title: Laboratory diagnosis and characteristics of breakthrough varicella in children.
abstract: The atypical features of varicella in vaccinated persons (breakthrough varicella [BTV]) present diagnostic challenges. We examined varicella-zoster virus (VZV) polymerase chain reaction (PCR) and immunoglobulin (Ig) M and IgG serologic test results for confirming BTV cases. Among 33 vaccinated children with varicella-like rash, we identified wild-type VZV in 58% overall and in 76% of those with adequate tissue specimens; no vaccine-type virus was found. Of the 12 subjects with PCR-confirmed BTV and acute-phase serum samples, 9 had detectable IgM, and all had highly elevated acute-phase IgG titers. Six subjects with negative PCR results had lower IgG titers and negative IgM results. Although PCR is the preferred method for laboratory confirmation of BTV, a positive serum varicella IgM test result should also be considered to be diagnostic in a suspected BTV case; however, a negative IgM test result cannot be used to rule out the diagnosis. The value of highly elevated IgG titers needs further evaluation. Larger studies are needed to confirm these results.
authors.affiliation: Center for Health Research, Kaiser Permanente Northwest, Portland, Oregon 97227, USA. Sheila.Weinmann@kpchr.org
authors.forename: Sheila
authors.initials: S
authors.lastname: Weinmann
authors.forename: Colleen
authors.initials: C
authors.lastname: Chun
authors.forename: John P
authors.initials: JP
authors.lastname: Mullooly
authors.forename: Karen
authors.initials: K
authors.lastname: Riedlinger
authors.forename: Heather
authors.initials: H
authors.lastname: Houston
authors.forename: Vladimir N
authors.initials: VN
authors.lastname: Loparev
authors.forename: D Scott
authors.initials: DS
authors.lastname: Schmid
authors.forename: Jane F
authors.initials: JF
authors.lastname: Seward
mesh_terms: D000208:Acute Disease; D000914:Antibodies, Viral / Q000097:blood; D002644:Chickenpox / Q000175:diagnosis* / Q000503:physiopathology* / Q000517:prevention & control / Q000821:virology; D019433:Chickenpox Vaccine / Q000008:administration & dosage*; D002648:Child; D002675:Child, Preschool; D003289:Convalescence; D004279:DNA, Viral / Q000032:analysis / Q000302:isolation & purification; D005260:Female; D014645:Herpesvirus 3, Human / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D016133:Polymerase Chain Reaction / Q000379:methods; D014611:Vaccination / Q000706:statistics & numerical data*
chemical_list: D000914:Antibodies, Viral; D019433:Chickenpox Vaccine; D004279:DNA, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M