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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 2

Clinical features and histories of patients with positive POWV IFA assay results, Wisconsin, July–August 2015*

Patient no. POWV test results Borrelia burgdorferi test results† Clinical features Comorbidities CDC case classification Travel history Location of tick exposure‡ Vaccine history§
Suspected TBD patients
IgG >1:40 IgG and IgM 56-year-old man with 2-wk history of erythema migrans. Treated with doxycycline for 14 d. Metabolic syndrome, hypertension, 9 y previous had WNV infection Midwest
2 IgG >1:40, PRNT 1:160 IgG and IgM 53-year-old man with 3-d history of urticarial rash, malaise, fever, and fatigue. Patient had chills 3 wks prior that resolved. CBC results: leukocytes 7.3 × 109/L, Hb 13.6 g/dL, Hct 39.9%, Plt count 322 × 103/µL; CRP 3.9 nmol/L. PCR neg for Anaplasma sp., Babesia sp., and Ehrlichia muris. Treated with doxycycline for 21 d with complete resolution of symptoms. No history of neuroinvasive disease or TBD. Hyperlipidemia
3 IgM >1:20 IgG and IgM 14-year-old girl with 3-d history of urticarial rash. CBC results: leukocytes 8.8 × 109/L, Hb 13.0 g/dL, Hct 40.3%, Plt 393 × 103/µL; CRP 3.6 nmol/L. Treated with doxycycline for 14 d. None
4 IgM >1:20 IgG and IgM 4-year-old girl with 1-wk history of fever (103°F), listless, headache, fatigue, and maculopapular rash. PCR neg for Anaplasma sp., Babesia sp., and Ehrlichia muris. Treated with amoxicillin for 21 d. None Probable
IgM >1:20
IgG and IgM
3-year-old girl with 1-wk history of intermittent fever, fussiness, and erythema migrans. After development of an urticarial rash, treatment with cefuroxime was changed to amoxicillin for 21 d.


Patients screened by chemical methods
1c IgG >1:40 Neg 68-year-old man with no signs or symptoms of acute infectious disease. No history of neuroinvasive disease or TBD. Died from liver cirrhosis. Coronary artery disease, liver cirrhosis, end stage renal disease
2c IgM >1:20, IgG >1:40 Neg 76-year-old woman with 2-d history of fever, chills, and MRSA infection of the right hand. Mild abdominal pain and diarrhea occurred later in course. CBC results: leukocytes 13.7 × 109/L, Hb 9.2 g/dL, Hct 29.7%, Plt 180 × 103/µL; CRP 1.5 nmol/L; Procalcitonin 0.1 µg/L. Received daptomycin for 16 d with full recovery. Currently deceased, unknown cause of death. Congestive heart failure, rheumatoid arthritis on immune-suppressive medications Probable

*CBC, complete blood cell count; CDC, Centers for Disease Control and Prevention; CRP, C-reactive protein; Hb, hemoglobin; Hct, hematocrit; IFA, immunofluorescence antibody; MRSA, multidrug-resistant Staphylococcus aureus; neg, negative; Plt, platelet; POWV, Powassan virus; PRNT, plaque reduction neutralization test; WNV, West Nile virus; TBD, tickborne disease; –, no history.
†Samples were screened by EIA and followed up by Western blot.
‡Patient-reported tick exposure.
§Known history of vaccination against yellow fever virus, Japanese encephalitis virus, or tick-borne encephalitis virus.
¶Cross-reactivity on POWV IgG IFA assay is consistent with a history of West Nile virus infection.

Main Article

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

Page created: July 17, 2017
Page updated: July 17, 2017
Page reviewed: July 17, 2017
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