Rapid Detection of Herpes Simplex Virus and Varicella‐zoster Virus in Clinical Specimens by the Use of Staphylococcus Aureus Rich in Protein A

Herpes simplex virus (HSV) type 1 and type 2 and varicella-zoster virus (VZV) were detected in cytospin preparations from clinical material by using specific antisera and Staphylococcus aureus, Cowan 1 strain, rich in protein A (SRA). Virus was isolated in tissue culture from 22 of the 30 specimens submitted for examination. Eighteen isolates showed cytopathic effect characteristic of HSV infection and 4 of VZV. In the cytospin preparations of the same samples HSV was detected in 15, two contained too few cells to allow a reliable diagnosis and one sample was negative when the SRA reagent was used. In the cytospin preparations of 2 of the 8 samples, which did not show cytopathic effect on isolation in tissue culture, HSV was detected by the SRA. This points to the possible presence of inactive virus in the specimens. All 4 cases of VZV infection were diagnosed correctly with the staphylococcal reagent. No reaction was observed between VZV antigens and rabbit anti-HSV sera. Cells in which viral infection was detected by specific antisera and SRA did not show staphylococcal adherence to their surface after interaction with normal rabbit or normal human serum. Similarly, cells from healthy donors, treated with positive and negative sera were found negative. The method is easy to perform and results can be obtained within three hours from the time specimens are received at the laboratory. Its use offers a rapid diagnosis in suspected cases of herpetic infections in which early therapy is recommended.