Mycoplasma Pneumoniae (MP): Symptoms, Spread and Treatment

Synopsis

Mycoplasma pneumoniae is a common respiratory pathogen that can cause upper respiratory infections, tracheobronchitis, and pneumonia. Often called "walking pneumonia" because symptoms tend to be mild enough for patients to carry on with daily activities, it is especially prevalent among children and adolescents, though adults can also be affected. This guide covers the key symptoms in children and adults, how the infection spreads, treatment options including antibiotics, how it differs from Chlamydia pneumoniae, and practical hygiene measures to reduce transmission.

Mycoplasma pneumoniae is a common respiratory pathogen that can cause respiratory tract infections, tracheobronchitis and pneumonia. Because the symptoms of pneumonia caused by Mycoplasma pneumoniae are often relatively mild, affected individuals may still be able to carry on with their daily activities. For this reason, it is often referred to as "walking pneumonia". Mycoplasma pneumoniae infection is particularly common among children and adolescents, although adults can also become infected.

Understanding Mycoplasma pneumoniae symptoms, how it spreads, its incubation period and available treatments can help parents and adult patients recognise the condition early and seek medical advice when needed.

FAQs on Mycoplasma pneumoniae symptoms

1. What Is Mycoplasma Pneumoniae Infection?

Mycoplasma pneumoniae infection is a respiratory illness caused by the bacterium Mycoplasma pneumoniae. It can occur at any time of year, with community outbreaks tending to emerge every three to seven years. Most patients experience only mild upper respiratory tract symptoms, but approximately 5% to 10% develop atypical pneumonia.1 Older adults and immunocompromised individuals are at greater risk of serious complications, including severe pneumonia, encephalitis, kidney impairment and haemolytic anaemia.

2. Is Mycoplasma Pneumonia Contagious?

Yes. Mycoplasma pneumoniae spreads primarily through respiratory droplets produced when an infected person coughs or sneezes. It can also spread through direct contact with nasal and throat secretions, or indirectly by touching recently contaminated surfaces.

As transmission generally requires close or prolonged contact, outbreaks are more commonly seen in households, schools, student residences and other crowded settings.

3. How Long Is the Incubation Period of Mycoplasma Pneumoniae?

According to Hong Kong's Centre for Health Protection, the incubation period for Mycoplasma pneumoniae infection is approximately 2–3 weeks. This means symptoms may not appear until several weeks after exposure to the pathogen.

What Are the Symptoms of Mycoplasma Pneumoniae Infection?

Mycoplasma pneumoniae infection usually develops gradually, with symptoms appearing over time. Common symptoms include:

Fever
Cough
Sore throat
Headache
Fatigue

Symptoms of Mycoplasma Pneumonia in Children

Younger children may present differently from older children and adults.

Children under five may develop:

Runny nose
Sneezing
Wheezing/ coughing
Sore throat
Vomiting
Diarrhoea

School-age children with Mycoplasma pneumoniae infection more commonly experience:

Fever (typically low-grade)
Headache
Persistent cough
Sore throat
Malaise
Pneumonia

If your child has a persistent high fever, a noticeably worsening cough, shortness of breath or declining alertness, seek medical attention promptly.

Symptoms of Mycoplasma Pneumonia in Adults

Onset is typically gradual and insidious, developing over several days to weeks. Many adult infections are mild or even asymptomatic.

Adults commonly experience:

Persistent dry cough
Low-grade fever
Sore throat
Headache
Fatigue
General malaise
Chills

In more severe cases or when pneumonia develops:

Dyspnoea
Productive cough with non-bloody sputum

Diagnosis of Mycoplasma pneumoniae

A combination of clinical assessment and targeted investigations can help identify M. pneumoniae infection.

Laboratory testing

PCR: nose/throat swab, with fast and accurate results.
Blood test (serology): Looks for the body's immune response to the infection

Treatment for Mycoplasma Pneumonia

Most mild Mycoplasma pneumoniae infections resolve on their own. However, if the infection has progressed to pneumonia or symptoms are more severe, your doctor may prescribe antibiotics.

Because Mycoplasma pneumoniae lacks a cell wall, beta-lactam antibiotics such as penicillins are typically ineffective. Depending on the patient's age, clinical presentation and risk of antibiotic resistance, your doctor may consider macrolides, tetracyclines or fluoroquinolones.

Antibiotics for Children

When antibiotic treatment is needed for children, doctors usually consider macrolide such as azithromycin. The choice of treatment will depend on the child's age, severity of illness and local resistance patterns.

If a patient with suspected or confirmed Mycoplasma pneumoniae infection does not improve on macrolides, the doctor may consider a second-line option such as doxycycline, though the potential side effects in children and pregnant women require careful consideration.

How Can You Prevent Mycoplasma Pneumoniae Infection?

There is currently no vaccine to prevent Mycoplasma pneumoniae infection. Prevention therefore focuses on maintaining good personal and environmental hygiene to reduce the spread of respiratory droplets.

Wash your hands frequently with soap and water, especially before touching your mouth, nose or eyes, and after coughing or sneezing.
Cover your mouth and nose with a tissue when coughing or sneezing and dispose of the tissue properly.
If you develop a fever or respiratory symptoms, wear a surgical mask, stay home from work or school, and see a doctor as soon as possible.
Keep indoor areas well-ventilated and regularly clean frequently touched surfaces.
Avoid close contact with children, older adults and immunocompromised individuals until your symptoms have improved.
Sanitise frequently touched surfaces such as doorknobs and mobile phones every 4 hours using approved, appropriate disinfecting solutions.

Summary

Mycoplasma pneumoniae is a common respiratory pathogen that can affect both children and adults. Clinical presentations can range from mild upper respiratory tract infections to mycoplasma pneumonia. Because early symptoms resemble those of a cold or other respiratory infections, the condition can easily be overlooked. However, if you experience a persistent cough, ongoing high fever, shortness of breath, or worsening symptoms, you should seek medical assessment promptly. Most patients recover well with appropriate treatment and rest, but good personal hygiene, including regular handwashing, covering your mouth and nose when coughing and avoiding close contact with infected individuals, remains essential for reducing transmission.

If you have young children, older family members or immunocompromised individuals at home, it is particularly important to stay vigilant, recognise symptoms early and seek appropriate treatment to reduce the risk of complications.

Dr Andrew Kong

Family Medicine, General Practice

LMCHK
MBBS (Newcastle University, UK)
FRACGP
FHKCFP
Dip Med (CUHK)

View Profile

Health Articles by Dr Andrew Kong

References

Centers for Disease Control and Prevention. (2026). 'Clinical overview of Mycoplasma pneumoniae infection.' Centers for Disease Control and Prevention. Available at: https://www.cdc.gov/mycoplasma/hcp/clinical-overview/index.html [Accessed: 8 July 2026].
Saraya, T. (2017). 'Mycoplasma pneumoniae infection: basics.' Journal of General and Family Medicine, 18(3), pp. 118 to 125. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC5689399/.
Centre for Health Protection. (2025). 'Mycoplasma pneumoniae infection.' Centre for Health Protection. Available at: https://www.chp.gov.hk/en/healthtopics/content/24/21283.html [Accessed: 8 July 2026].
Centers for Disease Control and Prevention. (2026). 'About Mycoplasma pneumoniae infection.' Centers for Disease Control and Prevention. Available at: https://www.cdc.gov/mycoplasma/about/index.html [Accessed: 8 July 2026].
Abdulhadi, B. and Kiel, J. (2023). 'Mycoplasma pneumonia.' StatPearls. Available at: https://www.ncbi.nlm.nih.gov/books/NBK430780/ [Accessed: 8 July 2026].
Centers for Disease Control and Prevention. (2024). 'Information for laboratories: Mycoplasma pneumoniae.' Available at: https://www.cdc.gov/mycoplasma/php/laboratories/index.html [Accessed: 8 September 2026].
Pahal, P., Rajasurya, V. and Sharma, S. (2023). 'Mycoplasma infections.' StatPearls. Available at: https://www.ncbi.nlm.nih.gov/books/NBK536927/ [Accessed: 8 September 2026].