Smallpox

Smallpox Menu Workers' Rights

Control

There are vaccines to protect people from smallpox, however, smallpox vaccines are not recommended for the general public since the last natural case of smallpox occurred in Somalia in 1977 and the World Health Organization (WHO) officially declared smallpox eradicated in 1980.

There are a variety of controls that should be implemented to protect workers from exposure to smallpox. 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 Smallpox Disease and Smallpox as a Bioweapon sections of this Safety and Health Topics Page provide extensive information on the hazards associated with smallpox and applicable controls. Additional guidance specific to various types of workers, and associated issues on recognizing and controlling exposure to smallpox is provided in the following sections.

Emergency Responders

What personal protective equipment (PPE) should emergency responders use when responding to a potential biological/bioterrorist-attack involving smallpox? How should workers decontaminate themselves if they think they have been exposed to smallpox?

In a covert attack involving aerosolized smallpox, 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 biological/bioterrorist-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.

Healthcare Workers, Mortuary Workers, and Others

What personal protective equipment (PPE), infection control, and related precautions should healthcare workers use when treating patients with smallpox?

The Centers for Disease Control and Prevention (CDC) 2007 Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings (updated July 2023) prescribe specific precautions to be taken when treating patients with known or suspected smallpox. These precautions include standard, droplet, airborne, and contact precautions, under certain circumstances. Patient isolation and similar precautions may also be necessary. The following references provide detailed information regarding infection control procedures for smallpox.

  • OSHA Best Practices for Hospital-Based First Receivers of Victims. 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, PPE, employee training, and also includes several informational appendices.
  • Bioterrorism Readiness Plan: A Template for Healthcare Facilities. Association for Professionals in Infection Control and Epidemiology (APIC) and the Centers for Disease Control and Prevention (CDC), (April 13, 1999). Provides information on infection control, patient treatment, post-exposure management, decontamination, prophylaxis, and laboratory procedures. Specific information on smallpox is contained in Section II, pp. 23-26.
  • 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 smallpox?

Similar infection control precautions, as listed previously for live individuals, should be implemented for the post-mortem care of smallpox patients. These precautions apply to all workers performing post-mortem procedures on smallpox patients, including healthcare workers, morticians, forensic personnel, or others.

  • Bioterrorism Readiness Plan: A Template for Healthcare Facilities. Association for Professionals in Infection Control and Epidemiology (APIC) and the Centers for Disease Control and Prevention (CDC), (April 13, 1999). Provides information on infection control, patient treatment, post-exposure management, decontamination, prophylaxis, and laboratory procedures. Specific information on smallpox is contained in Section II, pp. 23-26.

How should workers decontaminate themselves if they think they have been exposed to smallpox virus?

The risk of re-aerosolization of smallpox virus from contaminated persons is considered low. In situations where there may have been gross exposure to smallpox, personal decontamination can be performed by removing contaminated clothing and washing exposed skin with soap and water. Additional decontamination procedures may be found in the following document:

  • Bioterrorism Readiness Plan: A Template for Healthcare Facilities. Association for Professionals in Infection Control and Epidemiology (APIC) and the Centers for Disease Control and Prevention (CDC), (April 13, 1999), Provides information on infection control, patient treatment, post-exposure management, decontamination, prophylaxis, and laboratory procedures. Specific information on smallpox is contained in Section II, pp. 23-26.

What cleaning and disinfection procedures should be utilized in facilities that treat smallpox patients or handle the bodies of patients who have died from smallpox?

The principles of Standard Precautions are generally applied for the cleaning, disinfection, and sterilization of equipment and environmental control in facilities. For additional information, refer to the following:

  • Bioterrorism Readiness Plan: A Template for Healthcare Facilities. Association for Professionals in Infection Control and Epidemiology (APIC) and the Centers for Disease Control and Prevention (CDC), (April 13, 1999). Provides information on infection control, patient treatment, post-exposure management, decontamination, prophylaxis, and laboratory procedures. Specific information on smallpox is contained in Section II, pp. 23-26.
Laboratory Workers

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

Specific biosafety procedures, including vaccinating laboratory personnel against smallpox if there is potential work involving receiving and handling smallpox specimens, personal protective equipment (PPE), engineering controls, and additional work practices that have been established for handling smallpox virus in laboratories. The following references provide additional information:

Environmental Persistence, Identification, and Decontamination

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

Aerosolized smallpox virus may persist for up to 24 hours, or somewhat longer under favorable conditions. However, the virus can be destroyed within 6 hours under conditions where there is high temperature and high humidity. However, it is believed that the smallpox virus can remain viable in contaminated laundry for extended periods.

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

There are various methods that can be utilized for detecting bioterrorist agents, including smallpox. These include surface and air sample gathering techniques, followed by identification methods such as culture growth or polymerase chain reaction (PCR). However, smallpox virus is relatively 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 smallpox, 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 smallpox?

There is no evidence to suggest that environmental decontamination following an aerosol release is warranted. By the time patients became ill and it had been determined that an aerosol release of smallpox virus had occurred, there would be no viable virus in the environment. The following reference provides additional information on susceptibility to disinfectants, physical inactivation, and survival outside host of smallpox virus:

Public Health Response

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

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

  • Smallpox. Centers for Disease Control and Prevention (CDC). Contains extensive smallpox information, including fact sheets, overviews, FAQs, diagnosis and evaluation, infection control, laboratory testing, surveillance and investigation, selected publications, and education and training materials.
  • Strategic National Stockpile (SNS). Administration for Strategic Preparedness and Response (ASPR), U.S. Department of Health and Human Services (HHS).

Is a vaccine available to prevent smallpox?

Currently, the smallpox vaccine is the only approved way to prevent the disease. The vaccine was used to successfully eradicate smallpox from the human population, and therefore routine vaccination of the American public stopped in 1972. However, the U.S. government has recently implemented plans to ensure there is sufficient vaccine available, and procedures in place to immunize everyone who might need it in the event of an emergency.

There are only 2 licensed smallpox vaccines in the United States, ACAM2000® and JYNNEOSTM (also known as Imvamune or Imvanex). ACAM2000® provides active immunization against smallpox disease for persons determined to be at high risk for smallpox infection. JYNNEOSTM can be used for vaccination of people 18 years and older with certain immune deficiencies or conditions, such as HIV or atopic dermatitis against smallpox and mpox.

Certain emergency healthcare teams, military, and civilian personnel who are or may be deployed in high threat areas have already been given the vaccine. In addition, vaccination within 3 days of exposure will completely prevent or significantly modify smallpox in the vast majority of persons. Vaccination 4 to 7 days after exposure likely offers some protection from the disease or may modify the severity of the disease. The following references provide additional information on the smallpox vaccine.