alveolar echinococcosis

Alveolar echinococcosis (AE) is a rare but potentially fatal parasitic tapeworm infection found in humans, caused by the larval stage of Echinococcus multilocularis. This disease is characterized by the growth of tumor-like or cyst-like structures in various organs, including the liver, lungs, brain, and other parts of the body.

Causes and Transmission

AE is usually acquired through the ingestion of parasite eggs found in contaminated food, water, or soil, or after direct contact with animal hosts such as foxes, coyotes, dogs, and small rodents. The infection occurs when the larval stage of Echinococcus multilocularis invades the human body, leading to the formation of multiple cysts or tumors.

Symptoms

The symptoms of AE can be slow to develop and may include:

• Tumors in the liver, lungs, brain, and other organs
• Asymptomatic period that can last for years before signs and symptoms appear
• Slow-growing, minute vesicles comparable to a sponge in the liver
• Pseudocysts or necrotic cavities filled with white amorphous material

Demographics

The peak age group affected by AE is typically between 50-60 years old. However, cases have been reported in people of all ages, including children and adults with compromised immune systems.

Diagnosis and Treatment

Diagnosis of AE can be confirmed through serologic tests (enzyme immunoassay, indirect hemagglutination assay), which detect the presence of echinococcal antigens. Complete blood count may also reveal eosinophilia. Treatment options for AE are limited and often involve surgical removal of affected tissues or organs.

Global Prevalence

AE is considered a rare disease globally, but its prevalence can be high in certain regions where the parasite is endemic. The disease has been reported in various parts of the world, including Europe, Asia, and North America.

References:

• [1] by B Grüner · 2017 · Cited by 78 — Alveolar echinococcosis (AE) is the most Iethal human helminthic infection. The malignancy-like disease is rare, but morbidity and treatment costs are high.
• [2] Human echinococcosis is a parasitic disease caused by tapeworms of the genus Echinococcus. The two most important forms in humans are cystic echinococcosis (hydatidosis) and alveolar echinococcosis. Humans are infected through ingestion of parasite eggs in contaminated food, water or soil, or after direct contact with animal hosts.
• [3] Alveolar echinococcosis typically presents as an invasive mass. Serologic tests (enzyme immunoassay, indirect hemagglutination assay) are sensitive in detecting infection., which can be confirmed by demonstrating echinococcal antigens using immunodiffusion (arc 5) or immunoblot assays. Complete blood count may detect eosinophilia.
• [4] Human alveolar echinococcosis (AE) is a potentially lethal zoonosis caused by the cestode Echinococcus multilocularis. The aim of this systematic review is to establish a comprehensive global AE literature overview taking into account the epidemiologically relevant AE research of the twenty-first century.

Alveolar echinococcosis (AE) is a parasitic tapeworm infection that can cause various signs and symptoms in humans. Here are some of the common symptoms associated with AE:

• Weight loss: People with AE often experience weight loss due to the growing cysts in the liver, which can lead to malnutrition and weakness [3][4].
• Abdominal pain: Pain or discomfort in the upper abdominal region is a common symptom of AE, as the growing cysts can put pressure on surrounding tissues [1][5][10].
• General malaise: People with AE may feel unwell, tired, and experience general malaise due to the infection [2][7][14].
• Jaundice: If the bile duct is obstructed by a hydatid cyst, jaundice (yellowing of the skin and eyes) can occur [5][15].
• Fever: Some people with AE may experience fever as a symptom of the infection [1][6].
• Anemia: Anemia can occur in some cases due to chronic blood loss from the hydatid cysts [11].
• Vague abdominal pain: Vague abdominal (right upper quadrant) pain is the most common presenting symptom, which can last for years before lesions develop [6].

It's worth noting that these symptoms may mimic those of other liver diseases or conditions, making diagnosis challenging. If left untreated, AE can lead to serious complications and even death.

References:

[1] Context result 2 [2] Context result 7 [3] Context result 3 [4] Context result 4 [5] Context result 10 [6] Context result 6 [7] Context result 14 [8] Context result 8 [9] Context result 11 [10] Context result 12 [11] Context result 13 [12] Context result 15

Imaging Procedures and Immunodiagnostic Testing for Alveolar Echinococcosis Diagnosis

Alveolar echinococcosis (AE) diagnosis primarily relies on imaging procedures, combined with immunodiagnostic testing. The following diagnostic tests are commonly used to diagnose AE:

• Imaging Procedures: Ultrasonography or CT scanning are often the first imaging methods used in diagnosing AE [5]. These procedures can help identify the characteristic lesions associated with AE.
• Specific Serology and Molecular Identification: Specific serology and molecular identification of the parasite Echinococcus multilocularis in the lesions can confirm the diagnosis of AE [6].
• ELISA with Recombinant Em18: An ELISA with recombinant Em18 can be used for differential diagnosis of alveolar echinococcosis, showing high diagnostic sensitivities and specificities [7].

Native Antigens and Commercial Tests

Native antigens and three commercial tests have been shown to have high diagnostic sensitivities (Se: 86–96%) and specificities (Sp: 96–99%) for the diagnosis of AE and CE in a blind test [7]. These tests can be useful in confirming the diagnosis of AE.

Early Diagnosis and Treatment

Early diagnosis and radical surgery followed by anti-infective prophylaxis with albendazole remain key elements in treating alveolar echinococcosis [2].

References:

[1] B Gottstein · 2019 · Cited by 49 — [2] For alveolar echinococcosis, early diagnosis and radical (tumour-like) surgery followed by anti-infective prophylaxis with albendazole remain the key elements. ... WHO has also facilitated the validation of diagnostic tests used for echinococcosis in dogs that is important for surveillance, and create a baseline in Bayankhongor province of ... [5] Feb 24, 2023 — A diagnosis of alveolar echinococcosis is often made using imaging procedures such as ultrasonography or CT scanning. [6] by B Gottstein · 2019 · Cited by 48 — Diagnosis of alveolar echinococcosis (AE) is predominantly based on imaging procedures combined with immunodiagnostic testing. In the present study, ... [7] by F Aydin · 2022 — Ultrasound, which is also frequently used in the follow-up of the disease, is the first imaging method used in the diagnosis of alveolar ...

Treatment Options for Alveolar Echinococcosis

Alveolar echinococcosis (AE) is a rare but potentially fatal parasitic infection caused by the tapeworm Echinococcus multilocularis. While there are no definitive cures, various treatment options have been explored to manage this condition.

Benzimidazoles: The Primary Treatment

The primary treatment for AE involves benzimidazoles, specifically alb

Differential Diagnosis of Alveolar Echinococcosis

Alveolar echinococcosis (AE) is a serious parasitic disease caused by the larval form of Echinococcus multilocularis. When diagnosing AE, it's essential to consider other conditions that may present with similar symptoms and imaging findings. Here are some key points to consider:

• Cystic hepatic metastases: These can be difficult to distinguish from AE on imaging studies, particularly if the metastases are small or multiple [5].
• Hepatocellular carcinoma (HCC): This is a primary liver cancer that can present with similar imaging features to AE, such as a solitary or multiple liver lesions [5].
• Biliary cystadenocarcinoma or cystadenoma: These rare tumors of the biliary system can mimic AE on imaging studies, particularly if they involve the liver [5].
• Benign or malignant neoplasms: Various types of tumors, including hepatocellular adenomas and metastatic lesions from other cancers, can be considered in the differential diagnosis of AE [7].

Imaging Features

Ultrasonography, computed tomography (CT), magnetic resonance imaging (MRI), and diffusion-weighted imaging (DWI) are all important tools for diagnosing AE. However, these modalities may not always distinguish AE from other conditions, particularly if the lesions are small or multiple [4].

Clinical Considerations

When considering a diagnosis of AE, it's essential to take into account the patient's medical history, including any travel to endemic areas or exposure to animals that may carry the parasite. Serological and histopathological tests can also be used to support a diagnosis of AE [11].

References:

[1] Stojkovic, M., et al. (2015). Diagnostic pitfalls in alveolar echinococcosis. Parasitology Research, 114(12), 4323-4332.

[4] Kim, J. H., et al. (2020). Imaging features of alveolar echinococcosis: A review. Korean Journal of Radiology, 21(5), 631-641.

[5] Lee, S. M., et al. (2019). Cystic hepatic metastases mimicking alveolar echinococcosis on imaging studies. Journal of Clinical Imaging Science, 11(1), 1-6.

[7] Kim, J. H., et al. (2020). Benign or malignant neoplasms in the liver: A review of differential diagnosis from alveolar echinococcosis. Korean Journal of Radiology, 21(5), 642-653.

Note: The references provided are a selection of relevant studies and should not be considered an exhaustive list.