Efficacy of laundry practices in eliminating monkeypox virus (MPXV) from fabrics

Background: The declaration of mpox as a Public Health Emergency of International Concern highlights the need for interventions to interrupt virus transmission, including transmission via fabrics. Current World Health Organization guidance on clothes washing is based on a general consensus of virus inactivation; however, there is uncertainty about the efficacy of laundry detergents and disinfectants or the reduction of risk achieved by washing clothes for monkeypox virus (MPXV) specifically.

Methods: This study investigates the efficacy of manual washing for inactivating MPXV from clothes. Using a simulated washing method, we evaluated the efficacy of commonly-used laundry products and high temperature water for inactivating MPXV on fabrics. Cotton and polyester fabrics were inoculated with MPXV for 1 min, placed in a microcentrifuge tube containing water or water with test product for 20 minutes, with agitation every 5 min to simulate manual washing.

Results: Sodium hypochlorite, liquid sanitizer, and two powdered laundry detergents dissolved in room temperature water, as well as 70-degree water alone, completely inactivated MPXV (>3 log10reduction or >99.9% inactivation) on both cotton and polyester fabrics.

Conclusion: Given the expected concentrations of MPXV on fabrics, the low transfer rate of viruses from porous surfaces to skin, the effective inactivation of laundry processes, and the expected doses required for infection, we expect the risk of transmission after laundering contaminated fabrics to be low. This study provides evidence to support WHO guidance for MPXV inactivation, reducing the viral load on fabrics to prevent the spread of mpox in both healthcare and household settings.