BACKGROUND: Mycoplasma pneumoniae pneumonia is regarded as a community
-acquired pneumonia, rarely requiring hospitalization, with sporadic c
ases car limited outbreaks occurring after close contacts with an infe
cted patient. Few reports mention M pneumoniae pneumonia acquired duri
ng hospitalization. PATIENTS AND METHODS: M pneumoniae was diagnosed i
n patients who developed pneumonia following perioperative and postope
rative assisted ventilation by the isolation of M pneumoniae from bron
chial washing, the detection of M pneumoniae DNA from bronchial washin
g, and serologic testing for the presence of specific immunoglobulin M
(IgM) antibodies. RESULTS: Four patients were diagnosed as having M p
neumoniae pneumonia following mechanical ventilation over a 1 1/2-year
period. They were men, older than 50 years, and were hospitalized for
vascular surgery. They developed febrile hypoxemia and intersticial p
neumonia. Isolation of M pneumoniae and detection of M pneumoniae DNA
were positive in 1 case; specific IgM antibodies were present in 4 cas
es. CONCLUSIONS: These observations allow the description of a new cli
nical entity and highlight the role of M pneumoniae as an agent of nos
ocomial infections. This diagnosis should be considered in any patient
with precocious post-assisted ventilation febrile hypoxemia and diffu
se interstitial pneumonia, and empiric treatment protocols may include
M pneumoniae in their spectrum.