U. S. Department of Labor

Occupational Safety and Health Administration

Directorate of Science, Technology & Medicine

Office of Occupational Medicine

SHIB 12-13-2004

Avian Influenza

Protecting Poultry Workers at Risk

Safety and Health Information Bulletin

Introduction

Avian influenza is a viral disease that can cause

sickness and death among poultry. On rare

occasions, avian influenza virus can be transmitted

to poultry workers or others who come in contact

with infected poultry or contact contaminated

surfaces. Examples of such workers who could be at

risk include poultry growers and their employees;

service technicians of poultry processing companies;

caretakers, layer barn workers, and chick movers at

egg production facilities; and workers involved in

disease control and eradication activities, including

state, federal, contract, and company employees.

This Safety and Health Information Bulletin

describes measures for protecting poultry workers

when an avian influenza outbreak occurs. It

presents basic information about avian influenza

and describes measures for minimizing exposure to

the virus. Links to Internet sites are provided for

those wanting more detailed information on avian

influenza, biosecurity measures, and personal

protective equipment. This document complements

avian population disease control and eradication

strategies of state governments, industry, and the

U.S. Department of Agriculture (USDA).

Avian Influenza

Avian influenza is a disease caused by infection

of poultry with type A influenza viruses. The

disease occurs worldwide, and all species of birds

are thought to be susceptible to it. Strains of avian

influenza are classified as being of either low

pathogenicity (most strains) or high pathogenicity.

Low-pathogenic strains typically cause few or no signs

in infected birds. When signs are seen, they may

include respiratory problems, diarrhea, a decline in

egg production, or an increase in mortality. However,

under field conditions, some low-pathogenic strains

(H5 and H7 subtypes) can mutate and become highly

pathogenic, leading to the deaths of entire flocks.

Highly pathogenic avian influenza is extremely

contagious and a fatal form of the disease for poultry.

This Safety and Health Information Bulletin is not

a standard or regulation, and it creates no new

legal obligations. The Bulletin is advisory in

nature, informational in content, and is intended to

assist employers in providing a safe and healthful

workplace. Pursuant to the Occupational Safety

and Health Act, employers must comply with

hazard-specific safety and health standards promulgated by OSHA or by a state with an OSHAapproved state plan. In addition, pursuant to

Section 5(a)(1), the General Duty Clause of the

Act, employers must provide their employees

with a workplace free from recognized hazards

likely to cause death or serious physical harm.

Employers can be cited for violating the General

Duty Clause if there is a recognized hazard and

they do not take reasonable steps to prevent or

abate the hazard. However, failure to implement

any recommendations in this Safety and Health

Information Bulletin is not, in itself, a violation of

the General Duty Clause. Citations can only be

based on standards, regulations, and the General

Duty Clause.
2

Although avian influenza A viruses rarely infect

humans, since 1997, instances of human infection

have occurred; some (outside the United States)

have resulted in death. The virus is excreted in the

droppings of infected birds and in their respiratory

secretions. Transmission to humans is thought to

have resulted from contact with infected sick or

dead poultry or their droppings, or contact with

contaminated litter or surfaces (e.g., egg flats). The

suspected routes of entry of the virus to humans

are the mouth, nose, eyes, and lungs. Although the

human health risk of low-pathogenic avian

influenza viruses is not well established, protective

measures should be taken by persons likely to have

prolonged direct or indirect exposure to any avian

influenza virus in an enclosed setting.

Measures for Protecting Poultry Workers

Follow biosecurity practices

Poultry workers should know and follow

biosecurity practices to prevent the introduction of

avian influenza and other diseases into a poultry

flock. An understanding of how infection can be

spread is important for both effective biosecurity

and worker safety and health practices. Poultry

processing companies should provide a written

copy of biosecurity practices to each of their

contract growers.

A 2004 USDA fact sheet lists eight general

biosecurity practices for poultry farms (http://

www.aphis.usda.gov/lpa/pubs/fsheet_faq_notice/

faq_ahhpai.pdf). Guidance is also available in the

free biosecurity CD, Infectious Disease Risk

Management: Practical Biosecurity Resources for

Commercial Poultry Producers, which is available

from the U.S. Poultry and Egg Association (http://

www.poultryegg.org/).

Depending on temperature and moisture conditions,

avian influenza A viruses can survive in the

environment for weeks. However, they are generally

sensitive to most detergents and disinfectants and are

inactivated by heating and drying. Contact with

organic material such as dust, dirt, litter, and manure

can decrease the effectiveness of some disinfectants,

and thus the possibility persists that viruses will

survive. U.S. Environmental Protection Agency

(EPA)-registered products that have a claim of being

effective against influenza viruses should provide some

measure of activity against avian influenza A viruses.

The label of an EPA-registered disinfectant

describes how to use the product safely and

effectively and includes measures that applicators

should take to protect themselves. The personal

protective equipment listed on a disinfectant label

is based on the chemical’s toxicity and may not be

appropriate for all exposure conditions and

handling activities. Thus, an exposure assessment

should also be done when selecting personal

protective equipment for applicators.

Know the signs indicating birds are infected with

avian influenza viruses

The signs of illness seen in domestic poultry

infected with avian influenza viruses are variable

and affected by the virus strain, age and species of

infected birds, concurrent bacterial disease, and the

environment. Such signs may include –

• Sudden death without any signs

• Lack of coordination

• Purple discoloration of the wattles, combs, and

legs

• Soft-shelled or misshapen eggs

• Lack of energy and appetite

• Diarrhea

• Swelling of the head, eyelids, comb, wattles, and

hocks

• Nasal discharge

• Decreased egg production

•Coughing, sneezing

 Some birds might be otherwise healthy-looking but

still infected with avian influenza virus. The severity of

disease in poultry can also vary during an outbreak.

Poultry workers should be aware of signs of disease in

poultry so when necessary they can take immediate

steps to protect themselves and other workers,
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quarantine the farm to prevent spread of disease, and

report the disease to the responsible animal health

authorities.

Take antiviral medication and get the current

season’s influenza vaccine if appropriate

In the event of an avian influenza outbreak,

workers who will be involved in disease control

and eradication activities should consult their

healthcare provider about the advisability of taking

antiviral medications for influenza. The Centers for

Disease Control and Prevention (CDC) has

recommended that workers receive an influenza

antiviral drug daily for the entire time they are in

direct contact with infected poultry or

contaminated surfaces. In the absence of sensitivity

testing, oseltamavir is the antiviral drug currently

of choice because the likelihood that the virus will

be resistant to it is less than with amantadine or

rimantadine.

The CDC recommends that workers involved in

avian influenza disease control and eradication

activities should get the current season’s human

influenza vaccine. Human influenza vaccine will

not prevent infection with low pathogenic or highly

pathogenic avian influenza A viruses, but this

precautionary measure could reduce the possibility

of dual infection with avian and human influenza

viruses. Although dual infection is unlikely, it is

plausible that such a situation might cause new and

different viral strains to be created; such new

strains might be transmissible among people and

lead to more widespread infections. Although this

CDC recommendation is only for workers involved

in disease control and eradication activities, other

poultry workers should consider getting the current

season’s influenza vaccine for the same reason.

Current information suggests that limited

human-to-human transmission of avian influenza A

viruses has occurred but is very uncommon. Public

health authorities are monitoring outbreaks of

human illness associated with avian influenza, and

to date, human infections with avian influenza

viruses identified since 1997 have not resulted in

sustained human-to-human transmission.

Additional CDC information on concerns about

dual infection, the use of antiviral medications, and

vaccination of poultry workers is available at http:/

/www.cdc.gov/flu/avian/protectionguid.htm.

Know the signs and symptoms of human

infection with avian influenza viruses

All poultry workers should know the signs and

symptoms of avian influenza virus infection in

humans so that measures can be taken for

immediate treatment. The signs and symptoms may

include fever, cough, sore throat, conjunctivitis

(eye infections), and muscle aches. Infection with

avian influenza viruses can also lead to pneumonia,

acute respiratory distress, and other severe and

life-threatening complications. A worker who

experiences any of these symptoms or illnesses, or

who might have been exposed to avian influenza

virus should seek medical care and tell the

healthcare provider before arrival that exposure to

avian influenza virus may have occurred.

More information concerning human infection

with avian influenza viruses is available at http://

www.cdc.gov/flu/avian/professional/

han081304.htm and http://www.who.int/csr/don/

2004_01_15/en/.

Wear personal protective equipment

People, including children, working daily in poultry

confinement units are at risk of exposure to a variety

of contaminants including organic dusts, gases such as

ammonia, and microorganisms (viruses, bacteria, and

fungi) that can cause illness. Thus, for many poultry

workers, wearing personal protective equipment is a

routine practice. For example, wearing a respirator

can reduce exposures to airborne organic dusts that

might pose a risk of respiratory disease and decreased

breathing capacity. These exposures in the poultry

industry can lead to chronic lung disease and

premature death. The National Institute for

Occupational Safety and Health (NIOSH)

recommends that children should not do any work that

requires wearing a respirator. Respirators are
designed to fit adults and the likelihood that they will fit

and protect children is doubtful. (See NIOSH

Recommendations to the U.S. Department of

Labor for Changes to Hazardous Orders. This

document and others concerning young workers

can be found at http://www.cdc.gov/niosh/topics/

youth.)

Most cases of avian influenza virus infection in

humans are thought to have resulted from contact

with infected poultry or contacting contaminated

surfaces followed by self-inoculation of the virus

into the eyes, nose or mouth. Other means of

transmission are possible, such as airborne material

containing the virus entering a person’s mouth,

nose, or eyes, or being inhaled into the lungs.

The CDC and the Occupational Safety and

Health Administration (OSHA) have made

recommendations for protecting workers involved

in avian influenza outbreak disease control and

eradication activities concerning the respiratory

protection, eye protection, and protective clothing

that should be worn and the hand-hygiene practices

that should be followed. (See http://www.cdc.gov/

flu/avian/protectionguid.htm and http://

www.osha.gov/dsg/guidance/avian-flu.html.)

The following information describes why

respiratory protection, eye protection, protective

clothing, and hand-hygiene practices are

recommended for disease control and eradication

activities and gives guidance on selecting personal

protective equipment for workers responding to

outbreaks of avian influenza. This information was

prepared as an aid to the development of

biosecurity guidelines and standard operating

procedures for the various sectors of the poultry

industry.

The process of selecting an appropriate

ensemble of personal protective equipment requires

an understanding of the work activities associated

with possible exposures; the health effects that may

result from exposure; properties of the virus (such as

whether it is low pathogenicity or high pathogenicity);

host factors (e.g., a worker’s susceptibility and

immunization status); and the advantages,

disadvantages, and protective capabilities of the

different types of personal protective equipment.

Because changes to the initial ensemble may occur

during the course of a response to an outbreak, the

persons with responsibility for making revisions should

be identified in the biosecurity guidelines.

Respiratory Protection

Because infectious diseases such as avian

influenza may be transmitted by breathing

contaminated dust, poultry workers should wear

respirators. Respirators that have filters or

cartridges are called air-purifying respirators.

These types are the most practical and appropriate

choices for poultry workers to wear when they

might be exposed to infected birds or during dayto-day activities in poultry barns. The table below

lists the advantages, disadvantages, and costs of

the five types of air-purifying respirators in order

of increasing levels of protection. More

information on the advantages and disadvantages

of different respirators and guidance on selecting

respirators for infectious agents can be found in the

respirator selection section of the CDC/NIOSH

histoplasmosis guidelines at http://www.cdc.gov/

niosh/docs/2005-109. Also, for guidance on the

protective capabilities of respirators, see 2004

NIOSH Respirator Selection Logic (http://

www.cdc.gov/niosh/docs/2005-100/default.html).

While all of the listed respirators can protect

poultry workers, they will not be protective unless

all of the elements of a written respiratory

protection program are followed. Examples include

providing respirator training to workers and fit

testing tight-fitting facepieces to ensure a secure

and comfortable face seal. Also, every respiratory

protection program must have an administrator

who is responsible for overseeing the program’s

functioning and who can answer questions workers

might have about respirator use; workers need to

be informed about who the program administrator is.

 The need for respiratory protection presents a

challenge to many poultry workers, such as

4
contract poultry growers and their employees.

Workers at risk of prolonged direct or indirect

exposure to any avian influenza virus in an enclosed

setting should always be included in a respiratory

protection program.

 Information describing all of the elements of a

complete respiratory protection program and the

use of respirators can be found at http://

www.osha.gov/SLTC/respiratoryprotection/

index.html.

Eye Protection

Eye protection will reduce direct exposure of the

eyes to contaminated dust and aerosols and help

keep workers from touching their eyes with

contaminated fingers. To prevent the mucous

membranes of the eyes from being exposed to the

avian influenza virus, poultry workers should wear

safety goggles or a respirator that has a full

facepiece, hood, helmet, or loose-fitting facepiece.

If safety goggles are worn, they should be

nonvented (eyecup goggles, for example) or, at a

minimum, indirectly vented.

 Properly fitted, indirectly vented safety goggles

with a good antifog coating may be a good choice

for poultry workers who have lower risks of

exposure. However, such goggles are not airtight,

and consequently, they will not completely prevent

exposures to airborne material. Directly vented

goggles and safety glasses will provide limited

protection, but are not recommended for

protection against fine particles, splashes, or

aerosols such as required in situations when

workers will be exposed to infected birds.

Workers who wear prescription lenses should

wear eye protection that has the correction built

into the safety lenses of the protective eyewear, has

lens inserts, or can be fitted over regular streetwear prescription glasses without compromising eye

or respiratory protection. Although regular

prescription glasses cannot be worn with full

facepiece respirators, they can be worn with some

types of powered air-purifying respirators (those

with hoods and some with helmets) and some styles of

goggles. However, for goggles to be effective they

must fit snugly, especially from the corners of the eyes

across the brow. Additionally, protective eyewear

should be selected that does not interfere with the

worker’s vision by disturbing the proper position of

the prescription lenses. Contact lenses may be worn

with goggles, safety glasses, or any respirator and thus

provide excellent corrective vision while maximizing

the protective eyewear selected.

Eye protection should be fitted together with a

respirator because some goggles can alter the fit of

a half-facepiece respirator. To ensure that the eye

protection does not interfere with a facepiece seal,

it should be worn when half-facepiece respirators

are fit tested and when workers conduct seal

checks each time they put on the respirator.

Caution should also be used when removing eye

protection to ensure that contaminated equipment

does not come in contact with the eyes or other

mucous membranes. Eye protection that is

properly selected and used will help prevent

conjunctivitis (redness, swelling and pain in the

eyes and eyelids). Poultry workers exposed to birds

infected with avian influenza should see a physician

at the first signs of conjunctivitis.

More information on eye protection for infection

control and other documents concerning eye safety

are available at http://www.cdc.gov/niosh/topics/

eye/.

Protective Clothing and Hand-hygiene

Practices

Protective clothing (which includes gloves,

aprons, outer garments or coveralls, and boots or

boot covers) should be used to prevent direct skin

contact with contaminated materials and surfaces

and reduce the likelihood of transferring contaminated

material outside a poultry barn or work site.

Disposable protective clothing is preferred.

 Because protective clothing can be more insulating

than regular work clothing, precautions should be

5
taken to protect workers from the effects of heat

stress. For example, wearing a lightweight cotton

coverall might create less of a heat stress risk for a

worker than a chemical resistant suit. Additionally,

workers should know the symptoms of heat-stressrelated illnesses and be able to take appropriate

measures to ensure that such illnesses do not occur.

Information concerning heat stress and possible

solutions can be found at http://www.osha.gov/SLTC/

heatstress/.

When selecting gloves, whether disposable ones

made of nitrile or vinyl that are lightweight (a

thickness of 8 to 12 mil) or ones that are heavy

duty (a thickness of 18 mil or greater) that can be

reused after being disinfected, factors to consider

include a worker’s activities, the importance of

dexterity, and whether the gloves need to be

durable and resistant to tearing and abrasion.

Regardless of the type of glove selected, care is

needed to ensure that wearing protective gloves

does not aggravate existing dermatitis or damage

healthy skin because of prolonged exposure to

water or sweating hands. For example, a thin

cotton glove can be worn beneath a glove to

protect against dermatitis, which can occur from

prolonged skin exposure to moisture in gloves

caused by perspiration.

Workers should always remove protective

clothing (except for gloves) first and discard or

secure the clothing for disinfection before

removing their respirators and goggles. It is

important that workers understand the importance

of strict adherence to hand washing after

contacting infected birds or surfaces that might be

contaminated. Having suitable hand-washing

facilities and a good supply of soap and disposable

towels is essential. Before removing their gloves,

workers should wash their gloved hands

thoroughly with soap and water, and after removing

the gloves, they should wash their hands again. If

hand-washing facilities are unavailable at the site of an

outbreak response, alternative hand-disinfection

procedures will be specified. If waterless soaps or

alcohol-based sanitizers are provided, care should be

taken because they are very harsh on the skin, which

might lead to dermatitis if used too frequently.

It is important to take measures for preventing the

avian influenza virus from being spread to other areas.

To do this, disposable items of personal protective

equipment should be discarded properly, and nondisposable items should be cleaned and disinfected

according to outbreak-response guidelines.

Where to get more Information

Links to Internet sites are provided in this Safety

and Health Information Bulletin for those wanting

more detailed information on the topics presented.

In addition, for those wanting sources of personal

protective equipment, manufacturers of protective

clothing, respirators, eye protection, and other

items of personal protective equipment are listed in

the Buyer’s Guide of the International Safety

Equipment Association at http://

www.safetyequipment.org.

For answers to workplace safety and health

questions, check the Web sites of NIOSH (http://

www.cdc.gov/niosh/homepage.html) or OSHA

(http://www.osha.gov), or telephone NIOSH at

(800) 356-4674 or OSHA at (800) 321-6742.

6
7

Acknowledgements

This Safety and Health Information Bulletin is a

product of the OSHA-NIOSH Issues Exchange

Group. Appreciation is extended for the insightful

reviews of this document by scientists from the

National Center for Infectious Diseases of the CDC

and the Animal and Plant Health Inspection Service of

the U.S. Department of Agriculture. Appreciation is

also extended to Ms. Priscilla Wopat of the NIOSH

Spokane Research Laboratory for editing the

document.

Disclaimer

 Mention of company names or products does not

constitute endorsement by the National Institute

for Occupational Safety and Health (NIOSH),

Centers for Disease Control and Prevention

(CDC).

Material contained in this document is in the

public domain and maybe reproduced, fully or

partially, without the permission of the Federal

Government. Source credit is requested but not

required.
8

Advantages, Disadvantages, and Costs of Air-purifying Respirators for Protecting Poultry Workers

Respirator 

type Advantages 

 

Disadvantages 

Cost 

(2004 dollars) 

Filtering facepiece 

(disposable; 

 dust mask) 

– Lightweight. 

– No maintenance or cleaning needed. 

– No effect on mobility. 

– Provides no eye protection. 

– Provides no protection against irritant gases such 

 as ammonia. 

– Can add to heat burden. 

– Inward leakage at gaps in face seal. 

– Many models do not have adjustable head straps. 

 Difficult for a user to do a seal check. 

– Level of protection varies greatly among models. 

– Communication may be difficult. 

– Fit testing required to select proper facepiece size. 

– Some eyewear may interfere with facepiece fit. 

$0.70 to $10 

Elastomeric 

half-facepiece 

– Low maintenance. 

– Reusable facepiece and replaceable 

 filters and cartridges. 

– Dual cartridges can be used to protect workers 

 from exposures to particles, gases, and vapors. 

– No effect on mobility. 

– Provides no eye protection. 

– Can add to heat burden. 

– Inward leakage at gaps in face seal. 

– Facepiece must be cleaned and disinfected before 

 reuse, this can be a contact-exposure risk. 

– Communication may be difficult. 

– Fit testing required to select proper facepiece size. 

– Some eyewear may interfere with facepiece fit. 

facepiece: $12 to 

$35 

filters: $4 to $8 

each 

Powered with 

hood, helmet, 

or loose-fitting 

facepiece 

– Provides eye protection. 

– Protection for people with beards, missing 

 dentures, or facial scars. 

– Low breathing resistance. 

– Combination cartridges can be used for 

 exposures to particles, gases, and vapors. 

– Flowing air creates cooling effect. 

– Face seal leakage is generally outward. 

– Fit testing is not required. 

– Prescription glasses can be worn. 

– Communication less difficult than with rubber 

 half-facepiece or full-facepiece respirators. 

– Reusable components and replaceable filters. 

– Added weight of battery and blower. 

– Awkward to wear for some tasks. 

– Components must be cleaned and disinfected 

 before reuse; this can be a contact-exposure risk. 

– Battery requires charging. 

– Air flow must be tested with flow device before use. 

unit: $400 to $1000 

filters: $10 to $30 

Elastomeric 

full-facepiece with 

N-100, 

R-100, or P-100 

filters 

– Provides eye protection. 

– Low maintenance. 

– Reusable facepiece and replaceable filters 

 and cartridges. 

– Combination cartridges can be used for 

 exposures to particles, gases, and vapors. 

– No effect on mobility. 

– More effective face seal than that of filtering 

 facepiece or rubber half-facepiece respirators. 

– Can add to heat burden. 

– Reduced field-of-vision compared to half-facepiece. 

– Inward leakage at gaps in face seal. 

– Facepiece must be cleaned and disinfected before 

 reuse; this can be a contact-exposure risk. 

– Fit testing required to select proper facepiece size. 

– Facepiece lens can fog without nose cup 

 or lens treatment. 

– Spectacle kit needed for people who wear 

 corrective glasses. 

facepiece: $90 to 

$240 

filters: $4 to $8 

each nose cup: $30 

Powered with tightfitting half-facepiece 

or 

full-facepiece 

– Provides eye protection with full-facepiece. 

– Low breathing resistance. 

– Face seal leakage is generally outward. 

– Flowing air creates cooling effect. 

– Reusable components and replaceable filters. 

– Combination cartridges can be used for 

 exposures to particles, gases, and vapors. 

– Added weight of battery and blower. 

– Awkward to wear for some tasks. 

– No eye protection with half-facepiece. 

– Components must be cleaned and disinfected 

 before reuse; this can be a contact-exposure risk. 

– Fit testing required to select proper facepiece size. 

– Battery requires charging. 

– Communication may be difficult. 

– Spectacle kit needed for people who wear 

 corrective glasses with full-facepiece respirators. 

– Air flow must be tested with flow device before use. 

unit: $500 to $1000 

filters: $10 to $30