Determining the Efficacy, Safety and Suitability of Disinfectants to Prevent Emerging Infectious Disease Transmission

The scale of the 2014-2017 West African Ebola Virus Disease outbreak overwhelmed the international response capacity. This has led to inconsistencies in international guidance documents, particularly around chlorine disinfection of surfaces and hands to prevent transmission. To provide evidence for the disinfection recommendations, three research strands were conducted: (1) impacts of chlorine chemistry; (2) efficacy of surface cleaning recommendations; and (3) safety and efficacy of handwashing recommendations. Strand 1 research found that the compound chemistry of the chlorine source has an impact on the chlorine solution shelf-life (< 1 day-30 days), with testing of chlorine solutions recommended to ensure accuracy. Strand 2 research found that surface cleaning with 0.5% chlorine solutions with a 15-min exposure time is efficacious in reducing transmission risk. Strand 3 research found that community handwashing with chlorine solutions is as safe and efficacious as handwashing with soap and water or sanitizer, which offers a benefit of reducing pathogens in the rinsing water. Using calcium hypochlorite as the chlorine source compound provided a particularly good performance in chemistry and handwashing studies. The research was successful at providing information to align with the inconsistent international guidelines. Further research is needed to proactively establish the efficacy, safety and suitability of disinfection for the seven viral pathogens that are considered likely to cause severe outbreaks with few/no medical countermeasures.