Atlanta, Georgia – New research from a team of scientists at the United States’ National Institute of Allergy and Infectious Diseases (NIAID) suggests that human body lice may have played a more significant role in historical pandemics than previously believed. Their study challenges the common belief that fleas and rats are the primary culprits behind the spread of plague outbreaks.
The findings, published in the open-access journal PLOS Biology, indicate that human body lice are highly efficient at transmitting Yersinia pestis, the bacterium responsible for causing plague. This revelation could reshape our understanding of past pandemics, including the devastating Black Death that claimed millions of lives in Europe during the Middle Ages.
Historically, Y. pestis has been associated with plague pandemics, with fleas and rats typically thought to be the main carriers of the bacterium. Body lice, which feed on human blood, have been considered less effective at spreading the disease. However, the results of the laboratory study conducted by Bland and his team suggest otherwise.
Through a series of experiments involving body lice feeding on blood samples containing Y. pestis, the researchers found that the lice were able to become infected and transmit the pathogen. Interestingly, lice with infected salivary glands known as the Pawlowsky glands were more likely to transmit the disease consistently compared to those with infections limited to their digestive tracts.
These new findings propose a bite-based mechanism through which infected lice may spread Y. pestis to humans. The researchers suggest that contaminated secretions from the lice’s mouthparts could potentially transmit the pathogen to humans when bitten, highlighting the potential role of body lice in plague transmission.
Overall, the study indicates that body lice may have been more efficient spreaders of Y. pestis than previously assumed, opening up new possibilities for understanding the dynamics of historical pandemics. As scientists continue to unravel the complexities of plague transmission, the role of body lice in past outbreaks may warrant further investigation.