Most respiratory infections are ‘community acquired’. Sometimes, however, they may be directly related to specific occupations. Common viral or, more rarely, bacterial infections may affect those working in crowded environments, schools, hospitals and other communities.
Tuberculosis (TB) is a well-recognised risk in health workers. However, other categories of workers may also be at risk, such as prison guards or social workers involved with immigrants or asylum seekers originating from areas with a high TB prevalence.
Zoonoses (infectious diseases transmitted from animals), such as pneumonia caused by Chlamydia psittaci (ornithosis) or Coxiella burnetii (Q-fever), affect agricultural workers and those in other jobs involving direct or indirect contact with animals.
In outbreaks of Legionella pneumonia, such as those associated with cooling towers, fountains and whirlpools, or cruise ships, maintenance or other attending personnel are at risk of contracting the infection. Epidemiological evidence also exists that metal-exposed workers, such as welders, are at increased risk of infectious pneumonia and it has therefore been argued that these workers should receive pneumococcal vaccination.
The dissemination of anthrax and other microorganisms by terrorists is a definite threat to various categories of workers, such as postal workers, maintenance workers, law-enforcement personnel and health workers.
In addition, emerging infections pose a particular threat to hospital workers and their families, as shown by the outbreak of the severe acute respiratory syndrome (SARS). Another issue of recent years has been the emergence of drug-resistant microorganisms. Historically, this was mainly considered to be a risk to hospital personnel, but the high use of antibacterials in livestock production among pig and veal farmers has broadened the population at risk to workers in this sector, and even the general public.
Although fungi (e.g. Stachybotrys ) and their mycotoxins may be implicated in building- related illnesses caused by flooding or other types of water damage, the role of fungal contamination in causing such occupational respiratory diseases is not clearly established. Nevertheless, in immune-compromised subjects (due to steroid treatment, organ transplantation, or other causes) the risk of acquiring invasive fungal infections caused by ubiquitous fungi, such as Aspergillus , is real, but the quantitative relationship between exposure load (e.g. in some work environments) and the risk of becoming infected is still unknown. Further study of this relationship is required and there is a need to develop health-based standards of fungal and microbial exposures for the indoor and outdoor environment.
Sick building syndrome
This common syndrome refers to the occurrence, in a large proportion of the workforce, of nonspecific work-related respiratory and other complaints among occupants of sealed air-conditioned buildings. It is not established to what extent microorganisms and biological contaminants, together with indoor climate factors and volatile organic compounds, as well as psychosocial factors, are responsible for outbreaks of the syndrome.