Utility of polymerase chain reaction and direct fluorescent antibody test for diagnosis of mucocutaneous herpes virus infection

BACKGROUND: Herpes simplex virus (HSV) and varicella-zoster virus (VZV) infections have a wide range of clinical manifestations; they may resemble each other and can be confused with other diseases. OBJECTIVES: In this retrospective study, we aimed to compare direct fluorescent antibody testing (DFA) with polymerase chain reaction (PCR) for the detection of VZV or HSV in mucocutaneous lesions, and to assess whether DFA should be used additionally for faster diagnosis. Further, we investigated whether laboratory results affect treatment initiation. METHODS: Mucocutaneous swabs of 182 cases were tested for VZV, HSV-1 and HSV-2 using DFA and PCR between January 2019 and August 2021 at the University Hospital Zurich. The diagnostic accuracy of DFA was assessed by comparing it to the PCR results. The turnaround time (TAT) of both methods was evaluated and the time until treatment initiation in relation to results reporting was measured. RESULTS: Significant disagreement between DFA and PCR results were observed (p