Cockroaches as vectors of Sarcocystis muris and of other coccidia in the laboratory.

To assess the roles of the German cockroach (Blatella germanica) and the American cockroach (Periplaneta americana) in the transmission of Sarcocystis muris and of 3 other coccidia of cats-Toxoplasma gondii, Isospora felis, and Isospora rivolta, cockroaches exposed to feces containing these coccidia were periodically fed to mice, as was a portion of the fecal matter. Sarcocystis muris sporocysts, which in feces remained infectious for at least 20 days, were also transmitted to mice by P. americana for at least 20 days and by B. germanica for 5 days after exposure to infectious feces. Toxoplasma gondii oocysts were transmitted by P. americana intermittently up to 10 days, but by B. germanica only immediately after exposure to feces. Oocysts of 2 species of Isospora, when associated with fecal matter, remained infectious for 20 days. Those of I. rivolta were transmitted by both cockroach species for 10 days, but I. felis was transmitted only by by B. germanica, and for only 2 days.