potentially pathogenic. Many of these “opportunists” take advantage of a debilitated
host—in particular, a person who is immunosuppressed. Immunosuppression in
humans can result from an infectious disease (HIV/AIDS is the best known example
but there are many others, such as malaria), malnutrition or some form of medica-
tion which is reducing the immune response. It is therefore wise to assume that sick
or dead birds represent a source of pathogens for humans. If this precautionary
approach is followed, and appropriate safeguards are taken, the risks involved in car-
rying out an examination of the bird will usually be low.
The specific precautions that should be implemented to minimize the spread
of zoonotic infections depend on the circumstances. In some countries health and
safety legislation may require the employer of those embarking upon postmortem
examinations or sample-taking to compile a risk assessment before the work is
done. The avian biologist or veterinarian who is likely to be involved in such work
will need to follow the rules and to take appropriate precautions. In other coun-
tries, adherence to the same level of risk assessment and protection of staff will
probably not be possible. Nevertheless, the scientist who is involved in such work,
regardless of the country involved, has a moral responsibility for assistants and
other staff, and it is therefore wise to draw up and adhere to a code of practice
aimed at minimizing the risk of infection. A similar approach is usually needed in
the field, where good facilities for the examination of birds are seldom available and
improvisation is necessary. Again, in some countries there are health and safety
obligations on employers and employees relating to field work but elsewhere these
may not exist and instead a voluntary code of practice may need to be instigated
(Cooper 1996). This is further discussed later, under 8.7 (Legal Aspects).
Basic rules that will help to reduce the spread of zoonoses are as follows:
- Be aware of the risks from birds, by reading the literature and by consulting
veterinarians, physicians, and others who have the appropriate knowledge - Familiarize colleagues and others involved in the study with the possible
hazards - Draw up a risk assessment, even if this is not a statutory requirement where
you are working; follow this with a Standard Operating Procedure (SOP) in
order to reduce the risks to a minimum - Ensure that you and your colleagues understand how microorganisms can
be spread and how best such spread may be prevented - Operate the “clean/dirty” principle; whereby during a postmortemexamina-
tion one person keeps “clean” and handles only the note-books, tape recorder,
and the outside of specimen bottles, while the other is “dirty” and comes into
direct contact with the dead bird and its tissues.
186 |Information from dead and dying birds