FROM: CENTERS FOR DISEASE CONTROL AND PREVENTION
Outbreak of Human Pneumonic Plague with Dog-to-Human and Possible Human-to-Human Transmission — Colorado, June–July 2014
This outbreak highlights 1) the need to consider plague in the differential diagnosis of sick domestic animals from plague endemic areas, including dogs, 2) the limitations of automated diagnostic systems for identifying rare bacteria such as Yersinia pestis, and 3) the potential for milder forms of illness in patients taking antimicrobial agents. Hospital laboratories in plague-endemic areas should be aware of the limitations of current diagnostic methodologies in diagnosing rare diseases such as plague. In July 2014, the Colorado Department of Public Health and Environment Laboratory identified Yersinia pestis in a blood sample collected from a middle-aged man hospitalized with pneumonia. An investigation led by Tri-County Health Department revealed that the man’s dog had been ill and was euthanized. The dog later tested positive for Y. pestis. Three additional persons with contact with the dog and/or patient were ill and tested positive for Y. pestis. One of the cases may have resulted through person-to-person transmission from the index patient, potentially the first such event in North America since 1924. Human illness due to plague remains an ongoing risk in endemic areas. Early recognition of plague, especially the pneumonic form, is critical to clinical management and a timely public health response.