Select Committee on Science and Technology Fourth Report


Chapter summary

Diagnosis and treatment is one of the key tasks required to tackle infection and involves a wide variety of health professionals and scientists. Diagnosis and treatment is necessary for care of individuals but also can inform control measures and preventative activity (see chapter 4).

We are concerned that there is a shortage of infectious disease experts able to diagnose unusual infection. In addition, we have found that training in infectious disease of health professionals who are not infection specialists is insufficient to enable effective diagnosis and treatment to take place at all times. Laboratory scientists able to exploit new sophisticated techniques are also in short supply.


3.1 The management of infection in an individual firstly requires a symptom-based diagnosis; this may be supported by laboratory investigations which identify the infectious micro-organism [Wright II, p56]. Knowledge of the infection will guide any intervention and treatment. Some infections, particularly viral infections, the common cold for example, cannot be effectively treated but symptoms can be managed until the patient's immune system has fought off the infection.

3.2 Doctors are the primary players involved in diagnosing and treating infection with support from laboratory scientists who identify the responsible micro-organisms [Little, II Q414]. Nurses also increasingly have a role in identifying patients with infections: they staff NHS Direct (a telephone and web-based advice service accessible to the public) [Beeching, Q122; PHLS Prim Care Ad Gp, I p131; Howard, Little, Perry, Williams, Q409-12]. In addition people manage much simple infection (such as the common cold) without resorting to advice from health services although they sometimes consult a pharmacist [Little, Q371].

General Practitioners

3.3 General Practitioners (GPs) diagnose and treat the majority of infection that comes to the attention of the health services: patients with an infection account for forty percent of consultations [see Box 2; Stewart, II p316].

3.4 We heard throughout this inquiry, including from some GPs, that GPs receive inadequate training about best practices relating to identifying and treating infection. There are particular concerns that GPs do not use laboratories effectively enough [Little, Q407-8; Wiltshire Food Liaison Grp, I p171; Birmingham, II p394].

Basing diagnosis on symptoms or laboratory investigation

3.5 GPs are sufficiently familiar with common infections in their local area to be able to diagnose and manage an infection on the basis of symptoms in most cases. Diagnosing on the basis of symptoms has advantages in that it is often accurate, is quick and may occur on the basis of one consultation [Little, Q403]. An alternative method would be to take a sample (such as a throat swab) and send it to a laboratory to identify the underlying micro-organism; using this method would not, in most cases, result in different advice about treatment for common infection.

3.6 Sending samples off for laboratory investigation is often time-consuming. Results may take several days, depending on the type of micro-organism, by which time the patient could have fought off the infection [Duerden, Q283]. As patients are often unhappy to return home without a prescription, the GP might deem it necessary to provide some treatment for the patient whilst awaiting laboratory results. It is arguable whether, even if GPs did send more samples to laboratories, there are sufficient resources to cope with extra demand. Thus, sending samples to laboratories for most cases of common infection could increase burden on laboratories without, in the majority of cases, improving patient care [Little, Q376].

3.7 Laboratory diagnosis is however vital to identifying and therefore treating serious infection. We heard that sending samples to laboratories is useful as it can inform doctors about what treatment regime to recommend. This then benefits the patient by reducing the length and severity of illness [Assoc Brit Pharm Industry, I p11; Haworth, I p75; Roche Diags, I p140-3]. In addition, we heard that microbiological diagnosis contributes to a body of knowledge about infection which can be used for prevention purposes [see chapter 4].

3.8 The Institute of Medicine in the United States of America recently warned against reducing use of laboratory investigations, particularly in the case of infection treated with antibiotics[10]. Identifying the exact micro-organism can guide the doctor about the most appropriate antibiotic to prescribe. This prevents treating with a "broad spectrum" or antibiotic which contributes to continuing and worrying increases in antibiotic resistance [Spec Ad Cttee Antimicrobial Resistance, I p159].

3.9 We heard about the importance of diagnosing viral infections. Correct diagnosis of viruses can also help to reduce inappropriate treatment with antibiotics (as antibiotics are ineffective against viral infections). As new anti-viral treatments become available it may be important to ensure appropriate use of such treatments in order to prevent resistance to those drugs developing. There is a shortage of experts in this area (virology, a sub-set of microbiology) [Clin Virol Network, II p90; Pillay, Q180].

3.10 Gathering information from laboratory investigation and using to alongside information about symptoms of disease can help to develop best practice guidelines about treating on the basis of syndromes alone (thus saving on laboratory testing in the future) [Black, I p28-33; Little, Q376].


3.11 One way of ensuring that treatment and management is informed by knowledge of the micro-organism is to further develop and use "near patient" diagnostic tests (NPTs). These can produce results straight away and can also be used within the general practice [PHLS Prim Care Ad Gp, I p132].

3.12 There is a certain degree of caution expressed about NPTs. The cost of new diagnostics is significant and we heard that quality control issues have not been sufficiently well addressed. In particular, it is not known what conditions must be met outside of a laboratory setting to ensure reliability [CAMR, I p42; Roche Diags, I p142; PHLS Prim Care Ad Gp, I p132]. Also, increasing use of NPTs could reduce further collecting of information for public health use [Boriello, Q492; PHLS, II p139].

3.13 NPTs provide good opportunities to improve diagnosis and treatment, but there should be further research into their effectiveness and their impact on public health. We discuss the importance of such research in chapter 8.

Contact nurses: tracing people in the community

3.14 Community infection control nurses (CICNs) play a significant role in identifying people with infection and in ensuring that they receive treatment. For example, specialist tuberculosis (TB) CICNs identify people at increased risk of TB and ensure that they are diagnosed and treated if necessary [Williams, Q411; Birmingham, II p395]. Many CICNs also fulfil other roles, including implementing infection prevention strategies [Perry, Q409].

3.15 We heard that there are enormous disparities in community based infection control across the country: a recent PHLS study found that the ratio of CICNs to head of population ranged from 0 to 4.5 whole time equivalent CICNs per 500,000 population [Inf Control Nurses Assoc II p176]. There are particularly serious gaps in expertise in contact tracing for TB in some areas of the country [Birmingham, II p395].

3.16 The shortage of information about individuals who are at increased risk of infection was cited as being a barrier to effective contact tracing. Ms Crisp, a CICN, described how information about people's country of origin for all new immigrant arrivals was not made available to CICNs. This information is vital to identifying those most likely to have been exposed to TB and being able to treat appropriately [Birmingham, II p395].

3.17 Infectious disease may be exacerbated in individuals who live in poor social conditions. Such individuals often find it difficult or are unwilling to use conventional means of health care advice, which makes it hard to identify and manage infection in these groups. The Felton TB centre in Harlem, New York recognises this and employs outreach workers to work with local churches and alternative therapists in order to better identify and treat people with both latent and active TB[11] [US, II p390]. We heard that similar tactics in England might help to follow up people who did not turn up for appointments at TB clinics [Birmingham, II p395]. Mrs Gini Williams, a TB Research Nurse at City University, recommends adopting "a whole systems approach" where treatment is not viewed simply as medical but also considers housing and social circumstances and human behaviour, as this could help to improve the effectiveness of medical treatment and prevent recurrence of infection [II p196-204]. Considering adopting such techniques is particularly important given recent significant increases in TB [Williams, Q386].

Hospital doctors

3.18 Within hospitals there are a range of specialists who are responsible for diagnosis and treatment of patients with infection. A number of skills are required, but in particular there is need for abilities to

·  carry out clinical diagnosis and manage a range of infections; and to

·  understand laboratory diagnosis and translate this understanding to bedside care.

3.19 At present many general and specialist doctors diagnose and manage infection. For example, a chest physician may care for a patient with TB and a renal physician may care for a patient with a kidney infection. Non-infection specialists are, with laboratory support, able to care for infections in many cases. However, we heard that knowledge about diagnosing and managing unusual infection amongst non-infection specialists was limited [Beeching, Finch Q88].

3.20 There are also around 80 infectious disease (ID) physicians in England, mostly located in teaching hospitals. They care for patients with severe or complex infectious disease problems [Beeching, Q121]. Most doctors rely on such specialists to look after unusual infections. However, there was some concern that there were insufficient numbers of such specialists [Beeching, Q121].

3.21 We heard that there are more doctors entering training to become infectious disease physicians than there are available posts and they have little presence in district general hospitals. The number of ID physicians in England appears to be low, currently at 1 per 750,000 people (in the USA there is approximately 1 per 53,000) []. The Netherlands, where the structure relating to microbiologists and infectious disease physicians is comparable to England, has 1 per 250,000 people. [Beeching, Q121; DoH, II p32].

3.22 The use of laboratory diagnosis in the hospital is normal, partly because of the risk of serious infection and because there is an increased risk that infection will spread to other patients. Medical microbiologists, along with laboratory scientists supply this service. They also act as a link between the laboratory and the bedside, providing advice to non-infection specialists on treatment and control.

3.23 We also heard that there are insufficient numbers of doctors with both laboratory and clinical skills. We are concerned that despite a number of initiatives to encourage and nurture clinical microbiologists they continue to be in short supply with posts remaining unfilled [Prof Amyes, I 2; AcMedSci Q43, 46, II p36; MRC and Wellcome Trust Q736; Resistance to antibiotics].

Laboratory scientists

3.24 Sophisticated laboratory techniques are increasing, particularly with the advent of molecular technologies. These could be used in microbiology laboratories to improve rapidity and accuracy of diagnosis [Amyes, I p1-3; Assoc Brit Pharma Industry, I p11]. For example, molecular techniques can be used to understand the spread of infection or a problem such as anti-microbial resistance by tracking individual clones of bacteria through human populations [Amyes, I p2].

3.25 Many laboratories still use techniques that are outdated and less reliable or informative, as there is a shortage of scientists and medical microbiologists with the necessary expertise to have confidence to use them [Amyes, I p2; Pub Health Med Env Grp, I p114].


3.26 There is shortage of expertise in both primary and secondary care in identifying and managing unusual infection and in being able to understand laboratory diagnosis and manage clinically. In addition, laboratory expertise needs to be developed in order to benefit from advances in diagnostic technologies. We make recommendations in chapter 7 on training and chapter 8 on research and development.

3.27 We also conclude that there should be better understanding of how organisation of services, social issues and human behaviour impact on diagnosis and treatment outcomes. We discuss this further in chapter 8.

10   Smolinski, Hamburg and Lederberg (eds). Microbial Threats to Health: Emergence, Detection, and Response. Institute of Medicine Committee on Emerging Microbial Threats to Health in the 21st Century. [] Back

11   Latent TB is where someone is infected with TB bacteria but has fought it sufficiently to prevent it from causing symptoms. People with latent TB cannot spread TB to others and do not feel ill but it can develop into active TB at a later stage. When active TB causes illness and may spread to others. Back

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