Species Of Raillietina Research Articles

Two Cases of Raillietina Infection in Infants in Thailand, with a Discussion of the Taxonomy of the Species of Raillietina (Cestoda) in Man, Rodents and Monkeys

Three well-preserved specimens of tapeworms of the genus Raillietina were obtained by the junior author from children in Bangkok. One worm was passed spontaneously from a 2-year-old child in a liquid stool, without any drug having been administered. This child was the son of a janitor at the Siriraj Hospital and lived in the employee quarters of the hospital, in an urban area. The worm was immediately preserved in 10% formalin. The other 2 worms were spontaneously passed some time previously by a 5-year-old child who was a private patient of a pediatrician in the city. All 3 worms were preserved in formalin, and were in a very good state of preservation when stained and mounted. They were also all remarkably similar both in size and in anatomical features. Since both of the children who harbored the worms lived in urban areas, the most likely reservoir host is a commensal rat of the genus Rattus. Since these worms are in a much better state of preservation than those previously described from man in the Far East, and since the taxonomic status is un-

Raillietina demerariensis (Cestoda), from Proechimys cayennensis trinitatus of Venezuela

Cestodes collected by the Plague Mission to Venezuela 1950, which was sponsored by the Pan American Sanitary Bureau, the Venezuelan Government and the Bureau of Medicine and Surgery, U. S. Navy, were submitted to the writer by Doctor Ernst Schwarz, U. S. Naval Medical School, Bethesda, Md., for study and identification. The worms were found in the small intestine of a hystricomorph rodent, Proechimys cayennensis trinitatis (Or. No. 158; male; from Campamento Raphael Rangel, Sierra Maestra, Estado Aragua, Venezuela; altitude 1260 meters; collected by E. Schwarz, J. M. Amberson, H. K. Schwarz, July 27, 1950). Members of the genus Proechimys are found in tropical forest in Central and South America from Nicaragua to southern Brazil. Grateful acknowledgment is made to Doctor Schwarz for the opportunity to study this material. The tapeworms are referable to the genus Raillietina and to the subgenus Raillietina in which the genital pores are unilateral and each egg-capsule contains more than one egg. Specific determination, however, presents a very difficult problem. The genus Raillietina is cosmopolitan in distribution; the worms infect birds and mammals and have been reported repeatedly from man. In a review of the genus, Hughes and Schultz (1942) listed 226 described species and many others have since been added. In human hosts the worms have been found only sporadically, in widely separated localities, and usually in small numbers. Joyeux and Baer (1929) postulated that rare cestodes of man are accidental infections by species naturally parasitic in other animals, especially rodents, which live in the same areas. The first report of human infection by a species of Raillietina was given by Davaine (1870)* who described Taenia madagascariensis from two specimens passed by children living on the Comores islands near Madagascar. Blanchard (1891) transferred the species to the genus Davainea, and Fuhrmann (1920) included it in the new genus Raillietina. This or other closely related species have been reported from man and rats at various places in southern and eastern Asia. Leuckart (1891) reported it from man in Siam and Garrison (1911) from man in the Philippine Islands. The earlier accounts pertained to human infections but, as wild animals were examined for parasites, many species of Raillietina were described from birds and mammals of the Eastern Hemisphere (see Meggitt and Subramanian, 1927). L6pez-Neyra (1930, 1931) suggested that many of the species described from Africa and Asia represent varieties of a single species which infects rodents and occasionally man. Narihara (1935) reported R. miadagascariensis from both men and rats in Formosa, and Miyazaki (1950) found the species in Rattus norvegicus and R. rattus in Japan. Joyeux and Baer (1936) found specimens of

A New Human Helminthic Infection in Cuba

Since 1935 we have found in eleven human cases a species of CYCLOPHYLLIDEA not previously reported in Cuba. After studying the first few specimens, we thought that we had found a new species of Raillietina.2 Later, with the kind cooperation of Professor J. G. Baer, study of new material containing scoleces caused us to rectify our first impression. According to Professor Baer, this species, possibly new, must be placed in the Genus Inermicapsifer Janicki, 1910; Subfamily LINSTOWINAE Fuhrmann, 1907; Family ANOPLOCEPHALIDAE, Fuhrmann 1907. The characteristics of this cestode are as follows: