Volume 23, Number 8—August 2017
Serologic Evidence of Powassan Virus Infection in Patients with Suspected Lyme Disease1
|Patient no.||TBEV-C IgM EIA||TBEV-C IgG EIA||POWV IgM IFA assay†||POWV IgG IFA assay‡||POWV PRNT§||POWV RT-PCR¶||B. burgdorferi#|
|Suspected TBD patients|
|2††||–||+||–||+||+||–||IgG and IgM|
|3††||+||–||+||–||–||–||IgG and IgM|
|4††||+||–||+||–||–||–||IgG and IgM|
|6||+||–||+||–||–||–||IgG and IgM|
|8||+||+||+||+||+||–||IgG and IgM|
||IgG and IgM
|Patients screened by chemical methods|
*EIA, enzyme immunoassay; IFA, immunofluorescence antibody; NA, not assayed; POWV, Powassan virus; PRNT, plaque reduction neutralization test; PRNT90, >90% plaque reduction neutralization test; RT-PCR, reverse transcription PCR; TBD, tickborne disease; TBEV-C, tick-borne encephalitis virus complex.
†Titers >1:20 were considered positive.
‡Titers >1:40 were considered positive.
§Positive if sample had a PRNT90 titer.
¶Not performed in specimens with a negative POWV IgM IFA assay result.
#Samples were screened by EIA and followed up by Western blot.
**Cross-reactivity on POWV IgG IFA assay is consistent with a history of West Nile virus infection.
††Clinical data were available.
1Preliminary results from this study were presented at IDWeek; October 26–30, 2016; New Orleans, Louisiana, USA.