BK virus

The BK virus is a member of the polyomavirus family. Past infection with the BK virus is widespread, but significant consequences of infection are uncommon.

The BK virus was first recognized from a renal transplant patient. This BK virus is similar to another virus called the JCV since their genome sequence share 75% homology. Both of these viruses can be identified and differentiated from each other by carrying out serological tests using specific antibodies.

The BK virus rarely causes disease since many people who are infected with this virus are asymptomatic. If symptoms do appear then many of them will be mild such as having a respiratory infection or a fever. These are known as the primary infections. Latent infections can occur in the kidneys and sometimes in the brain. A latent infection occurs when the virus becomes reactivated. However it is not known how this virus is transmitted. It is known however that the virus is spread from person to person and not from an animal source. It has been suggested that this virus may be transmitted through respiratory fluids.

Clinically, BK virus becomes relevant in immunocompromised patients. It is notable as a cause for hemorrhagic cystitis in bone marrow transplant recipients. In renal transplant patients, it is associated with ureteral stenosis and interstitial nephritis. In addition, the presence of BK polyoma in the bladder is statistically linked to the development of bladder carcinoma.

This virus can be diagnosed by carrying out a biopsy in the kidneys. PCR techniques and LAMP (Loop mediated isothermal amplification) can also be carried out to identify the virus. Renal transplant patients infected with this virus can be treated by using cidofovir which is an antiviral drug. Cidofovir is a nucleotide analogue that has the ability to interfere with the action of the BK virus. It is known to have treated individuals with a renal transplant that were infected with this virus.