Anyone can get the disease, but it most often affects older children and young adults. Mycoplasma infections occur sporadically throughout the year. Widespread community outbreaks may occur at intervals of four to eight years. Mycoplasma infection is most common in late summer and fall. Mycoplasma is spread through contact with droplets from the nose and throat of infected people when they cough and sneeze.
Transmission is thought to require prolonged close contact with an infected person.
Spread in families, schools and institutions occurs slowly. The contagious period is probably fewer than 10 days and occasionally longer. Typical symptoms include fever, cough, bronchitis, sore throat, headache and malaise. Symptoms may persist for a few days to more than a month. Symptoms generally begin 15-25 days after exposure.