Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

Volume 23, Number 8—August 2017


Serologic Evidence of Powassan Virus Infection in Patients with Suspected Lyme Disease1

Holly M. FrostComments to Author , Anna M. Schotthoefer, Angela M. Thomm, Alan P. Dupuis, Sue C. Kehl, Laura D. Kramer, Thomas R. Fritsche, Yvette A. Harrington, and Konstance K. Knox
Author affiliations: Marshfield Clinic Research Foundation, Minocqua, Wisconsin, USA (H.M. Frost); Marshfield Clinic Research Foundation, Marshfield, Wisconsin, USA (H.M. Frost, A.M. Schotthoefer, T.R. Fritsche); Coppe Laboratories, Waukesha, Wisconsin, USA (A.M. Thomm, Y.A. Harrington, K.K. Knox); New York State Department of Health, Slingerlands, New York, USA (A.P. Dupuis II, L.D. Kramer); Medical College of Wisconsin, Milwaukee, Wisconsin, USA (S.C. Kehl)

Main Article

Table 1

TBEV-C and Borrelia burgdorferi serologic test results and POWV RT-PCR test results of patients with positive POWV IFA assay results, Wisconsin, July–August 2015*

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
1**†† + +
2†† + + + IgG and IgM
3†† + + IgG and IgM
4†† + + IgG and IgM
5 + + +
6 + + IgG and IgM
7 + + IgM
8 + + + + + IgG and IgM


IgG and IgM
Patients screened by chemical methods
1c + + NA
2c†† + + + + NA

*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.

Main Article

1Preliminary results from this study were presented at IDWeek; October 26–30, 2016; New Orleans, Louisiana, USA.