Transient retention of Strongyloides ratti in the caecal mucosa during infection in mice.

Adult worms of Strongyloides ratti, after elimination from the small intestine, were retained in the caecum for at least three days during the infection in mice. This retention was a biological event but not due to a simple mechanical trapping in faeces. In addition to the local mucosal mastocytosis, eosinophil infiltration was remarkable in the caecum around day 10 when adult worms were expelled from there.