Mesocestoides lineatus (Goeze, 1872) is a tapeworm of numerous canida species. Average lenght is 52,12 cm. In Serbia, during epidemiological studies in 1988-2003 we found the parasite in foxes (38,15%) and dogs (2,17%).

Life cycle and transmission: Mesocestoides sp. circulates in two intermediate hosts. The first intermediate host is a coprophagus arthropods (oribatid mites of the genus Trichoribate and Sheloribates). Cysticercoids are produced and when the infected mite is eaten by a second intermediate host a tetrahyridium is formed, and may persist in an encapsulated form. The second intermediate hosts are vertebrate [rabbits, rodents, and other mammals, various birds (especially family Corvidae), reptiles and amphibians]. Dogs, foxes, and other wild carnivores are final hosts, but in some cases they are secondary intermediate hosts too.

Two Mesocestoides species have been recognized as occasional human parasites worldwide, M. variabilis and M. lineatus. Human infection is linked with the accidental and/or deliberate ingestion of raw viscera or blood of second intermediate hosts like quall, rabbits and etc containing the infective metacestode stage (tetrathyridium). Clearly, the presence of these interesting yet poorly understood parasites in the red foxes provides a useful opportunity to study the epidemiology of the tapeworms, especially since it is now recognized as a human pathogen. The first case of human infection was described by Chandler (1942) and later by Fain and Herin (1954) in Rwanda. Other reports of human infection were reported in the Far East, especially in Japan and Korea. Human infection was also reported in USA. Until now, 26 cases concerning humans have been reported: 18 of these were due to M. lineatus (14 in Japan, 2 in Korea, and 2 in China) and 8 were due to M. variabilis or Mesocestoides sp. (6 in United States, 1 in the former Ruanda-Burundi, and 1 in Greenland) ⁴. In all cases the strobilar (adult) form of mesocestoides tapeworms was observed. In Serbia, therefore, where we have a high prevalence of M.lineatus in foxes, we have never described human cases of infection with this tapeworms species.

Figures 1-7: Mature proglottids of Mesocestoides lineatus

Referance PAVLOVIĆ I. (1994): Helmithoses of foxes (Vulpes vulpes L.) hunting at Belgrae area during 1988-1992.years PhD disertation, Fakultet veterinarske medicine u Beogradu PAVLOVIĆ I.,Kulišić Z. , Valter D. (1995): Cestodes of red foxes (Vulpes vulpes L.) hunting in Belgrade area Abstracts of XXV Congress of the World Veterinary Association, Yokohama, Japan, 5-9.9.1995.,111 PAVLOVIĆ I., Kulišić Z., Valter D., Milutinović Marija (1996): The occurence of Mesocestoides lineatus (Goeze, 1772) and Mesocestoides litteratus (Batsch, 1786) in red foxes (Vulpes vulpes L.) hunting in Belgrade area Parasitologia 38 (1-2), 268 FUENTES M. V. A new case report of human Mesocestoides infection in the United States Am. J. Trop. Med. Hyg., 68(5), 2003, pp. 566-567