Trend in seroprevalence of HTLV‐1/2 in Taiwanese blood donors—A 10‐year follow‐up

Objectives This study evaluated the Human T‐lymphotropic virus (HTLV) screening policy impact on the HTLV seroprevalence from 2009 to 2018 as well as the differences between administrative districts in terms of prevalence distribution in Taiwan. Background Since February 1996, the Taiwan Blood Services Foundation (TBSF) had conducted HTLV screening of blood donors. The HTLV seroprevalence was 0.032% in 1999. Materials and Methods This cross‐sectional study included donors' data collected from blood donation centres across Taiwan from 2009 to 2018. Enzyme immunoassay and Western blot assay were used for screening and confirmation of HTLV infections. In this study, the researchers calculated the trends in the HTLV rates of first‐time and repeat donors across time as well as the HTLV prevalence distribution across the 22 administrative districts of Taiwan. Results Amongst 17 977 429 employed blood donations, 739 HTLV‐seropositive donations (4.11 per 100 000 donations) were identified. The HTLV‐positive donors were aged between 17 and 64 years, with a median age of 49 years. The overall seropositivity rates of first‐time and repeat donors were 34.36/100 000 and 1.27/100 000. HTLV seroprevalence in first‐time blood donors significantly decreased by 57% (crude odds ratio [95% confidence interval] (crude OR [95% CI]) = 0.43 [0.28–0.64]) within 10 years. A slight decline was also identified in repeat donors (crude OR [95% CI] = 0.73 [0.4–1.32]). Donors from different districts showed significantly varied prevalence. Most districts with high prevalence are situated in eastern Taiwan, for both donation types. Older blood donors were more likely to be infected with HTLV than younger ones in first time and repeat donors. Middle age donors (50–65 years) had an 18.47–39.65 greater risk than those aged