Rapid Diagnostic Test For Plague

An important step towards controlling bubonic and pneumonic plague may soon be possible with the use of a straightforward and accurate diagnostic test, according to authors of a study in this week’s issue of THE LANCET.

Plague is a flea-borne rodent disease that is occasionally transmitted to man, with around 3000-4000 cases annually in more than 20 countries, mainly in Africa. A rapid diagnostic test for the disease is urgently needed as current diagnosis is not possible until severe symptoms develop. Early diagnosis would also be crucial if the plague bacterium was used in biological warfare—pneumonic plague is always fatal unless treatment is initiated within 24 hours of disease onset.

Suzanne Chanteau and colleagues from the Pasteur Institute and the Ministry of Health, Madagascar, developed a diagnostic test where conjugated gold particles were able to detect antigens of plague bacteria. The test detected antigens at low concentrations within 15 minutes of infection; furthermore it was both 100% sensitive and reliable (ie. It did not create false diagnoses) and detected more infections than conventional laboratory assessments.

Suzanne Chanteau comments: “We have shown that with this test, the rapid and cost-effective diagnosis of bubonic and pneumonic plague could easily be achieved by health workers in remote sites. Use of the test could help to reduce mortality (through rapid and efficient treatment of patients), morbidity (by rapid implementation of preventive measures), and insecticide resistance of fleas (through rational use of expensive insecticides).”

“The current study is remarkable for its comprehensive evaluation under plague-endemic situations”, state David Dennis and May Chu from the Centers for Disease Control and Prevention, USA, in an accompanying Commentary (p 191). “The test has been distributed to health centres in Madagascar, and it is anticipated that it will soon be available in plague-endemic areas worldwide, providing opportunities for validations under various conditions. In addition, the test…is expected to fill an important need in bioterrorism preparedness and response.”