Factors associated with pain in individuals infected by human T-cell lymphotropic virus type 1 (HTLV-1)

Despite the high prevalence of chronic pain in individuals infected with HTLV-1, predictive and protective factors for its development are still unclear.

To identify factors associated with chronic pain in individuals with HTLV-1.

This cross-sectional study was conducted in a reference center for treatment of patients infected with HTLV-1 in Salvador, Bahia, Brazil. The study included individuals infected with HTLV-1, over 18 years, and excluded those with difficulty to respond the pain protocol. Data on sociodemographic, health behavior, and clinical characteristics were collected in a standardized way. The prevalence ratio (PR) of pain is described, as well as the factors independently associated with the presence of pain, which were assessed by multiple logistic regression.

A total of 142 individuals were included in the study, mostly female (62.7%), aged 20-64 years (73.2%), married (61.3%), with less than eight years of education (54.2%), and with a steady income (79.6%). Multivariate analysis showed that being symptomatic for HTLV-1 - sensory manifestations, erectile dysfunction, overactive bladder, and/or HAM/TSP (PR=1.21, 95% CI: 1.05 to 1.38), self-medication (PR=1.29, 95% CI: 1.08-1.53), physiotherapy (PR=1.15, 95% CI: 1.02-1.28), and depression (PR=1.14, 95% CI: 1.01-1.29) were associated with an increased likelihood of presenting pain. On the other hand, physical activity (PR=0.79, 95% CI: 0.67-0.93) and religious practice (PR=0.83, 95% CI: 0.72-0.95) were associated with a decreased likelihood of having pain.

The use of self-medication, physiotherapy and the presence of depression are independently associated with neurological symptoms in HTLV-1 infected patients. Religious practice and physical activity are both protective for the development of pain.