Infections and immunity

Hepatitis B is a blood-borne virus that can be transmitted sexually, by blood exposure and from mother to child during birth. Prevention of blood-exposures at work through safe working practices offers best protection.

All staff working in clinical areas or having direct contact with blood or body fluids should be fully immunised if they have not developed natural immunity through exposure to the virus in the past.

Vaccination against hepatitis B takes the form of a course of three injections followed by a blood test to check if the vaccination has been effective. Following a satisfactory antibody response, one booster dose five years later is currently recommended.

Even with several doses of vaccine, not all staff can be effectively immunised. Those who do not raise adequate levels of antibodies should consider themselves at risk of infection. It is therefore particularly important to report any sharps injury immediately, as passive immunisation is available if the donor/source patient is infected with hepatitis B. Some staff may be naturally immune and will be advised accordingly.

Hepatitis C is a blood-borne virus transmitted from person to person via blood by sharing needles and less commonly through sexual contact.

There is no vaccine available for hepatitis C, so prevention of blood-exposures at work through safe working practices offers best protection. Cases of chronic infection can now be treated, although the treatment is long-term and can be quite debilitating.

The Equality Act 2010 includes HIV as a specific named condition which is defined as being a disability, from the point of diagnosis. This means that an employer must not treat someone less fairly because they have a diagnosis of HIV infection. Now that there is effective treatment for HIV, it is rare that any formal restrictions are needed because of this condition. Where there are any complications or secondary infections, an individual medical and/or occupational health assessment should be made.

Information for health care workers who may be infected with HIV

The Department of Health has issued guidelines on HIV-infected healthcare workers and guidance has recently been updated for HIV-infected healthcare workers who want to perform exposure-prone procedures. HIV infection does not warrant any formal restrictions at work, unless work involves exposure-prone procedures, such as surgical, dental and midwifery procedures. If an HIV-positive healthcare worker wants to perform exposure-prone procedures further assessment by occupational health professionals and ongoing monitoring are required.

Further information on professional responsibilities is also available from:

• the General Dental Council (GDC)
• the General Medical Council (GMC)
• the Nursing and Midwifery Council (NMC)

All healthcare workers have an overriding ethical and legal duty to protect the health and safety of their patients. Those who believe they may have been exposed to infection with HIV, in whatever circumstances, must seek medical advice, and diagnostic HIV antibody testing if appropriate. Healthcare workers who are infected with HIV must seek appropriate clinical and occupational health advice.

It is rare that any restrictions on work will need to be made in order to protect patients. Much more commonly it is necessary to consider the risks to the individual member of staff affected. If the individual's immunity has become low, there is a real risk of acquiring infections more readily from patients. Infections such as tuberculosis are potentially very dangerous, particularly to someone who is immuno-compromised.

All staff who think that they are at risk for HIV, or who know they have acquired the virus, should have regular check-ups with their own GUM/HIV specialist and be reviewed regularly by the occupational health nurse or physician to ensure that every attempt is made to keep the risks to their health to a minimum. For example, if a member of healthcare staff's immunity is known to be suppressed (not only because of HIV),they should not nurse a known case of open tuberculosis.

All consultations and enquiries will be dealt with in strict confidence.

Tuberculosis (TB) is a chronic infection which can affect any part of the body. It is only infectious when an individual is coughing up phlegm that contains the TB bacteria. The symptoms of TB are:

• A persistent cough, usually for three weeks or longer, that does not respond to antibiotics
• The cough may be dry or productive (i.e. coughing up sputum or phlegm)
• Haemoptysis (coughing up blood)
• Unexplained lethargy
• Unexplained loss of appetite
• Unexplained weight loss
• (Profuse) night sweats
• Persistent fever

Tuberculosis (TB) cases are again becoming more common in the UK. Not all cases are infectious. It is only those that have TB bacteria in the sputum (phlegm) that are infectious; this is known as open TB. In most cases, after two weeks of treatment the patient with TB is no longer infectious.

Healthcare staff should try to be aware of the possibility of TB in patients or themselves. Early reporting of symptoms allows more effective treatment and will limit the spread to others. When there is known contact with an open case of TB, either with a colleague or a patient, the occupational health service and infection control team will advise on any specific measures needed.

Latent TB

Often, people acquire the TB infection and develop an immune response to contain the infection, so that no illness follows. This is called latent TB infection.

Groups most at risk are those who have lived in countries with high rates of TB infection, worked in healthcare settings with patients who have had TB, or shared a home with a person with open TB. Latent TB is not infectious to other people but it may reactivate later and develop into active infection. If TB infection is active in the chest, the infection can be passed to others (open TB).

The risk over a person's lifetime of reactivation of latent TB has been estimated to be 5-10% if there are no other risk factors, but can be 20% or more if any of the following risk factors apply:

• HIV infection
• anti-TNF treatment, such as infliximab
• strongly positive tuberculin skin test
• signs of previous TB infection on chest X-ray
• work activities, including clinical work with patients, do not need to be restricted for people with latent TB.

TB infection, including latent TB infection, can now be detected using an interferon-gamma blood test (IGT). People who have a positive or indeterminate test result should be assessed in their local chest clinic. Advice will be given on taking special antibiotics which can eradicate the infection and help avoid reactivation.

Public health measures are in place across the UK to protect the public from TB as far as possible. These include an immunisation programme for babies and young children at risk, notification of cases as they are diagnosed, and contact tracing. National guidance on the detection and treatment of TB is updated periodically. Public Health England advises on contact follow-up.

Measles

Measles is still quite rare but there has been a number of outbreaks in the last few years due to a fall in the uptake of the measles vaccination. Measles infection can have serious complications and even be fatal.

Vaccination is given using the measles, mumps and rubella (MMR) vaccine. Two doses of measles vaccine are recommended to achieve the best rates of protection. Healthcare workers are expected to have the vaccine if they haven't already done so.

Rubella (German measles)

Rubella infection in pregnant women can cause severe damage to the unborn baby. Fortunately, vaccination has helped to almost eradicate this as a risk in the UK.

We aim to ensure that all NHS staff are immune to rubella. Staff who are not immune are offered vaccination, again using the measles, mumps and rubella (MMR) vaccine.

Chickenpox

Chickenpox (varicella) and shingles are caused by the herpes zoster virus. Chickenpox is usually a mild illness in childhood with an itchy blistering rash which starts to go in about one week, although in adults the symptoms are often worse. For neonates and patients with low immunity there can be more serious complications.

There is now a vaccine for varicella. Healthcare staff who have not had chickenpox should be tested and vaccinated if they are not immune.

Information leaflets about chickenpox and shingles for healthcare professionals, employees and employers are available from NHS at Work, where you can also find the full NHS evidence-based varicella zoster guidelines.