Echinococcosis is caused by infection with the larval stages of tapeworms (Cestoda) of the genus Echinococcus. The development of all Echinococcus species requires an obligatory host change: carnivores act as final hosts, while intermediate hosts are mostly herbivores.
The sexually mature worms of the small fox tapeworm (Echinococcus multilocularis) (3-4 mm) live in the intestinal tract of carnivores (in Europe mainly the red fox Vulpes vulpes and the raccoon dog Nyctereutes procyonoides; rarely dogs and cats) which shed mature cestode eggs with their faeces into the environment. These eggs are highly resistant to environmental influences and may stay infectious for several months under favourable conditions. Eggs can only be destroyed by brief boiling or by freezing for several days at -80°C.
Intermediate hosts (mainly prey animals of the final hosts, especially Microtidae) ingest the eggs with their food. Larval stages develop in their organs (especially in the liver). Humans can also become infected and act as dead-end intermediate hosts. In both, intermediate and dead-end intermediate host, growth of the larval stages of E. multilocularis results in alveolar echinococcosis: protoscolices develop in small chambers (2-15 mm) filled with a gelatinous substance; budding leads to infiltration and in the end complete pervasion of the liver by larval tissue. Ingestion of prey animals infected with larvae leads to infection of the final host. In humans, untreated alveolar echinococcosis is usually fatal. It is therefore considered to be an „extremely important parasitosis in Central Europe and Germany” (Lucius & Loos-Frank 2008).
Cystic echinococcosis, which is caused by larvae of the small dog tapeworm E. granulosus (5 mm), is less common in Central Europe. Eggs are also shed into the environment with the faeces of the final hosts (carnivores, usually dogs) and remain infectious for several months. The larvae develop in fluid-containing cysts (hydatids), which settle in liver, lung, other organs and the skeletal system of the host organism. The damage caused by these hydatids, which can reach a size of up to 15 cm in diameter, consists in an impairment of the organ function due to the pressure exerted by the strong growth of the cysts (e.g. dyspnoea, accumulation of liquid in bile ducts and portal vein).
Echinococcosis has been notifiable in Germany since 2004.
- Contact for federal and state authorities on questions relating to the epidemiology and control of Echinococcus multilocularis
- Confirmatory testing
- Supply of reference material
- Evaluation, standardization and further development of diagnostic methods
- Participation in the organization of international proficiency tests
- Participation in EU proficiency tests
- Organisation of national proficiency tests
- Training of laboratory staff in echinococcosis diagnostics
- Cooperation in workgroups and research projects