Larva released from the capsule
|( Owen , 1835)|
Trichinella spiralis is a roundworm and the most important representative of the trichinae in Central Europe. It occurs worldwide, but it is not of great importance in tropical areas. T. spiralis causes trichinella , which isnow only rarein Central Europe because of the trichinae examinations . In principle, all mammals are susceptible, but natural infections aremost likelyin carnivores and omnivores such as foxes and pigs . In Central Europe, the red fox is considered to be the most important reservoir for the pathogen. In Germany and Switzerland, the infection in humans must be reported .
Adult males of T. spiralis are 1.4 to 1.6 mm long, have no spiculum and have two small humps above the cloaca . Females are 3 to 4 mm long, the vulva lies roughly in the middle of the esophagus. The anus is at the end of the worm.
T. spiralis is separate from the sexes. After fertilization, the females release live larvae for five days, which enter various organs via lymphatic vessels and then via the host's bloodstream . They are encapsulated in the skeletal muscles and remain infectious for up to 30 years until they calcify and die. Infection occurs through the ingestion of meat containing larvae, whereby the larvae are released in the small intestine, dig into the intestinal mucosa and develop into adults within two days. In the small intestine again fertilization takes place, and five days after infection the females give birth to larvae, which starts the cycle again. The intestinal phase of trichinae is highly dependent on the host. It lasts about a week in domestic dogs, but three or four months in humans.
Encapsulated larvae in the diaphragm of a pig
In Germany, the direct or indirect detection of Trichinella spiralis must be reported by name in accordance with the Infection Protection Act (IfSG) if the evidence indicates an acute infection. The obligation to notify primarily concerns the management of laboratories ( IfSG).
In Switzerland, the positive laboratory analysis findings to be Trichinella spiralis laboratory reportable namely after the Epidemics Act (EpG) in connection with the epidemic Regulation and of the Regulation of EDI on the reporting of observations of communicable diseases of man .
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