The second week of the illness progression may show sputum
production and localized crackles or wheezes. These symptoms
may extend for over a month beyond the incubation period.
However, these general symptoms do not provide any clue to
the likely diagnosis. Confrmation of M. pneumoniae infection can
be provided by culture or serology, but most clinical laboratories
do not culture for the organism, and serologic response can take
weeks to peak. Consequently, antimicrobial therapy for CAP
is initiated empirically before infection with M. pneumoniae is
confrmed.