HTLV‐1 and ‐2 in a first‐time blood donor population in Northeastern Brazil: Prevalence, molecular characterization, and evidence of intrafamilial transmission

• Published in: Journal of medical virology 2018-10, Vol.90 (10), p.1651-1657
• Main Authors: Ribeiro, Ivonizete Pires, Kozlowski, Aline Garcia, Dias de Matos, Marcia Alves, da Costa e Silva, Ágabo Macedo, dos Santos Carneiro, Megmar Aparecida, Vicente, Ana Carolina Paulo, Martins, Regina Maria Bringel
• Format: Article
• Language: English
• Subjects: Blood; Blood & organ donations; Blood donors; Enzyme immunoassay; Enzymes; Epidemiology; human T‐cell lymphotropic virus type 1 and 2 (HTLV‐1 and ‐2); Immunoassay; Infections; intrafamilial transmission; Lymphocytes T; Polymerase chain reaction; prevalence; Subgroups; subtype; Virology; Viruses
• ISSN: 0146-6615; 1096-9071
• DOI: 10.1002/jmv.25231

Independent epidemiology for respective human T‐cell lymphotropic virus (HTLV) types 1 and 2 is little known in blood donors in Brazil, where screening for HTLV‐1/2 is mandatory at blood banks, but no testing to confirm/differentiate these viruses. Therefore, this study aims to assess the prevalence of HTLV‐1 and ‐2 in a first‐time blood donor population in Northeastern Brazil and to carry out molecular characterization of respective isolates. A cross‐sectional study was conducted at the State Blood Bank in Piauí. Samples were screened for anti–HTLV‐1/2 by enzyme immunoassay, and reactive samples were confirmed using a line immunoassay and polymerase chain reaction (PCR). Of 37 306 blood donors, 47 were anti–HTLV‐1/2 reactive by enzyme immunoassay. After confirmed by line immunoassay, 22 were positive for HTLV‐1 (0.59 per 1000; 95% CI: 0.38‐0.87), 14 were positive for HTLV‐2 (0.37 per 1000; 95% CI: 0.21‐0.61), 1 was indeterminate, and the remaining donors were negative. The HTLV‐1 infection was also confirmed by PCR in all anti–HTLV‐1‐positive samples, and sequencing classified these isolates as belonging to the Transcontinental (A) subgroup of the Cosmopolitan (1a) subtype. Of 14 anti–HTLV‐2‐positive samples, 11 were also PCR positive, which belonged to subtype a (HTLV‐2a/c). In addition, 38 family members of 5 HTLV‐1‐ and 3 HTLV‐2‐infected donors were analyzed. Familial transmission of HTLV‐1 and ‐2 was evidenced in 3 families. In conclusion, in Northeastern Brazil, where HTLV‐1 and ‐2 are endemic, counseling blood donor candidates and their families might play a key role in limiting the spread of these viruses. This is the first study to investigate the epidemiological and molecular aspects of HTLV‐1 and HTLV‐2 infections among the first‐time blood donors in Piauí, Northeastern Brazil. In addition, this study shows the existence of intrafamilial transmission of both viruses in this region despite the small number of families evaluated.