Prospective investigation of the impact of West Nile Virus infections in renal diseases

Abstract

An increased incidence of chronic kidney disease (CKD) after West Nile Virus (WNV) infections has been suggested but the association of WNV infections with renal damage remain inconclusive. This study was undertaken to characterize WNV infections in individuals with acute kidney injury (AKI) and CKD, and to evaluate hemodialysis as a probable transmission route. A total of 463 plasma and urine samples were collected from 45 AKI and 77 CKD patients. Nested and real-time polymerase chain reaction (PCR) assays were employed for viral RNA detection. Specific immunoglobulins were investigated via immunofluorescence and plaque reduction neutralization assays. Consecutive pre and post-dialysis samples were evaluated in CKD cases. WNV RNA and specific immunoglobulins were detected in 7 (5.7%) and 5 (4.1%) individuals, respectively. The AKI patients with WNV RNA in blood and urine had underlying diseases requiring immunosuppressive therapy and demonstrated moderate to high viral loads. No clinical symptom related to WNV infection were observed in CKD cases with detectable viral nucleic acids. All WNV sequences were characterized as lineage 1 clade 1a and several amino acid substitutions with unknown impact were noted. Detailed epidemiologic investigation of WNV RNA positive CKD cases revealed probable vector-borne virus exposure, without the evidence for transmission via hemodialysis.

Visualization of West Nile Virus in Urine Sediment using Electron Microscopy and Immunogold up to Nine Years Postinfection

“…10 The authors speculated that the discrepancy in testing results was a result of low numbers of viral copies that were below the threshold of detection by PCR. Conversely, other studies have been successful in detecting viral RNA in urine, particularly during the acute phase (up to 30 days) after onset of symptoms, [11][12][13][14][15] with immunosuppressing conditions and history of neuroinvasive disease enhancing the opportunity for detection. Similar to our observation, one study by Papa et al 15 described differences in the ability to detect viral RNA if specimens were not properly handled and stored before testing.…”