Development of lung tumors in Syrian hamsters with a mixed Mycoplasma pneumoniae and influenza virus infection

: The authors studied morphological alterations in the lungs of Syrian hamsters infected intranasally with Mycoplasma pneumoniae and influenza virus. The animals were first infected with M. pneumoniae and after 7 days with influenza A/PR8 virus. On days 1-3 after infection with influenza virus (days 8-11 following infection with M. pneumoniae) the animals showed the appearance of multiple foci of bronchiolar epithelium proliferation. At the later stages of experiment the size of the foci of proliferation increased. On days 14-21 after infection with influenza virus (days 21-28 of experiment) the animals developed lung tumors.