Volume 23, Number 8—August 2017
Dispatch
Serologic Evidence of Powassan Virus Infection in Patients with Suspected Lyme Disease1
Table 1
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 |
9†† |
+ |
– |
+ |
– |
– |
– |
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.
1Preliminary results from this study were presented at IDWeek; October 26–30, 2016; New Orleans, Louisiana, USA.