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

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.

2004 ◽  
Vol 11 (6) ◽  
pp. 1130-1133 ◽  
Author(s):  
Denise A. Martin ◽  
Amanda Noga ◽  
Olga Kosoy ◽  
Alison J. Johnson ◽  
Lyle R. Petersen ◽  
...  

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.


2006 ◽  
Vol 42 (3) ◽  
pp. 170-177 ◽  
Author(s):  
Reid Gerhardt

The accidental introduction of West Nile Virus into New York City from the Old World in 1999 resulted in an epidemic in humans, horses, and birds that swept to the west coast in just 3 years. The virus is transmitted by infective mosquitoes among susceptible native birds, which serve as amplifying hosts. Clinical disease occurs in humans and horses, but not enough virus is produced in their blood to infect other mosquitoes; therefore, humans and horses are considered dead-end hosts. Humans can best protect themselves by remaining indoors during periods of high mosquito activity and/or by using recommended repellents. Effective vaccines are available for horses.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S239-S239
Author(s):  
Arunmozhi S Aravagiri ◽  
Scott Kubomoto ◽  
Ayutyanont Napatkamon ◽  
Sarah Wilson ◽  
Sudhakar Mallela

Abstract Background Aseptic meningitis can be caused by an array of microorganisms, both bacterial and non-bacterial, as well as non-infectious conditions. Some etiologies of aseptic meningitis require treatment with antibiotics, antiviral, antifungals, anti-parasitic agents, immunosuppressants, and or chemotherapy. There are limited diagnostic tools for diagnosing certain types of aseptic meningitis, therefore knowing the differential causes of aseptic meningitis, and their relative percentages may assist in diagnosis. Review of the literature reveals that there are no recent studies of etiologies of aseptic meningitis in the United States (US). This is an epidemiologic study to delineate etiologies of aseptic meningitis in a large database of 185 HCA hospitals across the US. Methods Data was collected from January 2016 to December 2019 on all patients diagnosed with meningitis. CSF PCR studies, and CSF antibody tests were then selected for inclusion. Results Total number of encounters were 3,149 hospitalizations. Total number of individual labs analyzed was 10,613, and of these 262 etiologies were identified. 23.6% (62) of cases were due to enterovirus, 18.7% (49) due to HSV-2, 14.5% (38) due to West Nile virus, 13.7% (36) due to Varicella zoster (VZV), 10.5% (27) due to Cryptococcus. Additionally, we analyzed the rate of positive test results by region. Nationally, 9.7% of tests ordered for enterovirus were positive. In contrast, 0.5% of tests ordered for HSV 1 were positive. The southeastern United States had the highest rate of positive tests for HSV 2 (7% of tests ordered for HSV 2 were positive). The central United States had the highest rate of positive test for West Nile virus (11% of tests ordered for West Nile were positive). The northeastern region and the highest rate of positive tests for varicella zoster (18%). Table 1: Percentage of positive CSF tests (positive tests/tests ordered) Table 2: Lists the number of HIV patients and transplant patients that had positive CSF PCR/serologies Figure 1: Percentage of positive CSF tests in each region Conclusion Approximately 40% of aseptic meningitis population had treatable etiologies. A third of the Cryptococcus meningitis population had HIV. Furthermore, enteroviruses had the majority of cases within the US, which are similar to studies done in other parts of the world. Disclosures All Authors: No reported disclosures


2015 ◽  
Vol 92 (5) ◽  
pp. 1013-1022 ◽  
Author(s):  
Micah B. Hahn ◽  
Roger S. Nasci ◽  
Mark J. Delorey ◽  
Rebecca J. Eisen ◽  
Andrew J. Monaghan ◽  
...  

Acta Tropica ◽  
2018 ◽  
Vol 185 ◽  
pp. 242-250 ◽  
Author(s):  
Justin K. Davis ◽  
Geoffrey P. Vincent ◽  
Michael B. Hildreth ◽  
Lon Kightlinger ◽  
Christopher Carlson ◽  
...  

2014 ◽  
Vol 91 (4) ◽  
pp. 677-684 ◽  
Author(s):  
Michael C. Wimberly ◽  
Aashis Lamsal ◽  
Paolla Giacomo ◽  
Ting-Wu Chuang

2001 ◽  
Vol 75 (9) ◽  
pp. 4040-4047 ◽  
Author(s):  
Brent S. Davis ◽  
Gwong-Jen J. Chang ◽  
Bruce Cropp ◽  
John T. Roehrig ◽  
Denise A. Martin ◽  
...  

ABSTRACT Introduction of West Nile (WN) virus into the United States in 1999 created major human and animal health concerns. Currently, no human or veterinary vaccine is available to prevent WN viral infection, and mosquito control is the only practical strategy to combat the spread of disease. Starting with a previously designed eukaryotic expression vector, we constructed a recombinant plasmid (pCBWN) that expressed the WN virus prM and E proteins. A single intramuscular injection of pCBWN DNA induced protective immunity, preventing WN virus infection in mice and horses. Recombinant plasmid-transformed COS-1 cells expressed and secreted high levels of WN virus prM and E proteins into the culture medium. The medium was treated with polyethylene glycol to concentrate proteins. The resultant, containing high-titered recombinant WN virus antigen, proved to be an excellent alternative to the more traditional suckling-mouse brain WN virus antigen used in the immunoglobulin M (IgM) antibody-capture and indirect IgG enzyme-linked immunosorbent assays. This recombinant antigen has great potential to become the antigen of choice and will facilitate the standardization of reagents and implementation of WN virus surveillance in the United States and elsewhere.


2006 ◽  
Vol 42 (11) ◽  
pp. 1527-1535 ◽  
Author(s):  
C. D. Paddock ◽  
W. L. Nicholson ◽  
J. Bhatnagar ◽  
C. S. Goldsmith ◽  
P. W. Greer ◽  
...  

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