Ehrlichia canis in dogs in a semiarid region of Northeastern Brazil: Serology, molecular detection and associated factors

This study investigated infection by Ehrlichia spp. agents by PCR, immunofluorescence assay test (IFAT), and by Giemsa-stained blood smears in 108 dogs from a semiarid region of the state of Paraíba, Northeastern Brazil. Seventy-five (69.4%) of the 108 dogs were found to be seropositive to Ehrlichia canis, while only four dogs (3.7%) were positive in real-time PCR for E. canis. In six dogs (5.6%) E. canis-like morulae were observed in monocytes. Animals that stayed in environment whose floor was dried dirt, and dogs whose owners reported low frequency of cleaning the dog environment had higher (P < 0.05) PCR positivity for E. canis. Increasing seropositivity was found in older dogs (P = 0.012). This study provides the first molecular detection of E. canis in the semiarid region of Northeastern Brazil.