Table of Contents
Morphology :
1. Schistosoma haematobium is a parasitic flatworm, belonging to the group of blood flukes.
2. It has a cylindrical body with a distinct oral and ventral sucker.
3. The male and female worms are sexually dimorphic, with the female being larger and longer than the male.
4. The adult worms reside in the venous plexuses around the urinary bladder.
Life Cycle of Schistosoma haematobium:
Eggs Production: Female worms lay eggs within the veins of the urinary bladder.
Excretion: The eggs are excreted in the urine of the infected host.
Water Contamination: In freshwater bodies, the eggs hatch, releasing miracidia, the larval stage of the parasite.
Intermediate Host Infection: Miracidia penetrate specific freshwater snails (intermediate hosts) and develop into cercariae.
Human Infection: Cercariae are released from snails and penetrate the skin of humans during contact with contaminated water.
Migration and Maturity: Inside the human body, cercariae migrate to the venous plexuses around the bladder, where they mature into adult worms.
Prevalence and Epidemiology:
Geographical Distribution: Schistosoma haematobium is prevalent in Africa, the Middle East, and parts of Asia.
Prevalence: It is one of the leading causes of schistosomiasis, particularly urogenital schistosomiasis.
Transmission: Transmission occurs in areas with freshwater bodies contaminated with infected snails.
Pathogenicity:
Urinary Tract Damage: The adult worms in the urinary system cause inflammation and tissue damage, leading to symptoms such as hematuria (blood in urine), dysuria (painful urination), and urinary tract infections.
Chronic Complications: Chronic infections can lead to bladder fibrosis, calcification, hydronephrosis, and potentially squamous cell carcinoma of the bladder.
Diagnosis:
Diagnosis of Schistosoma haematobium infection involves:
(i) Microscopic examination of urine samples for the presence of parasite eggs.
(ii) Serological tests such as enzyme-linked immunosorbent assay (ELISA) for detecting antibodies against Schistosoma antigens.
Prophylaxis:
Water Sanitation and Hygiene (WASH): Improvement of sanitation facilities and access to clean water sources.
Health Education: Educating communities about the risks of contact with contaminated water and promoting safe water practices.
Chemoprophylaxis: Mass drug administration with praziquantel in endemic areas to reduce the burden of infection.
Treatment:
Praziquantel: It is the drug of choice for treating schistosomiasis, including Schistosoma haematobium infection. It effectively kills adult worms.
Treatment may also include management of complications such as urinary tract infections and bladder damage.