Protection from avian influenza in connection with work potentially involving contact with infected animals

This information is based on WHO recommendations and has been adapted to Swedish conditions following consultations with other relevant authorities. It can form the basis of the employer’s risk assessment concerning measures which may be necessary in order to meet the requirements of Provisions of the Work Environment Authority in this context. The information will be updated as and when necessary.

Background
Avian influenza (“bird flu”) is caused by an influenza A virus which differs from the influenza viruses normally spread between humans. Avian influenza is highly infectious among poultry. During bird flu outbreaks in recent years, a few persons have been infected through direct contact with poultry, but as yet there are no absolutely firm indications of infection being transmitted between humans. Avian influenza comes under the Epizootics Act, enforcement of which is the responsibility of the Board of Agriculture, and infection among animals is notifiable on suspicion.

Employers in the egg production or poultry breeding industries, for example, or sanitation enterprises engaged for decontamination following outbreaks of avian influenza in the plants concerned, are obliged to inform themselves of the working operations entailing risks of avian influenza and to take measures whereby those risks are averted.

Mortality among infected humans has been high, and so there is every reason for maintaining a high level of protection among persons who may come into direct contact with birds in the event of an outbreak also occurring in Sweden.

Risk
Work in close contact with animals can involve infection risks. Contact with infected poultry, with their droppings and with dust, soil, implements and suchlike contaminated by droppings can entail a greater risk of transmission to humans. The risk is especially high e.g. in connection with the culling of infected birds.

Measures to be taken
It is the employer’s duty to carry out a risk assessment, which in the present instance must be in writing and shall form the basis of the employer’s decisions on measures to be taken.

General measures
The employer shall ensure that knowledge is available concerning risks and other matters of importance to the work environment, e.g. working methods and symptoms. Good personal hygiene and careful washing of hands after dirty work and before putting anything in one’s mouth are important in all work involving contact with poultry, irrespective of whether bird flu is suspected. Use of protective clothing, with change of clothing and showering when work is over, is also important.

If avian influenza is suspected on the premises
The employer must always consider safety precautions if there is any suspicion of avian flu on the premises. The employer shall issue the employees with written instructions on the conduct of their work.

Points which the employer may need to consider include the following.

• The number of persons needing to come into contact with possibly infected animals or material must be kept to a minimum.
  
• Those persons must be instructed to be observant on symptoms of illness and, in the event of symptoms appearing, to report the matter to their employer and to turn to the nearest hospital infectious diseases department.
  
• Depending on the duties involved and the degree of suspicion concerning avian flue, it may be appropriate for the precautions described below to be applied already at this stage to personnel categories coming into close contact with the animals. 
  

If avian influenza is established or strongly suspected
The employer shall always consider safety precautions for personnel employed for the culling and disposal of infected animals and carcases, the transport of infected carcases and the decontamination of a plant or vehicle. The employer is responsible for assessing the measures needed in different situations. On this point the WHO recommendations have been adapted to Swedish conditions, but the employer must always consider the need for other or additional preventive measures where there is a risk of infection.

• Personal protective equipment 
  • Full-length protective clothing, e.g. impermeable long-sleeved overalls to which a plastic apron or suchlike can be added if necessary.
  • Stout, impermeable protective gloves which can be disinfected.
  • A respiratory protective device (RPD) of at least filter class P2, individually fitted. A power assisted filtering device with a hood (class TH2P or higher) may be easier to work in and can be used as an alternative to a respiratory mask and safety googles. Note that if potentially harmful gaseous or volatile substances are used, another more adequate class of RPD might be needed depending on the substance situation. 
  • Close-fitting safety goggles.
  
• Disinfection of the hands after removing gloves and other personal protective equipment
  
• Showering after protective clothing has been removed 
  
• Safe disposal of laundry and waste at all stages until the infection risk has been eliminated.   

Workers should be trained in proper techniques of donning, removing and disposing of PPE, without contaminating themselves. Summary of order of removal of protective attire/equipment:  

- Remove gloves  
- Remove gown  
- Wash/decontaminate hands  
- Remove eye protection  
- Remove mask/respirator  
- Wash/decontaminate hands again  

Antiviral medication
Provisions issued by the Work Environment Authority require employers to offer and pay for the preventive medical measures needed for the prevention of ill-health. Antiviral medication, i.e. pharmaceuticals against viral infections, need to be available as a contingency measure if persons are liable, through their work, to come into contact with poultry infected with avian influenza or suspected of carrying the infection. “Smittskyddsläkaren” can advice on pre- and post exposure prophylaxis in keeping up with recommendations issued by the National Board of Health and Welfare. Antiviral treatment for persons who may have been exposed to avian influenza virus without being protected (post exposure treatment) is given within the regular health care system, following contact with an infectious diseases department or “Smittskyddsläkaren”. It is also appropriate for the employer, as a part of preventive work environment management, to contact the necessary agencies and list the phone numbers which may be needed in an emergency.

Provisions issued by the Work Environment Authority
Microbiological Work Environment Risks – Infection, Toxigenic Effect, Hypersensitivity, AFS 2005:01
Use of Personal Protective Equipment, AFS 2001:03 (see also information on Respiratory protective devices and surgical masks for situations involving infection risks)

Further reading
Further information is obtainable from the National Board of Health and Welfare, the Swedish Institute for Infectious Disease Control (SMI), the Swedish Board of Agriculture and the National Veterinary Institute.