About Schistosomiasis
The disease causes of schistosomiasis are:
- Schistosoma parasites: The disease is caused by infection with Schistosoma parasites, specifically Schistosoma mansoni, which is one of the most common types responsible for the disease.
- Snail intermediate host: The parasites need freshwater snails to complete their life cycle. These snails act as an intermediate host, where the parasite grows and develops before it can infect humans.
- Human contact with contaminated water: Individuals become infected when they come into contact with freshwater that contains parasite larvae. The larvae enter the body through the skin, usually while swimming, bathing, or wading in contaminated water.
Risk factors for schistosomiasis include:
- Geographic location: Schistosomiasis is more prevalent in tropical and subtropical regions, particularly in areas where there is poor sanitation and limited access to safe water.
- Poverty: Individuals living in poverty-stricken areas are at higher risk due to limited resources for sanitation and hygiene practices.
- Water-related activities: Activities such as bathing, swimming, or playing in contaminated freshwater increase the risk of infection.
- Poor sanitation and hygiene practices: Lack of access to clean water for washing and inadequate sanitation facilities contribute to the transmission of the parasite.
It's important to note that prevention and control strategies focus on improving access to safe water, promoting proper sanitation and hygiene practices, and providing health education on the transmission of schistosomiasis.
The most common early symptoms of schistosomiasis may include:
- Fever
- Headache
- Fatigue
- Muscle pain
- Itchy rash
As the disease progresses or becomes more severe, other common symptoms that may occur include:
- Hematuria (blood in urine)
- Difficulty urinating
- Abdominal pain
- Diarrhea or dysentery (severe intestinal infection with bloody diarrhea and abdominal pain)
- Stomach swelling
- Ascites (abdominal fluid accumulation)
- Blurred vision
- Sensory organ alterations: Changes in the normal function of the senses
- Seizures
- Paralysis or muscle weakness
- Urinary incontinence
It's important to note that these symptoms can vary depending on the type of Schistosoma infection and individual factors. If you are experiencing any concerning symptoms, it is recommended to consult with a healthcare professional for an accurate diagnosis and appropriate treatment.
To diagnose schistosomiasis, the following examinations, tests, and procedures are commonly performed:
- Microscopy-based tests: These involve examining stool or urine samples under a microscope to detect the presence of parasite eggs. However, these tests have low sensitivity and may not detect infections with low parasite burden.
- Serological assays: Antibody-based tests can be used to detect antibodies produced in response to Schistosoma infection. However, these tests may have low diagnostic accuracy and cannot tell the difference between past and current infections.
- Parasite antigen detection assays: These tests detect circulating parasite antigens in the blood or urine. They offer relatively higher accuracy compared to microscopy and antibody detection methods.
- DNA detection methods: Polymerase chain reaction (PCR)-based procedures can detect Schistosoma DNA in stool, urine, or serum samples. These tests may be considered when available.
To determine the severity of schistosomiasis, additional examinations, tests, and procedures that may be recommended include:
- Multiple testing: Test results can sometimes vary, so the test may need to be repeated multiple times to make sure the diagnosis is correct.
- Circulating antigen assays: Blood tests that detect circulating antigens (proteins from the parasite) can help identify specific types of Schistosoma, such as circulating anodic antigen (CAA) and circulating cathodic antigen (CCA). CCA-based tests are used as quick, on-the-spot tools for diagnosing S. mansoni but may not work for S. haematobium.
- Tissue biopsy: In selected cases with high diagnostic suspicion, a tissue biopsy may be considered when less invasive methods fail to confirm the diagnosis.
Remember, it is important to consult with your healthcare provider for personalized advice on which examinations, tests, and procedures are appropriate for your individual situation.
The goal of treatment is to eliminate the infection. The recommended medication for treatment is praziquantel. It is an oral (taken by mouth) medication that can kill the worm that causes schistosomiasis. It is important to take the medication as prescribed for the full course of treatment, even if you begin to feel better. Sides effects from praziquantel include headache, fever, nausea, and itching. Allergic reactions may occur. Contact the healthcare provider immediately if hives (itchy skin rash), swelling, breathing problems, or other signs of a possible allergic reaction occur.
To reduce the risk of schistosomiasis, take precautions in lakes or rivers in areas known to have parasites that cause schistosomiasis. These precautions include:
- Avoiding swimming or bathing in the water.
- Not washing clothes in the water.
- Not fishing from the water.
Medication dosing may be affected by many factors. Check with your health care professional about dosing for your individual situation. Other side effects can occur. Check with your health care professional or read the information provided with your medication for additional side effect information.