Rickettsia felis in Ctenocephalides felis felis from five geographic regions of Brazil.

This study evaluated rickettsial infection in 701 Ctenocephalides felis felis fleas that were collected from dogs and cats in 31 municipalities, encompassing all regions and major biomes of Brazil. A total of 268 (38.2%) fleas from 30 municipalities were polymerase chain reaction (PCR) positive for the rickettsial gltA gene. The PCR products from 44 fleas, consisting of at least 1 PCR-positive flea from each of 30 municipalities, generated DNA sequences identical to Rickettsia felis. Rickettsial prevalence was highly variable among 30 municipalities, with values ranging from 2.9% to 100%. Significantly higher infection rates by R. felis were associated with the Pampa biome (southern Brazil), and the temperate climate that prevails in southern Brazil. In contrast, lowest R. felis-infection rates were significantly associated with the Caatinga biome, and its semiarid climate. Further studies should evaluate the effect of temperature and moisture on the R. felis infection in Ctenocephalides fleas world widely. © The American Society of Tropical Medicine and Hygiene.