Small Rodents Fleas from the Bubonic Plague Focus Located in the Serra dos Órgãos Mountain Range, State of Rio de Janeiro, Brazil
Vol. 96(5): 603-609, July 2001
Raimundo Wilson de Carvalho/+, Nicolau Maués Serra-Freire/++, Pedro Marcos Linardi*/++, Adilson Benedito de Almeida**, Jeronimo Nunes da Costa**
Laboratório de Ixodides, Departamento de Entomologia, Instituto Oswaldo Cruz-Fiocruz, Av. Brasil 4365, 21045-900 Rio de Janeiro, RJ, Brasil *Departamento de Parasitologia, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil **Serviço de Operações de Campo, Fundação Nacional de Saúde, Rio de Janeiro, RJ, Brasil
Eleven species of fleas were collected from 601 small rodents, from November 1995 to October 1997, in areas of natural focus of bubonic plague, including the municipalities of Nova Friburgo, Sumidouro and Teresópolis, State of Rio de Janeiro, Brazil. Among 924 fleas collected, Polygenis (Polygenis) rimatus (Rhopalopsyllidae) was the predominant species regarding the frequency, representing 41.3% (N:382), followed by P. (Neopolygenis) pradoi, representing 20% (N:185) and Craneopsylla minerva minerva (Stephanocircidae), representing 18.9% (N:175). The host Akodon cursor harbored 47.9% of these fleas. Other six host species were infested by 52.1% of the remaining fleas. Fleas were found on hosts and in places within the focus not previously reported by the literature.
Key words: Siphonaptera - small rodent fleas - bubonic plague focus - Rio de Janeiro - Brazil
Rodent fleas are biological vectors of bubonic plague, as demonstrated 100 years ago (Simond et al. 1998). Although the order Siphonaptera includes approximately 3,000 species (Lewis 1998) and at least 100 of them can transmit plague, only 59 species were recorded in Brazil up to now (Linardi & Guimarães 2000). According to Marshall (1981), fleas infest exclusively mammals (94%) and birds (6%). In Brazil, rodents are the preferred hosts, among 12 orders of mammals found to be parasitized (Linardi 1999).
After arriving in Brazil in 1899 by the Santos seaport, State of São Paulo, the plague dispersed in rural zones, exhibiting periodicity as a wild enzootic and rural zoonosis due to the persistence in natural foci in the northeast and southeast Brazilian regions (Freitas 1969). Within the southeast region there is a focus located in the Serra dos Órgãos mountain range which, although not being the most important focus in Brazil, has been of great scientific interest due to its geographic location.
Due to two human plague deaths recorded, studies in this focus have been intensified since 1967. Serologic surveys by hemaglutination demonstrated the circulation of Yersinia pestis among small rodents and dogs (Almeida et al. 1985, Vieira et al. 1994). Excepting the reports of fleas in Teresópolis, State of Rio de Janeiro (Gomes 1969), the potential vectors of the plague in this area have been poorly studied and fleas have been misidentified. The present study reviews the flea fauna and verify the abundance of fleas on hosts from the focus of Serra dos Órgãos mountain range, State of Rio de Janeiro.
ACKNOWLEDGMENTS
To the staff of the Plague surveillance laboratory, State of Rio de Janeiro, the National Health Foundation, for the aid in the collections and rodent captures, to Paulo Cesar de Azevedo Silveira for the drawing of the used map, to Silvia Cristina Barbosa da Silva for the assembly and identification of fleas and to Guilherme Franco Netto and Cibele Rodrigues Bonvicino for the revision of the text.
Figure | Table I | Table II | Table III
Supported by Brazilian National Health Foundation.
+Corresponding author. Fax: +55-21-590.3545.
E-mail: rwcar@uol.com.br or raicar@ioc.fiocruz.br++Research fellow CNPq
Received 1 August 2000
Accepted 8 February 2001
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