Schistosomiasis-CDCreport

In endemic areas, visible hematuria or positive reagent strip for hematuria, or with eggs of schistosomiasis hematobium in urine.

Case classification
• Probable case: Any visible hematuria associated with abdominal pain.
• Suspected case: Any terminal hematuria with the reagent strip associated with abdominal pain.
• Confirmed case: Microscopic examination showing eggs of schistosomiasis hematobium in urine.
Infectious agent

Schistosoma hematobium

Occurrence

S. hematobium is found in Africa and the Middle East. In Iraq it is found in the middle and southern regions. The risks groups are farmers and children ages 5-19 years old.

Reservoir

Humans are the principal reservoir.

Mode of transmission

Infection is acquired from water containing free swimming larval forms (cercariae) that have developed in snails. The eggs leave the body mainly in the urine and hatch in water and the liberated larvae (miracidia) penetrate into suitable freshwater snail hosts. After several weeks, the cercariae emerge from the snail and penetrate human skin, usually while the person is working, swimming or wading in water; they enter the bloodstream, are carried to blood vessels of the lungs, migrate to the liver, develop to maturity and then migrate to veins of the abdominal cavity. Adult forms migrate through anastomoses into the vesical plexus of the urinary bladder and eggs are deposited in venules and escape into the lumen of urinary bladder.