What Is Echinococcosis?

Echinococcosis is a serious tapeworm infection that can affect humans. Exposure to the responsible parasite, a worm of the Echinococcus species, often occurs when a person consumes food tainted by the worm in its larval stage. Symptoms of echinococcosis are intense and can quickly become life-threatening, so prompt medical treatment is key to a good prognosis. Depending on the larval-stage of the parasite at the time its consumed, surgery may be necessary to remove the resulting parasitic cysts.

It is essential that a diagnosis of echinococcosis, also known as hydatid disease, is made in a timely manner due to the risk for complication. Complete medical, personal and professional histories of the patient are recorded since it is entirely possible exposure could have occurred through means other than food contamination. A blood panel is usually performed to check for markers indicative of bacterial infection contributing to one’s symptoms. Additional imaging tests, including a computerized tomography (CT) scan, may also be conducted to check for cysts in the abdominal region.

Symptoms of hydatid disease are often centered in the digestive tract. Individuals develop abdominal discomfort that is accompanied by fever. Frequently, symptomatic individuals also experience a persistent cough that produces blood-tinged sputum. As infection progresses, chest discomfort and skin irritation may occur. If symptoms are ignored, or treatment is delayed, infection will progress placing the individual at risk for shock and death.

The first approach to echinococcosis treatment involves the administration of drug therapy designed specifically to purge the body of tapeworm infection. Individuals are given an oral anthelmintic medication, such as mebendazole, to take in its entirety over the course of several months. If the individual is diagnosed as having several tapeworm-laden cysts, as may form when multiple eggs remain settled in the digestive tract, surgery may be performed to remove the growths. As with any surgery, removing remaining cysts can carry significant risk depending on their location and numbers.

Echinococcus species granulosus and multilocularis are most commonly responsible for echinococcosis infection. Considered a rare diagnosis in the West, hydatid disease is common throughout areas that include Asia, the Middle East, and the Mediterranean. Exposure to the Echinococcus tapeworm occurs when egg-laden foods are eaten, such as beef and eggs. Once the tapeworm enters the digestive system, it normally settles in the liver, but may also journey to other parts of the body, including the kidneys and spleen.

There are distinct types of hydatid disease determined by the type of tapeworm consumed. According to the Centers for Disease Control and Prevention (CDC), alveolar echinococcosis (AE), also known as alveolococcosis, is associated with the tapeworm multilocularis, which is found in feral animals. Infection transmission can occur through a puncture in the skin, as may occur with a bite, or direct contact with contaminated feces. The second form of echinococcosis, known as cystic echinococcosis, is related to exposure to the granulosus species of tapeworm. The CDC suggests the granulosus worm is more common to domesticated animals and those that are a part of the food chain, such as pigs and cattle.