Echinococcosis (ICD-10-GM B67.-: Echinococcosis) is an infectious disease caused by the parasites Echinococcus multilocularis (fox tapeworm) and Echinococcus granulosus (dog tapeworm). The following forms of echinococcosis can be distinguished:
- Alveolar echinococcosis (AE) – caused by Echinococcus multilocularis (fox tapeworm).
- Cystic echinococcosis (ZE) – caused by Echinococcus granulosus (dog tapeworm).
Echinococcus vogeli plays only a minor role in human infections.
Echinococcus multilocularis (fox tapeworm)
Echinococcus multilocularis is a tapeworm two to four millimeters in size. The main host is the fox (red fox), but dogs and cats are also affected.Intermediate hosts are small mammals and lagomorphs. Occurrence: The parasite is distributed worldwide. In Europe, mainly southern Germany (Baden-Württemberg and Bavaria; Ulm and surroundings are considered the “epicenter”), northern Switzerland, western Austria and eastern France are affected. Furthermore, Echinococcus multilocularis is highly endemic in northern China, Siberia and northern Japan. Infections of humans with Echinococcus multilocularis lead to the clinical picture of alveolar echinococcosis (AE). Human-to-human transmission: No. Peak incidence: The mean age of onset is between 50 and 60 years of age. The annual incidence (frequency of new cases) in France, Switzerland, Austria, and Germany is 0.03-0.3 cases per 100,000 population per year; although in certain regional “clusters of infection” the incidence may rise to 8.1/100,000.Of more than 18,000 new cases per year worldwide, about 90% originate in China alone.
Echinococcus granulosis (dog tapeworm)
Echinococcus granulosus is a circa four to seven millimeter tapeworm. Main hosts are the dog and wolf, rarely the cat. Intermediate hosts are usually sheep and cattle; other intermediate hosts are pigs and other livestock. Occurrence: It is distributed worldwide. In Europe, mainly the Mediterranean region as well as the Balkans are affected. Sheep breeding areas in southern and southeastern Europe, in countries of the former Soviet Union, in the Middle East as well as in Asia are particularly affected. Infections of humans with Echinococcus granulosus lead to the clinical picture of cystic echinococcosis (CE). Human-to-human transmission: No. Humans of all ages are affected. The following statements apply to both forms of the causative agent of echinococcosis. Transmission of the pathogen (route of infection) occurs by oral ingestion of the eggs of the parasites and by contact or smear infection (fecal-oral: infections in which pathogens excreted in the feces (fecal) are ingested by mouth (oral)) with the feces or fur of infected animals. The incubation period (time from infection to onset of disease) of alveolar echinococcosis is up to 15 years. The incubation period of cystic echinococcosis ranges from several months to many years. Infections are rare: 25 to 40 new cases are registered annually nationwide. Course and prognosis The course of alveolar echinococcosis is gradual. In more than 90% of cases, the disease leads to death within 10 years if left untreated. However, if the infection is detected in time and treatment is given early and consistently, the disease can be cured. If curative resection (surgical removal aimed at curing the disease), R0 resection (removal of parasite foci in healthy tissue; histopathology shows no parasite foci in the resection margin) of all parasite foci is possible, the 10-year survival rate is close to 100%. Cystic echinococcosis has a relatively benign course. With 70 %, the liver is most frequently affected, but in principle all organs can be affected. In Germany, direct or indirect detection of the pathogen is reportable by name according to the Infection Protection Act (IfSG), insofar as the evidence indicates an acute infection.
