From the Guidelines
The most effective method for diagnosing urinary schistosomiasis is through microscopic examination of urine samples for Schistosoma haematobium eggs, ideally collected between 10 AM and 2 PM when egg excretion peaks, as this approach offers the highest sensitivity and specificity for detecting the infection 1.
Diagnosis
To diagnose urinary schistosomiasis, the following steps should be taken:
- Microscopic examination of urine samples for Schistosoma haematobium eggs
- Collection of urine samples between 10 AM and 2 PM when egg excretion peaks
- Detection of terminal-spined eggs in urine sediment
- Multiple samples over consecutive days to improve sensitivity
Treatment
For treatment, praziquantel is the drug of choice, administered as a single oral dose of 40 mg/kg body weight, as it has been shown to be effective in causing paralysis and death of the adult worms 1.
Important Considerations
- Hematuria (blood in urine) is a common presenting symptom that should prompt testing
- Serological tests and PCR may be used in low-prevalence settings or when egg detection is challenging
- Follow-up urine examination should be conducted 3 months after treatment to confirm cure
- Preventive measures should be emphasized, including avoiding contact with potentially contaminated freshwater sources and community-based prevention programs
- Treatment is particularly important to prevent complications such as bladder fibrosis, urinary obstruction, and increased risk of bladder cancer that can develop from chronic infection 1
From the Research
Diagnosis of Urinary Schistosomiasis
- The diagnosis of urinary schistosomiasis can be challenging, especially in chronically infected adults who may pass few eggs in their urine 2.
- A novel method of collecting and filtering urine specimens has been introduced, which allows for the detection of specific DNA fragments of Schistosoma haematobium in human urine 2.
- This method has been shown to be more sensitive than traditional egg detection methods, with 57.3% of urine specimens from school children in Niger testing positive for parasite-specific DNA, compared to 49.4% testing positive for eggs 2.
Treatment of Urinary Schistosomiasis
- Praziquantel is the most commonly used drug for treating urinary schistosomiasis, with a single 40 mg/kg dose reducing the proportion of people still excreting eggs in their urine by around 60% compared to placebo 3.
- However, there have been reports of therapeutic failure of praziquantel in the treatment of Schistosoma haematobium infection, with some studies suggesting that repeated treatments may be necessary 4.
- Metrifonate is another drug that has been shown to be effective in treating urinary schistosomiasis, although it requires multiple administrations and may have more side effects than praziquantel 3, 5.
- A recent study found that three monthly doses of 60 mg/kg praziquantel is a safe and effective treatment regimen for Schistosoma haematobium infection, with an estimated cure rate of 96.4% after the third dose 6.
Comparison of Treatment Options
- Praziquantel and metrifonate are both effective treatments for urinary schistosomiasis, although praziquantel is generally considered to be more convenient and have fewer side effects 3, 5.
- The use of artemisinin derivatives, such as artesunate, has also been investigated as a potential treatment for urinary schistosomiasis, although the evidence is currently inconclusive 3, 5.
- Combination therapies, such as the use of praziquantel and metrifonate together, may also be effective in treating urinary schistosomiasis, although further research is needed to fully evaluate their potential 3, 5.