scholarly journals Equine seroprevalence of West Nile virus antibodies in the UK in 2019

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Arran J. Folly ◽  
Elisabeth S. L. Waller ◽  
Fiona McCracken ◽  
Lorraine M. McElhinney ◽  
Helen Roberts ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Rna Virus ◽  
Clinical History ◽  
Immunoglobulin M ◽  
Serum Samples ◽  
West Nile ◽  
Recent Infection ◽  
Igm Antibodies ◽  
Epidemiological Surveys ◽  
The Uk

Abstract Background West Nile virus (WNV) is a single-stranded RNA virus that can cause neurological disease in both humans and horses. Due to the movement of competent vectors and viraemic hosts, WNV has repeatedly emerged globally and more recently in western Europe. Within the UK, WNV is a notifiable disease in horses, and vaccines against the virus are commercially available. However, there has been no investigation into the seroprevalence of WNV in the UK equine population to determine the extent of vaccination or to provide evidence of recent infection. Methods Equine serum samples were obtained from the Animal and Plant Health Agency’s equine testing service between August and November 2019. A total of 988 serum samples were selected for horses resident in South East England. WNV seroprevalence was determined using two enzyme-linked immunosorbent assays (ELISAs) to detect total flavivirus antibodies and WNV-specific immunoglobulin M (IgM) antibodies. Positive IgM results were investigated by contacting the submitting veterinarian to establish the clinical history or evidence of prior vaccination of the horses in question. Results Within the cohort, 274 samples tested positive for flavivirus antibodies, of which two subsequently tested positive for WNV-specific IgM antibodies. The follow-up investigation established that both horses had been vaccinated prior to serum samples being drawn, which resulted in an IgM-positive response. All the samples that tested positive by competition ELISA were from horses set to be exported to countries where WNV is endemic. Consequently, the positive results were likely due to previous vaccination. In contrast, 714 samples were seronegative, indicating that the majority of the UK equine population may be susceptible to WNV infection. Conclusions There was no evidence for cryptic WNV infection in a cohort of horses sampled in England in 2019. All IgM-seropositive cases were due to vaccination; this should be noted for future epidemiological surveys in the event of a disease outbreak, as it is not possible to distinguish vaccinated from infected horses without knowledge of their clinical histories.

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 Induction of Epitope-Specific Neutralizing Antibodies against West Nile Virus

2007 ◽  
Vol 81 (21) ◽  
pp. 11828-11839 ◽  
Author(s):  
Theodore Oliphant ◽  
Grant E. Nybakken ◽  
S. Kyle Austin ◽  
Qing Xu ◽  
Jonathan Bramson ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Human Serum ◽  
Neutralizing Antibodies ◽  
Immunoglobulin M ◽  
Late Time ◽  
Loss Of Function ◽  
Serum Samples ◽  
West Nile ◽  
E Protein ◽  
Low Levels

ABSTRACT Previous studies have established that an epitope on the lateral ridge of domain III (DIII-lr) of West Nile virus (WNV) envelope (E) protein is recognized by strongly neutralizing type-specific antibodies. In contrast, an epitope against the fusion loop in domain II (DII-fl) is recognized by flavivirus cross-reactive antibodies with less neutralizing potential. Using gain- and loss-of-function E proteins and wild-type and variant WNV reporter virus particles, we evaluated the expression pattern and activity of antibodies against the DIII-lr and DII-fl epitopes in mouse and human serum after WNV infection. In mice, immunoglobulin M (IgM) antibodies to the DIII-lr epitope were detected at low levels at day 6 after infection. However, compared to IgG responses against other epitopes in DI and DII, which were readily detected at day 8, the development of IgG against DIII-lr epitope was delayed and did not appear consistently until day 15. This late time point is notable since almost all death after WNV infection in mice occurs by day 12. Nonetheless, at later time points, DIII-lr antibodies accumulated and comprised a significant fraction of the DIII-specific IgG response. In sera from infected humans, DIII-lr antibodies were detected at low levels and did not correlate with clinical outcome. In contrast, antibodies to the DII-fl were detected in all human serum samples and encompassed a significant percentage of the anti-E protein response. Our experiments suggest that the highly neutralizing DIII-lr IgG antibodies have little significant role in primary infection and that the antibody response of humans may be skewed toward the induction of cross-reactive, less-neutralizing antibodies.

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 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 Significance of IgG avidity test in diagnosis of west Nile virus infection

2017 ◽  
Vol 70 (11-12) ◽  
pp. 395-401
Author(s):  
Ivana Hrnjakovic-Cvjetkovic ◽  
Jelena Radovanov ◽  
Gordana Kovacevic ◽  
Aleksandra Patic ◽  
Natasa Nikolic ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Virus Infection ◽  
Acute Infection ◽  
Late Phase ◽  
West Nile Virus Infection ◽  
Igg Antibodies ◽  
Serum Samples ◽  
West Nile ◽  
Igm Antibodies ◽  
Igg Avidity

Introduction. Serological tests appear to be the method of choice for establishing the diagnosis in the late phase of West Nile virus infection. Long persistence of IgM antibodies against West Nile virus is described and may be a problem for determination of the time of acquisition of West Nile virus infection. The aim of the study was to estimate the significance of IgG avidity determination in establishing the diagnosis of West Nile virus infection. Material and Methods. In a study 56 serum samples seropositive against West Nile virus were included. 24 serum samples were collected in 2012 from healthy residents of South-Backa district and 32 serum samples were collected in 2014 from 124 patients suspected of having West Nile virus infection. Commercial enzyme-linked immunosorbent tests were used for the detection of West Nile virus-specific IgM and IgG antibodies and IgG avidity. Results. Out of 124 patients suspected of having West Nile virus infection, 32 (25.8%) were seropositive for West Nile virus antibodies. Acute infection was laboratory confirmed in 15 (46.9%) cases. All patients with acute infection were West Nile virus IgM positive, 13 (85%) were West Nile virus IgG positive, and 2 (15%) had a borderline result for West Nile virus IgG antibodies. Out of 32 seropositive patients the presence of IgM antibodies was determined in 22 (68.7%). In a group of samples with high IgG avidity values, 6 were IgM positive, while 8 were IgM negative. Conclusion. West Nile virus IgM and IgG antibody serological assays alone are not sufficient for the accurate and reliable diagnosis of WNV infection. West Nile virus IgG avidity testing is necessary to ensure the differential diagnosis of acute from past West Nile virus infection.

Suspect West Nile virus encephalomyelitis in an imported horse in the UK

2016 ◽  
Vol 29 (6) ◽  
pp. 321-324 ◽  
Author(s):  
S. Gonzalez-Medina ◽  
R. Alzola ◽  
J. R. Newton
Keyword(s):  
West Nile Virus ◽  
West Nile ◽  
The Uk

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

Animals ◽  
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.

Sign in / Sign up

Export Citation Format

Share Document