Peracetic acid-based disinfectant is the most appropriate solution for a biological decontamination procedure of responders and healthcare workers in the field environment.

AIMS: An effective decontamination procedure of personnel wearing personal protective equipment is required by CBRN responders and healthcare workers when dealing with biological warfare agents or natural outbreaks caused by highly contagious pathogens. This study aimed to identify critical factors affecting the efficacy of peracetic acid (PAA)-based disinfectants and products containing either hydrogen peroxide or sodium hypochlorite under the same conditions. METHODS AND RESULTS: The influence of concentration, application (contact) time, erroneous human behaviour, interfering substance, technical assets and weather conditions on disinfection efficacy against Bacillus subtilis spores were assessed in 14 experimental groups. Residual contamination of protective suits was measured to provide responders with readily understandable information (up to 100 colony forming units classified a suit as disinfected). Weather conditions, short application time and erroneous human behaviour substantially affected the effectiveness of PAAs (P < 0·05). Non-PAA-based disinfectants (either liquid or foam) did not reach comparable efficacy (P < 0·001). CONCLUSIONS: Peracetic acid was effective at a concentration of 6400-8200 ppm and an application time of 4 min. SIGNIFICANCE AND IMPACT OF THE STUDY: The study provides operationally relevant data for the use of PAA-based disinfectants in preparedness planning and management of biological incidents and natural outbreaks.

The influence of low-level sarin inhalation exposure on the host resistance and immune reaction of inbred BALB/c mice after their infection with Francisella tularensis LVS.

To study the influence of low-level sarin inhalation exposure on immune functions, inbred BALB/c mice were exposed to two low concentrations of sarin for 60 minutes in the inhalation chamber and then infected with Francisella tularensis LVS on the 7th day following the exposure to sarin. 24 hours after infection, the level of some isotypes of antibodies (IgM, IgA) against tularaemia was significantly decreased regardless of the sarin concentration used while the lymphoproliferation was significantly increased regardless of the mitogen and sarin concentration used. Later, the level of some isotypes of antibodies (IgM, IgA) against tularaemia and the vitality of Francisella tularensis LVS was significantly increased in the case of exposure of mice to clinically symptomatic concentration of sarin (7 days after infection) while the lymphoproliferation was significantly decreased regardless of the concentration of sarin when specific tularaemic antigen Ag4 was used as a mitogen (3 weeks after infection). Thus, the results indicate that not only symptomatic but also asymptomatic dose of sarin is able to alter the host resistance and reaction of immune system, especially at 24 hours and 7 days following infection with Francisella tularensis LVS. Nevertheless, the alteration of immune functions following the inhalation exposure to a symptomatic concentration of sarin seems to be more pronounced.