A positive Mycoplasma pneumoniae does not mean pneumonia. Mycoplasma pneumoniae is only a pathogen that can cause respiratory tract infections. When Mycoplasma pneumoniae is positive, it only means that an infection with this pathogenic microorganism may be present, and it is not 100% certain that an infection exists. The presence of this pathogenic microorganism can be indicated only if the corresponding antibody is positive and has a titer that increases fourfold or more during the course of the disease. The presence of this pathogenic microorganism may only lead to upper respiratory tract infection or bronchitis, but not necessarily to pneumonia. The symptoms of Mycoplasma pneumoniae infection are more consistent with a dry cough, no sputum, and a prolonged fever, if the symptoms are evident on a chest CT. If the corresponding symptom is a cough with significant sputum, or if there are other manifestations that do not fit well with Mycoplasma pneumoniae infection, it does not clearly indicate that the cause of the pneumonia is Mycoplasma pneumoniae.