by Larry Kociolek, MD, MSCI, FSHEA, FPIDS, Doneen West, PharmD, MBA, Danielle Zerr, MD, MPH
In October 2024, both the Centers for Disease Control and Prevention (CDC) and American Academy of Pediatrics (AAP) reported on the increasing trend of infections caused by Mycoplasma pneumoniae. This increase trend, especially in children ages 2-4 years of age, started last spring and remains high. While there is no national reporting or dedicated surveillance system, the CDC monitors these trends utilizing syndromic and commercial laboratory data. M. pneumoniae emergency department discharges have been increasing since March 2024 with the highest increase among children. Over the last 7 months, the percentage grew from 1.0% to 7.2% among children ages 2-4 years and 3.6% to 7.4% among children 5-17 years of age (data from bioMerieux BIOFIRE® Syndromic Trend program).
Providers should have an increased suspicion of M. pneumoniae in children with “walking pneumonia” who are not spontaneously improving, as well as patients with community-acquired pneumonia who are not improving with antibiotics that are not effective against M. pneumoniae, such as beta-lactams.
Transmission
M. pneumoniae spreads by inhaling respiratory droplets produced when an infected person coughs, talks, or sneezes. Outbreaks can be prolonged due to the long incubation period of M. pneumoniae (1-4 weeks), the persistence of the bacteria in the respiratory tract, and the prolonged presence of symptoms such as coughing.
Symptoms
M. pneumoniae infections, sometimes called “walking pneumonia”, are generally characterized by mild symptoms including nasal congestion/rhinorrhea, cough, and sore throat. Children may also present with fever, headache, and a rash. Children younger than 5 years of age may present with wheezing, vomiting, and diarrhea.
Severe complications are uncommon and include severe pneumonia, encephalitis, hemolytic anemia, renal dysfunction, septic arthritis, gastrointestinal complaints, and Stevens-Johnson syndrome (and very rarely toxic epidermal necrolysis). Rarely, these complications may be fatal.
Diagnosis
Clinical microbiology laboratories can provide diagnostic testing for M. pneumoniae using commercially available molecular or serological tests. Cultures of M. pneumoniae are performed by specialized labs only. When testing, consider swabbing both the throat and nasopharynx to improve the likelihood of detection.
Prevention
There is no vaccine against M. pneumoniae. The CDC recommends the use of core prevention strategies that are also effective for preventing respiratory viral infections, including hand hygiene, staying home when ill, and covering coughs and sneezes.
Treatment
Most patients with mild disease will recover on their own without medication. Macrolides, such as azithromycin, are the first-line antibiotic treatment for M. pneumoniae. The use of second-line antibiotics, such as fluoroquinolones and tetracyclines, may be used for patients who are not improving on macrolides or who have a contraindication for macrolide use.
Resources
Mycoplasma Pneumoniae Infections Have Been Increasing | NCIRD | CDC
Mycoplasma pneumoniae Infection Surveillance and Trends | M. pneumoniae | CDC