title: Calodium hepaticum (Nematoda: Capillariidae) in synanthropic rodents (Rattus norvegicus and Rattus rattus) in Eastern Amazonia.
abstract: Calodium hepaticum (syn. Capillaria hepatica) is a trichurid nematode that parasitizes the hepatic parenchyma of rodents and other mammals. Infections in humans are rare, although they have been reported worldwide. A number of factors contribute to the distribution of this zoonosis, particularly the presence of dense populations of rodents associated with relatively poor urban environments, such as those found in parts of the northern Brazilian city of Belém in the eastern Amazon Basin. This study quantified Calodium infections in commensal synanthropic rodents in Belém. Rodents were captured in three neighborhoods characterized by poor public sanitation and the city's highest incidence of human leptospirosis. A total of 50 rodents were captured (26 Rattus rattus and 24 R. norvegicus), and 23 (10 R. rattus and 13 R. norvegicus) presented macroscopic lesions typical of C. hepaticum. Light microscopy of fresh samples and histological specimens permitted the identification of larvae and adult specimens containing numerous eggs with a double-striated shell and bipolar opercula with plugs. This is the first report of C. hepaticum in R. rattus and R. norvegicus from the Amazon Basin, and it shows a considerable risk of transmission to the local human population.
authors.affiliation: Laboratório de Biologia Celular e Helmintologia Profa. Dra. Reinalda Marisa Lanfredi, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, PA, Brazil.
authors.forename: Vera Lúcia Coimbra
authors.initials: VL
authors.lastname: Moreira
authors.forename: Elane Guerreiro
authors.initials: EG
authors.lastname: Giese
authors.forename: Djane Clarys Baía da
authors.initials: DC
authors.lastname: Silva
authors.forename: Francisco Tiago de Vasconcelos
authors.initials: FT
authors.lastname: Melo
authors.forename: Adriano Penha
authors.initials: AP
authors.lastname: Furtado
authors.forename: Arnaldo
authors.initials: A
authors.lastname: Maldonado
authors.forename: Jeannie Nascimento dos
authors.initials: JN
authors.lastname: Santos
mesh_terms: D000818:Animals; D001938:Brazil; D002195:Capillaria / Q000502:physiology*; D017189:Enoplida Infections / Q000662:veterinary*; D005260:Female; D008297:Male; D051381:Rats / Q000469:parasitology*