Factors Influencing Atypical Clinical Presentations during the 2017 Madagascar Pneumonic Plague Outbreak: A...

Area of Science:

• Epidemiology
• Infectious Diseases
• Public Health

Background:

• The 2017 Madagascar pneumonic plague outbreak presented with atypical symptoms and lower mortality than expected.
• This prompted an investigation into potential contributing factors.
• Understanding these deviations is crucial for future outbreak response.

Purpose of the Study:

• To investigate the reasons behind atypical pneumonic plague presentations during the 2017 Madagascar outbreak.
• To assess the impact of community antibiotic use on plague diagnosis and presentation.
• To identify challenges in clinical case definitions and triage during urban plague outbreaks.

Main Methods:

• A prospective, multicenter observational study was conducted during the outbreak.
• Data collection included patient symptoms, treatment history, and serum antibiotic levels.
• Confirmed plague cases were identified through laboratory testing.

Main Results:

• A significant proportion of patients had received antibiotics with anti-plague activity prior to or upon hospital admission.
• Overdiagnosis of plague by clinicians was suggested as a contributing factor.
• Community antibiotic use may have influenced clinical presentation and reduced culture-positive results.

Conclusions:

• Community antibiotic use likely contributed to atypical plague presentations and lower observed mortality.
• Overdiagnosis and widespread antibiotic use complicate accurate plague detection and management in urban outbreaks.
• Revised clinical case definitions and triage strategies are needed for future urban pneumonic plague events.