RESUMO
Rickettsioses caused by Rickettsia felis are an emergent global threat. Historically, the northern region of the province of Caldas in Colombia has reported murine typhus cases, and recently, serological studies confirmed high seroprevalence for both R. felis and R. typhi. In the present study, fleas from seven municipalities were collected from dogs, cats, and mice. DNA was extracted and amplified by polymerase chain reaction (PCR) to identify gltA, ompB, and 17kD genes. Positive samples were sequenced to identify the species of Rickettsia. Of 1,341 fleas, Ctenocephalides felis was the most prevalent (76.7%). Positive PCR results in the three genes were evidenced in C. felis (minimum infection rates; 5.3%), C. canis (9.2%), and Pulex irritans (10.0%). Basic Local Alignment Search Tool (BLAST) analyses of sequences showed high identity values (> 98%) with R. felis, and all were highly related by phylogenetic analyses. This work shows the first detection of R. felis in fleas collected from animals in Colombia.
Assuntos
Ctenocephalides/microbiologia , DNA Bacteriano/isolamento & purificação , Genes Bacterianos , Rickettsia felis/isolamento & purificação , Tifo Endêmico Transmitido por Pulgas/epidemiologia , Animais , Doenças do Gato/epidemiologia , Doenças do Gato/parasitologia , Gatos , Colômbia/epidemiologia , Vetores de Doenças , Doenças do Cão/epidemiologia , Doenças do Cão/parasitologia , Cães , Infestações por Pulgas/veterinária , Camundongos , Filogenia , Reação em Cadeia da Polimerase , Rickettsia felis/genética , Análise de Sequência de DNA , Estudos Soroepidemiológicos , Tifo Endêmico Transmitido por Pulgas/veterináriaRESUMO
Rickettsia typhi and R. felis are the etiological agents of murine typhus and flea-borne spotted fever, respectively. Both are emerging acute febrile zoonotic diseases for which fleas are vectors; they also have similar clinical characteristics and global distribution. In 2005, we identified the circulation of murine typhus in 6 towns within the mountainous coffee-growing area north of Caldas, Colombia. We now report the specific seroprevalence against R. typhi and R. felis, and associated risk factors in 7 towns of this province. The combined seroprevalence against the 2 flea-borne rickettsioses is the highest yet reported in the literature: 71.7% (17.8% for R. felis, 25.2% for R. typhi, and 28.7% for both). We also report a prospective analysis of 26 patients with a febrile illness compatible with rickettsioses, including murine typhus; 9 of these patients had a rickettsiosis. This supports our sero-epidemiological results and highlights the diagnostic complexity of febrile syndromes in this region.
