Infections at work are those created by exposure to harmful micro-organisms such as bacteria, fungi, viruses, internal parasites, and other infectious proteins known as prions. These are called 'biological agents' in health and safety legislation. You may be harmed by micro-organisms by being infected with the micro-organism, by being exposed to toxins produced by the micro-organism, or by having an allergic reaction to the micro-organism or substances it produces.
Micro-organisms are found virtually everywhere in the natural environment. Most of these are harmless to humans and do many important jobs. They are used to make medicine. They can break down the oil from oil spills. They make about half of the oxygen we breathe. However, certain micro-organisms can cause harm - either by infection, allergy or being toxic.
You may come into contact with micro-organisms at work because you intentionally work with them, eg in a microbiology laboratory. But you are more likely to be exposed as a result of the kind of work you do, eg as a farmer, or a healthcare worker ie the exposure is incidental to the purpose of the work.
There were over 2000 new cases of occupationally acquired infection reported in 2002, an increase on the previous year's figure. The most common type of infection was diarrhoeal disease and most cases of infection were reported in healthcare workers.
In most work premises where there is either intentional work with micro-organisms (eg microbiology laboratories and research facilities) or a relatively high likelihood of occupational exposure (eg hospitals and nursing homes) the HSE is the regulatory body. However, in some cases where the possibility of exposure is incidental to the purpose of the work (see above) the regulatory body may be the local authority. Examples of such workplaces, where the regulation of safety is the responsibility of the local authority, are skin piercing and tattoo parlours (where there may be a risk of transmission of bloodborne viruses) and large office blocks (where cooling towers could be source of Legionnaires' disease). Guidance on these issues is therefore available elsewhere on the website in the Local Authority Unit site.
Healthcare
Healthcare workers are a key risk group because of the nature of their work. We do not have accurate data on infections and ill health in this group - but data from physician reporting schemes indicates infection rates of about 30 per 100 000 workers per year amongst nurses and about 100 per 100 000 per year amongst care givers in residential homes. Most of these infections are diarrheal diseases. However, more serious infections do sometimes occur. For example, four health workers have died after having accidentally incurred needlestick injuries during work with HIV patients. Another nine are also known to be sero-positive as a result of this kind of accident.
The control of occupational exposure to biological agents in the healthcare setting is covered by the Control of Substances Hazardous to Health Regulations 2002 (COSHH). There is detailed guidance available from the Advisory Committee on Dangerous Pathogens (ACDP) or the Department of Health on the control of various micro-organisms such as blood borne viruses (eg HIV and hepatitis B), vCJD, viral haemorrhagic fevers and TB. The HSE's Health Services Advisory Committee (HSAC) also publishes guidance on clinical waste and post-mortem rooms. ACDP are currently preparing new guidance on biological agents in the laboratory and healthcare settings.
Healthcare-associated infection (HAI) is an important cause of morbidity and mortality amongst hospital patients, especially with the increasing resistance of many human pathogens to antibiotics (eg methicillin-resistant Staphylococcus aureus: MRSA). However, the HSE do not generally deal with clinical matters as these are more appropriately dealt with elsewhere. One exception to this is where there are management failures or failures of systems of work and in such cases HSE do sometimes become involved.
The Department of Health has produced several documents covering the control of infection in hospitals. Perhaps the most important of these are as follows:
- "Getting ahead of the curve", strategy document for combating infectious diseases
- "Winning Ways", strategy document following on from "Getting ahead of the curve"
- DoH strategic guidelines for implementation of control of infection measures
Laboratories
Laboratory workers who come into contact with COVID-19
Under the COSHH Regulations, employers must minimise the risk to laboratory staff working with biological agents which cause COVID-19.
There is guidance from the UK Health Security Agency on safe handling and processing of COVID-19 for samples in laboratories.
People who work in microbiology laboratories and related disciplines are at risk from exposure to biological agents. Some will work with biological agents themselves, eg by culturing them.
Others will work with material, which is likely to contain micro-organisms although the micro-organisms are not actually being grown, eg blood typing in a haematology laboratory.
In addition to the general duties of COSHH, there are additional provisions in Schedule 3 of the regulations, which apply, primarily, to laboratory and large-scale work with biological agents. The choice of control measures in laboratories is largely based on the hazard group of the biological agent that is being used (or that may be present). Biological agents are classified into one of four hazard groups from 1 (the lowest) to 4 (highest, eg Ebola) based on their ability to infect healthy adults. The classification is set out in the Approved List of Biological Agents.
There are about 230,000 people who work in biomedical sciences - with an estimated 12,500 scientists working in NHS laboratories. Research carried out for HSE in 1994/5 estimated that infection rates are about 16 per 100 000 person years, with the majority of these being caused by Hazard Group 2 biological agents in diagnostic laboratories.
In addition to using specific control measures, those working with biological agents also need to notify HSE the first time that agents in HG2, HG3 and HG4 are used at a particular premises. Notification is also required of the subsequent use of certain agents (ie when agents in hazard groups 3 and 4 and those agents in hazard group 2 that are listed in Part V of Schedule 3 of COSHH are used for the first time).
Much of the guidance that is relevant to laboratory work is produced by the Advisory Committee on Dangerous Pathogens (ACDP). There is also guidance available from other HSC advisory committees and specific regulations for those working with genetically modified organisms.
ACDP also issue a free publication, the Biological Agents Bulletin - available on the HSE Website or by direct email - which covers laboratory issues as well as new information about biological agents in general.