Select Committee on Science and Technology Fourth Report


Chapter summary

Surveillance should ultimately underpin and inform the diagnosis, treatment, prevention and control of infection. We argue that this activity could be improved by ensuring that laboratories are sufficiently well funded to carry out surveillance work. In addition there is need to use a wider range of innovative techniques for collating and analysing information. We also recommend that surveillance of human, animal and food-borne infection should be more integrated in order to provide important information about likely outbreaks.

What is surveillance?

"Surveillance should be the life-blood that powers clinical practice and public safety" [Dr Black, I p28].

5.1 Surveillance is the "ongoing systematic collection, collation, analysis, and interpretation of data and the dissemination of information to those who need to know in order that action may be taken" [ref]. It is needed in order take informed action to counter the spread of infectious disease at local, national and international levels. It also can determine the effectiveness of interventions and guide policy in preventing future outbreaks [Assoc Brit Pharm Ind, I p5; Assoc Clin Microb, I p15]. We provide an overview of the surveillance process in relation to influenza in Box 12 (p28).

Surveillance at present

5.2 Surveillance is mostly based on notifications of clinical disease and laboratory reports. Doctors are legally obliged to notify the authorities of certain infections or symptoms (tuberculosis, food poisoning symptoms for example)[13]. We understand that the Government is currently addressing this and we look forward to seeing their proposals in the near future. This is sent to the local authority's "proper officer", usually the CCDC. Laboratory reports on relevant micro-organisms are also sent to the CCDC. Reports of other infections are made on a discretionary basis because of their perceived value, for example notification of HIV/AIDS.

5.3 The completeness of surveillance does not appear to depend on a legal requirement. Some conditions for which there are legal requirements to report are inadequately reported, for example symptoms of food poisoning. HIV reporting, for which there is no legal reporting requirement, appears to be effective. It is important that the system is seen by those providing reports to produce information relevant to their clinical practice [Seminar, II p378].

5.4 Microbiology laboratories play a crucial role in surveillance by providing reports on micro-organisms to CCDCs and by sending on information and samples for more detailed analysis to national reference laboratories (managed by the HPA). Representative information of infection can be effectively provided through a network of laboratories. These local laboratories involved in reporting information to national reference laboratories can also help in responding to emerging threats [Assoc Med Microb II, p70-1].
Box 9

Surveillance: building a picture of burden of infection

Sending samples to laboratories not only provides information about how to treat a particular patient but is also an essential component of the body of information about types and levels of infection present in the community. The Consultant in Communicable Disease Control collates all information about cases of infection and sends it to the Communicable Disease Surveillance Centre (CDSC - part of the Health Protection Agency) via the Regional Epidemiologist (RE). The RE and CDSC routinely look at the pattern of infectious disease to detect untoward events. Information is also collected on numbers of children who have been immunised.

5.5 We heard that surveillance in England has developed in a somewhat ad hoc manner [Pub Health Med Env Group, II p113; Pennington, I p121], but we also heard that the surveillance network, which was largely based around the Public Health Laboratory Service (PHLS) (this function has been incorporated in the HPA, see Box 6) is well regarded internationally [Amyes, I, p1; BioIndustry Assoc I, p26; USA, II p385].

5.6 However, there are concerns regarding surveillance. Many of those concerns could be addressed by designing better information systems and providing information technology and we address this in chapter six. We turn here to consider other concerns, particularly that:

·  Laboratories, particularly those run by the NHS, have not always met their obligations by contributing surveillance information and sending samples on to reference laboratories;

·  Surveillance information does not provide a representative picture of infection;

·  Potential innovative sources of information and methods for analysing information are under-used;

·  Information is not shared between all those responsible for surveillance.

Maintaining the information base: public health laboratories

5.7 Some of our witnesses were concerned that laboratories have not always discharged their public health obligations effectively and may not do so in the future following the transfer of the majority of former public health laboratories to NHS Trust management[14] [Bradford MDC, I p34-5; Hawker, II p116, Kesley, Q142]. Under the new set-up laboratory support for public health at local level will be provided by these local NHS laboratories with support from the HPA's regional laboratories[15].

5.8 Laboratories which had a public health focus will now be managed by NHS Trusts, whose primary focus is the clinical care of patients [Faculty Pub Health Med, I p55; Lachmann, Q75; Sheffield, I p151]. Public health and clinical medicine are by no means incompatible but effective public health may require laboratories to carry out tests in addition to those that would be necessary for clinical diagnosis. For example, as part of infection control, it may be necessary to see whether strains of an infection are from the same source, or whether people who appear well are carriers of, or have been exposed to infection.

5.9 Of particular concern is the Department of Health's statement, that part of NHS laboratory funding will be removed and redistributed to Primary Care Trusts (PCTs) as part of general allocations in 2004; and that laboratory funding for public health work will be guaranteed at its present level only until March 2005 [Minister Blears, Q879; PHLS, II p137]. This would provide PCTs with significant additional responsibility for public health aspects of infectious disease [Spencer, Q152; see ch 9].

5.10 We heard that laboratories specialising in food, water and environmental microbiology provide an essential service, working closely with local CCDCs, EHOs and the food and water industries [Bradford MDC, I p34-5; Food Standards Agency, I p64]. We are concerned that the position of this essential component of the response to infectious disease might be threatened. This is of particular concern if funding comes through PCTs, which are primarily concerned with providing clinical services related to human infection [PHLS, II p137].

5.11 We heard that the ability to direct activity within a managed network of laboratories, such as existed under the PHLS, was beneficial [Faculty Pub Health Med, I p53; PHLS South West, I p133]. Managed networks allow resources to be directed towards current problems in a coordinated manner. For example, a wide variety of laboratories across the country could be directed to sample for a particular organism of concern, as occurred with E coli O157. Such networks provide surge support.

5.12 We were concerned to find that, given the significant demands placed on NHS trusts to fulfil their clinical role, there were no plans as of yet to provide any material incentive for NHS laboratories to rise to the public health challenge [PHLS, II p137]. We note that the House of Commons Health Committee report on Sexual Health[16] recently expressed concern in relation to the impact of recent changes to management of laboratories on surveillance of sexually transmitted infections.

5.13 We believe that it is important that the essential functions described above are not disrupted as a result of the recent transfer of some public health laboratories to NHS Trust control. Changes in management structure and funding streams can easily cause disruption and this would be unacceptable in relation to surveillance and the public health function.

5.14 We recommend that the Department of Health should ensure that Primary Care Trusts provide NHS laboratories with at least the same level of extra resources for public health work (including food, water and environmental activity) that was previously received through the Public Health Laboratory Service.

5.15 We recommend that the Department of Health ensures that microbiology laboratories managed by the HPA and NHS Trusts act in a coordinated manner to deliver effective surveillance and to provide surge capacity.

Surveillance is unrepresentative

5.16 Concerns that surveillance information is unrepresentative of the incidence of infection fall into three categories: that there is too much reliance on passive surveillance; that priorities based on health care need have not been set; and that infection is under-reported.


5.17 Much surveillance relies on a report of disease following diagnosis (passive surveillance) [Little, Q376]. An alternative method of surveillance is to seek patients who display a set of symptoms (active surveillance). This allows more cases of infection to be detected rather than relying on formal reports [Br Infect Soc, I p37; PHLS, II p143].


5.18 Surveillance systems are not based on priorities or health care need [Inf Control Nurses Assoc, II p176; Williams, Q383-5]. For example, campylobacter, a bacterial infection causing diarrhoea, resulted in 63,000 laboratory confirmed cases in 2001 and, according to the Food Standards Agency and Institute of Food Research, is likely to pose an increasing threat in the foreseeable future [I, p63, Inst Food Res, II p383]. However, because there is no priority-setting there is no comprehensive UK laboratory surveillance of campylobacter [Pennington, I p121]. E coli O157 leads to much more serious symptoms than campylobacter but is much less common with only about 1,500 infections reported annually, yet there are two E coli O157 reference laboratories [AcMedSci, II p35].

5.19 There should also be connections between surveillance and vaccination. Continued surveillance is necessary to provide information both about the incidence of side-effects following vaccination and of the efficacy of vaccination programmes in controlling infection [CAMR, I p42; Crowcroft, I p45-9; see para 4.5].

5.20 We recommend that the Government should fund enhanced surveillance of the impact of vaccine programmes on the incidence of disease particularly when new vaccines are introduced.


5.21 We heard repeatedly that GPs, and other front-line staff, are an excellent yet under-exploited source of surveillance information. However, they are often unsure about the link between contributing to surveillance and being able to improve patient care [Black, I p30; Beeching, II p49; Faculty Pub Health Med, I p53Gelletlie, Q241]. Professor Little spoke about the need to provide primary care workers with a better understanding of the importance of contributing to surveillance [Q395; see also chapter 7]. In addition, those that provide information should receive better and more timely feedback about relevant current findings as a result of surveillance [Beeching, II p49; Monk, Q244; see ch 6].


5.22 There are some innovative approaches to gathering information from GPs, such as the population-based Royal College of General Practice's sentinel surveillance in primary care. This is based on information about incidence of disease recorded in GP practices across the UK [Little, Q370]. Sentinel surveillance in primary care can provide a framework within which more precise sampling for specific enhanced surveillance objectives can occur (guided by issues such as socio-demographic representation, seasonal variation, required precision and cost) [Catchpole Q629; Haworth, I p75; Little, Q370; Pattison, Q652; Birmingham, II p394].

5.23 We heard that developing enhanced sentinel surveillance would significantly increase the workload in the practices involved. It may be that it would be desirable to spread the workload of enhanced surveillance between practices, with different sentinel practices taking responsibility for different infections [Birmingham, II p394].

5.24 We commend the Royal College of General Practice for its sentinel practice initiatives and would like to see the scheme extended.

Innovative systems, sources and analysis of information

5.25 There is a wide variety of information from different sources that would be useful to better understand the prevalence and degree of infection [AcMedSci, II p48; Hawker, II p117; Inf Control Nurses Assoc, II p176; Little, Q709; Paton, II p258]. For example, there is some surveillance activity based on information held by NHS Direct [Zambon, Q214], although we heard that if this were to include geographical location of callers it would be improved as it would provide information about geographical incidence of infection [Black, I p31]

5.26 We note that many people now approach pharmacists or alternative therapists to obtain advice about ailments. It would be useful to develop systems to capture information from sources such as these, as well as others, such as figures of school absenteeism, attendance at accident and emergency units and water utility customer complaints [Black, I p34, Griffiths, Q221; Mowat, I p113; Stewart, II p319].

5.27 Furthermore, many clinicians diagnose infection on the basis of symptoms rather than laboratory analysis [Spencer, Q159]. As we suggest in the previous chapter, this is, in cases of common infection, desirable. However, we heard that the current surveillance systems do not facilitate reporting on the basis of symptoms alone [Kelsey, Q161]. Developing systems where syndromes could be reported would be particularly useful in those cases where a micro-organism has not yet been isolated, for example with "severe community acquired pneumonia" [Beeching, I p49; Black, I p32-3; Zambon, Q193].

5.28 In addition to innovative sources of information there are a number of powerful analytical techniques used in other settings such as meteorological and financial forecasting that are not currently used in fighting infection. They could be adopted to develop forecasts of outbreaks and spread of infection [PHLS, p139]. Innovations in this area could improve our understanding of infection and hence delivery of services and we discuss the need for research to explore such options in chapter seven.

Integrating surveillance


5.29 In order to develop understanding of infectious disease it is necessary to gather information not only about incidence of infection in humans but also about food and water-borne infection and zoonoses (animal infections that transmit to humans). Furthermore, infectious disease does not occur in isolation from other countries [Duerden, Q322; Nicoll, II p160; Salmon, II p 287]. Sharing of information on an international basis informs knowledge about infection on a global scale. International surveillance provides warning about likely occurrence of infection and can therefore inform, in a timely manner, control measures in this country [Troop, Q818-9].

5.30 The wide variety of relevant information means that a number of organisations must play a role in surveillance [see Box 15]. Responsibility for surveillance across the United Kingdom is spread between relevant administrative offices. The HPA has overall responsibility for surveillance in England, some responsibility in Wales and has a Service Level Agreement with Northern Ireland. The National Public Health Service for Wales, with responsibility for surveillance in Wales, reports to the National Assembly for Wales. The formal links between the HPA and different Government departments and agencies are as yet unclear [Salmon, Q699]. We discuss this further in chapter nine.


5.31 A significant amount of evidence flagged up the importance of zoonoses, warning that "we neglect the study of animal sources of infection at our peril" [Humphrey, II p366; Soc General Microb, I p157; Uni Edinburgh, I p169]. We heard that many emerging human infections are zoonotic and in order to predict possible outbreaks more accurately it is essential to have good collaboration between specialists in human and animal infection [Faculty Pub Health Med, I p56; Pennington, I p121; Thorns, Q431, see Box 1, 10, 11]. For example we heard in the USA that it was imperative for experts in animal and human infection to share surveillance information about West Nile fever (a mosquito borne infection which is also carried by birds) [USA, II p390].

5.32 Responsibility for surveillance of zoonoses is spread across a number of different agencies, which rely on different databases [CAMR, I p42; Thorms, Q438;]. For example, samples of Salmonella enteritidis phage-type 4 disease (a zoonosis which causes diarrhoea) may be investigated by one or more microbiology laboratories run by different agencies, yet these laboratories cannot share information as they do not have common datasets or standards [CAMR, I p42; Kealy, I p98].
Box 10

Role of wild animals in infection

Tick and mosquitoes borne encephalitides can lead to severe disease in humans and horses. The West Nile virus which occurs in migrating birds and mosquitoes has become a significant problem recently in the USA.

Rabies is one of the most serious infections carried by wild animals and is endemic in many parts of the world in dogs and wild carnivores.

Lyme disease occurs in wild rodents and deer and is transmitted to humans by ticks.

Ebola virus is severe and usually fatal and transmitted from primates. May be imported into the UK by travellers or primate carcasses.

5.33 Surveillance of infection in animals is usually driven by concerns over the economic impact of infection in animal rather than public health [Thorns, Q208]. Therefore, an organism which does not cause an animal ill-health and has no adverse economic impact in relation to agriculture, such as campylobacter, is often not investigated, even though it may cause considerable illness in humans [Food Standards Agency, I p64]. Some witnesses were also concerned about the lack of surveillance of companion and wild animals, which are a significant potential source of infection [BMA, I p 39; Reilly, Thorns, Q432-3; see Box 10, 11]. This could be an increasing problem as dogs and cats may now travel overseas with their owners under the PETS scheme and do not undergo quarantine on leaving or returning to the UK [BMA, I p39].

Box 11

Role of companion animals in infection

Infections carried by companion animals include:

Visual or ocular larva migrans is carried by dogs infected with a roundworm. Fouling in public parks, playgrounds by dogs is a significant source of infection in children and can lead to visual impairment.

Cat Scratch Fever is common in cats and though human infection is self limiting it may be severe in immunocompromised individuals.

Campylobacter is common in dogs and cats and one of the main sources of companion animal derived food poisoning in the UK.

Salmonellosis is common in terrapins and causes many cases of human salmonella.

Monkeypox. In June 2003 Centers for Disease Control and Prevention (a US Federal Agency) received reports of patients with a febrile rash illness who had close contact with pet prairie dogs and other animals. Laboratory testing at CDC indicated that the causative agent was Monkey pox virus, a virus not previously seen in the US. 53 cases had been investigated in Illinois, Indiana, and Wisconsin so far. This outbreak has been traced to pet prairie dogs exposed to infected Gambian giant rats imported from Ghana in April 2003 to a wildlife importer in Texas.

5.34 Concern was also expressed that surveillance of food borne infection should be better integrated [Assoc Brit Pharma Industry, I p9; O'Brien, I p119]. A variety of organisations are responsible for reducing risk of food-borne infection. The local authorities, the Food Standards Agency, CCDCs and others are involved in gathering information [CAMR, I p42; AcMedSci, II p47; Emery, Monk, Q229; Humphrey, II p366].

5.35 The Government has recently attempted to coordinate surveillance across departments through holding some cross-departmental meetings [Minister Ms Blears, Q840]. We welcome these developments.

5.36 However, the Faculty of Public Health Medicine (a Faculty of the Royal Colleges of Physicians) when they warn that "despite the experience of BSE and foot and mouth disease, the degree of joined-up working needs further improvement" [I p56]. The Faculty suggests introducing joint work programmes on animal and human health which would need budgets for surveillance and control at regional and local levels.

5.37 We heard repeatedly throughout the inquiry that better exchange of surveillance information and improving links between experts and health professionals in animal and human infection was fundamental to improving response to infectious disease [Kealy, I p97, see above paragraphs also].

5.38 We recommend that the HPA be provided with resources to take on specific and primary responsibility for integrating surveillance related to human, animal and food-borne infection at national, regional and local levels in order to bridge the gaps that currently exist between these areas of speciality.

Box 12: Surveillance of influenza

13   A number of witnesses referred to the need to revise public health legislation. We are pleased to see that the Government intend to address this shortly (see House of Commons Hansard, 12th May, 109W). In particular we refer the reader to Dr Monaghan's overview and recommendations on this subject [I, p105-113]. Back

14   This took place in 1st April 2003 with the establishment of the HPA. Back

15   Getting Ahead of the Curve (January 2002): the Chief Medical Officer's Strategy for infectious disease and other aspects of health protection:

Health Protection: a Consultation Document on creating a health protection agency (June 2002). Back

16   Sexual Health, House of Commons Health Select Committee, Fourth Report Session 2002-03, HC 69. Back

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