scholarly journals Performance Characteristics of an In-House Assay System Used To Detect West Nile Virus (WNV)-Specific Immunoglobulin M during the 2001 WNV Season in the United States

2003 ◽  
Vol 10 (1) ◽  
pp. 177-179 ◽  
Author(s):  
Harry E. Prince ◽  
Wayne R. Hogrefe
Keyword(s):  
West Nile Virus ◽  
The United States ◽  
Immunoglobulin M ◽  
Enzyme Linked Immunosorbent Assay ◽  
Screening Assay ◽  
West Nile ◽  
Elisa System ◽  
Igm Elisa ◽  
Specific Immunoglobulin ◽  
Control And Prevention

ABSTRACT During the 2001 U. S. West Nile virus (WNV) season, 163 specimens were reactive in an in-house WNV-specific immunoglobulin M (IgM) screening enzyme-linked immunosorbent assay (ELISA) and were referred to either the Centers for Disease Control and Prevention or the appropriate state public health laboratory (CDC/SPHL) for additional testing. CDC/SPHL supplied results for 124 specimens that could be further evaluated in-house: 70 specimens were nonreactive in the CDC/SPHL WNV-specific IgM screening assay, and 54 specimens were reactive. These specimens were used to evaluate a modified in-house WNV-specific IgM ELISA that incorporated background subtraction to identify nonspecific reactivity and thus improve assay specificity. Of the 70 CDC/SPHL nonreactive samples, 49 (70%) were nonreactive in the modified ELISA; of the 54 CDC/SPHL reactive samples, 51 (94%) were reactive in the modified ELISA. Confirmatory studies performed by CDC/SPHL indicated that 38 CDC/SPHL screen-reactive specimens represented true WNV infection; all 38 specimens were reactive in the modified in-house WNV-specific IgM ELISA. These findings demonstrate that an in-house ELISA system for WNV-specific IgM effectively identifies patients with WNV infection.

scholarly journals Detection of West Nile Virus (WNV)-Specific Immunoglobulin M in a Reference Laboratory Setting during the 2002 WNV Season in the United States

2003 ◽  
Vol 10 (5) ◽  
pp. 764-768 ◽  
Author(s):  
Harry E. Prince ◽  
Wayne R. Hogrefe
Keyword(s):  
West Nile Virus ◽  
Serum Sample ◽  
The United States ◽  
Immunoglobulin M ◽  
Enzyme Linked Immunosorbent Assay ◽  
Reference Laboratory ◽  
Sample Collection ◽  
Serum Samples ◽  
West Nile ◽  
Specific Immunoglobulin

ABSTRACT Between 1 June and 31 December 2002, 30,677 serum samples and 4,554 cerebrospinal fluid (CSF) samples were tested for West Nile virus (WNV)-specific immunoglobulin M (IgM) by an in-house enzyme-linked immunosorbent assay (ELISA); 1,481 serum samples (4.8%) and 345 CSF samples (7.6%) were positive for WNV IgM. Positive samples were forwarded to public health service laboratories (PHSLs) for further testing. PHSLs supplied results from their WNV IgM ELISAs for 654 samples; 633 (97%) were positive. PHSLs supplied WNV plaque reduction neutralization test results for 128 samples; 123 (96%) were positive. WNV IgM seroconversion and seroreversion trends were evaluated for 749 patients who each provided two serum samples that were tested during the study period. Of 574 patients whose first serum sample was IgM negative, 41 (7%) seroconverted (the second serum sample was IgM positive); of 175 patients whose first serum sample was IgM positive, 22 (13%) seroreverted (the second serum sample was IgM negative). The seroreversion rate was directly proportional to the time between serum sample collection; whereas only 1% of patients whose sera were collected <20 days apart showed seroreversion, 54% of patients whose sera were collected >60 days apart showed seroreversion. Conversion and reversion trends for CSF were evaluated for 68 patients. Of 54 patients whose first CSF specimen was IgM negative, 9 (17%) converted; none of 14 patients whose first CSF specimen was IgM positive reverted. Concomitant detection of WNV IgM in serum and CSF was assessed for 1,188 patients for whom paired serum and CSF specimens were available; for all 130 patients for whom IgM was detectable in CSF, IgM was also detectable in serum. These findings show that an in-house WNV IgM ELISA accurately identifies patients with WNV infection, document WNV IgM conversion and reversion trends, and demonstrate that WNV IgM detection in CSF is accompanied by WNV IgM detection in serum.

scholarly journals Evaluation of a Diagnostic Algorithm Using Immunoglobulin M Enzyme-Linked Immunosorbent Assay To Differentiate Human West Nile Virus and St. Louis Encephalitis Virus Infections during the 2002 West Nile Virus Epidemic in the United States

2004 ◽  
Vol 11 (6) ◽  
pp. 1130-1133 ◽  
Author(s):  
Denise A. Martin ◽  
Amanda Noga ◽  
Olga Kosoy ◽  
Alison J. Johnson ◽  
Lyle R. Petersen ◽  
...  
Keyword(s):  
United States ◽  
West Nile Virus ◽  
Immunosorbent Assay ◽  
Diagnostic Algorithm ◽  
The United States ◽  
Encephalitis Virus ◽  
Immunoglobulin M ◽  
Enzyme Linked Immunosorbent Assay ◽  
Virus Infections ◽  
West Nile

ABSTRACT A diagnostic algorithm was developed to differentiate between human infections of West Nile virus (WNV) and St. Louis encephalitis virus (SLEV) using positive-to-negative (P/N) ratios derived from the immunoglobulin M capture enzyme-linked immunosorbent assay (MAC-ELISA). To validate this algorithm, we tested 1,418 serum and cerebrospinal fluid (CSF) samples from confirmed WNV and SLEV infections collected during the WNV epidemic of 2002 in the United States. WNV P/N-to-SLEV P/N ratios (W/S ratios) were calculated and used to identify the infecting virus. These results were compared to results from the plaque reduction neutralization test (PRNT), which is currently the standard assay used to discriminate between closely related flavivirus infections. If the W/S ratio was ≥1, the predictive value positive (PNP) for WNV was 97.8%, where 95% of flavivirus cases were due to WNV infection and only 3.7% of specimens would require PRNT to differentiate WNV from SLEV infection. Use of the W/S ratio as part of the testing algorithm to interpret MAC-ELISA results generates reportable probable cases quickly, alleviating the need for PRNT in most instances.

West Nile Virus

2016 ◽  
Author(s):  
Matthew Finn
Keyword(s):  
West Nile Virus ◽  
Rna Virus ◽  
Immunoglobulin M ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mosquito Vector ◽  
West Nile ◽  
Csf Analysis ◽  
Neuroinvasive Disease ◽  
Breeding Grounds ◽  
Arboviral Disease

West Nile virus (WNV) is a single-stranded RNA virus of the Flavivirus family that is transmitted via a mosquito vector, typically causing fever and capable of causing meningoencephalitis. Although mortality is low, it can lead to debilitating neuroinvasive disease in some patients. WNV is a leading cause of domestically-acquired arboviral disease and most commonly occurs in late August and early September. Consider WNV in otherwise unexplained cases of meningitis or encephalitis. Initial testing should consist of cerebrospinal fluid (CSF) analysis and West Nile immunoglobulin M enzyme-linked immunosorbent assay in serum and/or CSF. WNV is a nationally notifiable disease. Prevention remains the key to controlling this disease. Reducing the breeding grounds of the Culex mosquito and using insect repellant to prevent bites are two important strategies.

scholarly journals Rapidly progressive neurologic decline and morbilliform rash presenting in a patient with lymphoma

2018 ◽  
Vol 8 (4) ◽  
Author(s):  
Dean Ehrlich ◽  
Jennifer Phan ◽  
Gavin Hui ◽  
Alexandra Drakaki
Keyword(s):  
West Nile Virus ◽  
Lower Extremity ◽  
The United States ◽  
Immunoglobulin M ◽  
Initial Presentation ◽  
West Nile ◽  
Ongoing Research ◽  
Lower Extremity Weakness ◽  
Bilateral Lower Extremity ◽  
Morbilliform Rash

A 67-year-old male with past medical history of mantle cell lymphoma and atrial fibrillation presented with a truncal rash, bilateral lower extremity weakness, and confusion. Within three days of presentation, his condition rapidly deteriorated with the onset of diffuse flaccid paralysis, aphasia, and severe alteration in mental status. Initial results from serum studies, lumbar puncture, magnetic resonance imaging, and electroencephalogram were not diagnostic. However, on the ninth day after initial presentation, the West Nile Virus (WNV) immunoglobulin M antibody returned positive from the cerebrospinal fluid. West Nile Virus encephalitis is endemic worldwide, and is the most common viral encephalitis in the United States. WNV presents in a variety of ways, and the recognition by physicians is crucial due to the estimated 2- 12% mortality rate and significant longterm morbidity of neuroinvasive disease. The initial management and long term prognosis are points of ongoing research. This case represents a particularly profound example of neuroinvasive WNV. Our patient made a significant recovery after his initial presentation with aggressive supportive care, however still suffers from bilateral lower extremity weakness more than a year later.

scholarly journals NS1 Protein Secretion during the Acute Phase of West Nile Virus Infection

2005 ◽  
Vol 79 (22) ◽  
pp. 13924-13933 ◽  
Author(s):  
Joanne Macdonald ◽  
Jessica Tonry ◽  
Roy A. Hall ◽  
Brent Williams ◽  
Gustavo Palacios ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Real Time ◽  
Real Time Pcr ◽  
Diagnostic Marker ◽  
Nonstructural Protein ◽  
Immunoglobulin M ◽  
Enzyme Linked Immunosorbent Assay ◽  
Ns1 Protein ◽  
West Nile ◽  
Time Period

ABSTRACT The West Nile virus (WNV) nonstructural protein NS1 is a protein of unknown function that is found within, associated with, and secreted from infected cells. We systematically investigated the kinetics of NS1 secretion in vitro and in vivo to determine the potential use of this protein as a diagnostic marker and to analyze NS1 secretion in relation to the infection cycle. A sensitive antigen capture enzyme-linked immunosorbent assay (ELISA) for detection of WNV NS1 (polyclonal-ACE) was developed, as well as a capture ELISA for the specific detection of NS1 multimers (4G4-ACE). The 4G4-ACE detected native NS1 antigens at high sensitivity, whereas the polyclonal-ACE had a higher specificity for recombinant forms of the protein. Applying these assays we found that only a small fraction of intracellular NS1 is secreted and that secretion of NS1 in tissue culture is delayed compared to the release of virus particles. In experimentally infected hamsters, NS1 was detected in the serum between days 3 and 8 postinfection, peaking on day 5, the day prior to the onset of clinical disease; immunoglobulin M (IgM) antibodies were detected at low levels on day 5 postinfection. Although real-time PCR gave the earliest indication of infection (day 1), the diagnostic performance of the 4G4-ACE was comparable to that of real-time PCR during the time period when NS1 was secreted. Moreover, the 4G4-ACE was found to be superior in performance to both the IgM and plaque assays during this time period, suggesting that NS1 is a viable early diagnostic marker of WNV infection.

scholarly journals Identification of Novel Small-Molecule Inhibitors of West Nile Virus Infection

2007 ◽  
Vol 81 (21) ◽  
pp. 11992-12004 ◽  
Author(s):  
Amine O. Noueiry ◽  
Paul D. Olivo ◽  
Urszula Slomczynska ◽  
Yi Zhou ◽  
Ben Buscher ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Yellow Fever ◽  
High Throughput Screening ◽  
Yellow Fever Virus ◽  
The United States ◽  
Enzyme Linked Immunosorbent Assay ◽  
Chemical Library ◽  
Entry Site ◽  
West Nile ◽  
Subgenomic Replicon

ABSTRACT West Nile virus (WNV) has spread throughout the United States and Canada and now annually causes a clinical spectrum of human disease ranging from a self-limiting acute febrile illness to acute flaccid paralysis and lethal encephalitis. No therapy or vaccine is currently approved for use in humans. Using high-throughput screening assays that included a luciferase expressing WNV subgenomic replicon and an NS1 capture enzyme-linked immunosorbent assay, we evaluated a chemical library of over 80,000 compounds for their capacity to inhibit WNV replication. We identified 10 compounds with strong inhibitory activity against genetically diverse WNV and Kunjin virus isolates. Many of the inhibitory compounds belonged to a chemical family of secondary sulfonamides and have not been described previously to inhibit WNV or other related or unrelated viruses. Several of these compounds inhibited WNV infection in the submicromolar range, had selectivity indices of greater than 10, and inhibited replication of other flaviviruses, including dengue and yellow fever viruses. One of the most promising compounds, AP30451, specifically blocked translation of a yellow fever virus replicon but not a Sindbis virus replicon or an internal ribosome entry site containing mRNA. Overall, these compounds comprise a novel class of promising inhibitors for therapy against WNV and other flavivirus infections in humans.

scholarly journals Immunoglobulin G Avidity in Differentiation between Early and Late Antibody Responses to West Nile Virus

2006 ◽  
Vol 13 (1) ◽  
pp. 33-36 ◽  
Author(s):  
Janet L. Fox ◽  
Stuart L. Hazell ◽  
Leslie H. Tobler ◽  
Michael P. Busch
Keyword(s):  
United States ◽  
New York ◽  
West Nile Virus ◽  
The United States ◽  
Immunoglobulin M ◽  
West Nile ◽  
Marked Rise ◽  
Igm Antibodies ◽  
Igg Avidity ◽  
Igg Level

ABSTRACT In 1999 West Nile virus (WNV) surfaced in the United States in the city of New York and spread over successive summers to most of the continental United States, Canada, and Mexico. Because WNV immunoglobulin M (IgM) antibodies have been shown to persist for up to 1 year, residents in areas of endemicity can have persistent WNV IgM antibodies that are unrelated to a current illness with which they present. We present data on the use of IgG avidity testing for the resolution of conflicting data arising from the testing of serum or plasma for antibodies to WNV. Thirteen seroconversion panels, each consisting of a minimum of four samples, were used. All samples were tested for the presence of WNV IgM and IgG antibodies, and the avidity index for the WNV IgG-positive samples was calculated. Panels that exhibited a rise in the WNV IgM level followed by a sequential rise in the WNV IgG level were designated “primary.” Panels that exhibited a marked rise in the WNV IgG level followed by a sequential weak WNV IgM response and that had serological evidence of a prior flavivirus infection were designated “secondary.” All samples from the “primary” panels exhibited low avidity indices (less than 40%) for the first 20 to 30 days after the recovery of the index sample (the sample found to be virus positive). All of the “secondary” samples had elevated WNV IgG levels with avidity indices of ≥55%, regardless of the number of days since the recovery of the index sample. These data demonstrate that it is possible to differentiate between recent and past exposure to WNV or another flavivirus through the measurement of WNV IgG avidity indices.

scholarly journals Comparison of a Dipstick Assay for Detection of Brucella-Specific Immunoglobulin M Antibodies with Other Tests for Serodiagnosis of Human Brucellosis

2003 ◽  
Vol 10 (4) ◽  
pp. 612-615 ◽  
Author(s):  
Encarnación Clavijo ◽  
Ramón Díaz ◽  
Ángel Anguita ◽  
Antonio García ◽  
Alfonso Pinedo ◽  
...  
Keyword(s):  
Agglutination Test ◽  
Immunoglobulin M ◽  
Enzyme Linked Immunosorbent Assay ◽  
Human Brucellosis ◽  
Serological Response ◽  
Igm Elisa ◽  
Specific Immunoglobulin ◽  
History Of ◽  
Standard Serum ◽  
Serum Agglutination

ABSTRACT A dipstick assay for the detection of Brucella-specific immunoglobulin M (IgM) antibodies was evaluated by studying the serological response of 133 cultures and or serologically confirmed patients with brucellosis in its different stages along with those of 34 healthy controls. As regards patients with illness less than 3 months in duration, 93.1% tested positive by the dipstick assay, a percentage similar to that obtained in the standard serum agglutination test (SAT) (92.0%), somewhat lower than that obtained by culture (100%) and higher than that obtained by IgM enzyme-linked immunosorbent assay (ELISA) (80.5%). SAT was the most sensitive test (87.0%) for patients with illness more than 3 months in duration, followed by culture (50%), the dipstick assay (28.3%), and IgM ELISA (7.5%). The results demonstrate that the dipstick assay could well be used in the serodiagnosis of patients with acute brucellosis, as well as to identify patients with a long history of the illness. Under laboratory conditions this test has the advantage of being quick and IgM antibody-specific.

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