Chapter 3

Risk communication and promoting health

Health promotion in clinical practice

‘It is better to be healthy than ill or dead’, wrote Geoffrey Rose in Rose’s Strategy of Preventive Medicine.1 Few people would disagree, including most patients diagnosed with a new illness. Promotion of good health is a major focus of public health and epidemiological practice, but is also increasingly central to the practice of clinical medicine. Primary care practitioners are expected to contribute to the health of their patients, to reduce their risks of disease, as well as identifying and treating abnormalities at an early stage to improve outcome. All of these are part of the broad picture of prevention (see p.54). In secondary and tertiary care we are also expected to identify and tackle risks that will worsen outcomes for patients with existing disease, e.g. to advocate and support smoking cessation in people with cardiovascular disease.

In this chapter we describe the elements of promoting good health that are most relevant to clinical practice. These need to be informed by broad principles and information about prevention, so we include sections on how to discuss these issues with patients and the key activities of clinicians in this area. Later chapters in Section 2 (see pp.97–118) cover screening and preventive medicine at the population level including detailed discussion on the prevention and control of communicable and non-communicable disease.

Why me?

People who have been diagnosed with a disease will want to know ‘Why me?’. They will ask whether or not it could have been averted by either a change in their own behaviour, a change in some external factor, or by a change in your activity as a doctor. In some cases it may be clear:

• A woman has a broken leg after being knocked off her bike by a speeding motorist. The cause of her injury is relatively clear: the immediate (or proximate) cause is reckless driving by the driver of the car. Of course there are many other steps along the causal pathway including her decision to cycle along that route on that day (intermediate cause), and the lack of safe cycle tracks or effective speed restrictions (distal causes).
• A man is diagnosed with lung cancer after smoking for 30 years. The proximate cause is likely to be the smoking; more distal causes include social pressures to smoke, tobacco advertising, and social determinants of smoking such as social class. Inadequate smoking cessation services locally may have played a role, and perhaps there were some missed opportunities for intervention at earlier consultations with his GP.

Generally causation is complex with a web of determinants that are:

• Social
• Genetic
• Behavioural
• Environmental.

Preventive interventions can be directed towards all levels, many of which can involve clinicians.

The role of the clinician in prevention

• Helping patients avoid future problems through providing general advice about a healthy lifestyle (see Box 3.1).
• Identifying specific risk behaviours and advising/supporting patients to reduce or avoid them.
• Ensuring specific preventive interventions are made available to patients, e.g. vaccination.
• Identifying early disease or its precursors and offering early treatment or risk reduction, e.g. monitoring and treating hypertension.
• Counselling patients with a condition about possible causes and explanations as to why them, and why now, e.g. explaining that diabetes may relate to obesity.
• Advising patients with a condition about how to reduce poor outcomes, e.g. by weight loss, exercise, diet, and smoking cessation after a myocardial infarction.
• Exploring whether anyone else is at risk through common environmental, genetic, or infectious exposures, e.g. identifying which contacts need following-up in tuberculosis (TB), or whether future children of a woman with breast cancer are at risk of inheriting BRCA2.
• Lobbying for policies that promote and improve health.

Box 3.1 Sensible guidelines for patients (and yourself !)

There is a mountain of material and advice available to professionals and the public on what constitutes a healthy lifestyle. A number of evidence-based guidelines have been produced, but the following are widely agreed:

• Don't smoke.
• Eat a healthy diet:
• Eat more fruit, vegetables, and fibre.
• Cut down on saturated fat, red meat, salt, and sugar.
• Not too much alcohol, but 1 or 2 units a day may be beneficial.
• Exercise regularly—recommendations change but all agree that any is better than none, and generally the more and more intense the better.
• Avoid being overweight or obese.
• Avoid sunburn.
• Use condoms and effective contraception to reduce the risk of unwanted pregnancy and sexually transmitted infections (STIs).
• Keep up to date with vaccinations.
• Attend for screening when invited.

Could it have been prevented?

Once diagnosed, patients will ask whether anything else could have been done to prevent them having succumbed to this disease. Identifying specific risk factors may help to answer this question, and this requires reference to the epidemiological literature on causation. We outline research methods appropriate to the study of aetiology of disease elsewhere in the book (see p.197), and show that even at the population level, causation requires the demonstration of a complex set of criteria (see pp.156–161). At this point the focus is on the individual, and while often it is impossible to identify causation, there are examples where it is both possible and useful.

Why me and why now?

If a woman presents with an unplanned pregnancy and requests a termination, it would be useful to discuss why she became pregnant and how she can avoid this in future. This appears rather obvious, but is inconsistently done by clinicians, leading to repeat presentations and terminations in some women.

The causation may be complex and relate to:

• Lack of knowledge (e.g. of contraception, sexual health services).
• Incorrect knowledge (e.g. about ways of avoiding pregnancy).
• Inadequate provision of services (e.g. inaccessible, unacceptable).
• Contraceptive failure.

Considering which of these may have been contributory and which can be addressed may help prevent future episodes.

Extent of preventable illness

There are many other preventable diseases, with varying degrees of intervention available to the individual clinician, but consideration of determinants should be a routine part of any consultation with a view to informing future preventive interventions. Box 3.2 shows how 4 determinants—smoking, alcohol, diet, and exercise—are estimated to be responsible for 29.5% of morbidity in Europe1.

Box 3.2 Morbidity from selected causes, DALYs* Europe (high income countries)

• Smoking: 11.2%
• Alcohol consumption: 6.4%
• Diet (overweight, obesity, low fruit/vegetables): 7.5%
• Physical inactivity: 4.4%

*Disability-adjusted life years, see p.286.

Routinely identifying these and other risk factors—such as hypertension, raised serum cholesterol—can be used to focus consultations on preventive behaviours in the future. This should include a focus on the underlying behavioural/lifestyle ‘causes of the causes’ of disease–e.g. high salt intake, an important cause of raised BP.

The evidence base for prevention

Preventive messages should be based on:

• Evidence of the causes of a disease.
• Evidence of the efficacy of an intervention to reduce disease by addressing that cause.

Inferring causation is arguably the most complex part of epidemiology which requires a rigorous scientific interpretation of the evidence from different modalities (including observational and animal evidence as well as clinical trials) and a sound theoretical framework for that interpretation. A detailed discussion of this is beyond the scope of this book (see Further reading, p.55) but in clinical practice it is useful to understand some of the criteria used to assess causation and these are outlined in Chapter 7 (see p.156).

Evidence of effective interventions

Providing evidence of efficacy of preventive interventions can be equally challenging.

• Randomized controlled trials (see p.186) of preventive interventions are the gold standard, and can be used to show the effectiveness of a range of different interventions from vaccinations, to dietary interventions, to smoking cessation support.
• Community randomized trials: these can be used to test more complex interventions, particularly those that address community-or population-level determinants. The unit of randomization and intervention is the community rather than the individual. These are more difficult to carry out and to interpret than individual-level trials but nonetheless can give valuable information to guide policy. For example, the Portuguese salt prevention trial2 compared the effects on community blood pressure levels of dietary intervention to lower salt intakes in one village compared to another village (control) without the intervention.

Further reading

Bhopal R. Concepts of Epidemiology: Integrating the ideas, theories, principles and methods of epidemiology. Oxford: Oxford University Press; 2008.

Bibbins-Domingo et al. Projected effect of dietary salt reductions on future cardiovascular disease. NEJM 2010; 362:590–9.

Bradford Hill A. The environment and disease: association or causation? Proc Royal Soc Med 1965; 58:295–300. image http://www.edwardtufte.com/tufte/hill

Communicating risk

Individual patients diagnosed with a disease, and those who seek to avoid disease, may want you to quantify different risk factors for them. The different measures of risk each have different uses in epidemiology and in communication. Common measures that are used are defined here with a focus on how they might be used in communication between clinicians and patients. Methods for measuring and analysing them are covered in Chapter 7 (see p.145).

Probability

This is the chance of an event occurring, and ranges from 0 (no chance) to 1 (inevitable).

Absolute risk (incidence rate)

• The probability of occurrence of a disease, death, or other event over a period of time, i.e. Incidence rate.
• For a patient, absolute risk tells them the probability that they will develop a disease in the future.
• Since the outcome can rarely be known with certainty for an individual, the best indicator is the incidence rate in similar people.
• Absolute risk estimates are now used extensively for cardiovascular disease in order to indicate appropriate risk reduction interventions.

Relative risk

• The increase (or decrease) in probability of disease given a particular exposure or risk factor.
• Calculated by dividing the incidence rate in the exposed (Ie) by the incidence rate in the unexposed (Io) (see p.179) RR = Ie/ Io.
• Odds ratio is an estimate of relative risk and can be used in the same way (unless the incidence of the disease is >10%).
• Relative risk can be easily translated into health messages: ‘If you smoke you are 20 times more likely to die from lung cancer than if you do not’.
• It can be unhelpful if the background risk is very low.

Attributable risk

• A measure of the excess risk due to the factor concerned.
• Calculated by subtracting the incidence rate in the unexposed (the background risk) from the incidence rate in the exposed, i.e. Ie – Io (see p.179).
• It can be useful in counselling individual patients about why they have become ill, or how they can reduce future risks.

Attributable fraction

• Attributable fraction = attributable risk ÷ incidence rate in exposed, i.e. (Ie – Io)/ Ie = (RR − 1)/RR (by dividing top and bottom by Io).
• Assuming the factor is causal, then the attributable risk fraction is the proportion of disease risk that would be prevented/avoided if the risk was changed to that of an unexposed person.

Population attributable risk (PAR)

PAR = attributable risk × prevalence of risk factor in population

This is the proportion of the disease that is due to the risk factor in the population as a whole, and thus the proportion of disease in the population that should be prevented if the risk factor is removed.

Example 1: the Pill ‘doubles risk of clots’

In 1995 the UK Committee on the Safety of Medicines issued an urgent letter advising doctors of an increased risk of venous thromboembolism (VTE) for 3rd- compared with 2nd-generation oral contraceptive pills (OCP). The letter reported a relative risk of 2, i.e. a doubling in the risk of VTE for women on 3rd-generation compared with 2nd-generation pills. This was widely reported in the press, and thousands of women stopped taking their pills. There was an increase in unplanned pregnancies and subsequent termination referrals. Many women were frightened by the idea of a doubling in risk. Was there a better way of communicating the findings? Look at the data:

The absolute risk of VTE in women on 3rd-generation OCP (incidence rate in exposed, Ie) was 3 per 10,000 person-years while the absolute risk in women taking the 2nd-generation OCP (incidence rate in unexposed, Io) was 1.5 per 10,000 person-years.

Relative risk = Ie ÷ Io = 3 ÷ 1.5 = 2

It may have been better to explain the attributable risk: there is a small risk of VTE for women on the 2nd-generation pill: if 10,000 women took them for a year, between 1 and 2 would have a VTE. If instead they take a 3rd-generation pill, this increases to 3 women, i.e. the increased risk attributable to the 3rd-generation pill is 1.5 per 10,000 woman years.

Example 2: use of attributable risk in explaining causation (data in this example are for illustration only)

A woman aged 34 presents with a deep vein thrombosis (DVT). She has been taking the 3rd-generation oral contraceptive pill and asks whether that was to blame. Let’s assume that the background incidence rate of DVT in people under the age of 40 is around 1 per 10,000 per year, and that women taking the combined pill for oral contraception have an incidence rate of DVT of approximately 3 per 10,000 per year.

Relative risk = Ie ÷ Io = (3/10,000) ÷ (1/10,000) = 3

This means that for women taking the OCP, there is a 3-fold increase in the risk of DVT.

Attributable risk = Ie – I0 = (3/10,000) − (1/10,000) = 2/10,000

This means that the increased probability of a DVT increases by 2 per 10,000 per year to an absolute risk of 3 per 10,000 women per year. This can then be used to calculate the likelihood that the OCP contributed to the DVT in this woman:

Attributable fraction = (Ie − I0) ÷ Ie = 2/3 = 0.67

Therefore in women like this (under 40 who have a DVT and are on this OCP), two-thirds of DVT cases would be attributable to the OCP.

Health promotion in the clinic

Definition

Health promotion is the process of enabling people to increase control over, and to improve, their health (see Box 3.31).

What does health promotion involve?

• Public policy.
• Supportive environments.
• Community action.
• Personal skills.
• Health services.

Why clinicians?

Specific responsibility

• Clinicians have a specific responsibility for promoting and protecting health for their own patients.
• In the UK the GMC’s list of duties of a doctor includes the statement that you must ‘protect and promote the health of patients and the public’.

Unique position to promote health

• Access to people: the majority of people will consult their GP at least once a year, >90% over a 5-year period. Other people will be in contact with clinicians in community clinics, hospitals, accident and emergency departments, and sexual health clinics.
• Receptive audience: with almost all of these clinician–patient contacts there is an opportunity for health promotion, and people are often receptive in these situations.
• Effective interventions: many clinicians are sceptical, but the evidence shows that clinician interventions can be effective (see p.60).

How to do it (see pp.60–67)

• Advocate (and offer if appropriate) vaccination and screening.
• Ask about/identify risks (e.g. obesity, problem alcohol or drug use, smoking).
• Advise on reducing these risks.
• Assist people to reduce risks (through referral, prescription, etc.).
• Arrange follow-up.
• Don’t assume someone else will do it!

Box 3.3 Ottawa Charter for Health Promotion (WHO 1986)1

Health promotion

Health promotion is the process of enabling people to increase control over, and to improve, their health. To reach a state of complete physical mental and social wellbeing, an individual or group must be able to identify and to realize aspirations, to satisfy needs, and to change or cope with the environment. Health is, therefore, seen as a resource for everyday life, not the objective of living. Health is a positive concept emphasizing social and personal resources, as well as physical capacities. Therefore, health promotion is not just the responsibility of the health sector, but goes beyond healthy lifestyles to wellbeing.

Prerequisites for health

The fundamental conditions and resources for health are peace, shelter, education, food, income, a stable ecosystem, sustainable resources, social justice and equity. Improvement in health requires a secure foundation in these basic prerequisites.

Advocate

Good health is a major resource for social, economic and personal development and an important dimension of quality of life. Political, economic, social, cultural, environmental, behavioural and biological factors can all favour health or be harmful to it. Health promotion action aims at making these conditions favourable through advocacy for health.

Enable

Health promotion focuses on achieving equity in health. Health promotion action aims at reducing differences in current health status and ensuring equal opportunities and resources to enable all people to achieve their fullest health potential. This includes a secure foundation in a supportive environment, access to information, life skills and opportunities for making healthy choices. People cannot achieve their fullest health potential unless they are able to take control of those things which determine their health. This must apply equally to women and men.

Mediate

The prerequisites and prospects for health cannot be ensured by the health sector alone. More importantly, health promotion demands coordinated action by all concerned: by governments, by health and other social and economic sectors, by non-governmental and voluntary organizations, by local authorities, by industry and by the media. People in all walks of life are involved as individuals, families and communities. Professional and social groups and health personnel have a major responsibility to mediate between differing interests in society for the pursuit of health.

Health promotion strategies and programmes should be adapted to the local needs and possibilities of individual countries and regions to take into account differing social, cultural and economic systems.

Reproduced from The Ottawa Charter for Health Promotion, First International Conference on Health Promotion, Ottawa, 21 November 1986, image http://www.who.int/healthpromotion/conferences/previous/ottawa/en/, with kind permission from WHO.

Smoking and alcohol advice

Generic advice on the advantages of adopting a healthy lifestyle are mainly considered relevant to primary care and community health services, but there is evidence that patients are also receptive when they are in contact with secondary care. Indeed, patients may think it odd if they do not receive advice on remaining healthy when they are discharged after an acute episode.

Smoking

The evidence base for clinician interventions for smoking is strong. In a general setting, brief advice can motivate people to try and stop. It is important to assess their willingness to try and quit, and if they are interested then they should be provided with appropriate support, including nicotine-replacement therapy (NRT) and, if required, referral to smoking cessation services.

The evidence-based guidance on smoking cessation includes 4 essential

‘On its own, brief advice from a doctor increases the chance of a person quitting (odds ratio 1.69, 95% confidence interval 1.45 to 1.98) compared with no advice’ (Lancaster et al. 2000).1

features (the 4 As):

• Ask (about smoking at every opportunity).
• Advise (all smokers to stop).
• Assist (the smoker to stop, depending on their readiness to change).
• Arrange (follow-up).

Pharmacological interventions are a key and effective part of smoking cessation strategies; clinicians should offer NRT, varenicline, or bupropion, to people who are planning to stop smoking.

For full guidance refer to NICE.2,3

Alcohol

Screening for potentially harmful or hazardous alcohol use should also be carried out in primary care and in an opportunistic way in other clinical settings, particularly where the episode may be alcohol-related.

In the UK, NICE has developed guidance4 that includes screening of new patients registering in primary care, undergoing reviews or health checks, presenting with sexual health concerns, for antenatal care and with minor injuries. A simple screening tool such as AUDIT (Alcohol Use Disorders Identification Test) can be used.4

Where problems are identified the clinician should carry out a brief intervention—immediately if possible or through a referral. The exception to this is if a person is dependent on alcohol in which case they should be referred for specialist treatment. NICE recommend that the brief intervention should last 5–15min and cover:

• Potential harm from their current level of drinking.
• The potential benefits to health and well-being of reducing alcohol intake.
• Discuss barriers to change and develop practical strategies to reduce consumption.
• Produce a set of goals and arrange for these to be reviewed.

These, followed by an appropriate brief intervention have been found to be effective in reducing alcohol intake in some settings.5

Alcohol risk assessment tools

• Paddington Alcohol Test (for use in emergency departments, see Box 3.4).
• Alcohol Use Disorders Identification Test (AUDIT).

Box 3.4 The Paddington alcohol test6

Anyone attending with 1 or more of a list of ‘trigger conditions’ (such as a fall, collapse, head injury, assault, etc.) or people with obvious intoxication are given the screening test in which the patient is asked:

• Do you drink alcohol?
• What is the most you will drink in any 1 day?
• How often do you drink this much?
• Do you feel your attendance at A&E is related to alcohol?

Patients are considered ‘PAT +ve’ based on the amount they drink in a day (8 or more units in men and 6 or more in women); if they drink this level every day they are considered a dependent drinker, less than that a hazardous drinker, and potentially PAT +ve. PAT +ve patients are offered the following verbal advice:

‘We advise you that this drinking is harming your health. The recommended daily limits are 4 for men, 3 for women with two drink free days per week’.

They are then offered a referral to the alcohol nurse specialist.

Exercise, weight, and dietary advice

Exercise

Patients should also be assessed for their level of physical activity with the aim of identifying people who could benefit from advice and support. The General Practice Physical Activity Questionnaire (GPPAQ) is one way of quickly screening people and is available online.

The standard advice is for people to do at least 30min exercise on 5 or more days each week. If they need to lose weight then a longer duration of exercise may be advised. Where possible, exercise should be integrated into regular daily activities such as cycling or walking to work. Recommended methods for increasing physical activity include brief interventions in primary care (advice and discussion), exercise referral schemes, the use of pedometers, and community schemes to promote walking and cycling.1

Weight and diet

There are wide-ranging health benefits from maintaining a healthy weight and good diet. Screening for overweight and obesity should be carried out sensitively based on clinical judgement.

The basic indicator of whether intervention is required is body mass index (BMI), the weight (in kg) divided by height (in m) squared. Classification by BMI (Table 3.1).

Decisions about whether to offer brief advice, refer for weight loss support, use drugs, or refer for surgery should be based on a broader risk assessment that includes comorbidities such as diabetes, waist circumference, and motivation for change.

Interventions to reduce weight and maintain weight loss are complex; referral to specialist counsellors or weight loss organizations can help.

The basic intervention should include a discussion of the health risks of overweight and obesity, discussion of targets (aim for maximum of 0.5–1kg weight loss per week), the importance of weight loss and maintenance of that loss, and the importance of using exercise and diet.

It is important to consider the wider social setting and encourage partners and other family members to be involved.

In people who struggle to lose weight and who continue to be at risk of adverse health outcomes drug treatment (with orlistat) or bariatric surgery should be considered. Dietary advice is appropriate for everyone, whether or not they are overweight or obese. There are many resources available to help people maintain a healthy diet. The general recommendations are shown in Table 3.2.2

Table 3.1 Classification BMI (kg/m2)

Underweight <18.5
Healthy weight 18.5–24.9
Overweight 25–29.9
Obesity I 30–34.9
Obesity II 35–39.9
Obesity III 40 or more

Table 3.2 General dietary advice: recommendations2

Nutrient/food Recommendation
Total fat Reduce to no more than 35% food energy
Saturated fat Reduce to no more than 11% food energy
Total carbohydrate Increase to more than 50% food energy
Sugars (added) Reduce to no more than 11% food energy
Dietary fibre Increase non-starch polysaccharides to 18 g per day
Salt Reduce to no more than 6 g salt per day*
Fruit and vegetables Increase to at least 5 portions of a variety of fruit and vegetables per day

*The maximum amount of salt recommended for children is less than that for adults—see image http://www.salt.gov.uk

Sexual health

Interventions to prevent unplanned pregnancy and STIs are highly effective and should be delivered in a range of clinical settings.

As with other interventions to promote health, the first step is a risk assessment, in this case a good sexual history. This will establish whether someone is sexually active and who with, identify recent partner change, numbers of partners, whether sex is unprotected or not. It should also include contraceptive and reproductive history.

In the clinic setting, promotion of good sexual health should include the following:

• Advice on safer sex, recommendation of condom use for protection against STI and pregnancy.
• Advice and provision of contraception from a range of options.
• People at increased risk (those with multiple partners, who have recently had a STI, etc.) should be offered one-to-one counselling to reduce risk (NICE guidelines).1
• Tailored advice for the individual, e.g. men who have sex with men, sex workers and their clients.

In addition the following needs to be undertaken for specific groups:

• Screening for STIs: sexually active people <25 years should be offered Chlamydia screening in accordance with local guidelines.
• Testing for HIV in line with national guidelines (for UK in 2008—see UK National Guidelines on HIV testing, p. 64).
• Partner notification for people with a diagnosed STI including HIV.

UK National Guidelines on HIV testing2

Universal HIV testing is recommended for all patients in:

• Sexual health clinics.
• Antenatal services.
• Termination of pregnancy services.
• Drug dependency programmes.
• Healthcare services for those diagnosed with TB, hepatitis B, hepatitis C, and lymphoma.

In areas with a local prevalence of 2 in 1000 or higher, an HIV test should be offered to all new patients registering with a GP, and all general medical admissions.

HIV testing should also be routinely offered and recommended to:

• Patients where HIV enters the differential diagnosis (see table of indicator diseases in guidelines2).
• Patients diagnosed with a STI.
• Sexual partners of men and women known to be HIV positive.
• People reporting specific risk factors—men who have sexual contact with other men, people with a history of injecting drug use, people from a country of high HIV prevalence (>1%) and their sexual partners.

References

2 UK National Guidelines for HIV Testing 2008. image http://www.bhiva.org/HIVTesting2008

Outbreak investigation

An outbreak is the same as an epidemic, i.e. an increase in the number of cases above the expected level in a particular community or geographic area, but is usually applied to a localized increase. Outbreaks can be either infectious or non-infectious (environmental) in origin, but usually they are due to infectious disease. At the outset of an investigation of an outbreak both possibilities need to be borne in mind.

Types of outbreak

Common source

• Exposure to common factor.
• Can be over a prolonged time.

Point source

• Exposure to common factor.
• All exposed at same time, e.g. wedding reception meal.

Propagated

Where there is transmission from person to person.

Why investigate outbreaks?

• To stop the outbreak.
• To understand what happened and why.
• To prevent future outbreaks.
• To improve our knowledge.
• To improve surveillance and outbreak detection.
• For training.

Steps in an outbreak investigation

• Preliminary assessment:
• Is it an outbreak?
• Are these cases of the same condition?
• Are there any immediate control measures required?
• Set up investigation:
• Define cases.
• Establish case finding methods.
• Diagnostic processes.
• Data collection procedures.
• Descriptive epidemiology in order to generate hypotheses:
• Time: draw an epidemic curve.
• Person: include relevant history of exposure.
• Place: draw a map of the cases.
• Analytic epidemiology to test hypotheses:
• Cohort study: identify subset of population (cohort) exposed to factor and compare incidence in them compared with those not exposed to calculate a relative risk.
• Case–control study: identify cases and enquire about exposure; identify controls and enquire about exposure; calculate odds ratio (as an estimate of relative risk).
• Introduce control measures:
• Remove source.
• Isolate/treat case.
• Destroy/treat food or other source.
• Protect persons at risk.
• Hygiene/prophylaxis.
• Prevent recurrence.
• Make recommendations.
• Produce guidelines/change law.

Breaking the chain of infection

With any case of an infectious disease it is important to try and identify the likely source and any possible chains for onward transmission in order to try and prevent other cases. In clinical practice it is easy to forget this aspect of ‘protecting and promoting the health of patients and the public’, or to assume that someone else will do it. Don’t.

Identifying the source (this often helps with diagnosis as well)

Ask appropriate questions (dependent on condition), e.g.

• Food.
• Travel.
• Contacts with similar symptoms.
• Sexual contacts.

If the source is likely to be in the community and putting others at risk (i.e. not within the household) you need to inform the local public health department to arrange for investigation.

Contact tracing

Who is involved?

Ask the patient about other people who may be ‘involved’, e.g.

• The source (in person–to-person spread).
• Subsequent contacts.
• Others exposed to the same source (e.g. same food).

How will they be told?

Establish a method for informing and managing contacts, e.g.:

• Patient referral: a person with a STI informs their contacts and suggests that they attend for screening and treatment.
• Provider referral: the clinician (or other member of the team) obtains contact details from the patient and notifies the contacts directly. Care must be taken to protect the confidentiality of the index patient.
• Outbreak investigation: where multiple people may have been exposed, it is appropriate to ask the local public health authorities to investigate and take responsibility to informing people (see p.66).

How will they be managed?

This depends on the infection. They may be offered screening, presumptive treatment, vaccination (if available), or simply provided with information on how to recognize symptoms and what to do if they develop.

Preventing further transmission

Patients may provide an ongoing risk of infection to others depending on the specific infection. Think about who may be at risk and how that can be reduced/eliminated. For example:

• Quarantine: in the case of some infections this may be effective. This was key to limiting the transmission of SARS (severe acute respiratory syndrome) in 2003. For many infectious diseases it is ineffective since the maximum period of infectiousness is prior to the onset of symptoms.
• Advice to the patient (e.g. avoid sexual contact, no food handling).
• Specific precautions depending upon infection.

Appropriate precautions

It is crucial to reduce the risk of onward transmission in hospital and in the community. Universal precautions aim to reduce transmission of all agents, while specific precautions relate to the mode of transmission.

• Respiratory precautions.
• Enteric precautions (see Box 3.5 and Further reading, p.70).

Box 3.5 Enteric infections

Enteric precautions include:

• Handwashing.
• Safe disposal of excretions and soiled materials.
• Disinfection of toilet seats, flush handles, wash-hand basin taps, and toilet door handles.
• Education on personal hygiene.
• Hygienic preparation and serving of food.

Identify upstream and downstream contacts

• Identify others who may be involved as a source of infection, linked to common exposure, or who could have been infected by the patient.
• For food poisoning history to include travel, eating in different places and events, contact with anyone who was ill, food preparation for others.

Specific groups

Some people may pose a particular risk to others, and if they have an enteric infection with diarrhoea they should be prevented from resuming activity until 48 hours after their first normal stool:

• Food handlers.
• Staff of healthcare facilities who have direct contact, or contact through serving food, with susceptible patients.
• Children <5 years who attend nurseries or other groups.
• Older children and adults where hygiene is difficult (includes people with learning disabilities or special needs, residents in hostels or temporary camps, etc.).

Respiratory precautions (e.g. TB)

If a patient with smear positive respiratory TB is admitted to hospital then they should be kept with respiratory precautions:

• Single room, negative pressure where possible.
• Use of a fine mask.

Additional precautions for patients with multidrug-resistant TB (MDRTB) or extensively drug-resistant (XDRTB)

• Staff and visitors should wear dust/mist masks during patient contact while the patient is considered infectious.
• The patient should remain in isolation in a negative pressure room until assessed to be non-infectious.
• Before a discharge from hospital is made, secure arrangements for the supervision and administration of all therapy should have been made and agreed with the patient and carers.

Management of contacts

• Identify potentially exposed contacts.
• Close contacts of someone with pulmonary TB should be identified and asked about previous BCG.
• Close contacts in household are people who share a kitchen.
• Other people with symptoms.
• Others in the household.
• Close work colleagues.

Notification

• All forms of TB are compulsorily notifiable.
• The doctor making or suspecting the diagnosis is legally responsible for notification.

Further reading

Health Protection Agency. Health Protection Report: Enteric. image http://www.hpa.org.uk/cdr/pages/enteric.htm