801. A Century of Human Plague: United States, 1900-2008
Session: Abstracts: Oral Abstract Session: Bacterial Clinical Studies I
Friday, October 22, 2010: 3:45 PM
Background: Plague is a severe flea-borne zoonosis caused by Yersinia pestis.  The U.S. Public Health Service has collected information on human plague cases since the disease was introduced into the United States in 1900.

Methods: To describe changes in plague epidemiology in the US over the last century, we reviewed all confirmed and probable cases from 1900-2008.  Comparisons were made among cases occurring before and after 1944, the year antibiotics were first used to treat plague.

Results: A total of 989 plague cases were identified, with a single year maximum of 191 cases in 1907.  Median patient age was 28 years (range: <1-94); 65% were male.  Primary clinical manifestations were mostly bubonic (82%), but also septicemic (9%) and pneumonic (8%).  In the pre-antibiotic era, 515 plague cases (mean: 11/year) occurred in urban ports of 29 counties, mostly in CA (80%) but also in FL, LA, TX, and WA.  Most pneumonic cases (81%) were reported during this time; 83% of these were due to human transmissions in outbreaks.  The last human to human transmission was in 1924.  Patients were identified as White (56%), Asian (30%), and Hispanic (11%).  Pre-antibiotic mortality (66%) did not differ by sex, but was higher among Hispanics (81%) and Asians (95%) than among Whites (53%) (p<0.0001).  Since 1944, 474 cases (mean: 7/year) occurred in 110 rural and suburban counties in the West, with 54% of cases in NM.  Most septicemic cases (89%) were recorded during this time.  Exposures were in peridomestic, recreational and occupational settings.  The proportion of White non-Hispanics and Hispanics was similar as before 1944, however American Indians accounted for 33% of cases.  In the antibiotic era, 88% of patients received ≥1 effective drug, mortality declined to 16%, was lower in females (11%) than males (19%) (p=0.03), and did not differ by race.  Persons with known flea bite sought care earlier and had lower risk of mortality (RR: 0.7, 95%CI: 0.6-0.9) than those without a recognized bite.

Conclusion: In the last 109 years, plague has shifted from a disease of urban coastal populations capable of pneumonic outbreaks to a rare zoonosis in rural and suburban areas of the West.  Despite effective antibiotics, plague mortality still occurs.

Subject Category: C. Clinical studies of bacterial infections and antibacterials including sexually transmitted diseases and mycobacterial infections (surveys, epidemiology, and clinical trials)

Kiersten J. Kugeler , Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO
Alison F. Hinckley , Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO
Paul S. Mead , Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO


K. J. Kugeler, None

A. F. Hinckley, None

P. S. Mead, None

<< Previous Abstract | Next Abstract

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 21 with the exception of research findings presented at IDSA press conferences.


Copyright IDSA 2009 Infectious Diseases Society of America 1300 Wilson Boulevard, Suite 300 Arlington, VA 22209 info@idsociety.org