(P-BC-31) Epidemiological Profile and Factors Associated with HTLV Virus Seropositivity in Blood Donors

In the context of transfusion safety, the detection of infectious agents becomes a priority to ensure the integrity of blood donation. Human T-lymphotropic virus (HTLV) gains prominence due to its association with diseases such as adult T-cell leukemia and lymphoma (ATLL). This study aims to analyze the prevalence of HTLV virus in blood donors and identify demographic and socioeconomic factors associated with seropositivity.

Study

Design/Methods:

Retrospective study of blood donations from January 2012 to December 2022 at a blood bank service in the northern region of Rio Grande do Sul, Brazil, for the investigation of serological markers of HTLV virus, using ELISA and chemiluminescence. Positive samples were reanalyzed and confirmed by PCR or Western Blot.

Results/Findings:

Out of 148,378 donations analyzed, 220 (0.14%) resulted in reactivity or indeterminate results for HTLV during screening. The majority of cases were in the age group of 30 years or older (65%) and self-declared as white (91.3%); 47.7% were male; approximately 75% of donors called for second testing attended, with 49.7% showing reactive results. Among those subjected to confirmatory testing, eight (3.6%) were reactive on Western Blot, eight (3.6%) were indeterminate, and 118 (53.6%) were non-reactive. Regarding PCR, three (1.8%) were reactive and 16 (7.3%) were non-reactive. The overall prevalence of confirmed reactive tests was 9.4 cases per 100,000 people (0.0094%). A significant association (p = 0.007) was observed between age group and incidence of false positive results, with a higher percentage among donors aged 30 years or older (65.5%).

Conclusions:

The prevalence observed in this study was lower compared to other studies conducted in blood banks in Brazil, ranging from 0.03% in Santa Catarina to 0.48% in Bahia (Brazil, 2020). An increase in the incidence of false positives was observed in individuals over 30 years old, which is likely due to clinical conditions, medication use, and cross-reactivity caused by non-specific antibodies (Vo et al., 2016). The absence of data on prevalence in the southern region of Brazil highlights the need for further research and the importance of monitoring due to high rates of false positives. There are challenges regarding the return of these individuals, as the rate of absence in the collection of a second sample is very high.