Specific Antibody Responses to West Nile Virus Infections in Horses Preimmunized with Inactivated Japanese Encephalitis Vaccine: Evaluation of Blocking Enzyme-Linked Immunosorbent Assay and Complement-Dependent Cytotoxicity Assay

ABSTRACT An epitope-blocking enzyme-linked immunosorbent assay (b-ELISA) was evaluated for the diagnosis of West Nile virus (WNV) infections in humans. Sera from patients diagnosed with WNV infections from an outbreak in 2003 in Colorado and from patients diagnosed with dengue virus infections from Mexico and Thailand were tested with the b-ELISA. The b-ELISAs were performed using the WNV-specific monoclonal antibody (MAb) 3.1112G and the flavivirus-specific MAb 6B6C-1. Although the WNV-specific b-ELISA was effective in diagnosing WNV infections in humans from Colorado, it was not efficacious for diagnosing WNV infections in serum specimens from Mexico and Thailand. In serum specimens from patients from Colorado, the WNV b-ELISA and the WNV plaque reduction neutralization test showed an overall agreement of 91%. The sensitivity and specificity of the WNV b-ELISA were 89% and 92%, respectively, with a false-positive rate of 5%, based on receiver operating characteristic analysis. In contrast, false-positive rate results in specimens from the countries of Mexico and Thailand, where flaviviruses are endemic, were 79% and 80%, presumably due to the presence of antibodies resulting from previous dengue virus infections in Mexico and/or Japanese encephalitis virus infections or vaccination in Thailand. Thus, in regions where people have experienced previous or multiple flavivirus infections, the use of the b-ELISA for WNV diagnosis is contraindicated.

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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

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.11.6.1130-1133.2004 ◽

2004 ◽

Vol 11 (6) ◽

pp. 1130-1133 ◽

Cited By ~ 22

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.

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Epitope-Blocking Enzyme-Linked Immunosorbent Assay To Differentiate West Nile Virus from Japanese Encephalitis Virus Infections in Equine Sera

Clinical and Vaccine Immunology ◽

10.1128/cvi.00051-07 ◽

2007 ◽

Vol 14 (8) ◽

pp. 1024-1031 ◽

Cited By ~ 38

Author(s):

Yoko Kitai ◽

Mizue Shoda ◽

Takashi Kondo ◽

Eiji Konishi

Keyword(s):

West Nile Virus ◽

Japanese Encephalitis Virus ◽

Japanese Encephalitis ◽

Immunosorbent Assay ◽

Nonstructural Protein ◽

Encephalitis Virus ◽

Enzyme Linked Immunosorbent Assay ◽

West Nile ◽

Serological Tests ◽

Nonstructural Protein 1

ABSTRACT West Nile virus (WNV) is now widely distributed worldwide, except in most areas of Asia where Japanese encephalitis virus (JEV) is distributed. Considering the movement and migration of reservoir birds, there is concern that WNV may be introduced in Asian countries. Although manuals and guidelines for serological tests have been created in Japan in preparedness for the introduction of WNV, differential diagnosis between WNV and JEV may be complicated by antigenic cross-reactivities between these flaviviruses. Here, we generated a monoclonal antibody specific for the nonstructural protein 1 (NS1) of WNV and established an epitope-blocking enzyme-linked immunosorbent assay that can differentiate WNV from JEV infections in horse sera. Under conditions well suited for our assay system, samples collected from 95 horses in Japan (regarded as negative for WNV antibodies), including those collected from horses naturally infected with JEV, showed a mean inhibition value of 8.2% and a standard deviation (SD) of 6.5%. However, inhibition values obtained with serum used as a positive control (obtained after 28 days from a horse experimentally infected with WNV) in nine separate experiments showed a mean of 54.4% and an SD of 7.1%. We tentatively determined 27.6% (mean + 3 × SD obtained with 95 negative samples) as the cutoff value to differentiate positive from negative samples. Under this criterion, two horses experimentally infected with WNV were diagnosed as positive at 12 and 14 days, respectively, after infection.

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Hemagglutinin-specific antibody responses in immunoglobulin G, A, and M isotypes as measured by enzyme-linked immunosorbent assay after primary or secondary infection of humans with influenza A virus.

Infection and Immunity ◽

10.1128/iai.41.2.540-545.1983 ◽

1983 ◽

Vol 41 (2) ◽

pp. 540-545 ◽

Cited By ~ 49

Author(s):

D B Burlington ◽

M L Clements ◽

G Meiklejohn ◽

M Phelan ◽

B R Murphy

Keyword(s):

Influenza A Virus ◽

Immunosorbent Assay ◽

Specific Antibody ◽

Immunoglobulin G ◽

Influenza A ◽

Secondary Infection ◽

Antibody Responses ◽

Enzyme Linked Immunosorbent Assay

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West Nile Virus and Related Flavivirus in European Wild Boar (Sus scrofa), Latium Region, Italy: A Retrospective Study

Animals ◽

10.3390/ani10030494 ◽

2020 ◽

Vol 10 (3) ◽

pp. 494

Author(s):

Angela Petruccelli ◽

Tiziana Zottola ◽

Gianmarco Ferrara ◽

Valentina Iovane ◽

Cristina Di Russo ◽

...

Keyword(s):

West Nile Virus ◽

Wild Boar ◽

Specific Antibody ◽

Central Italy ◽

Enzyme Linked Immunosorbent Assay ◽

Rt Pcr ◽

Serum Samples ◽

West Nile ◽

Wild Boars ◽

European Wild Boar

Background: A retrospective sero-survey for evidence of West Nile virus (WNV) infection in European wild boar (Sus scorfa) was conducted in the Latium region, Italy, on stored serum samples of the period November 2011 to January 2012. Methods: Sera were collected from 168 European wild boars and screened for antibodies to WNV and other Flaviviruses by competitive enzyme linked immunosorbent assay (cELISA). All sera positive for Flavivirus antibodies by cELISA were further examined by virus neutralization test (VNT). To test the presence of Flavivirus RNA in samples, an RT-PCR was performed using a pan-Flavivirus primers pair. Results: Thirteen wild boars (7.73%) were seropositive for Flaviviruses. The hemolysis of serum samples limited the interpretation of the VNT for 7 samples, confirming the presence of specific antibody against WNV in a single European wild boar serum sample. The presence of ELISA positive/VNT negative samples suggests the occurrence of non-neutralizing antibodies against WNV or other antigen-related Flaviviruses. No samples resulted positive for Flavivirus by RT-PCR assay. Conclusion: Although a moderately high percentage of animals with specific antibody for WNV has been detected in wild boar in other surveillance studies in Europe, this has not been reported previously in Italy. Together, these data indicate that European wild boar are exposed to WNV and/or other related-Flavivirus in central Italy and confirm the usefulness of wild ungulates, as suitable Flavivirus sentinels.

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Persistence of Antibodies to West Nile Virus in Naturally Infected Rock Pigeons (Columba livia)

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.12.5.665-667.2005 ◽

2005 ◽

Vol 12 (5) ◽

pp. 665-667 ◽

Cited By ~ 61

Author(s):

Samantha E. J. Gibbs ◽

Douglas M. Hoffman ◽

Lillian M. Stark ◽

Nicole L. Marlenee ◽

Bradley J. Blitvich ◽

...

Keyword(s):

West Nile Virus ◽

Immunosorbent Assay ◽

Neutralization Test ◽

Columba Livia ◽

Maternal Antibodies ◽

Enzyme Linked Immunosorbent Assay ◽

West Nile ◽

Entire Study ◽

Plaque Reduction Neutralization Test ◽

Antibody Persistence

ABSTRACT Wild caught rock pigeons (Columba livia) with antibodies to West Nile virus were monitored for 15 months to determine antibody persistence and compare results of three serologic techniques. Antibodies persisted for the entire study as detected by epitope-blocking enzyme-linked immunosorbent assay and plaque reduction neutralization test. Maternal antibodies in squabs derived from seropositive birds persisted for an average of 27 days.

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