Investigations on the biological activity of bovine herpesvirus type 1 on copper, zinc, and stainless steel surfaces

Introduction The increasing prevalence of viral diseases highlights the need for the destruction or inactivation of viruses on diverse material surfaces. While extensive research exists for human viruses, the interaction between metal surfaces and animal pathogens like BoHV-1 is not well understood. This study investigated the impact of copper (Cu), zinc (Zn), and iron (Fe) surfaces on the biological activity, virus, and viral DNA half-life time of BoHV-1. Methods MDBK-adapted BoHV-1 (strain 4016) was used to investigate the virucidal effect of copper, zinc, and iron surfaces. The virus was exposed for 1 and 24 hours under humid and dry conditions. Inactivation was evaluated by measuring the reduction in TCID50 log10, real-time PCR Ct values, and calculating half-lives for both the virus and its DNA. Results Herpesviruses were inactivated most rapidly on copper-coated surfaces in all cases. The virucidal effect after 1 hour of contact under humid and dry conditions was highly effective (3.25±0.29 log10 TCID50 and 4.5±0.1 log10 TCID50; p<0.01, p<0.05), with similar results after 24 hours under both conditions (4.5±0.25 log10 TCID50 and 4.5±0.1 log10 TCID50; p<0.05). Inactivation half-life time for the virus and viral DNA after 1 hour were shorter under dry conditions (4 minutes and 27 minutes) compared to humid conditions (6 minutes and 10 minutes). However, after 24 hours, inactivation half-life times were shorter under humid conditions (1 hour 31 minutes and 6 hours 20 minutes) compared to dry conditions (1 hour 36 minutes and 4 hours 7 minutes). Viral activity studies in cell culture correlated with real-time PCR, confirming copper’s strong effect on viral DNA under both conditions. Conclusion Copper surfaces demonstrated the highest virucidal activity against herpesviruses. The kinetics of inactivation were biphasic: while the immediate efficacy was higher after 1 hour under humid conditions, the long-term effect, considering both half-life measurements, proved to be superior in a dry environment.