Pneumonia in China, Europe, and the US: Why Experts Aren’t Worried

Rather than a virus like the one behind flu, SARS, or COVID-19, Mycoplasma pneumoniae is a bacteria that can cause a form of pneumonia by damaging the linings of the throat, lungs, or trachea.

It’s quite common and does need a host to spread. It was identified more than 100 years ago as a factor in lung disease in cattle, but not recognized as a cause of “atypical” pneumonia in humans until 1944, when scientists named it after the Greek term for “fungus-formed” (they originally thought it was a fungus).

“It’s one of those bugs that doesn’t have a lot in its package, so it does need mammals, cells to replicate,” Dr. Jimmy Johannes, a pulmonologist and critical care medicine specialist at MemorialCare Long Beach Medical Center in Long Beach, CA, told Healthline. “It’s not like something that you find on dirt or in the ambient air, something like that, just hanging out.”

Respiratory infection from Mycoplasma pnuemoniae is quite common, with an estimated 2 million cases reported in the United States each year. In the early 1930s, it was characterized as “atypical” pneumonia because patients with it would maintain symptoms for a longer period of time without being significantly more sick, and because antibiotics had limited affects.

We often now hear it referred to as “walking pneumonia.” Symptoms include:

• Cough
• Fever
• Shortness of breath
• Chest pain
• Fatigue

“It does have some unusual features,” Dr. Elizabeth Talbot, professor of Medicine, Infectious Disease and International Health at Dartmouth’s Geisel School of Medicine, told Heathline. “It usually affects otherwise healthy patients 5 to 20 years old and can be spread person to person so we see it in clusters or outbreaks. We especially suspect it in late summer and fall when we hear from a young patient with pneumonia that they had a slow gradual onset of cough illness even over weeks.”

Dr. Talbot added that the “atypical” aspect of this type of pneumonia is also seen internally, in how the disease interacts with a patient’s body. “If the clinician chooses to do a chest X-ray, the whole lung may be affected, rather than one part like other bacterial pneumonias, which is why the disease Mycoplasma causes is sometimes called atypical pneumonia,” she said.

Many health officials have cautioned that there’s not a need to panic, although a number of them have suggested that more evidence needed from China, where a larger spectrum of respiratory diseases among children have been seen.

But, there’s no evidence that these pneumonia spikes are linked, Dr. Talbot said.

“Much more likely, as we move from the emergency phase of the COVID-19 pandemic, people are resuming more usual ways of interacting, like not wearing masks, not frequently washing hands or social distancing, and starting to travel more,” she said. “This is giving a chance for the usual causes of respiratory diseases to start circulating again. Children who were not routinely exposed to these usual causes (viruses and bacteria like Mycoplasma pneumoniae) during the pandemic are getting these illnesses now.”

The concept of “immunity debt” has been cited as a significant contributing factor to the surges in multiple respiratory illnesses, including flu and other strains of COVID-19, as different communities and countries emerge from different levels of lockdown measures.

“These things with Mycoplasma pneumoniae can kind of come and go,” Dr. Johannes said. “I think a lot of it depends on populations and close quarters; if that environment exists, you have a chance higher chance of transmission with this kind of bug.”

In the short term, the answer is no. Many of these recent outbreaks have been among children within the first few months of returning to school, and according to Dr. Talbot, close proximity among populations can accelerate them.

“Clusters and outbreaks of Mycoplasma pneumonia are indeed normal,” she said. “Epidemics of Mycoplasma pneumonia do tend to be cyclical, occurring every 4 to 8 years in the general population but can occur anytime among people living closely together, like those in military barracks and prisons.”

“Viruses and this kind of bacteria can spread reasonably easily in the community,” Dr. Johannes said. “If someone is susceptible or at high risk for complications, you just have to be mindful of that possibility and maybe take a little bit of extra precaution with good hand hygiene, and maybe even mask wearing.”

Recent pneumonia outbreaks around the world and in the United States have been attributed to Mycoplasma pnemoniae, the bacteria that many doctors know as a common cause of community-acquired pneumonia. It’s often known as “walking pneumonia” and can easily spread among populations, especially those in close quarters. These type of surges are normal and occur regularly.