Tropical Medicine Mission Index of Diseases About Tropical Medicine Tropical Medicine Home Page Tropical Medicine Staff

Next Page

Laboratory Diagnosis

Plague is diagnosed by identification of Yersinia pestis coccobacilli. In bubonic plague, seropurulent material aspirated from the bubo should be examined for the characteristic bipolar, pleomorphic bacilli using Gram's stain. In septicemic, pneumonic, or meningeal plague, smears of blood, sputum, or cerebrospinal fluid may be similarly examined; splenic puncture has been effective. Serological testing to demonstrate plague antibodies include indirect hemagglutination, ELISA (IgM and IgG), and radioimmunoassay. Development of a DNA probe for plague antigen detection was reported in 1988.

There is too great a delay in obtaining results from culture or animal inoculation or skin testing to provide an early diagnosis of plague, which is essential if the patient is to receive immediate treatment and survive. Any material suspected of containing Y. pestis should be handled with extreme care and all laboratory procedures carried out with strict aseptic technique.

There is a marked neutrophilic leukocytosis with counts reaching 40,000 or more WBC per mm³. Blood cultures are positive in about half the patients

Back to the Table of Contents

Copyright: Palmer and Reeder