Serological evidence of Borrelia circulation among blood donors in the São Paulo state, Brazil

Abstract

SUMMARY Objective The objective of this study was to examine the Borrelia seroprevalence among blood donors in Southeast Brazil. Background There is evidence that Borrelia spirochetes are circulating in Brazil; however, there are no studies that characterise these bacteria and investigate their seroprevalence in the Brazilian population. Such a situation, combined with a recent outbreak of tick‐borne Rocky Mountain spotted fever in the São Paulo state demonstrates the increasing role of ticks as arthropod vectors in Brazil. Methods For the purpose of the study, 452 blood donors from Ribeirão Preto city, São Paulo state were tested using anti‐Borrelia immunoglobulin G (IgG) assay. The positive results were also confirmed by Western blot for anti‐borrelia IgM/IgG. Results The anti‐Borrelia IgG enzyme‐linked immunosorbent assay (ELISA) showed nine positive and nine borderline reactive samples, giving a total seroprevalence of 2·0% of anti‐Borrelia IgG among Brazilian blood donors. The confirmation of the seropositive and borderline samples by Borrelia Western blot was demonstrated by IgG‐positive results in 16 samples (a seroprevalence of 3.5%). Anti‐Borrelia IgM antibodies were also detected in one sample. Conclusions Our results demonstrate that Borrelia‐like spirochetes may be circulating among blood donors from the São Paulo State and that the ticks have an important epidemiological role as vectors of bacterial infections in this Brazilian region. These results not only alert us to possible actions that might be undertaken in order to completely characterise the aetiological agents of Lyme‐like syndromes in Brazil but also the possible impact that these bacterial agents might have on haemotherapy practices.

Recent Advances in the Immunologic Method Applied to Tick-Borne Diseases in Brazil

“…Even though Brazilian Borrelia disease (BBD) is not notified, many cases have increased. The prevalence of IgG antibodies to Borrelia was 3.5% (16 samples) [28]. Bonoldi et al showed that BBD patients with clinical symptoms presented 50% (14/28) positive serology in the acute phase (<3 months) and 45% (10/22) positive serology in the later phase (>3 months) [29].…”