HTLV infection in blood donors from Mato Grosso do Sul state: a closer look at HTLV screening in Brazilian blood banks

Abstract Human T-lymphotropic virus (HTLV) infection has a worldwide distribution and currently, more than 2.5 million individuals have been infected in Brazil. The study aimed to investigate HTLV infection prevalence among blood donors in Mato Grosso do Sul, characterizing seroepidemiological profiles of HTLV-1/2 positive individuals and evaluating the blood bank's HTLV screening system. A cross-sectional survey was conducted among blood donors from Mato Grosso do Sul state (MS)—Central Brazil, between January to December 2021. The information was obtained from databases, samples from the collection of HEMOSUL, and active searching, with the completion of laboratory analyses. 35,278 blood donors were screened for anti-HTLV-1/2 by chemiluminescence immunoassay (CMIA). Among them, 78 were initially reactive for anti-HTLV-1/2 (2.21/1000). Out of 78, 67 returned to the blood center to collect a second sample for retesting with a second screening with CMIA. After confirmation, 8 samples were indeterminate, and 8 were confirmed as positive for HTLV antibodies. New tests were performed for the 8 positive samples, and 6 were confirmed as HTLV-1 infection (0.17/1,000), one as negative, and one as indeterminate. The present study describes the low prevalence of HTLV infection in blood donors from MS and contributes to the definition of the regional infection profile. The prevalence found in this study (0.017%–0.17/1000) shows to be a much lower value than the rates reported in other states in Brazil. We highlight the need for confirmatory testing for those seropositive donors in screening assays and the need for adequate counseling and patient management for those confirmed HTLV individuals

HTLV infection in Brazil's second-largest indigenous reserve

This study was supported by Governo do Estado de Mato Grosso do Sul, Fundação de Apoio ao Desenvolvimento do Ensino, Ciência e Tecnologia do Estado de Mato Grosso do Sul—FUNDECT/MS (Grant Number: No. 03/2016, TO 021/2017 FUNDECT/DECIT-MS/CNPq/SES-PPSUS-MS) and Conselho Nacional de Desenvolvimento Científco e Tecnológico—CNPQ (Grant Number: Nos. 442522/2019-3, 30295/2021-5). Tis study was fnanced in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES)—Finance Code 001.Universidade Federal de Mato Grosso do Sul. Campo Grande, MS, Brazil.Universidade Federal de Mato Grosso do Sul. Campo Grande, MS, Brazil.Universidade Federal de Mato Grosso do Sul. Campo Grande, MS, Brazil.Universidade Federal de Mato Grosso do Sul. Campo Grande, MS, Brazil.Universidade Federal de Mato Grosso do Sul. Campo Grande, MS, Brazil.Universidade de São Paulo. Faculdade de Medicina. São Paulo, SP, Brazil.Universidade Federal de Mato Grosso do Sul. Campo Grande, MS, Brazil / Secretaria de Estado de Saúde de Mato Grosso do Sul. Campo Grande, MS, Brazil.Universidade Federal da Grande Dourados. Dourados, MS, Brazil.Universidade Federal da Grande Dourados. Dourados, MS, Brazil.Ministério da Saúde. Secretaria de Ciência, Tecnologia, Inovação e Insumos Estratégicos. Instituto Evandro Chagas. Ananindeua, PA. Brasil.Universidade Federal do Pará. Belém, PA, Brazil.Universidade Federal de Mato Grosso do Sul. Campo Grande, MS, Brazil / Ministério da Saúde. Fundação Oswaldo Cruz - Mato Grosso do Sul. Campo Grande, MS, Brazil.Universidade Federal de Mato Grosso do Sul. Campo Grande, MS, Brazil / Ministério da Saúde. Fundação Oswaldo Cruz - Mato Grosso do Sul. Campo Grande, MS, Brazil.Human T-lymphotropic viruses 1 and 2 (HTLV-1/2) have a worldwide distribution. HTLV-1 has been associated with several diseases, including an aggressive malignant disease known as adult T-cell leukemia/lymphoma and a chronic inflammatory neurological disease called HTLV-1-associated myelopathy, while HTLV-2 has not been definitively associated with diseases. HTLV-2 is most prevalent in specific groups such as injecting drug users and the indigenous population. In Brazil, most studies about HTLV in indigenous are carried out in indigenous communities from the north of the country. Mato Grosso do Sul (MS), Central Brazil, has the second-largest indigenous population in Brazil. However, there is no available data about HTLV infection in this group. We conducted the first investigation of HTLV-1/2 infection prevalence in the indigenous population from Jaguapiru and Bororó villages in Dourados City, MS, to provide the prevalence and molecular characterization of HTLV. For that, a total of 1875 indigenous participated in the study. All the serum samples were screened by an enzyme-linked immunosorbent assay commercial kit for the presence of anti-HTLV-1/2 antibodies. Positive samples were confirmed by HTLV-1/2 Western Blot assay. The HTLV-1 5'LTR region was detected by nested PCR amplification and sequenced by Sanger. Most of the study population declared belonging to Guarani-Kaiowá ethnicity (69.18%), 872 (46.51%), and 1003 (53.49%) were from Jaguapiru and Bororó villages, respectively. The median age of participants was 31 years, and 74.24% were females. Two individuals were detected with HTLV-1 (0.1%; CI 95% 0.1-0.2). The phylogenetic analysis revealed that isolates belong to the Cosmopolitan subtype and the Transcontinental subgroup (HTLV-1aA). The low HTLV-1 prevalence found in this study is similar to that observed among blood donors, and pregnant populations from Mato Grosso do Sul. The absence of HTLV-2 infection among these Brazilian indigenous communities would suggest a distinct behavior pattern from other indigenous populations in Brazil