Mycoplasma pneumoniae: The threat of antibiotic-resistant pneumonia or ‘walking pneumonia’

There are more than 200 species of Mycoplasma pneumonia bacteria, and most people infected with this bacteria do not develop symptoms of pneumonia. This is why it’s called atypical pneumonia [3].

It’s also known as “walking pneumonia” because those infected often experience mild symptoms—or none at all—allowing them to go about their daily activities but continue to spread the infection.

Mycoplasma pneumoniae is highly contagious. M.pneumoniae typically spreads through respiratory droplets that are released when an infected person coughs or sneezes. These droplets linger in the air and can be inhaled by others, leading to respiratory tract infections [4].

Where is ‘walking pneumonia’ found?

M.pneumoniae infections are found worldwide. In temperate climates, infections peak during late summer and Fall (autumn) [5].

Antibiotic-resistant strains of M.pneumoniae were first identified in the early 2000s and have been largely reported in Asia, including China and Japan [2].

Who is most at risk?

Anyone can get sick with an m.pneumoniae infection. However, children, older adults, and people with lung disease may be more vulnerable. People with chronic diseases that affect the lungs or heart are also at a higher risk of getting a more severe infection [5].

Those who live or work in crowded spaces are also at a higher risk of getting infected. These locations include schools, military quarters, nursing homes, hospitals, and long-term care facilities [5].

2024 M.pneumonia outbreaks

In general, Mycoplasma pneumoniae infections are common. Globally, they occur every 3-7 years as community immunity wanes. However, after the COVID-19 pandemic, cases have been rising worldwide.

In the United States, these infections are not nationally notifiable, which means it’s hard to get the exact number of cases. However, the US CDC (Centers for Disease Control and Prevention) reports that there has been an increase in cases in all age groups, with the highest being in children 2-4 years old [6].

In Denmark, a study found that M.pneumoniae infections were three times higher in 2023-2024 compared to the years prior to the COVID-19 pandemic. Here, the highest increase was among adolescents [7].

One study reported a large-scale M.pneumoniae outbreak of 218 cases in Marseille, France, from 2023-2024 [8].

In China, M. pneumoniae infections rank as the second most common acute bacterial infection, making up nearly 19% of all bacterial infections nationwide. In 2023, there was a large wave of M. pneumonia cases in Northern China’s second-largest city, Tianjin, and other cities [9].

This prompted the WHO (World Health Organization) to release a statement in November 2023 on clusters of respiratory tract infections among children in Northern China [10].

GIDEON offers comprehensive data on Mycoplasma pneumonia cases, outbreaks, and more.

Mycoplasma pneumonia symptoms are usually mild. Common symptoms include:

• Fatigue
• Fever
• Headache
• Sore throat
• Cough [11].

According to the US CDC, children under five may have slightly different symptoms:

• Sore throat
• Runny nose
• Sneezing
• Diarrhea
• Wheezing
• Vomiting [11].

A more severe case of m.pnuemoniae infections results in pneumonia (lung infection) with symptoms like cough, fever, chills, and shortness of breath [11].

Younger patients may end up with more upper respiratory tract infections, while older patients may develop pneumonia [11].

How long does it take for symptoms to appear (incubation period)?

Symptoms of a mycoplasma pneumoniae infection can appear as early as two days or take over four weeks to develop after exposure. Individuals with a m.pneumoniae infection may remain contagious for up to 20 days. Even when on antibiotics, they can continue spreading the infection for up to 48 hours after starting treatment [11].

Is mycoplasma pneumoniae serious?

M.pneumoniae infections are usually quite mild. In fact, the infection is called ‘walking pneumonia’ because people who are infected feel well enough to walk around. Many often have no symptoms but carry and spread the infection to others [5].

However, some people are more vulnerable than others. Children, older adults, people who are immune compromised, and those with sickle cell disease are at a high risk of getting infected [5, 11].

Antibiotic-resistant strains of mycoplasma pneumonia can cause prolonged illness and greater complications, particularly in vulnerable populations. It may result in extended hospital stays, exposing patients to hospital-acquired infections (HAIs), and may require different antibiotics that are not as effective in children [5, 11].

Since most m.pneumoniae infections are not serious, a healthcare provider may not need to test for it. However, when required, lab tests may include a nasal or throat swab and a blood test to identify the infection [12].

If pneumonia develops, a chest x-ray may be necessary [12].

In most cases, people recover completely on their own and do not need medicines. Many people self-medicate their discomfort from symptoms like nasal congestion and cough with over-the-counter (OTC) drugs. If left untreated in adults, fatigue and cough may last for a month [1].

If pneumonia develops, antibiotics may be prescribed. In general, macrolides, doxycycline, or fluoroquinolones work against m.pneumoniae infections. Azithromycin, a macrolide antibiotic, is the most commonly used one [1,2].

Unfortunately, azithromycin and other macrolides have become ineffective against certain emerging strains of M.pneumoniae. These macrolide-resistant Mycoplasma pneumoniae (MRMP) strains pose a significant threat to global public health.

Mycoplasma bacteria do not have cell walls. So, antibiotics that work by targeting and destroying cell walls do not work against them. Instead, macrolides and other antibiotics that interfere with DNA and protein synthesis are what are used. Macrolides, in particular, are effective in children [2].

MRMP strain rates are on the rise, with higher occurrences reported in children than adults. Infected children face greater challenges in treatment, often enduring prolonged illness and more severe symptoms [2].

If healthcare providers are not careful with prescribing antibiotic treatment, more superbug strains could emerge. These strains could be resistant to doxycycline and fluoroquinolones as well, making it incredibly hard to treat severe infections [2].

There are no vaccines to prevent M.pneumoniae infections. And since most of them are mild, there is no need for them. However, even if the symptoms are not severe, fighting a cough, fever, fatigue, and sore throat can cause temporary discomfort and pain [13].

People who are infected can practice hand hygiene, wear a mask, cover their nose and mouth when they sneeze and cough and isolate when possible to help prevent the spreading of the infectious disease [13].

Quitting smoking can also reduce the risk of chronic lung disease or inflammation, which can make individuals more vulnerable to infection [3, 13].

Healthcare providers must be judicious with the use of antibiotics to treat mild infections.

Mycoplasma pneumoniae is a small bacterium that mostly causes mild infections. In fact, the infection is often referred to as ‘walking pneumonia’ because most people are able to go about their day despite feeling unwell.

However, the rise of antibiotic-resistant strains like macrolides-resistant Mycoplasma pneumonia (MRMP) is making treatment more challenging. These resistant strains spread easily, prolong illness, and can lead to severe complications, especially in vulnerable groups like children and older adults.

Without careful antibiotic use, we risk creating even harder-to-treat superbugs. While there’s no vaccine, simple preventive measures—like practicing good hygiene, wearing a mask, and isolating when sick—can help slow the spread.

GIDEON is one of the most well-known and comprehensive global databases for infectious diseases. Data is refreshed daily, and the GIDEON API allows medical professionals and researchers access to a continuous stream of data. Whether your research involves quantifying data, learning about specific microbes, or testing out differential diagnosis tools– GIDEON has you covered with a program that has met standards for accessibility excellence.

Learn more about more bacterial infections on the GIDEON platform.