Migration route of Strongyloides venezuelensis in rodents.

Infective larvae of Strongyloides venezuelensis were injected into the medial aspect of the thigh of Wistar rats and ddy mice to investigate their distribution within their hosts with the passage of time. The parasite migrated subcutaneously or intramuscularly towards the upper body and gradually arrived in the lung from 45 h post infection (p.i.) in rats and from 42 h p.i. in mice. After the larvae passed through the trachea, they first appeared in the small intestine at 60 h p.i., probably via the oesophagus and stomach. In comparison to the rats, more larvae were recovered from the mice at all times, and a higher concentration of larval localization was observed in the mice. The present study has established a good model of larval migration of S. venezuelensis in rodents, with the migration route apparently different from of Strongyloides ratti, another species found in rodents.