Amplification techniques for detection of herpes simplex virus in neonatal and maternal genital specimens obtained at delivery.

Viral culture amplification methods, including centrifugation, use of a cell pretreatment medium containing dimethyl sulfoxide and dexamethasone (DEX medium), and three commercial enzyme immunoassays (EIAs), were evaluated for use with low-titer, asymptomatic neonatal and obstetric samples obtained at delivery. The 4.5-h Ortho EIA was 59.7% sensitive at 16 h compared with 86.4% at 36 h in a spin-amplified format (SAT-EIA). After 36 h with DEX medium, the SAT-EIA was 97.3% sensitive using the 2.5-h modified Ortho EIA and 69.9% sensitive using the Fairleigh Dickinson EIA. Herpes simplex virus (HSV) cytopathic effect was reported in tube culture 1 to 2 days earlier in 8.1 to 35.9% of cells with DEX medium. Overall, the SAT-EIA using the modified Ortho EIA and cells with DEX medium detected 147 of 153 (96.1%) HSV isolates from samples obtained predelivery and 93.1% of 29 HSV positives from samples obtained at labor and delivery, with specificities of 100 and 99.9%, respectively, at 36 h.