Plague is an infectious disease caused by the bacteria, Yersinia pestis. Y. pestis is found in small mammals and their fleas. Plague is transmitted between animals and humans by the bit of infected fleas, direct contact with infected tissues, and inhalation of infected respiratory droplets or aerosolized bacteria. There are two main forms of plague infection: bubonic and pneumonic. Bubonic plague is the most common form and is characterized by painful swollen lymph nodes that are termed 'buboes'. This occurs when an infected flea bites a person or when materials contaminated with Y. pestis enter through a break in a person's skin. Pneumonic plague is the most severe form of disease and is spread by breathing in Y. pestis bacteria suspended in respiratory droplets from a person (or animal) with pneumonic plague. Pneumonic plague may also occur when advanced bubonic disease spreads to the lungs.

A small number of human plague infections occur annually in the western United States, but significantly more cases occur in parts of Africa and Asia. Notably, Y. pestis is considered a high priority biothreat by the U.S. government given the potential for aerosolized transmission and the high fatality rate associated with pneumonic plague.

Plague was responsible for killing millions of people in Europe during the middle ages. Fortunately, antibiotics are now available and are effective against plague, if treatment is administered in time. Early detection is crucial to prevent serious illness and potential death. Current diagnostics for plague require advanced laboratory equipment and can take 1-2 days for results. The group at our laboratory is focused on developing a rapid plague diagnostic, that can yield results in less than 15 minutes and can be performed at the point-of-need. Prototype assays have been developed using monoclonal antibodies produced to two separate Y. pestis protein targets, and initial studies show the assays to have the high sensitivity required for early detection of plague infection. Y. pestis diagnostic studies are ongoing and antibodies are being tested in multiple rapid immunoassay formats.

Project Investigator: P. AuCoin, Ph.D.

Grant support: This study has been is supported by the Defense Threat Reduction Agency contract# HDTRA1-16-C-0026, Design rules for vertical paper-based immuno-diagnostic system, 2016-2018.