TropicalMed, Vol. 8, Pages 177: Bovine Leptospirosis in Caatinga Biome, Brazil: New Insights into Diagnosis and Epidemiology

TropicalMed, Vol. 8, Pages 177: Bovine Leptospirosis in Caatinga Biome, Brazil: New Insights into Diagnosis and Epidemiology

Tropical Medicine and Infectious Disease doi: 10.3390/tropicalmed8030177

Authors: Nathanael Natércio da Costa Barnabé Rafael Rodrigues Soares Deivyson Kelvis Silva Barros Denise Batista Nogueira Flávia Teresa Ribeiro da Costa João Pessoa Araújo Júnior Camila Dantas Malossi Leila Sabrina Ullmann Diego Figueiredo da Costa Maria Luana Cristiny Rodrigues Silva Severino Silvano dos Santos Higino Carolina de Sousa Américo Batista Santos Sérgio Santos de Azevedo Clebert José Alves

Bovine leptospirosis causes economic losses and raises public health concerns. It is possible that there are peculiarities in the epidemiology of leptospirosis in regions with a semiarid climate, such as the Caatinga biome in Brazil, where the climate is hot and dry, and the etiological agent require alternative routes of transmission. This study aimed to close knowledge gaps to the diagnosis and epidemiology of Leptospira spp. infection in cows from the Caatinga biome, Brazil. Samples of the blood, urinary tract (urine, bladder and kidney) and reproductive tract (vaginal fluid, uterus, uterine tube, ovary and placenta) were collected from 42 slaughtered cows. Diagnostic tests included were the microscopic agglutination test (MAT), polymerase chain reaction (PCR) and bacterial isolation. Anti-Leptospira spp. antibodies were found in 27 (64.3%) of the animals analyzed using MAT at a 1:50 dilution (cut-off 50), while 31 (73.8%) animals had at least one organ/fluid where the presence of Leptospira spp. DNA was identified, and 29 animals (69%) were positive at bacteriological culture. The highest sensitivity values for MAT were obtained at the cut-off point of 50. In conclusion, even under hot and dry climate conditions, it is possible that Leptospira spp. can spread through alternative routes such as venereal transmission; moreover, a cut-off of 50 is recommended for the serological diagnosis of cattle from the Caatinga biome.