Kaposi's sarcoma herpesvirus seroprevalence among blood donors in Uganda.

Background: Kaposi's sarcoma herpesvirus (KSHV) causes a life-long infection that can progress to several types of KSHV-associated diseases. There is evidence for transfusion transmission of KSHV. In endemic regions, such as sub-Saharan African, KSHV seroprevalence is >40%. However, previous studies of blood donors utilized immunoassays that detect KSHV-associated disease-specific antigens, which may underestimate the true burden of KSHV in a healthy population.

Study design and methods: We utilized samples from an on-going transfusion transmitted infection clinical trial to estimate the seroprevalence of KSHV among 4921 blood donations from healthy donors in Uganda collected between October 2019 and December 2022. A multiplexed bead-based assay was used to measure plasma IgG against five antigens encoded by the K8.1, K10.5, ORF73, ORF38, and ORF25 genes of KSHV. Significant associations between donor characteristics and seroprevalence were assessed by chi-square tests.

Results: Overall, KSHV seroprevalence was 69.1%. Seroprevalence was higher in units collected from older donors compared with younger donors and male donors (71.9% [95% confidence interval (CI) = 70.4%-73.3%]) compared with female donors (61.3% [95% CI = 58.6%-64.0%]; p < .001). KSHV seroprevalnce was higher among units collected from donors positive for T. pallidum (82.5% [95% CI = 73.8%-89.3%]) compared with units collected from donors who were negative (68.8% [95% CI = 67.5%-70.1%]; p < .001). KSHV seroprevalence was higher in units that tested positive for HIV, HBV, or HCV, though these results were not statistically significant.

Conclusion: Given the high seroprevalence and limited availability of lab assays that detect active KSHV infections, methods such as leukoreduction or pathogen reduction should be considered to potentially reduce the risk of transfusion transmission of KSHV.