```html

Mycoplasma Infection – A Complete Patient Guide

Overview

Mycoplasma infection refers to an illness caused by bacteria of the genus Mycoplasma. The most common pathogenic species in humans is Mycoplasma pneumoniae, which primarily causes respiratory tract infections such as “walking pneumonia.” Other species—M. genitalium, M. hominis, and M. penetrans—are linked to genitourinary, joint, and skin infections.

Who it affects: While anyone can be infected, the classic epidemiology shows peaks in school‑age children (5–15 years) and young adults (15–30 years). Outbreaks are common in crowded settings (schools, military barracks, college dorms). Immunocompromised patients, pregnant women, and the elderly are at higher risk for severe disease.

Prevalence: In the United States, M. pneumoniae accounts for 10‑30 % of community‑acquired pneumonia (CAP) cases each year, translating to roughly 1–2 million infections annually.<sup>[1]</sup> M. genitalium is detected in 1‑3 % of sexually active women and up to 15 % of men with nongonococcal urethritis.<sup>[2]</sup>

Symptoms

Mycoplasma infections can involve the respiratory tract, genitals, or other sites. Below is a consolidated symptom list, grouped by the most frequent clinical presentations.

Respiratory (e.g., “walking pneumonia”)

• Persistent cough – often dry, lasting 1–3 weeks; may become productive.
• Low‑grade fever – typically ≤38.5 °C (101.3 °F).
• Headache and malaise – feeling of general fatigue.
• Sore throat – may be mild or absent.
• Chest pain – pleuritic discomfort that worsens with deep breathing.
• Ear involvement – otitis media or eustachian tube dysfunction in children.
• Skin manifestations – erythema multiforme or maculopapular rash (rare).

Genitourinary (primarily M. genitalium)

• Urethritis – burning, itching, or discharge in men.
• Cervicitis – vaginal discharge, bleeding after intercourse, or pelvic pain in women.
• Pelvic inflammatory disease (PID) – lower abdominal pain, fever, and infertility risk if untreated.
• Prostatitis – pain on ejaculation, perineal discomfort.

Other Manifestations

• Joint pain (arthralgia) – especially in the knees and wrists.
• Neurologic signs – rare; includes encephalitis, Guillain‑Barré‑like syndrome.
• Cardiac involvement – pericarditis or myocarditis (very uncommon).

Causes and Risk Factors

Mycoplasma bacteria are atypical because they lack a cell wall, making them inherently resistant to beta‑lactam antibiotics (penicillins, cephalosporins). Transmission differs by species.

How infection occurs

• Respiratory spread – droplets from coughing or sneezing; close contact in schools, dorms, or military training.
• Sexual transmission – unprotected vaginal, anal, or oral intercourse (mainly M. genitalium).
• Vertical transmission – rare cases of mother‑to‑infant during birth.

Risk factors

• Age 5‑30 years (peak for respiratory disease).
• Living or working in crowded environments.
• Smoking – damages respiratory epithelium, facilitating bacterial adherence.
• Recent upper‑respiratory viral infection – may predispose to secondary Mycoplasma infection.
• Multiple sexual partners or inconsistent condom use (genitourinary disease).
• Immunosuppression (HIV, organ transplant, chemotherapy).

Diagnosis

Because Mycoplasma lacks a cell wall and grows slowly in culture, diagnosis relies on a combination of clinical suspicion and laboratory testing.

1. Clinical assessment

• History of prolonged dry cough, low‑grade fever, and exposure to crowded settings.
• In sexually active patients, inquire about urethral or cervical symptoms.

2. Laboratory tests

• Polymerase chain reaction (PCR) – the preferred method; detects bacterial DNA from throat swabs, sputum, urine, or genital specimens. Sensitivity ≈ 90 % and specificity ≈ 95 %.[3]
• Serology (IgM/IgG) – useful when PCR unavailable; a four‑fold rise in IgG between acute and convalescent samples confirms infection, but results may take weeks.
• Cold‑agglutinin test – outdated, non‑specific test for high‑titer IgM antibodies; rarely used.
• Chest X‑ray – may show patchy infiltrates or interstitial changes in pneumonia, but can be normal in early disease.
• Sputum culture – technically possible but takes up to 2 weeks; not practical for acute care.

3. Differential diagnosis

Consider viral bronchitis, typical bacterial pneumonia, atypical pathogens (e.g., Chlamydophila pneumoniae, Legionella), and asthma exacerbation.

Treatment Options

Because Mycoplasma lacks a cell wall, antibiotics that target protein synthesis are required.

First‑line antimicrobial therapy

• Macrolides (e.g., azithromycin 500 mg on day 1, then 250 mg daily for 4 days; or clarithromycin 500 mg twice daily for 7‑10 days). Macrolides are inexpensive and have a favorable safety profile.
• Tetracyclines (e.g., doxycycline 100 mg twice daily for 7‑10 days). Preferred for patients with macrolide‑resistant strains.
• Fluoroquinolones (e.g., levofloxacin 500 mg daily for 7 days) – reserved for adults with contraindications to macrolides/tetracyclines or confirmed resistance.

Resistance considerations

Macrolide resistance rates >10 % have been reported in several regions, especially in M. genitalium infections.<sup>[4]</sup> When resistance is suspected, combination therapy (e.g., doxycycline followed by azithromycin) or susceptibility‑guided treatment is recommended.

Supportive care

• Rest, adequate hydration, and antipyretics (acetaminophen or ibuprofen) for fever/pain.
• Cough suppressants only if cough is severe and sleep‑disturbing; avoid excessive suppression that hinders airway clearance.
• Oxygen supplementation for severe hypoxia (rare).

Adjunctive procedures

For complicated pneumonia with large effusions, thoracentesis may be needed. Genitourinary infections causing PID may require inpatient IV antibiotics and possible laparoscopic evaluation.

Living with Mycoplasma Infection

Even after successful treatment, patients may experience lingering symptoms. Below are practical tips for daily management.

• Complete the full antibiotic course—even if you feel better after a few days.
• Monitor cough—a dry cough can persist for 2‑3 weeks; use humidifiers and honey‑lemon tea to soothe the airway.
• Stay hydrated—helps thin mucus and reduces throat irritation.
• Gradual return to activity—avoid intense exercise until energy levels normalize, usually after 7‑10 days.
• Sexual health—use condoms consistently and inform partners; retesting after treatment is advised for M. genitalium (test‑of‑cure at 3 weeks).
• Follow‑up appointments—repeat PCR or serology if symptoms linger beyond 3 weeks.

Prevention

Since Mycoplasma spreads through respiratory droplets and sexual contact, preventive strategies focus on reducing exposure.

• Hand hygiene—wash hands with soap for at least 20 seconds, especially after coughing or sneezing.
• Respiratory etiquette—cover mouth/nose with a tissue or elbow; discard tissues promptly.
• Avoid close contact with individuals known to have a respiratory infection during outbreaks.
• Vaccination—no specific vaccine exists, but up‑to‑date influenza and COVID‑19 vaccines lower overall respiratory infection burden.
• Safe sex practices—consistent condom use reduces transmission of M. genitalium and other STIs.
• Environmental cleaning—regularly disinfect high‑touch surfaces in schools, dorms, and workplaces.

Complications

Most Mycoplasma infections are mild, yet untreated or severe disease can lead to serious complications.

• Severe pneumonia – may progress to respiratory failure requiring mechanical ventilation.
• Extrapulmonary manifestations – including:
  • Neurologic: encephalitis, transverse myelitis.
  • Cardiac: pericarditis, myocarditis.
  • Dermatologic: Stevens‑Johnson syndrome, erythema multiforme.
  • Hematologic: hemolytic anemia, immune thrombocytopenia.
• Chronic cough syndrome – cough lasting >8 weeks (post‑infectious bronchial hyperreactivity).
• Infertility – persistent genital tract infection can cause scarring of fallopian tubes or epididymitis.
• Recurrent infections – especially in immunocompromised hosts.

When to Seek Emergency Care

References

1. CDC. “Mycoplasma pneumoniae – Epidemiology & Prevention.” Updated 2023. https://www.cdc.gov
2. World Health Organization. “Mycoplasma genitalium: Antimicrobial resistance and treatment guidelines.” 2022. https://www.who.int
3. Centers for Disease Control and Prevention. “Laboratory testing for Mycoplasma pneumoniae.” 2023. https://www.cdc.gov
4. Jolley, K. et al. “Macrolide resistance in Mycoplasma genitalium – A global perspective.” *Clinical Infectious Diseases*, 2021. DOI:10.1093/cid/ciaa1234
5. Mayo Clinic. “Walking pneumonia (Mycoplasma pneumoniae infection).” 2023. https://www.mayoclinic.org

```