Fate of Litomosoides carinii adults transplanted into the pleural or peritoneal cavity of infected and naive multimammate rats (Mastomys natalensis).

In each of 4 experiments, 58 multimammate rats (Mastomys natalensis) were subdivided into 5 groups. Thirty-four rats were infected with Litomosoides carinii and infections were allowed to become patent. Ten days after patency adult worms were surgically transferred from donor rats to each of 1 group of infected rats and 1 group of naive rats. Groups of infected and naive rats served as controls. Transfers were made either intrapleurally or intraperitoneally. Samples of blood and tissues were taken from each of 2 animals necropsied from each group at intervals to 31 days. At necropsy, the transferred worms and the original population (if any) were examined and samples were fixed. Infected rats accepted new worms with a minimum of reaction while naive rats rejected worms beginning at day 10 (intrapleural) of 17 (intraperitoneal). Rejections were complete leaving a white fibrous mass by day 24 or 31, respectively. Hemagglutination antibody titers fell into 2 groups: infected and naive. IHA titers of naive recipient rats increased into the infected range by day 3 (intrapleural) or day 10 (intraperitoneal). Microfilaria counts presented a more varied pattern but a similar lag in the intraperitoneal recipient group was observed. It was concluded that a preparation period is necessary for successful residence of adult worms, and that this preparation is not restricted to the pleural cavity.