Controls

There are a variety of controls that should be implemented in order to protect workers from exposure to plague. Workers that may be affected, either during regular work activities or during an emergency response, include, but are not limited to, emergency responders, healthcare workers, laboratory personnel, and others. The Plague Disease and Plague as a Bioweapon sections of this Safety and Health Topic provide extensive information on the hazards associated with plague and applicable controls. Additional guidance specific to various types of workers, and associated issues on recognizing and controlling exposure to plague is provided in the following sections:

• Emergency Responders
• Healthcare Workers, Mortuary Workers, and Others
• Laboratory Workers
• Environmental Persistence, Identification, and Decontamination
• Public Health Response

What personal protective equipment should emergency responders use when responding to a potential bio-attack involving plague? How should workers decontaminate themselves if they think they have been exposed to plague?

In a covert attack involving aerosolized plague, there would be no emergency response activity involving emergency responders. The first evidence that a potential attack had occurred would be diagnosis of the disease among exposed individuals, which would happen several days after the actual release. However, it is possible that emergency responders would be required to respond to a bio-attack incident, such as notification regarding an aerosol dissemination device or other suspicious release. The following references provide additional information regarding PPE, decontamination, and other precautions for emergency responders to consider during such an incident.

• Manual for plague surveillance, diagnosis, prevention and control. World Health Organization (WHO). Provides information on plague epidemiology and recommendations for surveillance, diagnosis, clinical management, and prevention.

What PPE, infection control, and related precautions should healthcare workers use when treating patients with plague?

National infection control guidelines prescribe specific precautions to be taken when treating patients with known or suspected plague. These precautions include "Standard", "Droplet" and "Airborne" Precautions, under certain circumstances. Patient isolation and similar precautions may also be necessary. The following references provide detailed information regarding infection control procedures for plague.

• OSHA Best Practices for Hospital-Based First Receivers of Victims from Mass Casualty Incidents Involving the Release of Hazardous Substances. OSHA, (January 2005). Provides hospitals with practical information to assist them in developing and implementing emergency management plans that address the protection of hospital-based emergency department personnel during the receipt of contaminated victims from mass casualty incidents occurring at locations other than the hospital. Among other topics, it covers victim decontamination, personal protective equipment, and employee training, and also includes several informational appendices.
• Inglesby TV, Dennis DT, et al. Plague as a Biological Weapon: Medical and Public Health Management. Journal of the American Medical Association (JAMA). May 3, 2000;283(17):2281-90. Considers the prospect of an aerosol release of Y. pestis bacteria, and provides information on epidemiology, infection signs and symptoms, diagnosis and monitoring, vaccination, medical treatment, infection control, environmental decontamination, and more.
• USAMRIID's Medical Management of Biological Casualties Handbook, Ninth Edition. U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID). Contains specific information on a number of potential bioterrorist agents.

What precautions are necessary when handling the bodies of patients who have died from plague?

It is unknown how long plague can survive in body fluids of a deceased person, but animals who died of plague have passed the infection 35 hours after death. Similar infection control precautions, as listed previously for live individuals, should be implemented for the post-mortem care of plague patients. These precautions apply to all workers performing post-mortem procedures on plague patients, including healthcare workers, morticians, forensic personnel, or others.

• Jullien S, de Silva NL, Garner P. Plague Transmission from Corpses and Carcasses. Emerg Infect Dis. 2021;27(8):2033-2041. doi: 10.3201/eid2708.200136.

How should workers decontaminate themselves if they think they have been exposed to plague bacteria?

The risk of re-aerosolization of plague bacteria from contaminated persons is considered low. In situations where there may have been gross exposure to plague, personal decontamination can be performed by removing contaminated clothing and washing exposed skin with soap and water.

What cleaning and disinfection procedures should be utilized in facilities that treat plague patients?

The principles of Standard Precautions are generally applied for the cleaning, disinfection, and sterilization of equipment and environmental control in facilities. One study found that diluted hypochlorite (bleach) was effective in killing Yersinia pestis on hard, non-porous surfaces.

• Richter WR, Sunderman MM, Fulton ML, Willenberg Z, Serre S, Oudejans L, Wood J, Calfee MW. Decontamination efficacy of common liquid disinfectants against non-spore-forming biological agents in soil matrices. J Appl Microbiol. 2022 Dec;133(6):3659-3668. doi: 10.1111/jam.15802. Epub 2022 Sep 13.

What biosafety procedures should laboratory personnel utilize when handling materials potentially contaminated with plague?

Specific biosafety procedures, including PPE, engineering controls, and additional work practices have been established for handling plague bacteria in laboratories. Refer to the following references for more information.

• DLS Safe Labs Portal. Centers for Disease Control and Prevention (CDC).
• Biosafety in Microbiological and Biomedical Laboratories (BMBL), 6th Edition. Centers for Disease Control and Prevention (CDC), (June 2020). This comprehensive reference on laboratory biosafety practices, including specific information on plague, is available in PDF sections.
• Hawley RJ, Eitzen EM Jr. Biological Weapons - A Primer for Microbiologists. Annual Review of Microbiology. Oct 2001;55:235-253. Provides biosafety information for laboratory and field personnel, including discussions on engineering controls, PPE, and decontamination methods.
• Guidance for Responding to a Plague Bioterrorism Event. Centers for Disease Control and Prevention (CDC).

How long would aerosolized plague from a bioweapon persist in the environment?

According to one study, aerosolized bacteria that cause plague decay rapidly on indoor surfaces and don’t survive for more than a few minutes. Plague bacteria do persist for many days in their natural environment (soil and water).

• Gut IM, Bartlett RA, Yeager JJ, Leroux B, Ratnesar-Shumate S, Dabisch P, Karaolis DKR. Extraction of Aerosol-Deposited Yersinia pestis from Indoor Surfaces To Determine Bacterial Environmental Decay. Appl Environ Microbiol. 2016 Apr 18;82(9):2809-2818. doi: 10.1128/AEM.03989-15.

Can plague be detected in the environment following a bioterrorist attack?

There are various methods that can be utilized for detecting bioterrorist agents, including plague. These include surface and air sample gathering techniques, followed by identification methods such as culture growth or polymerase chain reaction (PCR). However, plague bacteria is very fragile, would not persist for long in the environment, and therefore sampling and analysis would not be considered necessary. In the event of a bioterrorist attack involving plague, local, state, and federal responders would determine the need for sampling based on the specific circumstances associated with the release.

What environmental decontamination would be required following a release of aerosolized plague?

There is no evidence to suggest that environmental decontamination following an aerosol release is warranted. A plague aerosol would only remain viable for a very short time after release, long before the first cases of pneumonic plague would alert health personnel to a clandestine attack.

What actions would be taken by public health authorities in the event of a bioterrorist attack involving plague?

Various actions may be taken by public health authorities to treat and prevent further infections due to a release of plague bacteria. These measures may include mass distribution of medications, surveillance, quarantine, and communication procedures. The following references provide additional information.

• Bioterrorism and Plague: Preparedness. Centers for Disease Control and Prevention (CDC). Describes specific actions that would be taken in case of a bioterrorism event involving plague.
• Center for the Strategic National Stockpile (SNS). Administration for Strategic Preparedness and Response (ASPR). Provides basic information on the SNS system.
• Barbera J, Macintyre A, et al. Large-Scale Quarantine Following Biological Terrorism in the United States: Scientific Examination, Logistic and Legal Limits, and Possible Consequences. Journal of the American Medical Association (JAMA). Dec 5, 2001;286(21):2711-7. Includes information on possible logistics, legal limits, and possible consequences of initiating quarantine procedures. Discusses quarantine vs. isolation, legislative framework, considerations in making quarantine decisions, and recommendations for developing a disease containment strategy.