Diagnosis of West Nile virus infections:Evaluation of different laboratory methods  

作　　者：Tatjana Vilibic-Cavlek Maja Bogdanic Vladimir Savic Zeljka Hruskar Ljubo Barbic Vladimir Stevanovic Ljiljana Antolasic Ljiljana Milasincic Dario Sabadi Gorana Miletic Ivona Coric Anna Mrzljak Eddy Listes Giovanni Savini 

机构地区：[1]Department of Virology,Croatian Institute of Public Health,Zagreb 10000,Croatia [2]School of Medicine,University of Zagreb,Zagreb 10000,Croatia [3]Poultry Center,Croatian Veterinary Institute,Zagreb 10000,Croatia [4]Department of Microbiology and Infectious Diseases with Clinic,Faculty of Veterinary Medicine University of Zagreb,Zagreb 10000,Croatia [5]Department of Infectious Diseases,Clinical Hospital Center Osijek,Osijek 31000,Croatia [6]Medical Faculty,Josip Juraj Strossmayer University of Osijek,Osijek 31000,Croatia [7]Department of Gastroenterology and Hepatology,University Hospital Center Zagreb,Zagreb 10000,Croatia [8]Croatian Veterinary Institute,Veterinary Institute Split,Split 21000,Croatia [9]OIE Reference Center for West Nile Disease,Istituto Zooprofilattico Sperimentale,G.Caporale,Teramo 64100,Italy

出　　处：《World Journal of Virology》2024年第4期51-61,共11页世界病毒学杂志（英文）

基　　金：Supported by the Croatian Science Foundation,No.IP-2016-06-7456:CRONEUROARBO;the European Union Next Generation EU project supported by the Ministry of Science and Education of the Republic of Croatia,No.NPOO 1 of Croatian Veterinary Institute:FLAVIR.

摘　　要：BACKGROUND The diagnosis of West Nile virus(WNV)is challenging due to short-term and low-level viremia,flavivirus cross-reactivity,and long immunoglobulin M(IgM)persistence.AIM To evaluate different methods for WNV detection[reverse transcription-polymerase chain reaction(RT-PCR),IgM/IgG antibodies,IgG avidity]in serum,cerebrospinal fluid(CSF),and urine samples of patients with confirmed WNV infection.METHODS The study included patients with confirmed WNV neuroinvasive infection(n=62),asymptomatic WNV seropositive individuals(n=22),and individuals with false-positive WNV IgM antibodies(n=30).WNV RNA was detected using RT-PCR.A commercial ELISA was used to detect WNV IgM/IgG antibodies with confirmation of cross-reactive samples using a virus neutralization test(VNT).IgG-positive samples were tested for IgG avidity.RESULTS The WNV-RNA detection rates were significantly higher in the urine(54.5%)/serum(46.4%)than in CSF(32.2%).According to the sampling time,the WNV-RNA detection rates in urine collected within 7 days/8-14/≥15 days were 29.4/66.6/62.5%(P=0.042).However,these differences were not observed in the CSF.The median RT-PCR cycle threshold values were significantly lower in urine(32.5,IQR=28-34)than in CSF(34.5,IQR=33-36).The frequency of positive WNV IgM and IgG significantly differed according to the sampling time in serum but not in CSF.Positive IgM/IgG antibodies were detected in 84.3/9.3%of serum samples collected within 7 days,100/71.1%of samples collected 8-14,and 100%samples collected after≥15 days.Recent WNV infection was confirmed by low/borderline avidity index(AI)in 13.6%of asymptomatic individuals.A correlation between ELISA and AI was strong negative for IgM and strong positive for IgG.No significant correlation between ELISA IgG and VNT was found.CONCLUSION The frequency of WNV RNA and antibody detection depends on the sampling time and type of clinical samples.IgG avidity could differentiate recent WNV infections from long-persisting IgM antibodies.

关 键 词：West Nile virus Reverse transcription-polymerase chain reaction SEROLOGY IgG avidity CROSS-REACTIVITY 

分 类 号：R511[医药卫生—内科学]