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Smallpox

Smallpox is an acute, contagious, and sometimes fatal disease caused by infection with a virus known as the variola virus. Smallpox outbreaks have occurred from time to time for thousands of years, but in 1980 the disease was declared eradicated following worldwide vaccination programs. Except for stockpiles in high-security laboratories, the virus has been eliminated. However, if obtained and deliberately released as a bioweapon, smallpox could cause a public health catastrophe.

There are currently no specific OSHA standards for smallpox.

OSHA Standards

The following section includes standards, preambles to final rules (background to final rules), and directives (instructions for compliance officers) applicable to emergency response activities as a result of a bioterrorist attack. For additional information, see OSHA's Emergency Preparedness and Response Safety and Health Topics Page.

Note: Twenty-five states, Puerto Rico and the Virgin Islands have OSHA-approved State Plans and have adopted their own standards and enforcement policies. For the most part, these States adopt standards that are identical to Federal OSHA. However, some States have adopted different standards applicable to this topic or may have different enforcement policies.

General Industry (29 CFR 1910)

Preambles to Final Rules

Directives

Smallpox Disease

Smallpox is an acute, communicable disease caused by a virus known as the variola virus. The name "smallpox" comes from the Latin word for "spotted", which refers to the raised bumps that appear on the face and body of an infected person. Two forms of the disease, variola major and variola minor, have typical mortality rates of 30% and 1%, respectively. The symptoms of smallpox begin with high fever, chills, head and body aches, and sometimes vomiting. A rash then emerges on the tongue and mouth and spreads to the skin, forming on the arms and legs and then to the hands and feet. The rash progresses to raised bumps and pus-filled blisters that crust, scab, and fall off after about three weeks, leaving a pitted scar. There is no proven treatment for smallpox. However, eradication efforts have been successful. The last natural case of smallpox occurred in Somalia in 1977. The following references aid in recognizing disease characteristics and hazards associated with smallpox.

  • 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.

  • Public Health Image Library (PHIL). Centers for Disease Control and Prevention (CDC). Offers several images related to smallpox that include descriptions.

  • Smallpox. World Health Organization (WHO) Health Topics. Provides information on smallpox, including a fact sheet, disease outbreak information, publications, and related links.

  • Current Description of Smallpox. The University of California Los Angeles (UCLA), Department of Epidemiology, School of Public Health. Provides basic information on smallpox, including identification, infectious agent, global occurrence, reservoir, mode of transmission, incubation period, communicability, susceptibility and resistance, methods of control, and more.

Smallpox as a Bioweapon

Although naturally occurring smallpox has been eradicated, there is still heightened concern that the variola virus might be used as an agent of bioterrorism. In the first documented case of biological warfare, in the 18th century, contaminated blankets used by smallpox patients were distributed among Native American Indians by the British with the intent of initiating outbreaks. A smallpox epidemic occurred, killing more than 50% of affected tribes. If a strain of the variola virus could be obtained, it could be manufactured easily and disseminated widely in an aerosol release. A release of smallpox could escalate to a catastrophic global epidemic unless effective control measures can be implemented quickly.

Smallpox has been identified by the Centers for Disease Control and Prevention (CDC) as a "Category A" agent, meaning it has been given high priority due to its potential threat to national security. The following references provide information on the use of smallpox as a bioweapon and associated issues to be considered during a smallpox outbreak.

  • 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.

  • Henderson, Donald A. and Inglesby, Thomas V., et al. "Smallpox as a Biological Weapon: Medical and Public Health Management [361 KB PDF, 11 pages]." Journal of the American Medical Association (JAMA) 281.22(1999, June 9): 2281-2290. Considers the prospect of an aerosol release of variola virus, and provides information on epidemiology, infection signs and symptoms, diagnosis and monitoring, vaccination, medical treatment, infection control, environmental decontamination, and more.

  • Medical Aspects of Chemical and Biological Warfare: Chapter 27 - Smallpox [114 KB PDF, 21 pages]. US Army Medical Research Institute of Infectious Diseases (USAMRIID). Provides a thorough review of smallpox, including its history and epidemiology, as well as biological warfare and clinical issues.

  • Medical Management of Biological Casualties Handbook, Seventh Edition [2 MB PDF, 254 pages]. US Army Medical Research Institute of Infectious Diseases (USAMRIID), (2011, September). Contains specific information on a number of potential bioterrorist agents.

  • Fact Sheet - Smallpox Information for Professionals. Texas Department of State Health Services. Provides information on symptoms, diagnosis, and treatment available in the event smallpox virus is used as a bioterrorist weapon.

Controls

There are a variety of controls that should be implemented in order 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 bio-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 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.

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?

National infection control guidelines 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, (2005, January). 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.

  • Smallpox Response Plan and Guidelines (Version 3.0). Centers for Disease Control and Prevention (CDC). Outlines the public health strategies that would guide the public health response to a smallpox emergency and many of the federal, state, and local public health activities that must be undertaken in a smallpox outbreak. Includes detailed work practices and engineering controls to control infection, and other precautions that must be followed.

  • Bioterrorism Readiness Plan: A Template for Healthcare Facilities [112 KB PDF, 34 pages]. Association for Professionals in Infection Control and Epidemiology (APIC) and the Centers for Disease Control and Prevention (CDC), (1999, April 13). 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.

  • Henderson, Donald A. and Inglesby, Thomas V., et al. "Smallpox as a Biological Weapon: Medical and Public Health Management [361 KB PDF, 11 pages]." Journal of the American Medical Association (JAMA) 281.22(1999, June 9): 2281-2290. Considers the prospect of an aerosol release of variola virus, and provides information on epidemiology, infection signs and symptoms, diagnosis and monitoring, vaccination, medical treatment, infection control, environmental decontamination, and more.

  • Medical Management of Biological Casualties Handbook, Seventh Edition [2 MB PDF, 254 pages]. US Army Medical Research Institute of Infectious Diseases (USAMRIID), (2011, September). 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.

  • Smallpox Response Plan and Guidelines (Version 3.0). Centers for Disease Control and Prevention (CDC). Outlines the public health strategies that would guide the public health response to a smallpox emergency and many of the federal, state, and local public health activities that must be undertaken in a smallpox outbreak. Includes detailed work practices and engineering controls to control infection, and other precautions that must be followed.

  • Bioterrorism Readiness Plan: A Template for Healthcare Facilities [112 KB PDF, 34 pages]. Association for Professionals in Infection Control and Epidemiology (APIC) and the Centers for Disease Control and Prevention (CDC), (1999, April 13). 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.

  • Henderson, Donald A. and Inglesby, Thomas V., et al. "Smallpox as a Biological Weapon: Medical and Public Health Management [361 KB PDF, 11 pages]." Journal of the American Medical Association (JAMA) 281.22(1999, June 9): 2281-2290. Considers the prospect of an aerosol release of variola virus, and provides information on epidemiology, infection signs and symptoms, diagnosis and monitoring, vaccination, medical treatment, infection control, environmental decontamination, and more.

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 [112 KB PDF, 34 pages]. Association for Professionals in Infection Control and Epidemiology (APIC) and the Centers for Disease Control and Prevention (CDC), (1999, April 13), 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 [112 KB PDF, 34 pages]. Association for Professionals in Infection Control and Epidemiology (APIC) and the Centers for Disease Control and Prevention (CDC), (1999, April 13). 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 personal protective equipment (PPE), engineering controls, and additional work practices have been established for handling smallpox virus in laboratories. The following references provide additional information:

  • Biosafety. Centers for Disease Control and Prevention (CDC). Provides links to material on biosafety regulations, references, and related material.

  • Biosafety in Microbiological and Biomedical Laboratories (BMBL) 5th Edition. Centers for Disease Control and Prevention (CDC) and the National Institutes of Health (NIH), (2009, December). Comprehensive reference on laboratory biosafety practices, including specific information on smallpox.

  • Smallpox Response Plan and Guidelines (Version 3.0). Centers for Disease Control and Prevention (CDC). Outlines the public health strategies that would guide the public health response to a smallpox emergency and many of the federal, state, and local public health activities that must be undertaken in a smallpox outbreak. Includes detailed work practices and engineering controls to control infection, and other precautions that must be followed.

  • Henderson, Donald A. and Inglesby, Thomas V., et al. "Smallpox as a Biological Weapon: Medical and Public Health Management [361 KB PDF, 11 pages]." Journal of the American Medical Association (JAMA) 281.22(1999, June 9): 2281-2290. Considers the prospect of an aerosol release of variola virus, and provides information on epidemiology, infection signs and symptoms, diagnosis and monitoring, vaccination, medical treatment, infection control, environmental decontamination, and more.

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. In the presence of ultraviolet light, it will die even more quickly. 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 environmental detection, persistence, and decontamination of smallpox virus:

  • Henderson, Donald A. and Inglesby, Thomas V., et al. "Smallpox as a Biological Weapon: Medical and Public Health Management [361 KB PDF, 11 pages]." Journal of the American Medical Association (JAMA) 281.22(1999, June 9): 2281-2290. Considers the prospect of an aerosol release of variola virus, and provides information on epidemiology, infection signs and symptoms, diagnosis and monitoring, vaccination, medical treatment, infection control, environmental decontamination, and more.

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 medications, 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.

  • Smallpox Response Plan and Guidelines (Version 3.0). Centers for Disease Control and Prevention (CDC). Outlines the public health strategies that would guide the public health response to a smallpox emergency and many of the federal, state, and local public health activities that must be undertaken in a smallpox outbreak. Includes detailed work practices and engineering controls to control infection, and other precautions that must be followed.

  • Strategic National Stockpile (SNS). Centers for Disease Control and Prevention (CDC). Provides basic information on the SNS system.

  • Community-Based Mass Prophylaxis: A Planning Guide for Public Health Preparedness. Agency for Healthcare Research and Quality (AHRQ), (2004, August). Includes information on surveillance, stockpiling, distribution, dispensing, followup, and other planning and organizational concerns. Also describes the implementation of a comprehensive operational structure for dispensing/vaccination clinics based on the National Incident Management System (NIMS).

  • Barbera, Joseph, 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) 286.21(2001, December 5): 2711-2717. 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.

Is a vaccine available to prevent smallpox?

Currently, the smallpox vaccine is the only way to prevent the disease. This vaccine was used to successfully eradicate smallpox from the human population, and therefore routine vaccination of the American public stopped in 1972. However, the US 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. 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.

Additional Information

Related Safety and Health Topics Pages


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