The St Kilda boat cough under the microscope.

Area of Science:

• Epidemiology
• Virology
• Historical Medicine

Background:

• The isolated St Kilda archipelago experienced recurrent respiratory outbreaks termed "boat cough" from the 17th to 19th centuries.
• These episodes coincided with the arrival of visitors to the community.
• Traditionally, "boat cough" was misdiagnosed as influenza.

Observation:

• Contemporary records detail symptoms and transmission patterns of the "boat cough" outbreaks.
• Modern microbiological understanding provides a framework for re-evaluating historical disease etiologies.
• The pattern of introduction by strangers is characteristic of many viral infections.

Findings:

• Analysis of historical data and modern evidence indicates "boat cough" was likely caused by rhinovirus.
• Rhinoviruses are common causes of respiratory tract infections, aligning with observed symptoms.
• The historical misattribution to influenza highlights diagnostic limitations of the era.

Implications:

• This re-evaluation corrects the historical understanding of infectious disease on St Kilda.
• It underscores the importance of considering alternative pathogens in historical epidemics.
• Understanding historical rhinovirus outbreaks can inform current public health strategies for respiratory viruses.