Hydatid Disease: Causes, Symptoms & Prevention Tips

What is hydatid disease?

Hydatid disease, also known as cystic echinococcosis, is a parasitic infection caused by tapeworms of the genus Echinococcus, primarily Echinococcus granulosus. This disease is characterised by the formation of slow-growing cysts, most commonly in the liver and lungs, but occasionally in other organs as well. If left untreated, these hydatid cysts can lead to serious health complications. Hydatid disease is prevalent in regions where livestock is raised in close proximity to dogs, which serve as the definitive host for the tapeworm for these tapeworms.

Who gets hydatid disease?

Hydatid disease primarily affects individuals living in rural areas where livestock farming is prevalent and dogs are used for herding or guarding animals. People of all ages can be infected, but those who have frequent contact with dogs or livestock, such as farmers, shepherds, veterinarians, and their families, are at a higher risk. Children may also be more susceptible to hydatid disease due to poor hand hygiene after playing with dogs.

Hydatid disease is more common in regions like South America, Eastern Europe, the Middle East, Africa, and parts of Asia. Additionally, people who consume contaminated food or water are at risk of infection.

How does hydatid disease start?

Hydatid disease begins when a person accidentally ingests tapeworm eggs from the genus Echinococcus, most commonly Echinococcus granulosus. These eggs are typically found in the faeces of infected dogs, which shed them after consuming the organs of infected livestock. When a person swallows the eggs, often due to poor handwashing after handling dogs or contaminated environments, the eggs hatch in the intestine and release oncospheres (larvae), which then migrate through the bloodstream and settle in various organs, most frequently the liver or lungs. Over time, the larvae develop into hydatid cysts, which can grow slowly for years before causing noticeable hydatid disease symptoms.

In rare cases, cysts may form in other organs like the kidneys, brain, or bones. The disease's long incubation period means symptoms may not appear for years, making early detection challenging. Transmission is closely linked to areas with close human-livestock-dog contact, emphasising the importance of proper hygiene and animal health practices.

Is hydatid disease contagious?

Hydatid disease is not directly contagious between people. The infection spreads to humans through contact with dog faeces containing tapeworm eggs or by ingesting contaminated food or water. Person-to-person transmission of hydatid disease does not occur.

How common is hydatid disease?

Hydatid disease is more prevalent in rural regions where livestock and dogs are in close contact, such as parts of South America, Eastern Europe, the Middle East, Africa, and Asia. The disease is less common in developed countries that have strict animal health controls and hygiene practices in place, reducing the risk of transmission.

Symptoms of hydatid disease

Hydatid disease symptoms can vary based on the location and size of the cysts. In many cases, individuals remain asymptomatic for years until the cysts become large enough to interfere with normal organ function. When symptoms do appear, they may include:

• Abdominal discomfort or pain
• Diarrhoea
• Unexplained weight loss
• Abdominal swelling or bloating
• Fatigue or general weakness
• Persistent cough (especially with lung cysts)
• Coughing up blood or fluid (from ruptured cysts)
• Jaundice (if liver function is affected)

Because hydatid cysts can grow slowly and silently, early detection and treatment are essential to avoid severe complications.

Causes of hydatid disease

Hydatid disease develops when humans accidentally ingest the parasite's eggs. Common causes include:

• Ingesting eggs from contaminated dog faeces
• Consuming food or water tainted with Echinococcus eggs
• Close contact with infected dogs, which are definitive hosts
• Living or working in areas where livestock (intermediate hosts) and dogs coexist

The most common species responsible for hydatid cyst formation in humans is Echinococcus granulosus. Preventive measures such as hygiene, proper food handling, and deworming of dogs are crucial to avoid infection.

How does hydatid disease spread?

Hydatid disease spreads when humans ingest tapeworm eggs from dog faeces, often through poor hand hygiene after handling dogs or contaminated soil. Eating unwashed vegetables or drinking untreated water containing tapeworm eggs can also transmit the infection. Dogs become infected by eating organs from infected livestock, perpetuating the cycle and increasing the risk of human infection.

Treatment options: From medications to surgery

Treatment for hydatid disease depends on the size, location, and complications associated with the hydatid cysts. Small, uncomplicated cysts may be monitored or treated with antiparasitic medications, such as albendazole or mebendazole, often in combination with regular imaging to assess the cysts' response to treatment.

For larger or more complex cysts, hydatid cyst treatment may involve surgical removal, a procedure called cystectomy. In some cases, a technique called PAIR (puncture, aspiration, injection, re-aspiration) may be used to drain the cyst and inject a scolicidal agent to kill the parasites.

The choice of hydatid disease treatment depends on factors such as the patient's age, overall health, and the cyst's characteristics. Follow-up care and monitoring are essential to ensure complete eradication of the infection and prevent recurrence. Consulting with a healthcare provider experienced in treating hydatid disease is crucial for determining the most appropriate course of action.

5 Prevention Tips to Avoid Hydatid Disease

1. Practice good hygiene: Wash your hands thoroughly with soap and water after handling dogs, especially before eating or preparing food.
2. Deworm dogs regularly: Ensure that dogs, particularly those in close contact with livestock, are dewormed routinely to prevent the spread of tapeworm eggs.
3. Avoid feeding raw offal to dogs: Do not feed dogs raw organs from livestock, as this can perpetuate the life cycle of the parasite and increase the risk of human infection.
4. Wash fruits and vegetables: Thoroughly wash and peel fruits and vegetables, especially if they are consumed raw, to remove any potential tapeworm eggs.
5. Treat and dispose of animal carcasses properly: Ensure proper treatment and disposal of animal carcasses, especially organs (offal), to prevent dogs from accessing and consuming infected material

By following these prevention tips, you can significantly reduce your risk of contracting hydatid disease and protect yourself and your loved ones from this potentially serious parasitic infection.

Final Thoughts

Hydatid disease is a serious parasitic infection that can lead to significant health complications if not diagnosed and treated promptly. Understanding the causes, hydatid disease symptoms, and effective prevention strategies is key to protecting yourself and your family.

Metropolis Healthcare offers advanced diagnostic services, including imaging and serological testing, to aid in the accurate detection of hydatid cysts. With expert care, reliable test results, and appropriate hydatid cyst treatment, managing and overcoming this disease is achievable with timely diagnosis and appropriate care.