Select Committee on Health Appendices to the Minutes of Evidence


Attachment 8

UNEXPLAINED DEATHS AND SEVERE ILLNESS IN INJECTING DRUG USERS IN THE UNITED KINGDOM AND IRISH REPUBLIC: APRIL TO JULY 2000

PUBLIC HEALTH IMPORTANCE

  Unexplained outbreaks of illness may occur suddenly. Effective investigation and control of such incidents usually requires an alert health professional who raises the alarm. This is followed by a co-ordinated public health response that has to be rapid, multi-sectoral, and multi-agency, sometimes operating at international, national and regional as well as local levels of organisation. The current investigation of unexplained deaths and severe illness in injecting drug users (IDUs), which is still ongoing, is a potent example of the organisational challenge posed by such incidents.

  In early May of this year, a microbiologist in a Glasgow hospital alerted local public health doctors to an unusual and severe fatal illness in a number of injecting drug users, that had not been seen previously. An intensive public health investigation began in Scotland involving dozens of clinicians, microbiologists, pathologists, and public health staff, working closely with police and services for IDUs. By mid-May, between 20 and 30 cases had been recognised including 10 deaths.

  The PHLS was kept informed about the evolving outbreak in Glasgow and began providing reference and expert microbiological support. In the third week of May, the PHLS asked Consultants in Communicable Disease Control throughout England and Wales to liaise with medical staff locally to see whether illnesses in IDUs, similar to those in Scotland, were being seen. An "early warning" was circulated to competent authorities throughout the European Union to encourage active case finding in other countries. These messages were reinforced through scientific updates in surveillance bulletins that are disseminated widely.

  By 30 June, investigators had identified 91 IDUs in Scotland (49), Ireland (19) and England (23) with injection-site soft tissue inflammation and signs of severe systemic infection resulting in hospitalisation or death; 40 (45 per cent) have died. Recognition of separate clusters of cases in Dublin and North West England have led to intense local investigations which complement the ongoing national and international collaboration. Upon becoming aware of the outbreak of unexplained illness, the Centres for Disease Control (CDC) in the United States offered to assist the investigators. The investigation became trans-Atlantic when this offer was accepted.

  A large number of different bacteria, most of which are normally found on the skin or in the gut, were isolated from the cases. Special laboratory efforts were required to rule out anthrax infection as an IDU in Norway had died from this infection earlier in the year. The features of the illness, however, suggested an infection by a toxin producing bacteria in the muscle into which heroin and been injected. Some of the clostridia family of "anaerobic" bacteria, that require an absence of oxygen to grow, can produce these powerful toxins. After many days of painstaking work on specimens transported to PHLS reference laboratories in Colindale and Cardiff and to the CDC in the US, Clostridium novyi type A has been isolated from a number of the cases. This particular bacterium can exist for years in dust or soil as dormant spores that only become activated when conditions are right.

  The most likely source of infection seems to be contaminated heroin but this hypothesis has yet to be confirmed. Clinical, epidemiological, and laboratory investigations continue to further characterise these illnesses, confirm the role of C.novyi as the etiologic agent, identify risk factors for the syndrome, and to suggest preventive measures. Surveillance activities to identify additional cases in the United Kingdom and Ireland are ongoing, and efforts to find cases in the rest of Europe or the United States have been expanded.

COLLABORATING AGENCIES, ORGANISATIONS AND INSTITUTIONS INCLUDE:

    —  The PHLS in England and Wales, and the CDC in the United States are both providing reference and research microbiological facilities for the investigating collaborators.

    —  The PHLS together with public health colleagues in the North West are co-ordinating clinical and epidemiological investigations in England and Wales.

    —  Greater Glasgow Health Board and the Scottish Centre for Infection and Environmental Health are co-ordinating clinical, epidemiological and microbiological investigations in Scotland.

    —  The National Disease Surveillance Centre and the Eastern Health Board are co-ordinating clinical, epidemiological and microbiological investigations in the Irish Republic.

    —  Case ascertainment in other EU countries is being pursued through the EU Network for communicable diseases and participants in the European Programme for Intervention Epidemiology Training programme for field epidemiology.

    —  Other groups contributing to the investigation include local Police Services in England and Scotland, the Home Office, the Drug Tsar's Office, Drug Information Services, local Drug Action Teams, Centre for Applied Microbiology and Research, Guy's and St Thomas' Medical Toxicology Unit.

ORGANISATIONAL ISSUES

  This outbreak illustrates the constant threat of communicable diseases and the importance of maintaining and developing the capacity and expertise required to respond rapidly when an infection emerges unexpectedly. In these circumstances public health and microbiological resource have to be mobilised rapidly so that bodies such as the PHLS should be resourced to provide "surge capacity". Insofar as is possible it is also essential to maintain and develop channels of communication between all levels of those agencies that are likely to have to work together in an investigation. Inter-agency collaboration occurs best when there is mutual respect between highly professional organisations that have a clear purpose that is readily understood by the other agencies likely to become involved. Concerns about patient confidentiality complicate data and information exchange between laboratories and surveillance centres. There does not, as yet, seem to be a simple solution that will ensure confidentiality and yet allow daily exchange of updated information between several centres in several countries. Appropriate health care professionals in these exceptional circumstances should given consideration to the use of patient name as a genuinely unique identifier.

  Prepared by Drs Tamara Djuretic, Noel Gill, Rob George, Public Health Laboratory Service.


 
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Prepared 28 March 2001