Clinicians should consider human plague in any patient who has compatible symptoms and has reasonable risk factors, according to the Centers for Disease Control and Prevention. Key risk factors include residing or traveling in the western United States, recent proximity to rodent habitats, or direct contact with rodents or sick domestic animals.
Natalie Kwit, DVM, from the Epidemic Intelligence Service and the Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, and colleagues released their findings in an article published online August 25 in the Morbidity and Mortality Weekly Report.
Since April 1, 2015, a total of 11 cases of the infection have been found in residents of six states: Arizona (two), California (one), Colorado (four), Georgia (one), New Mexico (two), and Oregon (one). Investigators have linked two cases in Georgia and California with exposures at or near Yosemite National Park in the Sierra Nevada Mountains of California.
Overall, three patients (aged 16, 52, and 79 years) have died.
The number of human plague cases reported to date in 2015 is higher than usual. Between 2001 and 2012, the median number of cases annually was three, with a range of 1 to 17.
Plague spreads among wild rodents and their fleas in rural and semirural regions in the western United States. It is transmitted to humans through the bite of infected fleas, direct contact with infected body fluids or tissues, or inhalation of respiratory droplets from sick persons or animals, including domesticated cats and dogs.
In humans, it causes a sudden onset of fever and malaise and can also cause abdominal pain, nausea, and vomiting. When untreated, the mortality rate ranges from 66% to 93%; with antimicrobial treatment, however, mortality is reduced to about 16%. Outcomes are much better with prompt treatment with antimicrobials, including aminoglycosides, fluoroquinolones, or doxycycline.
Clinicians who suspect plague should
collect blood, bubo aspirate, or sputum samples for Yersinia pestis diagnostic testing;
implement isolation and respiratory droplet precautions for patients with respiratory involvement;
immediately begin antibiotic treatment before laboratory confirmation; and
notify public health officials.
Diagnostic testing and antibiotic treatment recommendations are available on the Centers for Disease Control and Prevention website.
The authors have disclosed no relevant financial relationships.
Morb Mortal Wkly Rep. Published online August 26, 2015. Full text
