In vitro inactivation of Chlamydia trachomatis and of a panel of DNA (HSV-2, CMV, adenovirus, BK virus) and RNA (RSV, enterovirus) viruses by the spermicide benzalkonium chloride

Kinetics of inactivation by the detergent spermicide benzalkonium chloride (BZK) of Chlamydia trachomatis and of a panel of DNA viruses [herpes simple x virus hominis type 2 (HSV-2), cytomegalovirus (CMV), adenovirus (ADV) and BK virus (BKV)] and RNA [respiratory syncytial virus (RSV) and enterovirus (ENV)] were established in accordance with a standardized in vitro protoco l. After a 5 min incubation, inactivation of >95% of HSV-2 and CMV was obta ined at a concentration of 0.0025% (w/v) (25 mug/L); concentrations as low as 0.0005%, 0.0050% and 0.0125%, induced a 3.0 log(10) reduction in infecti vity of HSV-2 and CMV, RSV and ADV, respectively. After a 60 min incubation , concentrations of 0.0125% and 0.050% provided a 3.0 log(10) reduction in infectivity of ENV and BKV, respectively. These features indicate that sens itivity to BZK was very high (HSV-2 and CMV) or high (RSV) for enveloped vi ruses, intermediate (ADV) or low (ENV and BKV) for, non-enveloped viruses. Furthermore, BZK had marked antichlamydial activity, showing >99% killing a fter only a 1 min incubation at a concentration of 0.00125%. BZK demonstrat es potent in vitro activity against the majority of microorganisms causing sexually transmitted infectious diseases, including those acting as major g enital cofactors of human immunodeficiency virus transmission. These attrib utes qualify BZK as a particularly attractive candidate for microbicide dev elopment.