Mycoplasma pneumoniae Infection Surveillance and Trends

Key points

  • There is no national reporting or surveillance system for Mycoplasma pneumoniae infections.
  • M. pneumoniae infections are common.
  • These infections may occur more often in summer and early fall.
  • View the data below to learn about recent trends in M. pneumoniae infections.
An illustration of generic data

Data sources

A M. pneumoniae infection isn't a nationally notifiable condition. This means that healthcare providers aren't required to report infections to their local public health department. However, CDC can monitor national trends using syndromic and commercial laboratory data collected by:

To understand the epidemiology of M. pneumoniae infections, researchers collect additional data from:

Studies

M. pneumoniae infections are common in the United States, with an estimated 2 million infections occurring each year12. However, many infections aren't diagnosed, so the actual number is likely higher.

Outbreaks

Outbreaks occur mostly in crowded environments like schools, college residence halls, and nursing homes.

Outbreaks can be prolonged due to the long incubation period of M. pneumoniae.

Trends

The number of M. pneumoniae infections varies over time. There are usually peaks of disease every 3 to 7 years13. Variation in strain types contributes to this pattern. In 2023, M. pneumoniae began to re-emerge globally. This re-emergence occurred after a prolonged period of low incidence of infections since the start of the COVID-19 pandemic.

M. pneumoniae infections can occur any time of the year. However, they may be more common in summer and early fall3.

Recent activity

In 2024, CDC identified an increase in M. pneumoniae infections, including in young children. This differed from previous years in which most infections were observed among older children and adolescents. Data from NSSP, NVSN, and TREND all indicated that M. pneumoniae infections began increasing in late spring/early summer of 2024. This increase began from a lower baseline observed since the start of the COVID-19 pandemic.

Since the beginning of 2025, data suggest M. pneumoniae infections have been decreasing. Despite the decrease, M. pneumoniae infections remain elevated in some regions of the United States in 2025.

CDC is continuing to track M. pneumoniae infections to better understand any differences in:

  • Demographics
  • Severity of illness (including skin disorders)
  • Outcomes as compared to M. pneumoniae infections prior to the COVID-19 pandemic

Bulletin

In October 2024, CDC issued a Bulletin about the increase in M. pneumoniae infections among children in the United States.
Read the Bulletin

Increases in emergency department visits

CDC looked at NSSP data for the percent of pneumonia-associated emergency department (ED) visits with a Mycoplasma-related diagnostic code. Diagnosed Mycoplasma infections increased steadily through the summer of 2024, peaking for the 2–4-year-old and 5–17-year-old age groups in August 2024.

The increase in 0–1-year-olds and 2–4-year-olds was notable because these infections have historically been thought to affect school-age more than younger children.

View data interpretation for similar discharge diagnosis based respiratory data.

Antibiotic resistance

CDC is tracking resistance to macrolides among M. pneumoniae causing infections. Monitoring occurs by testing specimens submitted by local and state public health departments and from surveillance systems.

Resistance to macrolides emerged in M. pneumoniae and has been increasing since the early 2000s45. Macrolides are the main type of antibiotic used to treat M. pneumoniae infections.

Current data suggest that the overall global prevalence of macrolide resistance in M. pneumoniae may be around 28%4. However, there's significant geographical variation4:

  • Canada: About 12%
  • China: About 80%
  • Europe: Averages around 5% (highest in Italy: 20%)
  • Japan: More than 50%
  • United States: Less than 10% overall; limited data show higher proportions (>20%) observed67in:
    • The South and East
    • Within clusters or outbreaks prior to the COVID-19 pandemic
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Content Source:
National Center for Immunization and Respiratory Diseases; Division of Bacterial Diseases
  1. Diaz M, Benitez A, Winchell J. . J Clin Microbiol. 2015;53(1):124–30.
  2. Jain S, Williams D, Arnold S, et al. . NEJM. 2015;372:835–45.
  3. Foy HM. . Clin Infect Dis. 1993;17(Supplement_1):S37–S46.
  4. Kim K, Jung S, Kim M, et al. . JAMA Netw Open. 2022;5(7):e2220949.
  5. Rothstein TE, Cunningham SA, Rieke RA, Mainella JM, Mutchler MM, Patel R. . Antimicrob Agents Chemother. 2022;66(4):e0243221.
  6. Waites KB, Ratliff A, Crabb DM, Xiao L, Qin X, Selvarangan R, Tang YW, Zheng X, Dien Bard J, Hong T, Prichard M, Brooks E, Dallas S, Duffy L, Mixon E, Fowler KB, Atkinson TP. J Clin Microbiol. 2019;57(11):e00968–19.
  7. Diaz MH, Benitez AJ, Winchell JM. . J Clin Microbiol. 2015;53(1):124–30.