400 likes | 534 Views
Outbreak of Mycobacterium tuberculosis Among Employees of an Elephant Refuge. Rendi Murphree, PhD CDR, USPHS Tennessee Department of Health EIS Field Assignments Branch, DAS (proposed), SEPDPO (proposed). Background. Captive Elephants in North America. 270 Asian elephants
E N D
Outbreak of Mycobacterium tuberculosisAmong Employees of an Elephant Refuge Rendi Murphree, PhD CDR, USPHS Tennessee Department of Health EIS Field Assignments Branch, DAS (proposed), SEPDPO (proposed)
Captive Elephants in North America 270 Asian elephants 12% have active TB disease 220 African elephants 2% have active TB disease
Elephant Refuge • South-central Tennessee • Founded in 1995 • Care of sick, old, abused or needy elephants • Nonprofit organization accredited, regulated and closed to the public
Elephant Refuge • 2700 acres with 3 distinct areas • 2 African elephants • 6 Asian elephants • 1 “cured” of TB disease in 2006 • 7 Asian elephants • All quarantined since 2006 for exposure to TB disease
The Outbreak Notification October, 2009 5 tuberculin skin test (TST) conversions among employees of the refuge Investigation objectives Determine extent of outbreak Identify risk factors for TST conversion in humans Prevent ongoing transmission
Cohort Study Interviews Review occupational health records TST screening
Onsite Assessment Facility design Barn management Husbandry practices
Outbreak Case Definition Refuge employee or intern, 2006–2009 At least one negative TST, followed by a TST of ≥5-mm induration
Employee Cohort, 2006–2009 • 46 employees interviewed • 30 caregivers • 11 administrators • 5 maintenance workers • 9 (20%) had positive TST • 8 had conversion during 2009
Risk Factors for TB Among Refuge Employees, 2006–2009 *Risk estimate not computed when at least one cell contained a zero
Risk Factors for TB Among Refuge Employees, 2006–2009 *Risk estimate not computed when at least one cell contained a zero
Risk Factors for TB Among Refuge Employees, 2006–2009 *Risk estimate not computed when at least one cell contained a zero
Risk Factors for TB Among Refuge Employees, 2006–2009 *Risk estimate not computed when at least one cell contained a zero
TST Conversion Timeline Among Quarantine Facility Employees, 2009
TST Conversion Timeline Among Quarantine Facility Employees, 2009
Quarantine Barn Admin Area Quarantine Facility
Quarantine Barn Admin Area Quarantine Facility Elephant with TB
Findings • Zoonotic Mtb transmission from an elephant to humans • Insufficient infection control • Inconsistent use of respirators • Aerosol generating procedures • Unrestricted air flow
Limitations • Small study population • 11 employees not contacted • Formal air flow studies pending
Recommendations Relocate nonessential personnel Increase use of respirators Revise infection control practices
Elephant refuge employees and leadership Tennessee Wildlife Regulatory Authority Walter Cook TN South-central Regional Health Office Lang Smith, MD Joy Smith, RN Lewis County Health Department Tennessee Department of Health John R. Dunn, DVM, PhD Jon V. Warkentin, MD, MPH Timothy F. Jones, MD Vanderbilt University School of Medicine William S. Schaffner, MD CDC W. Randolph Daley, DVM, MPH Acknowledgments The findings and conclusions in this report are those of the author and do not necessarily represent the official position of the Centers for Disease Control and Prevention.