3–10 years, but in some cases as long as 40 years, in their human hosts. Adult male and female worms live much of this time in copula, the slender female fitted into the gynaecophoric canal of the male, where she produces eggs and he fertilises them (appendix).

Where is schistosomiasis most common?

Epidemiology. Schistosomiasis is prevalent in tropical and subtropical areas, especially in poor communities without access to safe drinking water and adequate sanitation. It is estimated that at least 90% of those requiring treatment for schistosomiasis live in Africa.

Can schistosomiasis be cured?

Schistosomiasis can usually be treated successfully with a short course of a medication called praziquantel, that kills the worms. Praziquantel is most effective once the worms have grown a bit, so treatment may be delayed until a few weeks after you were infected, or repeated again a few weeks after your first dose.

How do Schistosoma japonicum differ from other trematodes?

Schistosoma. Unlike all other trematodes, schistosomes are not hermaphroditic but dioecious, forming separate sexes. Adult worms have elongate tubular bodies, each male having a unique gynecophoral canal (schisto-soma = split body) in which a female worm resides.

What are the characteristics of Schistosoma intercalatum?

Schistosoma intercalatum is related to S. haematobium, but restricted to east-central Africa. The eggs are similar to S. haematobium in general shape and in possessing a terminal spine, but are usually longer (140-240 µm), often have an equatorial (central) bulge and are shed in stool, not urine.

What is the causative agent of schistosomiasis?

Causal Agents. Schistosomiasis (Bilharziasis) is caused by some species of blood trematodes (flukes) in the genus Schistosoma. The three main species infecting humans are Schistosoma haematobium, S. japonicum, and S. mansoni.

What is the geographic distribution of schistosomiasis?

The geographic distribution of cases of schistosomiasis acquired by travelers reflects travel and immigration patterns. Most travel-associated cases of schistosomiasis are acquired in sub-Saharan Africa. Sites in Africa frequently visited by travelers are common sites of infection.

What are the possible complications of Schistosoma infections?

Occasionally, Schistosoma infections may lead to central nervous system lesions. Cerebral granulomatous disease may be caused by ectopic S. japonicum eggs in the brain, and granulomatous lesions around ectopic eggs in the spinal cord may occur in S. mansoni and S. haematobium infections.