Transmission of Chlamydia pneumoniae

To investigate the transmission of Chlamydia pneumoniae via hands and environmental sur-faces, its survival on various surfaces was studied. The organism remained viable on formica countertops for 30 h and in tissue paper for 12 h. Measurable quantities of chlamydiae were transferred from these environmental surfaces to hands. However, titers were low and survival time on hands was limited to 10-15 min. C. pneumoniae survived small particle aerosolization well and was infectious to mice by both direct inoculation and aerosolization. These observations suggest that several mechanisms of transmission of C. pneumoniae are possible, including the transfer of fomites from environmental surfaces with subsequent autoinoculation. Chlamydia pneumoniae (TWAR) is a recently recognized Chlamydia strain that is emerging as an important cause of respiratory disease in humans. C. pneumoniae has been im-plicated as a cause of bronchitis, pneumonia, sinusitis, and pharyngitis [l]. Although the disease is presumed to be spread via the respiratory route from person to person, the actual mechanism of transmission is not known. Three modes of transmission of respiratory pathogens are theoreti-cally possible: small particle aerosol « I0 ~m mass median diameter); direct inoculation by droplets or large particles; and self-inoculation after touching contaminated surfaces. We sought to describe the survival of C. pneumoniae on envi-ronmental surfaces and skin and in small particle aerosol and to determine whether animals can be infected with C. pneu-moniae by intranasal inoculation and by exposure to aerosol-ized organisms. Materials and Methods Study Design Recovery of C. pneul110niae from three surfaces, formica, tis-sue paper, and skin, was examined over time. Recovery of C. pneul110niae from hands that had touched contaminated surfaces was also determined. Finally, the infectivity of aerosolized C. pneul110niae was measured. A second set of experiments was done to assess two modes of transmission (aerosol and direct inoculation) in mice