Hydatid (Echinococcal) Cyst Disease Causes Symptoms and Treatment

Hydatid disease (also known as cystic echinococcosis) is a parasitic infection that can pose a serious risk to human health. It is caused by the larval stage of a parasite known as Echinococcus granulosus, which leads to the formation of fluid-filled cysts in various organs of the body, particularly the liver and lungs. Other organs, such as the brain and bones, may also be affected.The danger of this disease lies in the fact that these cysts can grow gradually without causing noticeable symptoms during the early stages. As they enlarge, however, they may begin to cause health problems that vary depending on their location and size.Infection usually occurs through the ingestion of parasite eggs found in contaminated food or water, or through contact with infected dogs or environments contaminated by their feces. Therefore, understanding the causes and symptoms of hydatid disease is essential for early detection and reducing the risk of complications.In this article from Dalili Medical, we explore how the infection spreads, which groups are most at risk, the main diagnostic methods, available medical and surgical treatments, and the most important tips for preventing the disease.

What Is Hydatid Disease (Cystic Echinococcosis)?

Hydatid disease is a parasitic infection caused by the larval stage of small tapeworms known as Echinococcus. The infection leads to the formation of fluid-filled cysts in various organs of the body, particularly the liver and lungs. Other organs, such as the brain, heart, and bones, may also be affected.

Is Hydatid Disease Contagious?

Yes. The parasite that causes the disease can spread from infected animals and contaminated environments to humans, mainly through the ingestion of parasite eggs in contaminated food or water. However, the disease is not usually transmitted directly from one person to another through touching or close contact.

Can Hydatid Cysts Cause Abdominal Pain?

Yes. Hydatid cysts may cause pain in the upper-right part of the abdomen, particularly when they develop in the liver and increase in size, putting pressure on surrounding tissues and organs. The pain may be accompanied by other symptoms, such as nausea, vomiting, and abdominal bloating.

Can Hydatid Cysts Affect the Brain?

Yes. Hydatid cysts can develop in the brain, although this is less common than liver or lung involvement. Brain cysts may cause neurological symptoms, such as headaches, seizures, vision and balance problems, and weakness in the limbs. In advanced cases, they may also lead to increased intracranial pressure.

Causes of Hydatid Disease (Cystic Echinococcosis)

Hydatid disease develops when Echinococcus eggs enter the human body, usually through contaminated food or water or through contact with contaminated environments. The main factors that increase the risk of infection include:

1. Contact with infected dogs: Handling dogs carrying the parasite, especially without washing hands thoroughly afterward or after contact with their feces, which may contain parasite eggs.

2. Eating contaminated food: Consuming fruits and vegetables that have not been washed properly and may be contaminated with parasite eggs from the feces of infected animals.

3. Drinking contaminated water: Consuming untreated or unclean water that may contain parasite eggs as a result of contamination with infected animal feces.

4. Poor personal hygiene: Failing to wash hands with soap and water after handling animals or before preparing and eating food increases the risk of transferring parasite eggs to the mouth.

5. Contact with contaminated soil: Handling soil that may contain parasite eggs, which can then be transferred to the mouth through contaminated hands, particularly when proper hygiene practices are not followed.

6. Keeping dogs in unsanitary environments: The risk of parasite transmission increases in areas where dogs, sheep, and livestock are raised without appropriate veterinary and preventive measures, such as regular animal screening and the safe disposal of animal waste.

Types of Hydatid Disease (Cystic Echinococcosis)

Hydatid disease is classified into several types based on the species of Echinococcus responsible for the infection and the way the cysts develop inside the body. The main types include:

1. Cystic Echinococcosis

This is the most common type of hydatid disease. It is caused by the parasite Echinococcus granulosus and leads to the formation of fluid-filled cysts that grow slowly and gradually inside the body, particularly in the liver and lungs. Other organs, such as the brain, heart, kidneys, and bones, may also be affected.

These cysts may remain symptom-free for long periods. Symptoms may gradually develop as the cysts enlarge and begin to put pressure on surrounding tissues and organs.

2. Alveolar Echinococcosis

This type is caused by Echinococcus multilocularis. It is characterized by the irregular growth of parasitic vesicles within the affected organ, in a pattern that resembles tumor growth, with the potential to spread into nearby tissues.

It primarily affects the liver but may also spread to other organs, including the lungs and brain. Its danger lies in its ability to infiltrate surrounding tissues and spread to other parts of the body, making early diagnosis and specialized treatment particularly important.

3. Polycystic Echinococcosis

This type is caused by Echinococcus vogeli and is characterized by the formation of multiple-compartment cysts within affected organs, particularly the liver. Other organs may also be involved.

It is relatively rare and is more common in certain regions of Central and South America. Its transmission is associated with the parasite's life cycle between wild animals and dogs.

Symptoms of Hydatid Disease (Cystic Echinococcosis)

Symptoms of hydatid disease vary from person to person depending on where the cysts develop, their size, and the extent to which they affect the involved organs. The disease may cause no noticeable symptoms during its early stages, particularly when the cysts are small. Symptoms may then develop gradually as the cysts grow and put pressure on surrounding tissues.

The most common symptoms of hydatid disease include:

1. Abdominal pain: This often occurs in the upper-right part of the abdomen when the liver is affected, as the growing cyst puts pressure on surrounding tissues.

2. Abdominal swelling: This may occur when hydatid cysts increase in size and press on nearby organs, particularly when large cysts develop in the liver.

3. Nausea and vomiting: Some patients may experience nausea and vomiting, sometimes accompanied by loss of appetite and discomfort, particularly after eating.

4. Weight loss: Unexplained weight loss may occur, especially in advanced cases or when the function of affected organs is impaired.

5. Jaundice (yellowing of the skin and eyes): This may develop when cysts compress the bile ducts, obstructing the flow of bile and causing bile substances to accumulate in the body.

6. Coughing and shortness of breath: These symptoms may occur when the lungs are affected by hydatid cysts. Patients may experience difficulty breathing or a persistent cough.

7. Chest pain: Patients may experience chest pain or a feeling of heaviness when cysts develop in the lungs or near other structures in the chest. Shortness of breath may also occur.

8. Fever and general fatigue: Some patients may develop a fever and feel tired or exhausted, particularly if inflammation or cyst-related complications occur.

9. Headaches and neurological symptoms: These may develop when hydatid cysts affect the brain. Symptoms can include headaches, seizures, limb weakness, and vision or balance problems, depending on the cyst's location and size.

10. Bone pain: This may occur when the bones are affected. It can be accompanied by weakened bone structure and an increased risk of fractures.

11. Severe allergic reactions: These may occur if the cyst ruptures or its contents leak, triggering allergic symptoms such as skin rash, itching, and swelling. In some cases, the reaction may progress to life-threatening anaphylactic shock.

Symptoms of Hydatid Disease According to the Affected Organ

The symptoms of hydatid disease vary depending on the organ in which the parasite develops. The most common symptoms associated with each affected organ include:

Affected Organ	Main Symptoms
Liver	Pain in the upper-right part of the abdomen, nausea, vomiting, and jaundice in some cases.
Lungs	Persistent cough, chest pain, shortness of breath, and sometimes coughing up blood.
Brain	Headaches, seizures, and movement, vision, and balance disorders.
Bones	Bone pain, weakened bone structure, and an increased risk of fractures.
Heart	Chest pain, heart rhythm disturbances, and impaired heart function in some cases.

Medical Treatment of Hydatid Disease (Cystic Echinococcosis)

Medical treatment for hydatid disease depends on several factors, including the species of parasite responsible for the infection, the size and location of the cyst, its stage of development, and the extent to which the infection has spread throughout the body. The aim of medication is to weaken the parasite and limit its activity and cyst growth. In some cases, treatment may also help reduce cyst size or prevent disease progression.

Medication may be used on its own in selected cases. It may also be prescribed before or after surgery to reduce the risk of persistent infection or recurrence. The main medications used include:

1. Albendazole

Albendazole is one of the most important and widely used medications for treating hydatid disease. It belongs to the benzimidazole class of antiparasitic drugs.

The medication works by disrupting the formation of microtubules inside parasite cells. This interferes with glucose absorption and utilization, depleting the parasite's energy stores and weakening it, thereby reducing the viability of the parasitic cysts.

Albendazole may be used in several situations, including:

• Treating selected cases of active hydatid cysts, depending on their stage, size, and location.

• Treating patients for whom surgery or certain interventional procedures are not suitable.

• Administering it before or after certain therapeutic procedures, according to the treatment plan determined by the physician.

• Treating alveolar echinococcosis, which may require long-term treatment.

Patients require regular monitoring of liver function and complete blood counts during treatment because albendazole may cause elevated liver enzyme levels or a reduction in certain blood cell counts, particularly when used for extended periods.

2. Mebendazole

Mebendazole is an antiparasitic medication used to treat worm infections. It belongs to the same drug class as albendazole.

The medication works by disrupting microtubule formation inside parasite cells, affecting the parasite's ability to absorb and utilize nutrients. This weakens the parasite and limits its growth.

Mebendazole has been used to treat hydatid disease and may be considered an alternative to albendazole in selected cases. However, it is less commonly preferred in many treatment protocols because of differences in its absorption and effectiveness.

3. Praziquantel

Praziquantel is an antiparasitic medication that may be used in certain cases in combination with albendazole, depending on the physician's assessment and the nature of the infection.

It may be added to the treatment plan in specific circumstances, such as certain cases requiring surgery or when there is a risk of hydatid cyst contents leaking, to help target released parasitic elements.

However, praziquantel is not considered a standard standalone treatment for hydatid disease, nor is it routinely prescribed to all patients. Its use is limited to selected cases determined by a specialist.

Surgical Treatment of Hydatid Disease (Cystic Echinococcosis)

Surgery is an important treatment option in selected cases of hydatid disease, particularly when cysts are large, exert pressure on surrounding organs and tissues, or cause complications that threaten the function of the affected organ.

The choice of surgical procedure depends on the cyst's location and size, the number of cysts, the extent to which they are attached to surrounding tissues, and the patient's overall health. Surgery aims to remove the parasitic cysts or drain their contents and manage the remaining cavity, while minimizing the risk of cyst-content leakage and parasite spread.

The main surgical procedures include:

First: Hydatid Cyst Removal Surgery (Hydatid Cyst Surgery)

This procedure is used to remove a hydatid cyst from the affected organ, particularly when it is large, puts pressure on surrounding tissues, or causes complications. During surgery, the surgeon takes precautions to prevent the cyst contents from leaking into nearby tissues, reducing the risk of parasite spread and allergic reactions.

How the procedure is performed:

1. The patient is placed under general anesthesia.

2. The surgeon makes an incision to access the affected organ, such as the liver or lung.

3. The cyst is isolated from the surrounding tissues, with precautions taken to prevent its contents from leaking.

4. The surgeon removes the cyst or its parasitic membranes, depending on its location and how closely it is attached to surrounding tissues.

5. The remaining cavity is examined, and any bleeding or bile leakage is managed, particularly in cases involving the liver.

6. The surgical incision is closed after potential complications have been addressed and the patient's condition is stable.

Second: Hydatid Cyst Removal with Partial Resection of the Affected Organ (Partial Organ Resection)

In some cases, the cyst may need to be removed along with part of the affected organ, particularly when it is embedded in the surrounding tissues, has caused extensive tissue damage, or cannot be removed separately.

This procedure may be used in certain cases involving the liver or lungs. It may involve removing part of the liver or one of the lung lobes, depending on the extent of the disease and the cyst's location.

How the procedure is performed:

1. The patient is placed under general anesthesia.

2. The surgeon makes an incision to access the affected organ.

3. The cyst's location and the boundaries of the surrounding damaged tissue are identified.

4. The cyst is removed along with the affected portion of the organ, while preserving as much healthy tissue as possible.

5. Bleeding is controlled, and the remaining tissues and their function are assessed.

6. The surgical incision is closed, and the patient is monitored medically after the procedure.

Third: Cyst Evacuation

This procedure is used when complete cyst removal is difficult or may result in damage to blood vessels, surrounding tissues, or adjacent organs.

It aims to drain the fluid inside the cyst and remove the parasitic membranes and daughter cysts, while managing the remaining cyst wall and cavity according to the condition of the affected organ.

How the Procedure Is Performed:

1. The patient receives the appropriate anesthesia, and the surgeon accesses the cyst through a surgical incision.

2. The surrounding area is isolated using special protective techniques to minimize the risk of cyst content spillage.

3. The fluid inside the cyst is aspirated using specialized surgical instruments and suction devices.

4. The parasitic membranes and daughter cysts are removed.

5. The remaining cavity is examined for possible openings or leaks, particularly bile leakage in cases involving liver cysts.

6. The surgeon determines the appropriate management of the residual cavity, which may include reducing its size, placing a drain, or performing an additional surgical procedure as needed.

Fourth: Partial Cystectomy / Unroofing

This procedure is also known as cyst unroofing. It is used in certain cases of hepatic hydatid cysts when complete removal is not appropriate, particularly when part of the cyst wall is firmly attached to major blood vessels or adjacent organs.

The procedure aims to remove the protruding portion of the cyst wall after draining its contents and removing the parasitic membranes, while leaving the attached portion in place to avoid damaging surrounding structures.

How the Procedure Is Performed:

1. The patient receives general anesthesia.

2. The surgeon accesses the hydatid cyst through an appropriate surgical incision.

3. The cyst is isolated from the surrounding tissues, with precautions taken to prevent leakage of its contents.

4. The cyst is drained, and the parasitic membranes and internal daughter cysts are removed.

5. The protruding portion of the cyst wall is excised, while the parts attached to major blood vessels or adjacent organs are preserved when necessary.

6. The remaining cavity is examined for possible bile leakage or bleeding.

7. The surgeon determines whether the residual cavity requires drainage or an additional procedure, then completes the operation according to the patient's condition.

Fifth: Total Pericystectomy

This operation aims to remove the entire hydatid cyst, including its surrounding fibrous pericyst, while preserving as much healthy tissue of the affected organ as possible.

It is performed in selected cases of hepatic hydatid cysts when the cyst's location and its relationship with the blood vessels and bile ducts allow safe removal.

How the Procedure Is Performed:

1. The patient receives general anesthesia.

2. The surgeon accesses the cyst and identifies its boundaries and relationship with the surrounding tissues and adjacent organs.

3. The fibrous pericyst is carefully separated from the tissue of the affected organ.

4. The cyst and its surrounding fibrous layer are completely removed whenever this can be achieved safely.

5. Any bleeding is controlled, and the surgical site is examined for possible bile leakage.

6. The incision is closed, and the patient's condition is monitored after surgery.

Sixth: Laparoscopic Hydatid Cyst Surgery

Laparoscopic surgery is one of the surgical techniques used to treat selected cases of hydatid disease, particularly hepatic cysts whose location and characteristics make them suitable for this approach.

The procedure is performed through small incisions in the abdominal wall rather than a large surgical incision. In appropriately selected patients, this approach may help reduce postoperative pain and shorten recovery time.

How the Procedure Is Performed:

1. The patient receives general anesthesia.

2. Several small incisions are made in the abdominal wall.

3. A camera and specialized surgical instruments are inserted to access the cyst.

4. The area surrounding the cyst is isolated using protective techniques to minimize leakage and parasite dissemination.

5. The cyst is drained, and its parasitic membranes and daughter cysts are removed, or the cyst is excised depending on the nature of the case.

6. The residual cavity is managed, and the surgical site is examined for bile leakage or other complications.

7. The instruments are removed, and the small incisions are closed.

Laparoscopic surgery is not suitable for all patients. It may not be the best option for complex cysts, cysts firmly attached to vital organs or major blood vessels, or cases associated with severe complications. The surgeon determines its suitability based on the cyst's location, size, characteristics, and the patient's overall condition.

Seventh: Percutaneous Cyst Drainage (PAIR)

PAIR is an abbreviation for four essential steps: Puncture, Aspiration, Injection, and Re-aspiration.

It is a minimally invasive medical procedure rather than open surgery and is used in selected cases of hydatid disease, particularly certain hepatic cysts.

How the Procedure Is Performed:

1. The location and size of the hydatid cyst are identified using ultrasound or computed tomography (CT).

2. A fine needle is inserted through the skin into the cyst under imaging guidance.

3. Part of the fluid inside the cyst is aspirated.

4. A parasiticidal agent is injected into the cyst according to a specific medical protocol.

5. The cyst contents are aspirated again after the appropriate interval.

6. The cyst is monitored using medical imaging to assess its response to the procedure.

Substances that may be used during this procedure include hypertonic saline or ethanol, depending on the medical protocol and cyst type.

Important Note: PAIR is not suitable for all hydatid cysts. It is generally contraindicated when there is communication between the cyst and the bile ducts. The procedure must be performed by a specialized medical team with appropriate facilities to manage potential complications, such as cyst content leakage or severe allergic reactions.

Albendazole may be administered alongside the procedure in appropriate cases, according to the physician's assessment.

Eighth: Surgery for Pulmonary Hydatid Cysts

Hydatid cysts affecting the lungs may require surgical intervention, particularly when they increase in size, cause symptoms such as shortness of breath and persistent coughing, or rupture into the bronchi.

The type of operation depends on the cyst's size, the extent of damage to the surrounding lung tissue, and the presence or absence of complications. Surgical options include:

• Cyst Removal with Preservation of Lung Tissue: This procedure aims to remove the cyst and its parasitic membranes while preserving as much healthy lung tissue as possible.

• Wedge Resection: This may be performed in selected cases where the cyst is associated with localized damage to the surrounding lung tissue.

• Lobectomy: This may be necessary in advanced cases involving severe damage or extensive destruction of an entire lung lobe.

How the Procedure Is Performed:

1. The patient receives general anesthesia.

2. The surgeon accesses the affected lung through a chest incision or, in suitable cases, using video-assisted thoracoscopic surgery (VATS).

3. The cyst and surrounding tissues are isolated using protective techniques to minimize leakage and prevent the spread of its contents into the chest cavity.

4. The cyst is drained, and the parasitic membranes and daughter cysts are removed while preserving healthy lung tissue whenever possible.

5. Any openings or communications between the cyst and the bronchi are closed, if present.

6. The surgical site is examined to ensure that leakage and bleeding are controlled, and a chest drain is inserted when necessary.

Surgery is one of the main treatment options for many cases of pulmonary hydatid disease, particularly active cysts that can be surgically removed. The appropriate intervention is determined according to the patient's condition and the characteristics of the infection.

Ninth: Surgery for Cerebral Hydatid Cysts

Hydatid cysts affecting the brain require careful evaluation by a neurosurgeon because they may increase intracranial pressure or compress brain tissue, potentially causing symptoms such as headaches, seizures, movement disorders, and visual disturbances.

The primary goal of surgical intervention is to remove the cyst while preserving the surrounding brain tissue as much as possible and avoiding cyst rupture during the operation. Leakage of the cyst contents may lead to parasite dissemination or a severe allergic reaction.

How the Procedure Is Performed:

1. The patient receives general anesthesia.

2. A surgical opening is made in the skull (craniotomy) to access the cyst.

3. The surgeon identifies the cyst's location and its relationship with the brain tissue, blood vessels, and adjacent neurological structures.

4. The appropriate surgical technique is used to carefully release and remove the cyst while avoiding rupture as much as possible.

5. The surgeon ensures that the cyst has been completely removed whenever possible without damaging healthy brain tissue.

6. The membranes surrounding the brain, the skull, and the surgical wound are closed.

7. The patient is monitored after surgery through neurological examinations and medical imaging to evaluate the surgical outcome and detect potential complications.

The surgical approach depends on the cyst's size, location, depth, and relationship with the surrounding neurological structures. Some cases may require specialized techniques to remove the cyst intact without causing rupture.

Tenth: Surgery for Hydatid Cysts of the Heart, Bones, and Other Organs

The surgical management of hydatid cysts varies depending on the affected organ, cyst size, extent of spread, and impact on organ function. Surgical interventions may include the following:

• Cardiac Hydatid Cysts: These may require cardiac surgery to remove the cyst, with careful precautions to prevent rupture or leakage of its contents into the bloodstream, given the risk of serious cardiac arrhythmias and embolic complications.

• Bone Hydatid Cysts: Treatment may involve removing the affected bone and tissues and cleaning the infected area. Bone reconstruction or stabilization may also be necessary, depending on the extent of damage.

• Renal Hydatid Cysts: The cyst may be removed while preserving healthy kidney tissue, or partial nephrectomy may be performed. In cases of severe damage, removal of the affected kidney (nephrectomy) may be necessary.

• Splenic Hydatid Cysts: Treatment may involve cyst removal or partial splenectomy. Total splenectomy may be required when the size or location of the lesion makes spleen preservation unsuitable.

The medical team determines the most appropriate surgical intervention after evaluating the condition through imaging and other necessary investigations, while prioritizing the preservation of the affected organ's function whenever possible.

Eleventh: Radical Surgery for Alveolar Echinococcosis

The treatment of alveolar echinococcosis differs from that of conventional cystic echinococcosis (CE). This type of infection is characterized by infiltrative growth of the parasite within liver tissue, resembling tumor growth, and may extend into adjacent organs and structures.

In cases where the infection is localized and surgically resectable, radical surgery may be performed to remove the entire parasitic lesion, leaving an adequate margin of healthy tissue around it to minimize the possibility of residual parasitic tissue.

How the Procedure Is Performed:

1. The patient receives general anesthesia.

2. The surgeon accesses the liver and assesses the extent of the infection and its relationship with the blood vessels, bile ducts, and adjacent organs.

3. The affected portion of the liver is removed along with the parasitic lesion, depending on the extent of disease.

4. The infected tissue is completely excised, aiming to achieve an adequate surgical margin whenever possible.

5. The removed tissue is examined, and the resection margins are assessed to confirm that the infection has been removed as completely as possible.

6. The patient is monitored after surgery and continues long-term albendazole treatment according to the physician's recommendations to reduce the risk of disease recurrence or progression.