Memórias do Instituto Oswaldo Cruz
Print version ISSN 0074-0276
On-line version ISSN 1678-8060
PACO, Julieta Machado; CAMPOS, Dulcinéa Maria Barbosa and OLIVEIRA, Jayrson Araújo de. Wild Rodents as Experimental Intermediate Hosts of Lagochilascaris minor Leiper, 1909. Mem. Inst. Oswaldo Cruz [online]. 1999, vol.94, n.4, pp.441-449. ISSN 0074-0276. http://dx.doi.org/10.1590/S0074-02761999000400003.
A total of 25 specimens of Cavia porcellus (guinea pig), 5 Dasyprocta agouti (agouti), and 22 Calomys callosus (vesper mice) were inoculated with infective eggs of Lagochilascaris minor. The inoculum was prepared with embryonated eggs and orally administered to each individual animal through an esophagus probe. In parallel, 100 specimens of Felis catus domesticus were individually fed with 55-70 nodules containing 3rd-stage larvae encysted in tissues of infected rodents. Animals were examined and necropsied at different time intervals. The migration and encystment of L3 larva was observed in viscera, skeletal muscle, adipose and subcutaneous tissues from all rodents. Adult worms localized at abscesses in the cervical region, rhino, and oropharynx were recovered from domestic cats inoculated with infected rodent tissues. Through this study we can conclude that: (1) wild rodents act as intermediate hosts, characterizing this ascarid heteroxenic cycle; (2) in natural conditions rodents could possibly act as either intermediate hosts or paratenic hosts of Lagochilascaris minor; (3) despite the occurrence of an auto-infecting cycle, in prime-infection of felines (definite hosts) the cycle is only completed when intermediate hosts are provided; and (4) in the wild, rodents could serve as a source of infection for humans as they are frequently used as food in regions with the highest incidence of human lagochilascariasis.
Keywords : Lagochilascaris minor; heteroxenic cycle; intermediate host; paratenic host.