Transmission ways of Echinococcus granulosus in rare muscular locations of hydatid disease.

The most common modality of transmission of the Echinococcus granulosus is through the alimentary tract. Other ways of infestation are questionable. Airborne penetration of bronchial venules to reach the heart and the systemic circulation has been advocated, but never demonstrated. Direct subcutaneous contamination through an injured skin has also been considered. Moreover, the hypothesis that a contamination different from eggs ingestion is not possible, is justified by the reason that eggs transform into larvae in the gastro-intestinal environment. Therefore, it is accepted the possibility that parasites might reach organs and tissues other than liver and lungs through a lymphatic or venous shunt that skip the portal filter. In cases of myocardial muscle or skeletal muscle involvement, it could be speculated that eggs of Echinococcus granulosus might hatch not only in the gastrointestinal tract, but also in soft tissues due to the lactic acid produced by the muscle. These unconventional ways of transmission suggest that the lifecycle of the Echinococcus is not at all known and must be revised. Issues that can help in ideating new therapies may emerge.