Pneumonia cases caused by M. pneumoniae, often called “walking pneumonia,” are increasing since late spring of 2024, especially among children. Symptoms include runny nose, sore throat, fatigue, and a persistent cough that gets worse over time. Younger children may have different symptoms like diarrhea, sneezing, sore throat, vomiting, watery eyes, a runny nose and wheezing. Parents should take their child to a healthcare provider if they develop persistent or worsening symptoms like those described above.

“Walking pneumonia” is a form of mild pneumonia often caused by the bacteria M. pneumoniae. It is called “walking pneumonia” because people may seem better than expected for someone with a lung infection.

The respiratory disease is spread through inhaling droplets after someone coughs, sneezes, or talks. It can also be spread by touching a contaminated surface then touching your eyes, mouth or nose.

The cases of pneumonia caused by M. pneumoniae have increased over the past six months among all age groups but highest among children 2-4 years. This increase is notable for young children because pneumoniae in this age group was historically not caused by M. pneumoniae and the bacteria typically affected school aged children and young adults.

M. pneumoniae infections are typically mild, but can lead to severe complications in some cases. Preventative measures for walking pneumonia are the same as other respiratory viruses and include washing hands often and covering coughs and sneezes.

Researchers are still learning why the rates of M. pneumoniae increased in young children when it has historically been seen mainly in school aged children and young adults.

Currently, there is no vaccine available to prevent M. pneumoniae infection, but research is ongoing.