Volume 22, Number 12—December 2016

CME ACTIVITY - Synopsis

Investigation of and Response to 2 Plague Cases, Yosemite National Park, California, USA, 2015

Mary Danforth, Mark Novak, Jeannine Petersen, Paul S. Mead, Luke Kingry, Matthew Weinburke, Danielle Buttke, Gregory Hacker, James Tucker, Michael Niemela, Bryan Jackson, Kerry Padgett, Kelly Liebman, Duc Vugia, and Vicki L. Kramer

Author affiliations: California Department of Public Health, Sacramento, California, USA (M. Danforth, M. Novak, G. Hacker, J. Tucker, M. Niemela, B. Jackson, K. Padgett, K. Liebman, D. Vugia, V. Kramer) ; Centers for Disease Control and Prevention, Fort Collins, Colorado, USA (J. Petersen, P. Mead, L. Kingry) ; National Park Service, El Portal, California, and Fort Collins, Colorado, USA (M. Weinburke, D. Buttke)

Cite This Article

Open modal

Introduction This activity has been planned and implemented through the joint providership of Medscape, LLC and Emerging Infectious Diseases. Medscape, LLC is accredited by the American Nurses Credentialing Center (ANCC), the Accreditation Council for Pharmacy Education (ACPE), and the Accreditation Council for Continuing Medical Education (ACCME), to provide continuing education for the healthcare team. Medscape, LLC designates this Journal-based CME activity for a maximum of 1.00 AMA PRA Category 1 Credit(s)™. Physicians should claim only the credit commensurate with the extent of their participation in the activity. All other clinicians completing this activity will be issued a certificate of participation. To participate in this journal CME activity: (1) review the learning objectives and author disclosures; (2) study the education content; (3) take the post-test with a 75% minimum passing score and complete the evaluation at http://www.medscape.org/journal/eid; and (4) view/print certificate. Release date: November 16, 2016; Expiration date: November 16, 2017 Learning Objectives Upon completion of this activity, participants will be able to: • Interpret laboratory and epidemiologic findings regarding 2 human cases of plague in 2015 in patients with recent travel history to Yosemite National Park • Assess environmental findings regarding 2 human cases of plague in 2015 in patients with recent travel history to Yosemite National Park • Identify critical risk reduction measures used to help prevent plague transmission to Yosemite visitors and staff. CME Editor P. Lynne Stockton Taylor, VMD, MS, ELS(D), Technical Writer/Editor, Emerging Infectious Diseases. Disclosure: P. Lynne Stockton Taylor, VMD, MS, ELS(D), has disclosed no relevant financial relationships. CME Author Laurie Barclay, MD, freelance writer and reviewer, Medscape, LLC. Disclosure: Laurie Barclay, MD, has disclosed the following relevant financial relationships: owns stock, stock options, or bonds from Pfizer. Authors Disclosures: Mary E. Danforth, PhD; Mark Novak, PhD; Jeannine Petersen, PhD; Paul Mead, PhD, MPH; Luke Kingry, PhD; Matthew Weinburke, MPH; Danielle Buttke, DVM, PhD, MPH; Gregory Hacker, MSc; James R. Tucker, MS; Michael Niemela, MS; Bryan T. Jackson, PhD; Kerry Padgett, PhD; Kelly Liebman, PhD, MPH; Duc Vugia, MD, MPH; and Vicki Kramer, PhD, have disclosed no relevant financial relationships.

Abstract In August 2015, plague was diagnosed for 2 persons who had visited Yosemite National Park in California, USA. One case was septicemic and the other bubonic. Subsequent environmental investigation identified probable locations of exposure for each patient and evidence of epizootic plague in other areas of the park. Transmission of Yersinia pestis was detected by testing rodent serum, fleas, and rodent carcasses. The environmental investigation and whole-genome multilocus sequence typing of Y. pestis isolates from the patients and environmental samples indicated that the patients had been exposed in different locations and that at least 2 distinct strains of Y. pestis were circulating among vector–host populations in the area. Public education efforts and insecticide applications in select areas to control rodent fleas probably reduced the risk for plague transmission to park visitors and staff.

Acknowledgments

We thank Ben Schwartz, Rachel Civen, Nicole Green, Amanda Kamali, Chelsea Foo, Cherie Drenzek, Amanda Feldpausch, Wendy Smith, and Laura Edison, who identified and interviewed the patients, assisted in the environmental investigation, and conducted the patient diagnostics. We are deeply grateful to Kenneth Gage, Rebecca Eisen, Karen Boegler, John Montenieri, Don Neubacher, Ron Bourne, Linda Mazzu, Caitlin Lee-Roney, Garrett Dickman, Myron Grissom, and David Wong. We also thank Gil Chavez and James Watt for their support of the investigation and response, and we thank the CDPH Vector Borne Disease Section staff for their assistance with the environmental investigation and rodent serology work, particularly Renjie Hu, Joe Burns, Sarah Billeter, Melissa Yoshimizu, Robert Payne, and Robert Dugger. In addition, we extend our appreciation to all the laboratory staff members who tested samples from patients and the environment, including Marty Schriefer, John Young, Ryan Pappert, Chris Sexton, Brook Yockey, Laurel Respicio-Kingry, Fengfeng Xu, Rose Longoria, Yismashoa Gebremichael, Margot Graves, Vishnu Chaturvedi, and Elizabeth Wheeler. We also thank the CDC Genome Sequencing Laboratory for PacBio sequencing. Last, we thank the Delaware North Corporation for their cooperation and assistance with the investigation. This study was partially supported by contract funding from the NPS to Public Health Foundation Enterprises.

References

Pollitzer R . Plague. Geneva: World Health Organization. 1954 . Perry RD , Fetherston JD . Yersinia pestis—etiologic agent of plague. Clin Microbiol Rev . 1997 ; 10 : 35 – 66 . PubMed Gage KL , Kosoy MY . Natural history of plague: perspectives from more than a century of research. Annu Rev Entomol . 2005 ; 50 : 505 – 28 . DOI PubMed Link VB . A history of plague in United States of America. Public Health Monogr . 1955 ; 26 : 1 – 120 . PubMed Caten JL , Kartman L . Human plague in the United States, 1900-1966. JAMA . 1968 ; 205 : 333 – 6 . DOI PubMed Kugeler KJ , Staples JE , Hinckley AF , Gage KL , Mead PS . Epidemiology of human plague in the United States, 1900-2012. Emerg Infect Dis . 2015 ; 21 : 16 – 22 . DOI PubMed Barnes A . Surveillance and control of bubonic plague in the United States. Symposium of the Zoological Society of London. 1982 ;50:237–70. Inglesby TV , Dennis DT , Henderson DA , Bartlett JG , Ascher MS , Eitzen E , ; Working Group on Civilian Biodefense . Plague as a biological weapon: medical and public health management. JAMA . 2000 ; 283 : 2281 – 90 . DOI PubMed Antolin JF , Gober P , Luce B , Biggins DE , van Pelt WE , Seery DB , The influence of sylvatic plague on North American wildlife at the landscape level, with special emphasis on black-footed ferret and prairie dog conservation. In: Transactions of the 67th North American Wildlife and Natural Resources Conference; 2002 Apr 3–7. Washington (DC): Wildlife Management Institute; 2002 . Centers for Disease Control and Prevention (CDC) . Human plague—four states, 2006. MMWR Morb Mortal Wkly Rep . 2006 ; 55 : 940 – 3 . PubMed Craven RB , Maupin GO , Beard ML , Quan TJ , Barnes AM . Reported cases of human plague infections in the United States, 1970-1991. J Med Entomol . 1993 ; 30 : 758 – 61 . DOI PubMed Wong D , Wild MA , Walburger MA , Higgins CL , Callahan M , Czarnecki LA , Primary pneumonic plague contracted from a mountain lion carcass. Clin Infect Dis . 2009 ; 49 : e33 – 8 . DOI PubMed Lowell JL , Wagner DM , Atshabar B , Antolin MF , Vogler AJ , Keim P , Identifying sources of human exposure to plague. J Clin Microbiol . 2005 ; 43 : 650 – 6 . DOI PubMed Smith CR , Tucker JR , Wilson BA , Clover JR . Plague studies in California: a review of long-term disease activity, flea-host relationships and plague ecology in the coniferous forests of the Southern Cascades and northern Sierra Nevada mountains. J Vector Ecol . 2010 ; 35 : 1 – 12 . DOI PubMed Wherry WB . Plague among the ground squirrels of California. J Infect Dis . 1908 ; 5 : 485 – 506 . DOI Lang JD . Factors affecting the seasonal abundance of ground squirrel and wood rat fleas (Siphonaptera) in San Diego County, California. J Med Entomol . 1996 ; 33 : 790 – 804 . DOI PubMed Centers for Disease Control and Prevention (CDC) . Imported plague—New York City, 2002. MMWR Morb Mortal Wkly Rep . 2003 ; 52 : 725 – 8 . PubMed Eisen RJ , Enscore RE , Biggerstaff BJ , Reynolds PJ , Ettestad P , Brown T , Human plague in the southwestern United States, 1957-2004: spatial models of elevated risk of human exposure to Yersinia pestis. J Med Entomol . 2007 ; 44 : 530 – 7 . DOI PubMed Kwit N , Nelson C , Kugeler K , Petersen J , Plante L , Yaglom H , Human Plague - United States, 2015. MMWR Morb Mortal Wkly Rep . 2015 ; 64 : 918 – 9 . DOI PubMed California Department of Public Health . Yearly summaries of selected general communicable diseases in California, 2001–2010. Sacramento (CA): The Department; 2015 . California Department of Public Health . Yearly summaries of selected general communicable diseases in California, 2011–2014. Sacramento (CA): The Department; 2015 . Centers for Disease Control and Prevention . Nationally notifiable diseases surveillance system: plague (Yersinia pestis) 1996 case definition [cited 2015 Dec 9]. . Nationally notifiable diseases surveillance system: plague (Yersinia pestis)case definition [cited 2015 Dec 9]. http://www.cdc.gov/nndss/conditions/plague/case-definition/1996 Chu MC . Laboratory manual of plague diagnostic tests. Washington (DC): US Department of Health and Human Services; 2000 . Kingry LC , Rowe LA , Respicio-Kingry LB , Beard CB , Schriefer ME , Petersen JM . Whole genome multilocus sequence typing as an epidemiologic tool for Yersinia pestis. Diagn Microbiol Infect Dis . 2016 ; 84 : 275 – 80 . DOI PubMed California Department of Public Health . California compendium of plague control; plague surveillance risk evaluation form. Sacramento (CA): The Department; 2015 . Hubbard CA . Fleas of western North America: their relation to the public health. Ames (IA): Iowa State College Press; 1947 . Liu J , Ochieng C , Wiersma S , Ströher U , Towner JS , Whitmer S , Development of a TaqMan array card for acute febrile illness outbreak investigation and surveillance of emerging pathogens including Ebola virus. J Clin Microbiol . 2016 ; 54 : 49 – 58 . DOI PubMed Bankevich A , Nurk S , Antipov D , Gurevich AA , Dvorkin M , Kulikov AS , SPAdes: a new genome assembly algorithm and its applications to single-cell sequencing. J Comput Biol . 2012 ; 19 : 455 – 77 . DOI PubMed National Park Service . Yosemite National Park. Park statistics [cited 2015 Dec 9]. . Yosemite National Park. Park statistics [cited 2015 Dec 9]. http://www.nps.gov/yose/learn/nature/park-statistics.htm Rosales R . Second human case of bubonic plague inside Yosemite National Park. Fox26 KMPH News. August 18, 2015 [cited 2015 Dec 9]. . Second human case of bubonic plague inside Yosemite National Park. Fox26 KMPH News. August 18,[cited 2015 Dec 9]. http://kmph-kfre.com/archive/second-human-case-of-bubonic-plaque-inside-yosemite-national-park Lowell JL , Antolin MF , Andersen GL , Hu P , Stokowski RP , Gage KL . Single-nucleotide polymorphisms reveal spatial diversity among clones of Yersinia pestis during plague outbreaks in Colorado and the western United States. Vector Borne Zoonotic Dis . 2015 ; 15 : 291 – 302 . DOI PubMed Clover JR , Hofstra TD , Kuluris BG , Schroeder MT , Nelson BC , Barnes AM , Serologic evidence of Yersinia pestis infection in small mammals and bears from a temperate rainforest of north coastal California. J Wildl Dis . 1989 ; 25 : 52 – 60 . DOI PubMed California Department of Public Health . Vector-Borne Disease Section annual report 2015 [cited 2016 Sep 27]. . Vector-Borne Disease Section annual report[cited 2016 Sep 27]. http://www.cdph.ca.gov/programs/vbds/Documents/VBDSAnnualReport15.pdf Fox M . Oregon girl is the 16th U.S. plague case this year. NBC News. October 30, 2015 [cited 2015 Dec 9]. . Oregon girl is the 16th U.S. plague case this year. NBC News. October 30,[cited 2015 Dec 9]. http://www.nbcnews.com/health/health-news/oregon-girl-16th-u-s-plague-case-year-n454496 Ben Ari T , Gershunov A , Gage KL , Snäll T , Ettestad P , Kausrud KL , Human plague in the USA: the importance of regional and local climate. Biol Lett . 2008 ; 4 : 737 – 40 . DOI PubMed Murray KF , Kartman L . Plague in California during 1959. California Vector Views. 1959 ; 6 : 66 – 7 .

Figures

Tables

Follow Up Earning CME Credit To obtain credit, you should first read the journal article. After reading the article, you should be able to answer the following, related, multiple-choice questions. To complete the questions (with a minimum 75% passing score) and earn continuing medical education (CME) credit, please go to http://www.medscape.org/journal/eid. Credit cannot be obtained for tests completed on paper, although you may use the worksheet below to keep a record of your answers. You must be a registered user on Medscape.org. If you are not registered on Medscape.org, please click on the “Register” link on the right hand side of the website to register. Only one answer is correct for each question. Once you successfully answer all post-test questions you will be able to view and/or print your certificate. For questions regarding the content of this activity, contact the accredited provider, CME@medscape.net. For technical assistance, contact CME@webmd.net. American Medical Association’s Physician’s Recognition Award (AMA PRA) credits are accepted in the US as evidence of participation in CME activities. For further information on this award, please refer to http://www.ama-assn.org/ama/pub/about-ama/awards/ama-physicians-recognition-award.page. The AMA has determined that physicians not licensed in the US who participate in this CME activity are eligible for AMA PRA Category 1 Credits™. Through agreements that the AMA has made with agencies in some countries, AMA PRA credit may be acceptable as evidence of participation in CME activities. If you are not licensed in the US, please complete the questions online, print the certificate and present it to your national medical association for review. Article Title:

Investigation of and Response to 2 Plague Cases, Yosemite National Park, California, USA, 2015 CME Questions 1. You are advising the National Parks Service about detection and prevention of plague. According to the public health report by Danforth and colleagues, which of the following statements about the laboratory and epidemiologic findings regarding 2 human cases of patients with plague in 2015 with recent travel history to Yosemite National Park is correct? A. Both patients had bubonic plague B. Both patients had similar travel itineraries and were diagnosed at the same time C. Distinct Yersinia pestis strains were isolated from the patients, with different whole-genome multilocus sequence typing (wgMLST) D. Both patients had fed squirrels and had seen dead rodents 2. According to the public health report by Danforth and colleagues, which of the following statements about the environmental findings regarding 2 human cases of patients with plague in 2015 with recent travel history to Yosemite is correct? A. Environmental samples indicated that the patients were exposed in the same location B. Isolates from rodent serum, fleas, and rodent carcasses showed at least 2 distinct Y. pestis strains circulating among vector-host populations in the area C. Plague antibodies were detected in all 8 rodent species live-trapped in Yosemite D. The findings contrast with a previous single-nucleotide polymorphism (SNP)–based study showing widespread plague epizootics caused by multiple Y. pestis clones arising independently at small geographic scales 3. According to the public health report by Danforth and colleagues, which of the following statements about critical risk reduction measures used to help prevent plague transmission to Yosemite visitors and staff is correct? A. Rapid interagency investigation and public health response to these patients lowered the risk for plague transmission to Yosemite visitors and staff B. The investigation was limited to recreational sites visited by the patients C. Insecticides were widely dispersed throughout the park D. Educational efforts targeted only Yosemite staff Activity Evaluation 1. The activity supported the learning objectives. Strongly Disagree Strongly Agree 1 2 3 4 5 2. The material was organized clearly for learning to occur. Strongly Disagree Strongly Agree 1 2 3 4 5 3. The content learned from this activity will impact my practice. Strongly Disagree Strongly Agree 1 2 3 4 5 4. The activity was presented objectively and free of commercial bias. Strongly Disagree Strongly Agree 1 2 3 4 5

Related Links More Medscape CME Articles

Table of Contents – Volume 22, Number 12—December 2016

Page created: November 16, 2016 Page updated: November 16, 2016 Page reviewed: November 16, 2016

The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.