Parasitology, Harold W. Manter Laboratory of
Date of this Version
12-1931
Document Type
Article
Citation
Philippine Journal of Science (December 1931) 46(4): 537-591
Abstract
Summary
Besides the role that they play as carriers and reservoirs of bubonic plague and other bacterial as well as spirochretal infections, rats often harbor parasitic worms, some of which are also a menace to human health. In view of this and because of the fact that the helminthic fauna of rats has never been studied extensively in the Philippine Islands, it seemed desirable to undertake a systematic examination of these animals for the purpose of finding out if they are infested with parasites that are transmissible to man.
The examination of nine hundred fifty rats (Mus norvegicus) resulted in the identification of the following sixteen species of helminths: Trematodes: Euparyphium ilocanum, E. guerreroi, and E. murinum sp. nov.; cestodes: Taenia taeniaformis (larval form), Raillietina garrisoni sp. nov., Hymenolepis diminuta, and H. nana, nematodes: Gongylonema neoplasticum, Hepaticola hepatica, Heterakis spumosa, Nippostrongylus muris, Protospirura muricola, Rictularia whartoni sp. nov., Strongyloides ratti, and Trichosomoides crassicauda; Acanthocephala: Moniliformis moniliformis.
The following parasites of rats have been reported from human beings: Euparyphium ilocanum, Hymenolepis diminuta, H. nana, Syphacia obvelata, Hepaticola hepatica, and Moniliformis moniliformis. The first four species mentioned in this paragraph have been reported to occur in man in the Philippine Islands.
It is also believed that Raillietina garrisoni should be included among the parasites of the rat that are transmissible to man because of its common occurrence and its close morphological resemblance to the human tapeworm described by Garrison in 1911 from the Philippines as Davainea madagascariensis.
The morphology and the life history, if known, of each of the different parasites are given and, in the case of the forms that are transmissible to man, methods of avoiding infestation are discussed.
Addendum
After the manuscript of the above paper was submitted for publication, I found in the literature a description by Hoeppli of a new nematode, Rictularia tani, from the brown rat in Amoy, China, with which Rictularia whartoni Tubangui should be compared. The two forms resemble each other in several important characters, such as, in the number of their cuticular combs and spines, the length of the oesophagus, and the location of the nerve ring, vulva and anus. They differ in the presence of a pair of ventrolateral cuticular dilatations in R. whartoni and m the fact that the last pair of spines of R. whartoni is found behind the anus, that of R. tani occurring in front of that level. Because of these differences it is decided to maintain the Philippine Rictularia as a separate species.
Very recently there also came to hand a paper by Lopez-Neyra that has an important bearing on the discussion of Raillietina garrisoni. I described this as a new species of rat tapeworm for, while recognizing its close alliance to Raillietina celebensis (Janicki) Meggitt and Subramanian, 1927, it differs from the latter in the number of its testes and uterine egg capsules and in the size of its cirrus pouch. I also gave reasons for suspecting its possible identity with Garrison's Davainea madagascariensis which, according to Joyeux and Baer, differs from the specimens described under the same name by other observers. Now, according to Lopez-Neyra, the following represent one and the same species of parasite that should be known as Kotlania madagascariensis (Davaine, 1869): the collections in the Parasitological Laboratory of the University of Paris denominated as Type No. 108 (Davaine), No. 109 (Davaine), No. 8 (Blanchard, Port-Louis) and No. 33 (Nossi-Be, 1873); Taenia madagascariensis Leuckart, 1891; Davainea madagascariensis Garrison, 1911; D. formosana Akashi, 1916; Raillietina celebensis (Janicki) Meggitt and Subramanian, 1927; R. funebris Meggitt and Subramanian, 1927; and possibly R. fluxa Meggitt and Subramanian 1927. If Lopez-Neyra's hypothesis is accepted, then Raillietina garrisoni will have to fall in line with the above synonymy.