A-Z Index × Submit A-Z Index × Submit A-Z Index Search Dropdown × Submit Facebook Twitter LinkedIn Syndicate Emerging Infectious Disease journal ISSN: 1080-6059 Disclaimer: Early release articles are not considered as final versions. Any changes will be reflected in the online version in the month the article is officially released.
Cite This Article Open modal Citation for Media
West Nile virus (WNV) is the most common cause of domestic human arboviral infection in the contiguous United States. WNV surveillance across the United States is not comprehensive and is limited. Nonclinical WNV surveillance is variable, and WNV surveillance in humans is limited by the percentage of symptomatic human infections and time it takes to seek healthcare and diagnosis. Wastewater surveillance has been used to detect viruses shed from asymptomatic and symptomatic persons; therefore, we assessed wastewater as a surveillance tool for WNV tracking. We tested archived RNA and raw wastewater from 6 states with documented human illness during the 2023 WNV transmission season for WNV RNA. WNV RNA was detected in 18% (n = 29/158) of samples from Arizona, California, Colorado, Illinois, Indiana, and Nebraska. Our results highlight the ability to detect WNV in wastewater and the potential of wastewater surveillance to augment current surveillance data.
West Nile virus (WNV) is an enveloped, positive-sense RNA orthoflavivirus transmitted by mosquitoes ( 1 ). Although several lineages of WNV exist, the most common and virulent for humans are lineage I, found worldwide, and lineage II, found in sub-Saharan Africa and Europe ( 2 ). Most WNV infections are asymptomatic or mild; however, each year ≈1,300 neuroinvasive disease cases are reported in the United States ( 3 – 6 ). Symptomatic WNV infection is marked by nonspecific symptoms such as headache, body aches, joint pain, vomiting, diarrhea, or rash ( 1 , 2 ). A severe neuroinvasive disease develops in < 1% of those infected with WNV ( 1 , 2 ). Because no vaccines or therapeutics for WNV have been approved, personal protective behaviors, vector control, and blood and organ donor screening for WNV are essential tools to reduce WNV disease–related illness and death ( 7 ).
Various modes of surveillance are used to monitor and control WNV transmission, including mosquito, dead bird, and sentinel animal surveillance. However, those surveillance methods are inconsistently used across the United States and rarely performed year-round. Surveillance for WNV in humans includes testing symptomatic persons and monitoring blood donations ( 1 , 2 , 8 , 9 ). Nevertheless, those methods miss mild infections in persons not seeking medical attention or donating blood, likely underrepresenting the number of WNV cases.
Wastewater surveillance was successfully implemented to monitor the prevalence and transmission of various viral pathogens including poliovirus, SARS-CoV-2, and monkey pox virus in humans regardless of reported clinical symptoms ( 10 – 12 ) and sometimes before reported human cases ( 13 ). Wastewater surveillance also proved informative during the COVID-19 pandemic. SARS-CoV-2 virions and viral RNA are shed in patient feces and recoverable in wastewater, which enabled the adaptation of wastewater monitoring to assist in estimating the prevalence of COVID-19 cases and detecting concerning variants ( 14 – 16 ). Since the COVID-19 pandemic began, wastewater surveillance has rapidly expanded as an effective method to…