The First Phylogenetically Confirmed Hemorrhagic Cystitis Outbreak Among Pediatric Hematopoietic Stem Cell Transplant Recipients.

BACKGROUND

BK virus-associated hemorrhagic cystitis (BKV-HC) still remains a life-threatening complication after Hematopoietic Stem Cell transplantation (HSCT). In this study, we analyzed a possible nosocomial transmission of BK virus (BKV) in a pediatric HSCT clinic.

METHODS

All the information of 131 patients who had HSCT in Akdeniz University Hospital pediatric HSCT clinic between July 2019 and July 2022 was screened for BKV-HC. Twenty-six patients developed BKV-HC and 21 of them were related to the nosocomial transmission. Phylogenetic investigation was conducted on a total of 19 patients, comprising 15 pediatric cases believed to be associated with nosocomial transmission. All the patients had BKV DNA positivity in their urine samples and 17 of them also had BKV-HC. A region approximately 677 bp in length was sequenced and after alignment, phylogenetic analysis was done.

RESULTS AND

CONCLUSION

In phylogenetic analysis, three clusters including 11, 5, and 3 patients having identical sequences were formed. To our knowledge, this is the biggest BKV-HC nosocomial transmission seen among HSCT patients. Nosocomial BKV transmission affecting HSCT patients was proven with phylogenetic and statistical analysis. Furthermore, this study presented a novel finding, describing two HSCT patients affected by nosocomial transmission, evidenced by the presence of BKV-DNA in their urine samples, who had not developed HC. This observation marks the first documented instance of such cases within the context of nosocomial transmission of BKV.