Persistence of human rhinovirus infectivity under diverse environmental conditions

Abstract

The persistence of human rhinovirus type 2 and type 14 infectivity was studied under various laboratory conditions designed to mimic those commonly found in the environment. The effects of temperature, ionic strength, protein content, and evaporation were compared. Both viruses were stable (<0.3-log decrease in titer) at 6 and 23°C for 24 h in the liquid state regardless of salt or protein additives; a titer decrease of <1.0 log was noted at 37°C. However, evaporation at 37°C reduced virus infectivity by 3.2 to 4.5 logs in buffered water, an effect which could be significantly lessened by the addition of bovine serum albumin in saline (2.0- to 2.6-log decrease in titer). These studies support and extend observations by others that the human rhinoviruses retain sufficient infectivity after drying on hard surfaces to permit their transmission to susceptible persons upon contact.