Improved detection of varicella zoster infection with a spin amplification shell vial technique and blind passage

Abstract

Background: Among the methods available for the diagnosis of varicella zoster virus (VZV) infections, only tissue culture yields an isolate available for antiviral susceptibility testing or pathogenesis studies. However, conventional tube tissue culture (TC) has a low sensitivity. Objective: To increase the recovery rate of VZV in tissue culture. Study design: Clinical specimens submitted for VZV isolation were processed by TC and rapid shell vial (SV) techniques followed by a blind passage (BP). For SV, two incubation times and two mAbs, directed against viral-early or immediate-early antigens, were compared. Results: Isolation of VZV using the SV stained at 72 h postinoculation was more sensitive (88–96%) than TC (50–67%), or the SV technique at 48 h (66–70%). It was also more rapid than TC (9.6 days). The comparison of mAbs yielded similar results in SV. Blind passage of SV at 7 days postinoculation further increased detection. Conclusions: SV combined with BP is the method of choice for VZV isolation.