Plague: history and contemporary analysis

Area of Science:

• Infectious Diseases
• Microbiology
• Epidemiology

Background:

• Plague outbreaks, historically devastating (e.g., Justinian Plague, Black Death), are caused by Yersinia pestis.
• The transmission vectors during historical pandemics are debated, but modern understanding points to rodent endemics and potential human ectoparasites.

Observation:

• Plague should be suspected in endemic rodent areas with symptoms like adenitis or pneumonia with bloody sputum.
• Diagnosis is challenging during plague reemergence, necessitating clinical suspicion and prompt intervention.
• Typical buboes are painful, red, and non-fluctuating adenitis, aiding clinical diagnosis.

Findings:

• Microbiological analysis, including gram-negative bacilli in lymph node aspirates and positive blood cultures for Yersinia pestis, confirms diagnosis.
• Biochemical tests and MALDI-TOF mass spectrometry facilitate Yersinia pestis identification.
• Pneumonic and septicemic plague without adenitis are difficult to diagnose, often identified retrospectively.

Implications:

• Early treatment with gentamicin or doxycycline is crucial upon suspicion due to plague's high fatality rate.
• Modern laboratory tools enhance the diagnosis of plague, validating clinical signs like buboes.
• Research into plague transmission, including human ectoparasites, offers new insights into disease control.