Schistosoma haematobium is a trematode (flatworm) belonging to the genus Schistosoma. It is one of the five main species known to cause schistosomiasis in humans. Unlike other schistosomes that affect the intestinal tract, S. haematobium primarily targets the urogenital system and is a public health issue in most of Africa and the Middle East. It has long-term morbidity if not treated and diagnosed early. An understanding of the lifecycle, transmission, clinical presentation, and treatment of S. haematobium is necessary for effective control and prevention of the disease.
Humans become infected through contact with freshwater bodies contaminated with larval forms of the parasite (cercariae), which are released by freshwater snails (the intermediate hosts). Once inside the human host, the larvae migrate through the bloodstream to the venous plexus of the bladder, where they mature into adult worms, mate, and produce eggs. https://www.cdc.gov/parasites/schistosomiasis
Causes and Transmission
The infection is acquired when skin comes in contact with freshwater sources harboring infected snails. Infection risk factors include:
Swimming, bathing, or washing in infested water
Poor sanitation facilities
Limited access to clean water
Living in endemic regions (e.g., Sub-Saharan Africa, some Middle Eastern nations)
The parasite lifecycle involves: https://medisom24.com/2025/04/19/schistosoma-treatment-guide/
Excretion of eggs in the urine of infected persons.
Eggs hatch into miracidia in water and infect snails of specific species.
Cercariae come out of snails and penetrate human skin.
Symptoms of S. haematobium
Symptoms can depend on the stage of infection and the intensity of parasite burden:
Acute Phase
Cercarial Dermatitis or Katayama Fever)
Itching rash or skin irritation at the point of entry
Fever, chills, muscle aches (in heavy infections
Chronic Phase
Hematuria: (blood in urine) – a classic symptom
Dysuria: (painful micturition)
Frequent urination
Inflammation and thickening of the bladder
Urinary tract infections
Complications (if untreated)
Calcification and fibrosis of the bladder
Obstructive uropathy
Renal impairment
Risk of bladder cancer: (particularly squamous cell carcinoma)
Infertility and reproductive issues in late stages
Diagnosis of Schistosoma haematobium
Early diagnosis is necessary for effective treatment. The diagnostic techniques are:
Urine microscopy: Detection of characteristic terminal-spined eggs in urine, especially between 10 a.m. and 2 p.m. when egg excretion is maximal.
Urine dipstick tests: Reveal hematuria and proteinuria.
Serological testing: For antigens or antibodies; in infections of low intensity.
Ultrasound imaging: Evaluates damage and potential complications to the urinary system.
PCR-based molecular assays: Highly sensitive and specific though more expensive and less available in endemic regions.
Treatment Options
The main treatment for infection with S. haematobium is the antiparasitic medication praziquantel, which is effective against the adult worms.
Praziquantel
Dosage: A single dose of 40 mg/kg body weight
Efficacy: Very effective in decreasing worm burden and symptoms
Safety: Moderately well tolerated; mild side effects may be nausea, stomach discomfort, or dizziness
cases of advanced disease with complications
Antibiotics for secondary infection
Surgery for obstruction of the urinary tract
Cancer treatment for schistosomiasis-related bladder cancer
Prevention and Control
Prevention of S. haematobium infection necessitates a combined public health strategy:
Better Sanitation and Clean Water Access
Supplying safe water supplies
Building and keeping latrines
Decreasing the contamination of freshwater sources with human excrement
Health Education
Promoting awareness of disease transmission and protection behavior
Promoting the wearing of shoes and protective attire while exposed to freshwater
Mass Drug Administration (MDA)
Regular administration of praziquantel in endemic areas, specifically to school-age children
Snail Control
Employment of molluscicides or environmental changes to limit snail habitats
Surveillance and Monitoring
Routine screening among high-risk group
Mapping of endemic areas for specific intervention
Conclusion
Schistosoma haematobium remains a significant public health concern in many parts of the world, particularly where access to sanitation and healthcare is inadequate. Effective control of this parasite relies on early diagnosis and treatment with praziquantel, which is the right medicine, and on long-term investment in public health infrastructure. Ongoing research, education, and community engagement are key to removing urogenital schistosomiasis as a public health issue.
Centers for Disease Control and Prevention (CDC) on schistosomiasis
