Select Committee on Science and Technology Minutes of Evidence



Memorandum by the Academy of Medical Sciences

EXECUTIVE SUMMARY

  The major successes of the last century in the prevention and treatment of bacterial infection encouraged a belief that the essential problems had been solved and that infectious disease would largely be eliminated as a public health problem. It is now widely appreciated that this optimism was misplaced.

  We note that the committee wishes to limit the focus of the report. However, we believe that infectious diseases surveillance must have a global perspective, and to discuss the infection risks to the UK divorced from considerations of the problems of antibiotic resistance, or to focus on community-acquired rather than hospital-acquired infections would be a mistake.

  The answer to the question "which infectious diseases pose the biggest threats in the foreseeable future" is that because of evolution—which is essentially unpredictable—nobody knows.

  The UK has a relative paucity of infection specialists. There are large areas of the country where there is no local expertise. We are particularly concerned by the weakness in academic public health medicine in the UK, and in particular public health aspects of infection. We suggest that a targeted effort to strengthen this area, with both clinical and non-clinical scientists working together, is an urgent need.

  High quality national surveillance is the cornerstone of infectious diseases epidemiology. The CMO strategy proposes the abolition of the PHLS as a body concerned exclusively with infection. We have serious concerns that the proposals run the risk of destroying a national resource that, although not perfect, provided a coherent and valuable service.

  We have grave misgivings that transferring the R&D funds currently managed by the PHLS and other agencies into the general fund under the control of the NHS Director of R&D may undermine the public health function.

  There is an urgent need to strengthen the academic base of molecular microbiology, infectious diseases and public health epidemiology in the UK, to exploit existing strengths in vaccinology, and to invest in the new technologies that underpin modern molecular surveillance and diagnosis.

1.   Continuing importance of infectious diseases

  1.1  In 1970, the Surgeon-General of the United States of America indicated that it was "time to close the book on infectious diseases, [and] declare the war against pestilence won. . .". There is broad agreement that this optimism was premature. It is appropriate to restate the observations made last year by a working party of the Academy when reviewing academic medical bacteriology: (1)

    "The major successes of the last century in the prevention and treatment of bacterial infection encouraged a belief that the essential problems had been solved and that infectious disease would largely be eliminated as a public health problem.

    It is now widely appreciated that this optimism was misplaced. There is a long list of items of unfinished bacteriological business with clinical relevance in the UK and elsewhere. Familiar pathogens like Mycobacterium tuberculosis have not gone away, recent outbreaks showing how little we know about the routes of spread of the organism globally or even within the UK. New pathogens like Escherichia coli O157:H7 appear without warning and highlight the danger of spread of disease between farm animals and human populations. The development of multiple antibiotic resistance has transformed relatively benign infections into life-threatening diseases, particularly in the context of hospital acquired infections. Microbiological food poisoning has been unequivocally identified as a growing public health problem."

  Although the Academy's report was concerned with bacterial infections, virtually the same considerations apply to infections caused by viruses, parasites and fungi.

  1.2  It is important to note that the importance of infectious diseases extends considerably beyond those that are normally thought of as communicable diseases. While acute outbreaks of communicable ("contagious") infections continue to represent a real threat, it is becoming increasingly apparent that micro-organisms are also responsible for a wide range of chronic diseases. In developed countries such as the UK, it is arguable that these may make an even greater contribution to ill health and are a significant burden to the healthcare economy. We describe some of these conditions below.

  1.3  A recent WHO report summarised the global impact of infectious diseases:

    "Infectious diseases cause 63 per cent of all childhood deaths and 48 per cent of premature deaths. Many of these deaths are caused by epidemic infectious diseases such as cholera, meningococcal disease, and measles. There are continuing threats of large epidemics with widespread mortality like the `Spanish flu' epidemic in 1918-19 which killed an estimated 40 million people worldwide, or the HIV/AIDS epidemic which has caused widespread morbidity and mortality, and reversed hard-won gains in life expectancy in Africa." (2)

  Globally, the growth in mega-cities and the linear rise in travel between major cities world wide will act to increase not only the rate of evolution of new pathogens (population density is directly related to net rate of evolutionary change) but also the speed of spread city to city, and country to country.

  The Chief Medical Officer's Report, "Getting Ahead of the Curve", (3) emphasised that infection is no less of a problem in the UK, albeit of a different nature, for example:

    40 per cent of people consult a health professional each year because of infection;

    infections account for 70,000 deaths each year, 5,000 as a result of a hospital-acquired infection;

    the case notification rate for tuberculosis in Newham, London (123 per 100,000) is the same as that in India.

  Several factors contribute to the spread and control of infectious diseases. Examples are (a) the increased connectedness of cities and towns in the UK, with large numbers of people frequently travelling between major centres of population (b) increased population density in the major cities; (c) growth in arrivals from overseas via airports (d) frequency of movement of patients between hospital settings.

2.   Which infectious diseases represent the greatest threat?

  2.1  We note that the committee wishes to focus on UK health issues and is not primarily concerned with antimicrobial resistance, hospital-acquired infection, or sexually-transmitted infection. However, while we recognise that there are some geographically-restricted infections that are only rarely imported into the UK, we believe that infectious diseases surveillance must have a global perspective, and to ignore this would be a mistake. Similarly, to seek to identify the infection risks to the UK divorced from considerations of the problems of antibiotic resistance, or to focus on community-acquired rather than hospital-acquired infections would weaken the analysis. For instance, a recent study in a London renal unit of diabetic patients who had migrated to the UK from TB-endemic areas reported an incidence of TB of 1,187 cases per 100,000, more than twice the rate reported in Zimbabwe or Botswana, two of the countries with the highest rates in the world (4). Similarly, antibiotic-resistance is no longer a problem restricted to hospitals. Increasingly, patients are admitted from the community with infection caused by antibiotic-resistant organisms. The key to the successful control of infection and infectious diseases is a surveillance system that can successfully integrate these different strands.

  2.2  It is axiomatic that the answer to the question "which infectious diseases pose the biggest threats in the foreseeable future" is that because of evolution—which is essentially unpredictable—nobody knows. The prospect of new or much changed pathogens appearing is always very real. Such threats can only be countered by having a surveillance system with a broader remit than just coping with existing pathogens using existing tests. It must have flexibility and built-in capacity for innovation so that it can respond rapidly to new problems. Hence, rather than provide a list of specific infections that may be a risk in the foreseeable future, we think it would be more useful to describe differing risk groups, with some examples.

    —  Acute outbreaks of communicable diseases. These are the classic point-source outbreaks, often food or water borne. It is impossible to predict which organisms will be implicated; recent examples included Ecoli 0157 in Scotland and tuberculosis in Leicestershire. Both required prompt recognition and a major public health exercise to bring them under control. Currently there is inadequate understanding of why the patterns of these endemic infections have been changing. Without that understanding, control is impossible.

    —  Sporadic community acquired infection. Infections such as rotavirus diarrhoea and respiratory viral infections are usually not of great severity but represent a very considerable burden in terms of morbidity and days lost from school and work.

    —  Imported infections. Isolated episodes of rare infections require surveillance at the local level, but of more general concern is the potential for the rapid spread in the community of unusual types of common infections. Influenza A is a good example.

    —  Antibiotic resistance. The implications of this continuing problem have been addressed elsewhere and do not need re-stating here.

    —  Tuberculosis and HIV. These are singled out for mention because in both cases the potential for unappreciated spread in the community is considerable, and because both are evolving anti-microbial resistance which requires careful monitoring.

    —  Bioterrorism.

    —  Chronic diseases. Micro-organisms have been clearly implicated in the pathogenesis of several chronic diseases including peptic ulcers and some forms of cancer. In addition, evidence is accumulating that they may also be involved in conditions as diverse as coronary heart disease and multiple sclerosis.

3.   Diagnosis and surveillance of infection

  3.1  Individual cases of infection are diagnosed by a doctor or other healthcare professional; surveillance refers to recognition of trends or outbreaks of infection in the community. Both are areas of concern.

  3.2  The UK has a relative paucity of infection specialists. There are approximately 350 microbiologists and about 80 infectious diseases physicians in England and Wales, fewer per head of population than are found in many European countries and in particular in the United States. Many of these specialists are congregated in tertiary centres so that there are large areas of the country where there is no local expertise. Furthermore, there is a national shortage of public health doctors, and relatively few of those that are in post have a particular interest in infectious diseases epidemiology. Of course, most infections are diagnosed and treated by non-specialists and that is perfectly appropriate, but the lack of specific expertise means that there is a risk that potentially significant events will be overlooked until a major outbreak becomes apparent.

  3.3 High quality national surveillance is the cornerstone of infectious diseases epidemiology. To quote the WHO again:

    "it is clear that effective public health surveillance is critical for the early detection and prevention of epidemics. There is a clear and urgent need for surveillance of (i) known existing communicable diseases, especially those with high epidemic potential, (ii) early recognition of new infections (over 20 new pathogens have been discovered since the mid-1970s), and (iii) monitoring the growing resistance to antimicrobial drugs". (2)

  The UK has benefited from a particularly strong surveillance network, largely based around the Public Health Laboratory Service. However, as noted in the CMO's report, a number of other agencies also play a key role including local authorities, parts of the NHS and several other national bodies such as the Environment Agency and DEFRA. This has resulted in fragmentation and duplication of the surveillance function, resulting in inevitable inefficiencies. It is only necessary to consider a simple scenario—an outbreak of gastroenteritis at a school, for example—to realise that this will potentially involve the local authority, the DPH of the primary care trust, the hospital microbiology laboratory, the Food Standard Agency, and the Central Public Health Laboratory at Colindale. Although these agencies have a good record of collaboration, the potential for problems developing is clear.

  3.4  Surveillance of human infectious disease is done better in the UK than in most other countries. However, it falls far short of what is achievable with current methods. The main deficiencies are (i) an excessive reliance on reactive surveillance. This is well illustrated in the DH document "Action to strengthen the microbiology function in the prevention and control of infectious diseases", which restricts itself exclusively to this topic. (ii) The fragmented nature of the surveillance network in the UK. It feeds on the rivalries that inevitably exist between agencies eg between different government departments, and between the NHS and universities. Surveillance of zoonoses is a good example, eg reference laboratories for Ecoli O157 are funded on the basis of the host species rather than the microbe; human and veterinary laboratory surveillance is not "joined up". Funding for surveillance is often driven by political pressure rather than by health needs, eg there is no comprehensive UK laboratory surveillance of Campylobacter (about 50k infections reported annually) but there are two Ecoli O157 reference laboratories (about 1.5k infections reported annually).

  3.5  The CMO strategy proposes the abolition of the PHLS as a body concerned exclusively with infection. We would caution that there are some risks associated with this strategy. The transfer of PHLS laboratories to the NHS is being done at breakneck speed. The reason for this is unclear. Its impact on surveillance will be negative. It destroys a network of laboratories with the public health function at their core. While we support the proposal that the PHLS should focus on its core activities of providing a national reference and surveillance function, rather than supporting routine diagnostic services in the NHS, it should be recognised that the "bread and butter" of national surveillance will still need to come from local microbiology laboratories, and if this public health function of NHS laboratories is not clearly identified and funded, and made a statutory responsibility, then much damage could be done. It is improbable that NHS hospital managers will give this the priority that it received from the PHLS. Inevitably, they will focus on diagnostic work for patient management rather than surveillance or outbreak control.

  3.6  We are on the verge of very major development in diagnostic technology. Details of the entire microbial genome are already available for some common pathogens, and others will soon follow. This information, coupled with newer genetic screening techniques will mean that rapid and precise identification of micro-organisms—even in GP surgeries—will have a major impact on our ability to track outbreaks of infectious diseases. In particular, it is important that we make significant investment in IT software to track unusual changes in the frequency and spatial distribution of morbidity and mortality events—virtually none is in use at present—although other developed countries have begun to invest heavily in this area. The digital patient records at primary health care settings act as a possible sentinel tool (the NHS Direct database). However development and implementation of these approaches will take a commitment of resource that at present does not seem to be available.

4.   Vaccines

  4.1  The UK has a good record on immunisation policy and practice, and such problems as there are at present are related to public perception rather than failure of process.

  4.2  Vaccines have made and will continue to make a significant impact on reducing the burden of infection. In global terms, the most important vaccines that need to become available are against malaria, HIV and tuberculosis.

  4.3  Sequencing of microbial genomes provides new and important opportunities for the rational design of vaccines. It is critical that the UK research community continues to make important contributions to this field, as it has done in the past. The Academy's report on Academic Medical Bacteriology draws attention to this and makes a number of specific recommendations.

  4.4  Advances in immunology and molecular biology provide a basis for developing novel vaccines for many infectious diseases. The UK has particular strengths in the area of vaccine development and could play a major role in developing new vaccines for AIDS, malaria and tuberculosis as well as other diseases, were adequate funding available.

5.   Research and training issues

  5.1  The Academy has previously drawn attention to the relatively weak state of academic bacteriology in the UK, and there is an urgent need to attract more high quality scientists into this area—including some with statistical, mathematical and molecular/genetic skills to improve the rigour of infectious disease epidemiology research, surveillance and control. We note with concern that the CMO report suggests that research and development funds currently managed by the PHLS and other agencies should be incorporated into the general fund under the control of the NHS Director of R&D. We have grave misgivings that this will further undermine the ability to capitalise on recent developments in diagnostic technology and will undermine the public heath function.

  5.2  Britain has an excellent track record in basic research on pathogens. For example, our fundamental work over the years on TSEs and animal pathogens like FMD has been, and is, of international quality. But our ability to link this work to policy has been dismal, as shown by BSE/vCJD and the 2001 FMD outbreak.It is vital that lessons must be learned from these events. Policy makers must learn how to make the best use of scientific information. BSE and FMD also showed the importance of linking policy making with accurate field knowledge. The PHLS played a very important role over the years in the generation, assessment, and promulgation of scientific knowledge and, through its network of laboratories, the collection and interpretation of local data, events and issues. We have grave concerns that replacing it with public health services whose levels and costs "will be the subject of service level agreements . . . normally . . . sustain(ing) existing service commitments" runs the risk of destroying a national resource that, although not perfect, provided a coherent and valuable service.

  5.3  We are particularly concerned by the weakness in academic public health medicine in the UK, and in particular public health aspects of infection. Academic departments of public health medicine with a focus on infection are very few in number, and the CMO report has thrown the whole area into turmoil. We suggest that a targeted effort to strengthen this area, with both clinical and non-clinical scientists working together, is an urgent need.

  5.4  The training function of the PHLS will disappear. This will be a major loss to UK medical microbiology; doctors and scientists with expertise, experience, and an interest in public health microbiology will in future emerge only capriciously and randomly through factors like personal interest. The training of medical microbiologists with broader interests than the diagnosis of infection and the provision of advice on therapy is already in very serious difficulties in the UK because of the collapse of academic bacteriology.

  5.5  Deans of medical schools need to be encouraged to recognise that public health aspects of medicine are a core component of the undergraduate curriculum and to ensure that sufficient time is devoted to this area.

REFERENCES
  (1)   Academic Medical Bacteriology in the 21st Century. A report of the Academy of Medical Sciences, July 2001.

  (2)  WHO Report on Global Surveillance of Epidemic-Prone Infectious Diseases. WHO/CDS/CSR/ISR/2000.1

  (3)   Getting Ahead of the curve—a strategy for infectious diseases (including other aspects of health protection). Department of Health, June 2002.

  (4)  Moore DA, Lightstone L, Javid D et al. Emerg Infect Dis 2002 8: 77-78

This response has been prepared for the Academy by a working group overseen by Professor Jonathan Cohen, FMedSci, Dean, Brighton & Sussex Medical School, the University of Brighton. The members of the group included Academy Fellows Professor Roy Anderson, Professor Adrian Hill, Professor Hugh Pennington and Professor Patrick Sissons.

The document was approved by the Officers of the Academy.


 
previous page contents next page

House of Lords home page Parliament home page House of Commons home page search page enquiries index

© Parliamentary copyright 2003