Laboratory Infection With Murine Typhus

Laboratory-acquired Scrub Typhus and Murine Typhus Infections: The Argument for a Risk-based Approach to Biosafety Requirements for Orientia tsutsugamushi and Rickettsia typhi Laboratory Activities

“…Laboratory-acquired infections with these organisms were often the result of accidental self-inoculation or skin puncture [28,32,33,35,37], animal bite [33], or aerosol exposure to high concentrations of the organisms in animal tissues collected at necropsy for vaccine production [33, 37–39], and all occurred in research facilities. The earliest recorded LAI was in 1931 when a technician in Japan sustained an accidental self-inoculation injury while inoculating a rabbit with R. orientalis [28], cited by Pike [29] (Table 2).…”

“…In 1941, Van den Ende and colleagues [37], detailed a series of 4 murine typhus LAIs at the NIMR during efforts to produce a vaccine. They indicated that precautions were taken to prevent staff infections, such as the use of gauze masks during inoculation of mice, and mice being inoculated in a glass and metal box.…”

“…The report indicated that the most likely source of infection was “inhalation” during the intranasal inoculation of mice. They also noted that 1 staff member who became infected was not involved in the inoculation of mice, and they surmised that “dust-borne infection” may be a possibility [37].…”

“…The majority of these infections occurred prior to the 1950s when there were no antibiotic treatments available and the high infectious dose of the LAI incident likely contributed to the scrub typhus mortalities. In the case of aerosol-derived LAIs, these often occurred when staff were provided with only the most basic PPE such as gauze masks, which provided inadequate respiratory protection from infection [33, 37], or did not wear PPE. However, there has long been recognition of the risks associated with rickettsial disease research.…”