Schistosomiasis (Bilharzia)– an overview

Summary

Schistosomiasis is a tropical parasitic disease affecting over 200 million people globally, primarily in Sub-Saharan Africa. The disease is caused by parasitic worms that cycle through humans, snails, and freshwater sources. It can lead to severe long-term health issues, including bladder cancer, liver damage, and anemia. Diagnosis is typically made through urine, stool, or biopsy, while treatment involves medication to eliminate the adult worms. Preventative measures focus on improving sanitation, reducing water contamination, and providing clean water sources to limit exposure.

Takeaways

• 😀 Schistosomiasis is a tropical disease caused by parasitic worms, with over 200 million people affected globally.
• 😀 The disease is also known as bilharzia, named after Theodore Billhartz, who first described the parasite.
• 😀 Schistosomiasis has a complex life cycle involving humans, snails, and freshwater bodies like lakes and ponds.
• 😀 Five main types of schistosomiasis affect humans, each causing different symptoms and affecting various organs.
• 😀 The life cycle of schistosomiasis starts with infected humans releasing eggs into water, which hatch into larvae that infect snails.
• 😀 Once the larvae mature in snails, they are released into the water as cercariae, which penetrate human skin and travel to the liver.
• 😀 The adult worms live in blood vessels, laying thousands of eggs that may either exit the body or become trapped in organs.
• 😀 Acute symptoms include itchy skin rashes, fever, diarrhea, and respiratory issues, while chronic effects lead to organ damage and cancer.
• 😀 Schistosomiasis can cause damage to the bladder, intestines, liver, spleen, and even the brain, with long-term consequences like anemia.
• 😀 Diagnosis is done through urine, stool tests, biopsy, and blood tests looking for antibodies, with no vaccine currently available.
• 😀 Treatment involves medication that kills adult worms, preventing egg production, and reducing organ damage. Early treatment improves recovery chances.

Q & A

What is schistosomiasis and what causes it?

Schistosomiasis is a tropical disease caused by parasitic worms known as schistosomes. These parasites infect humans through contaminated water and are transmitted via snails.

Why is schistosomiasis also called bilharzia?

Schistosomiasis is also called bilharzia after Theodore Bilharz, who first described the parasite responsible for the disease.

How many people are estimated to be infected with schistosomiasis worldwide?

It is estimated that over 200 million people around the world are infected with schistosomiasis, with the majority of cases occurring in sub-Saharan Africa.

What are the main types of schistosomes responsible for human disease?

There are five main types of schistosomes that cause human disease, including Schistosoma haematobium, Schistosoma mansoni, Schistosoma japonicum, Schistosoma mekongi, and Schistosoma intercalatum.

Where are Schistosoma haematobium, Schistosoma mansoni, and Schistosoma japonicum typically found?

Schistosoma haematobium is mostly found in parts of Africa and the Middle East, Schistosoma mansoni in Africa, South America, and the Caribbean, and Schistosoma japonicum in parts of China and Southeast Asia.

What is the life cycle of the schistosomiasis parasite?

The life cycle of schistosomiasis involves humans, snails, and freshwater. Infected humans pass eggs through urine or feces into the water, where they hatch into larvae that infect snails. After development in the snails, the larvae return to the water and penetrate human skin. The parasites travel through the body, eventually settling in organs like the liver or bladder.

What are the short-term and long-term effects of schistosomiasis?

Short-term effects include itching (swimmer's itch), rash, and a condition known as acute schistosomiasis, which presents with fever, diarrhea, and respiratory symptoms. Long-term effects can lead to severe organ damage, such as bladder cancer, liver scarring, and anemia, particularly in children.

How is schistosomiasis diagnosed?

Schistosomiasis can be diagnosed through urine and stool tests, biopsies of affected tissues, or blood tests to detect antibodies against the parasite.

Is there a vaccine for schistosomiasis?

Currently, there is no vaccine available for schistosomiasis, but effective medications exist to treat the disease by killing the adult worms and preventing further egg production.

What are the main strategies for preventing schistosomiasis?

Prevention strategies include treating affected communities with medication, improving sanitation, reducing water contamination, controlling snail populations, and minimizing human contact with contaminated water.