Exposure of herpes simplex virus type 1 and its host cells to cigarette smoke in vitro.

A 1.0 ml suspension of herpes simplex virus type 1 in tissue culture growth medium was exposed at 37 degrees C to eight puffs of smoke from one cigarette. Each puff consisted of 25.0 ml of mainstream smoke, and was delivered by a mechanical smoking apparatus. At 0, 15 and 60 min after exposure the virus was assayed for infectivity using HEp-2 cells as the host. Neither filter nor non-filter cigarette smoke affected the infectivity of the virus, or the viability of HEp-2 cells treated with smoke in a manner similar to the virus. The filter cigarette contained 19.0 mg of tar and 1.2 mg of nicotine, and the non-filter cigarette had 23.0 mg of tar and 1.4 mg of nicotine. Smoke from four non-filter cigarettes delivered over a 4 h period caused a 4-log10 drop in virus infectivity titre, and smoke from four filter cigarettes caused more than a 1-log10 drop in titre. Smoke from four non-filter or filter cigarettes was highly cytocidal for HEp-2 cells.