Experimental infection of Thailand Taenia (Chiengmai strain) in domestic animals.

Twenty-five gravid proglottides of a Thailand Taenia were obtained from a patient in Chiengmai, Thailand, and brought to our laboratory. The tapeworm was determined to be T. saginata-like by counting uterine branches (mean number 16, range 12-19 on each side). The eggs from these proglottides remained infective under storage at room temperature for 14 days followed by refrigeration (4-8 degrees C) for 131 days. Eight Small-Ear-Miniature pigs and two Holstein calves were each fed with 3000 eggs and sacrificed 12-76 days afterwards. Six pigs became infected and 16 cysticerci were recovered from the livers. Thirteen degenerated/calcified cysticerci were also recovered from the livers of the two calves. More cysticerci were found in the liver parenchyma (55%) than on the liver surface (45%) of the infected animals. Measurements of length, width, diameters of protoscolex, rostellum and sucker and hooklet pattern show that Thailand Taenia is similar to Taenia from Taiwan, Korea and Indonesia but different from T. saginata and T. solium. These findings indicate that Thailand Taenia, Taiwan Taenia, Korea Taenia, and Indonesia Taenia may be of the same species or sub-species.