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NIOSH Respiratory Diseases Research Program

Evidence Package for the National Academies' Review 2006-2007

NIOSH Programs > Respiratory Diseases > Evidence Package > 6. Infectious Diseases > 6.3 Emerging Infectious Diseases: SARS, Avian, and Pandemic Influenza

6.3b) Avian and Pandemic Influenza

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 Avian influenza (H5N1) is an influenza A virus subtype that occurs mainly in birds. It is highly contagious among birds and can be deadly to them. Outbreaks of H5N1 among poultry are ongoing in a number of countries in Asia, Africa, and Europe. Currently, there have been no reported H5N1 avian influenza outbreaks among poultry or birds in the U.S. Although, the current outbreak is not expected to diminish significantly in the short term, it is likely that H5N1 infection among wild birds has become endemic in certain areas.

While H5N1 does not usually infect people, but human cases of H5N1 infection associated with these outbreaks have been reported. Most of these cases have occurred from direct or close contact with infected poultry or contaminated surfaces; however, a few rare cases of human-to-human spread of H5N1 virus have occurred, though transmission has not continued beyond one person. Since 2003, avian flu outbreaks have been reported in 10 different countries across the world, causing morbidity, mortality, and substantial economic damage to affected countries. The mortality rate of avian flu in affected humans exceeds 50 percent.173

Pandemic influenza can occur when a strain of influenza A undergoes antigenic shift, potentially creating a virulent new strain for which human populations have little or no immunity. Pandemic influenza can spread easily from person to person, causing a global outbreak, or pandemic. Some pandemic strains have caused very severe illness, such as during the outbreak of 1918. Given the severity of disease caused by H5N1 avian influenza, there is concern that it could transform into a pandemic strain capable of causing severe disease. During a pandemic, transmission can be anticipated in the workplace, not only from patient to workers in health care settings, but also among co-workers in general work settings. A pandemic would cause high levels of illness, death, social disruption, and economic loss. Everyday life would be disrupted because so many people in so many places become seriously ill at the same time. Impacts could range from school and business closings to the interruption of basic services such as public transportation and food delivery.


 RDRP is actively working together with other elements of CDC, as well as groups outside of CDC, to develop and prepare an influenza response. Given its unique expertise within CDC, RDRP is taking the lead on workplace and industrial hygiene issues in the following workgroups: the CDC CONPLAN (internal operations plan for pandemic influenza), CDC “Non-Pharmaceutical Intervention Workgroup,” NIOSH/RDRP Working Group for Avian Influenza (not pandemic) issues only (providing recommendations for various work sectors, including the food preparation sector regarding personal protective equipment, work practices, surveillance, etc.), Respirator use for Pandemic Influenza, NIOSH/RDRP Work Group on Influenza (Avian/Pandemic/Seasonal). RDRP is also working with the OSHA Medical Director and others to exchange information and ensure collaboration regarding pandemic flu planning and common interests. RDRP presents emerging issue information to various groups (e.g. poultry industry, etc.) (A6-87). This presentation has been given over a dozen times.

 RDRP scientists are also working directly with the poultry industry, workers, and scientists in other organizations to develop a national program of guidance for the prevention of avian influenza among workers.

Outputs and Transfer

RDRP scientists have contributed to the development of documents, publications and Web sites for knowledge dissemination. They have organized and participated in meetings and other communications, and they have provided technical reviews and assistance:

Guidance/Publications/Web sites

A guidance document prepared in collaboration with OSHA: This is an ongoing project from the NIOSH-OSHA Issues Exchange Group to develop an existing safety and health bulletin into a NIOSH Alert. The draft Alert is in review: (External link) (A6-88)

“Guidelines for Protecting Healthcare Workers Caring for Patients with Avian Influenza:” This guidance, posted on CDC’s Web site, is designed to inform protection efforts for health care workers in the event of an outbreak. RDRP scientists provided guidance on occupational health issues covered in the document and proposed revisions to remove the aerosol precautions component: (A6-89)

Respiratory Hygiene/Cough Etiquette in Healthcare Settings:  (A6-90)

CDC Web site offering guidance on occupational health and safety aspects of avian influenza: (A6-91)

NIOSH “Topic page” covers occupational aspects of avian influenza. It provides guidance and a number of useful links to other sites with occupational health and safety information. It is frequently updated with new information: (A6-92)

“Pandemic Preparedness Checklist:” This two-page checklist addresses eight different sectors (Business, Community, Health Care, Schools, Workers, Faith and Community, Colleges/Universities, Families) and provides guidance on pandemic flu preparedness/action steps.

“Toolkit for Business Pandemic Flu Planning:” This checklist provides guidance for businesses in developing a pandemic flu response plan including essential plan elements and action steps to take to safeguard employees and business operations. The toolkit is to be one product that will exist in hard copy, but also on the Web, and on CD. A ‘Business’ page is on the CDC Web site  The checklist is one part of the toolkit and toolkit contents are intended to support implementation of checklist items.

CDC/DEOC Plans and Exercises: The CDC CONPLAN (internal operations plan for pandemic influenza) was released in February, 2006. It provides operational guidance in the event of pandemic flu. The NIOSH Emergency Response Office (which includes RDRP scientists) participated in development and review of this plan. Additionally, in April 2006, RDRP scientists participated in a CDC-wide pandemic flu exercise. CDC has formed a “Non-Pharmaceutical Intervention Work-Group,” of which we are a part, to address a number of items unrelated to vaccine or antiviral agents associated with flu.

 “HHS Worker/Employee Protection Guidelines and Policy:” DHHS asked RDRP scientists to take the lead in developing this chapter in the DHHS Pandemic Flu operations planning effort.

Extramural RDRP research on the efficacy of N95 respirators against virus size particles was presented at a national conference in 2005 (A6-93).

Technical Presentations

RDRP scientists have provided presentations on avian influenza and our prevention response efforts at professional meetings, including:

Meeting disseminations

Meeting on Public Use of Respiratory Protection (January, 2006). The meeting was called by RDRP. The impetus for the meeting was that in the event of an influenza pandemic, utilization of N-95 surgical masks, and other types of mouth/nose protection will likely become increasingly popular, thereby affecting availability and likely requiring prioritization or rationing of use. The public and other branches of government will need consistent, clear, and timely guidance. Issues related to prioritization and rationing were discussed. A range of participants attended the meetings, including: participants from across CDC, the International Safety Equipment Association, and respirator manufacturers.

Personal Protective Equipment on the Strategic National Stockpile: A series of meetings were held with DHHS, DHQP, DSNS, and NCID to discuss and determine the appropriate type and balance of PPE to place in the Strategic National Stockpile in the event of an influenza pandemic. Surgical N-95 respirators were recommended as a first priority to be purchased with the $65 million appropriation.

 NIOSH Interagency Workgroup Meetings

A working group has been formed for avian influenza issues to provide recommendations for various work sectors regarding PPE, work practices, and surveillance. The workgroup meets regularly to address technical issues related to AI prevention; the group has USDA and FDA representation.

Food and Drug Meetings

 RDRP scientists provide technical assistance to the U.S. FDA through participation in weekly meetings. They offer a resource to address occupational health and safety issues in the context of food safety.

Technical Reviews/Assistance

 Respirator use for pandemic influenza: The DHHS Office of the Assistant Secretary for Public Health preparedness, through a NIOSH/RDRP contract, engaged the IOM to address issues regarding the availability of surgical masks and N95 respirators in the event of a pandemic flu event. Issues of concern included availability and public use of respirators, reusability of respirators and surgical masks, how long current filtering facepieces may be worn, and the potential for new design types for N95. An IOM panel studied these issues. Their report on reusability of facemasks during an influenza pandemic, was completed in 2006.

OSHA Technical Assistance

 RDRP staff is working with the OSHA Medical Director and others to exchange information and ensure collaboration regarding pandemic flu planning and common interests.  

DHS Pandemic Flu Plan Review

The Department of Homeland Security (Coast Guard) has requested NIOSH/RDRP staff’s review and comment on their internal Pandemic Flu Plan (addressing protection of Department of Homeland Security Personnel). The plan is under the direction of the Department of Homeland Security Medical Director. The NIOSH Coordinating Office of Emergency Response is working with Department of Homeland Security on this project.

Homeland Security Council National Implementation Plan Review: The Homeland Security Council has requested NIOSH/RDRP scientists’ review of various aspects (personnel risk assessment, PPE) of the national pandemic flu implementation plan.

 Intermediate Outcomes

 Because respiratory protection is an important means of protecting worker health against infection, RDRP scientists met with respirator manufacturers to address very real concerns that the demand for NIOSH-certified N-95 disposable respirators might outrun supply. As a practical solution to this international problem, RDRP scientist played in integral role in convincing the WHO to revise their posted recommendations for respiratory protection by emphasizing that some respirators certified by governments of other countries provide protection equivalent to NIOSH-certified N-95s and thus are acceptable for use to protect against influenza (A6-94).

 Some of the major poultry corporations have implemented RDRP guidance into their avian influenza plans. RDRP has been asked by Tyson Foods to review and comment on its corporate plan for avian influenza.  

California OSHA requested RDRP technical assistance to their efforts to develop an airborne infectious disease standard. RDRP attended the California Division of Occupational Safety and Health Advisory Committee Meeting on this topic (December, 2005).

As noted in the Outputs and Transfer section directly above, RDRP scientists have worked with other external partners in collaborative information exchange on research issues, and to provide control recommendations for prevention. In so doing, RDRP has had some influence over their actions. These external partners have included the: Department of Homeland Security, OSHA, Department of Agriculture, FDA, U.S. Coast Guard, National Turkey Foundation, and United Food and Catering Workers.

End Outcomes

Fortunately, the impact that the activities of RDRP and others will have on transmission of avian and pandemic influenza remains to be tested.

 What’s ahead

 A NIOSH Alert to assist in prevention of avian influenza transmission to poultry workers will be released in the near future.

In 2006, RDRP issued a Request for Applications Number: RFA-OH-06-002 titled “Prevention of Airborne Infections in Occupational Settings” (A6-95). This RFA will fund extramural research in areas relevant to airborne transmission, including exposure assessment, assessment of dose-response, engineering controls and personal protective equipment.

RDRP is beginning a research effort to assess reusability of disposable filtering facepiece respirators used for protection against infectious aerosols (A6-96).

Limited availability of biosafety level (BSL)-3 laboratory space has limited the ability of RDRP researchers to work with infectious aerosols to study issues such as aerobiology and ability of various infectious agents to be transmitted via the airborne route, exposure assessment methods, dose-response, engineering controls, and personal protective equipment. RDRP researchers are therefore actively involved in a CDC initiative to establish a new laboratory devoted to environmental microbiology, which is proposed to be located on the National Biodefense Research Campus in Fort Detrick, Maryland. This laboratory would provide research infrastructure needed to address these issues.