West Nile Virus: Don't Underestimate Its Persistence

An interesting report in this issue of the Journal by Murray et al [ 1] provides compelling evidence that West Nile virus (WNV) can persist for years in the kidneys of humans convalescing from infection with this virus. Furthermore, WNV, as detected in the form of genomic RNA, was excreted in the urine for 6 years or more after recovery from acute disease. As discussed below, these findings could have important implications for flavivirus epidemiology and pathogenesis One of the many questions that occupy the minds of virologists is, what do pathogenic viruses do when they are not causing overt disease transmission?. We are all familiar with the concept of acute viremic …