Comment: seroprevalence of HTLV-1/2 among blood donors in the state of Maranhão, Brazil*

The human T-cell lymphotropic virus type 1 (HTLV-1) was the first retrovirus identified in humans, and is the causal agent of HTLV-1-associated myelopathy (also known as tropical spastic paraparesis [HAM/TSP]) and adult T-cell leukemia/lymphoma (ATLL). HTLV-1 has been neglected mainly due to the misconception that it is a low morbidity viral infection. Recently evidence has been accumulating that a large percentage of HTLV-1-infected subjects, previously only considered as carriers, have disease due to the virus, such as sicca syndrome, chronic periodontitis, overactive bladder, erectile dysfunction, uveitis, and HTLV-1-associated arthropathy.1 It is estimated that approximately 20 million individuals are infected by HTLV-1 worldwide; Brazil is considered to be the country with the highest number of cases. Epidemiologic studies have pointed out that HTLV-1 is documented in all states of Brazil.2 In this issue of the Revista Brasileira de Hematologia e Hemoterapia a seroepidemiologic study showed a prevalence of 0.15% of HLTV-1 infection among blood donors in the State of Maranhão.3 Moreover, there was a high percentage (68.6%) of co-infected individuals with hepatitis B virus (HBV). Epidemiologic studies performed over 20 years in Brazil have contributed to evaluate the changes in the prevalence Scientific comment