Bilharzia (Schistosomiasis)

What is bilharzia?

Bilharzia, also known as schistosomiasis, is a disease caused by tiny parasitic worms called cercariae. These worms enter the human body when a person comes into contact with freshwater sources like lakes, rivers, or streams contaminated with infected snail hosts. The disease can remain in a person’s body for years, silently causing serious damage to internal organs if left untreated.

Sub-Saharan Africa accounts for about 90% of the world’s bilharzia cases, affecting millions of people, especially those who live near water bodies or rely on them for daily activities like fishing, farming, or bathing.

Common misconceptions about bilharzia?

Many people do not recognize the dangers of bilharzia. Some common myths include:

  • “Passing bloody urine as a child is normal.” No, this could be an early sign of bilharzia.
  • “If symptoms disappear, the disease is gone.” Not true! The parasite may still be in the body, causing damage that can later lead to bladder cancer or liver disease.
  • “Only children get bilharzia.” Adults who work in or around contaminated water can also be infected.

How common is bilharzia in Africa?

Bilharzia is widespread in many African countries, especially in rural communities where people rely on freshwater bodies for daily activities. According to the World Health Organization (WHO), over 200 million people worldwide are infected with bilharzia, and more than 90% of them live in Africa. Countries such as Ghana, Nigeria, Tanzania, and Egypt report high infection rates, with schoolchildren being the most vulnerable.

Symptoms of bilharzia?

Bilharzia symptoms can be divided into two stages: early infection symptoms and chronic stage symptoms.

Early infection symptoms (3 to 8 weeks after exposure)

  • Itchy skin or rash
  • Fever
  • Headache and muscle aches
  • Breathing difficulties

Chronic stage symptoms (long-term effects if untreated)

Depending on the type of parasite, bilharzia can affect different parts of the body:

  • If it affects the intestines and liver:
  • Chronic diarrhoea or constipation
  • Blood in the stool
  • Liver damage (fibrosis)
  • High blood pressure around digestive organs
  • If it affects the urinary system:
  • Blood in the urine
  • Painful urination
  • Increased risk of bladder cancer
  • If it spreads to other organs:
  • Anaemia (low blood count)
  • Severe brain or lung complications (in rare cases)

How do people get bilharzia?

  • The parasite enters the body through the skin when a person comes into contact with contaminated water.
  • It happens when infected people urinate or defecate in water bodies, releasing parasite eggs into the water.
  • The eggs hatch, infect snails, and develop into larvae that later infect humans who swim, wash, or work in the water.

How is bilharzia diagnosed and treated?

  • Diagnosis: Doctors check a person’s stool or urine for parasite eggs and may conduct a blood test.
  • Treatment: The main drug used to treat bilharzia is Praziquantel, which kills the parasites and prevents further damage. This drug is safe, effective, and widely available.

How can bilharzia be prevented?

Since there is no vaccine for bilharzia, prevention is key. Here’s how:

  • Avoid contact with contaminated water. If you must enter a river or lake, try to wear protective clothing.
  • Drink and use clean water. Boil or filter water before use.
  • Use proper sanitation. Do not urinate or defecate in rivers, lakes, or ponds.
  • Take preventive medication if you live in a high-risk area. Community-wide treatment programs can help control the disease.
  • Control snails in water bodies. Governments and communities can work together to reduce the snail population using natural predators or chemical treatments.

Final thoughts?

Bilharzia is a serious but preventable disease that continues to affect millions of Africans.

If you live near a river, lake, or dam, protect yourself and your family by avoiding contaminated water, practicing good hygiene, and seeking medical attention if you experience any symptoms. Health education and awareness can save lives—spread the word and help stop bilharzia.