A20.2 Pneumonic plague

Name of the Condition

• Pneumonic plague

Summary

Pneumonic plague is a severe bacterial infection caused by Yersinia pestis. It is the most contagious form of plague, transmitted through respiratory droplets from person to person or via inhalation of infectious particles. Unlike other plague forms, it does not require flea vectors for transmission. The condition progresses rapidly and can be fatal if not treated promptly.

Causes

Pneumonic plague is caused by the bacterium Yersinia pestis. Primary transmission occurs when an infected individual coughs or sneezes, releasing droplets that others inhale. Secondary pneumonic plague may develop in patients with bubonic or septicemic plague if the bacteria spread to the lungs. Rarely, it can result from handling infected animal tissues and inhaling aerosolized bacteria.

Risk Factors

• Close contact with individuals or animals with pneumonic plague.
• Living in or traveling to plague-endemic regions (e.g., parts of Africa, Asia, the Americas).
• Occupations involving wildlife handling, veterinary work, or laboratory research with Yersinia pestis.
• Failure to use respiratory protection in high-risk settings.

Symptoms

• Sudden onset of fever, chills, and headache.
• Cough, chest pain, and difficulty breathing.
• Coughing up blood or bloody sputum.
• Rapid respiratory failure in severe cases.

Diagnosis

Pneumonic plague is diagnosed through clinical evaluation and laboratory testing. A chest X-ray may show signs of pneumonia. Confirmatory tests include sputum cultures, blood cultures, or rapid diagnostic tests (RDTs) for Yersinia pestis. Polymerase chain reaction (PCR) can detect bacterial DNA in respiratory samples.

Treatment Options

• Antibiotics are the primary treatment, including streptomycin, gentamicin, doxycycline, or ciprofloxacin.
• Supportive care, such as oxygen therapy or mechanical ventilation, may be necessary for respiratory distress.
• Isolation is critical to prevent person-to-person transmission during the infectious period.

Prognosis and Follow-Up

With early antibiotic treatment, the prognosis improves significantly. Delayed treatment increases mortality risk. Follow-up includes monitoring for treatment response and potential complications. Patients should remain isolated until they are no longer contagious, typically 48 hours after starting effective antibiotics.

Complications

• Respiratory failure requiring mechanical ventilation.
• Septic shock and multi-organ failure.
• Secondary septicemic or bubonic plague if the infection spreads.
• Death if treatment is delayed or ineffective.

Lifestyle & Prevention

• Avoid close contact with individuals suspected of having pneumonic plague.
• Use personal protective equipment (e.g., masks) in high-risk environments.
• Practice good hand hygiene and respiratory etiquette.
• Seek prompt medical care if exposure is suspected.

When to Seek Professional Help

Seek immediate medical attention if you experience sudden fever, cough, or difficulty breathing, especially after potential exposure to pneumonic plague. Early treatment is critical to improve outcomes.

Tips for Medical Coders

Code A20.2 is used for pneumonic plague. Documentation should specify the form of plague and any associated complications. Ensure the diagnosis is clearly supported by clinical findings and laboratory results. Follow local coding guidelines for infectious disease reporting.