A Systematic Review of BK and JC Polyomaviruses in Asia: Molecular Insights and Prevalence.

The Polyomaviridae family consists of small circular double-stranded DNA viruses. Two members of this family, BK polyomavirus (BKPyV) and JC polyomavirus (JCPyV) have been studied extensively since their discovery in 1971. These viruses are present in 80%-90% of populations worldwide. Although they usually do not cause any symptoms and remain inactive, they can become active when the immune system is weak. This activation can result in BK Virus-Associated Nephropathy and Progressive Multifocal Leukoencephalopathy for BKPyV and JCPyV, respectively. While there has been significant progress in understanding the molecular biology of polyomaviruses, most epidemiological studies have focused on European and American populations. These viruses have been involved in oncogenic processes due to their ability to disrupt cellular regulatory mechanisms resulting in uncontrolled cell proliferation. Consequently, there is limited data on the geographical distribution of these potentially cancer-causing viruses in Asian countries. This review offers a detailed review of studies on BKPyV and JCPyV, which shed light on their prevalence in Asian regions. These studies consistently demonstrate that both BKPyV and JCPyV are widespread among Asian populations. By categorising the data based on prevalence and disease development, it is evident that the Vietnam population has the highest frequency of BKPyV (77%), while JCPyV is most prevalent in Taiwan (90%). Given the widespread distribution of these viruses, continuous research is crucial to gain a nuanced understanding of their epidemiology and pathobiology in Asia.