Persistent infection with West Nile virus years after initial infection

Area of Science:

• Virology
• Infectious Diseases
• Public Health

Background:

• West Nile virus (WNV) is a mosquito-borne flavivirus that can cause neuroinvasive disease.
• Chronic symptoms following WNV infection are not well understood, and potential persistent viral reservoirs remain an area of investigation.

Purpose of the Study:

• To investigate the presence of persistent West Nile virus (WNV) RNA in urine samples from convalescent patients.
• To determine if WNV RNA in urine correlates with chronic symptoms or long-term renal infection.

Main Methods:

• Urine samples were collected from 25 patients 573-2452 days post-WNV infection.
• West Nile virus (WNV) RNA was detected using reverse transcription polymerase chain reaction (RT-PCR).
• Positive WNV amplicons were sequenced and compared to known WNV strains.

Main Results:

• West Nile virus (WNV) RNA was detected in 5 (20%) of the 25 urine samples.
• Sequencing of four WNV amplicons revealed >99% homology to the WNV NY99 strain.
• Detection of WNV RNA occurred between 1.6 and 6.7 years after the initial WNV infection.

Conclusions:

• Persistent West Nile virus (WNV) RNA can be found in the urine of convalescent patients for several years after infection.
• These findings suggest a potential for persistent renal infection in individuals experiencing chronic symptoms after WNV.
• The study highlights the possibility of long-term viral reservoirs contributing to chronic WNV sequelae.