DefinitionMycoplasma pneumonia is an infection of the lungs caused by by the bacteria Mycoplasma pneumoniae (M. pneumoniae).See also:Atypical pneumoniaViral pneumoniaCauses, incidence, and risk factorsMycoplasma pneumonia is a type of atypical pneumonia. It is caused by the bacteria M. pneumoniae. This type of pneumonia usually affects people younger than 40. Various studies suggest that it makes up 15-50% of all pneumonia cases in adults and an even more in school-aged children.People at highest risk for mycoplasma pneumonia include those living or working in crowded areas such as schools and homeless shelters, although many people who contract mycoplasma pneumonia have no identifiable risk factor.SymptomsThe symptoms are generally mild and appear over a period of 1 to 3 weeks. They may b