Introduction: BK virus is a DNA virus in polyomavirus family.  It is a ubiquitous human virus with a childhood asymptomatic primary infection, usually at the age of 2 to 5 years and a sero prevalence of more than 60-90% among the adult population worldwide. After the primary infection it become latent in the genitourinary tract and reactivates with immunosuppresion, hence become an important infection among post kidney transplant patients.It causes variety of clinical conditions ranging from asymptomatic viraemia with or without viruria to ureteral stenosis and obstruction, interstitial nephritis and subsequent graft damage and graft loss due to BK allograft nephropathy. Increase in number of renal transplants made BK vireamia and BK virus nephropathy a significant cause of graft dysfunction and our aim is to highlight BK virus as a cause for graft dysfunction in post kidney transplant patients.
Method: Nephrology and Transplant Unit, Kandy, Sri Lanka commenced screening their patients for BK virus since March, 2017. Screening is done at post transplant 1st,2nd,3rd ,6th, 9thmonths and then annually. Screening of blood was done routinely and then urine on request with Real Time PCR Quantification PCR assay by using validated commercial kit. Vireamia of 104 IU per milliliter was considered as significant and subjects to treatment. Vireamic analysis was done with the collaboration of the Department of Virology, Teaching Hospital, Kandy, Sri Lanka.
Results: A retrospective analysis of blood samples of 239 patients were done. In the analyzed population, 72.38% (n=173) were males and 27.61% (n=66) were females.  8 patients had significant vireamia, >104IU/ml (3.34%). Out of that 7 patients were males (87.5%) and the one was a female (12.5%). There were 13 patients (5.43%) with viraemia of 103-104 IU/ml and out of them 9 were males (69.23%) the rest were females (n=4, 30.76%). Percentage of BK vireamia with 102-103 IU/ml was 6.27% (n=15). Out of them 9 were males (60%) and 6 (30%) were females. There were 203 patients with viraemia of <102 IU/ml and counts 84.93% of the total population. Among them 72.90% (n=148) were males and 27.09% (n=55) were females.
Conclusion: The prevalence of BK vireamia in post kidney transplant patients is significant and should be considered as a cause for graft dysfunction.