Session Time: 5:30pm-6:30pm
Presentation Time: 5:30pm-6:30pm
Location: Exhibit Hall E
West Nile Virus (WNV) symptoms develop 2-15 days after exposure with a short period of viremia (6-7 days). It is possible to detect WNV in tissues long after viremia. In 2014* there were 733 cases of WNV with 23 deaths in California (CA). Organ donor-derived infection can occur despite a negative WNV NAT result. There is substantial serological cross-reactivity between WNV and other flaviviruses such as San Luis Encephalitis virus (SLEV) and Dengue virus (DENV). Previous studies indicate a high prevalence of organ donors with evidence of prior exposure to DENV in CA (ATC 2011). However, cross-reactivity between infections due to WNV and DENV at the population level is poorly documented.
Aim: To evaluate IgM anti-WNV cross-reactivity among organ donors in CA (4 years of data).
Material and Methods: Between 10/2011 and 11/2014, 1,511 donors were tested with EIA for IgM anti-WNV (Focus Technologies) and with the confirmatory Plaque Reduction Neutralization Test (PRNT) against WNV, DENV, and SLEV (Viral and Rickettsial Disease Laboratory, Richmond, CA). All donors were screened using WNV Procleix NAT (Novartis) for WNV RNA.
Results: Ten donors were repetitively reactive (RR) IgM anti-WNV+ by EIA. PRNT data were not available for 2 donors. Four (50%) donors were confirmed as WNV+ and 2 (25%) as DENV+ by PRNT. There were no WNV NAT+ donors. One showed PRNT reactivity compatible with recent DENV infection or, perhaps an original antigenic sin related to flaviviruses cross-reactivity.
|Yr.||Tested||RNA||RR EIA||Confirmed||Confirmed as DENV+||Confirmed as SLEV+|
|2012||464||0||4 (0.9%)||3 (100%)||0||0|
|2014*||412||0||3 (1.0%)||1 (33%)||2 (66%)||0|
Conclusions: More (p<0.01) IgM WNV reactive donors were identified in 2014 than in 2013. Donors with evidence of recent exposure to WNV or DENV are relatively common (∼1/200). WNV IgM screening potentially prevented multiple transmissions of WNV. Lack of WNV RNA+ donors during years of testing underscores the importance of screening for IgM WNV in addition to WNV NAT. A low level of IgM WNV cross-reactivity with other flaviviruses was found. OPOs should elect the most optimal WNV screening strategy.
To cite this abstract in AMA style:Chinchilla-Reyes C, Tanglao D, Mone T, Koss M, Nowicki M. Screening for West Nile Virus in California: Resolving IgM Anti-WNV in the Area With Dengue Seroprevalence [abstract]. Am J Transplant. 2015; 15 (suppl 3). https://atcmeetingabstracts.com/abstract/screening-for-west-nile-virus-in-california-resolving-igm-anti-wnv-in-the-area-with-dengue-seroprevalence/. Accessed March 8, 2021.
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