Viral Haemorrhagic Fevers in Europe - Effective Control Requires a Co-ordinated Response
Published: 29.04.04 Updated: 30.07.2004 11:08:44
N.S. Crowcroft, D. Morgan, D. Brown, Public Health Laboratory Service, CDSC, London, United Kingdom
Viral haemorrhagic fevers (VHF) have attracted the attention of the medical world and general public for many reasons, some based in reality and more on misinformation. They are amongst the highest profile infections in the public mind, because they are thought to be highly infectious and to kill most of their victims in a dramatic way (1,2). To add to the intrigue, mysteries remain about the source of some of the viruses involved. They emerge and re-emerge in many countries, most recently Ebola in Uganda in 2000 (3) and Gabon in 2001/02 (4), and Congo-Crimean Haemorrhagic Fever (CCHF) in Kosovo (5) and Pakistan in 2001 (6). Large outbreaks have affected populations in endemic areas, living mainly in inaccessible areas or refugee camps where living conditions are very difficult. Poorly resourced medical facilities have played a role in amplifying transmission and infection control measures have been difficult or virtually impossible to establish. These viruses are likely to remain a threat until the reservoir is identified and as long as endemic areas are afflicted with ecological change, poverty and social instability. Recent events since September 11, 2001 remind us of their potential to be used as weapons, and that fear can present a risk to public health.
In this context, it is important that we have a rational response when a case is imported into an industrialised country. Although global travel allows such infections to occur in any part of the world, the potential for epidemic spread is low. Despite known breaches of guidance on infection control, none of the contacts of viral haemorrhagic fever imported into Europe since 1999 developed clinical illness. This recent experience in Europe confirms earlier findings about transmissibility (7). Lassa fever is a significant public health threat in West Africa, not in Europe (8). Marburg and Ebola, first described in 1967 and 1976 respectively, trigger more fear in Europe than CCHF, identified long before the others in 1944. CCHF presents more of an immediate public health risk since it is endemic in a far greater area, including the European Region.
Accurate risk assessment
For clinicians, an accurate risk assessment of a patient presenting with fever should be based on good medical intelligence. Medical intelligence means all sources of information including surveillance and up to date reports on the situation in endemic areas and precise mapping of epidemics. Improvements in telecommunications and unrestricted websites mean that more effective communication is now possible. The Communicable Disease Surveillance and Response division of WHO provides regular information on epidemics of infection, including VHFs. It is crucial that the information and alerts are as timely and accurate as possible and that information gets to clinicians who need to know. One of WHO's main means of creating global surveillance systems has been the development of a "network of networks" which links together existing local, regional and international networks. These include the WHO Global Response Team (9) as well as training programmes such as the European Programme for Intervention Epidemiology Training (EPIET) (10). In this way, global surveillance can trigger appropriate local and international action. The networks are important for sharing information and skills at a global level. Members of such response teams who come from non-endemic areas bring back valuable clinical and epidemiological experience to share with their colleagues. Support from member states and the European Commission for such response capacity is easily justified.
We need to raise awareness of the possibility of the diagnosis of VHF in front-line medical staff. Recently, bioterrorism has featured prominently in the European news and medical media. This should have heightened the awareness of healthcare professionals to unusual or exotic infections. We need to sustain this momentum.
There has been a failure in the past to develop a European response when faced with a suspected or proven case of VHF. In response to fears that Europe is not prepared for such infections, a network of virologists created the European Network for diagnostics of Imported Viral Diseases (ENIVD) funded by the European Commission (11,12). ENIVD has produced recommendations for management and control of VHF which are largely based on guidance developed by the US Centers for Disease Control and Prevention (13,14). These recommendations are available on the ENIVD website at www.enivd.de. Despite this initiative the papers in this edition of Eurosurveillance show that the management of cases of VHF vary greatly within Europe and this is partly linked to different local interpretation of legislation on containment of such dangerous pathogens. Communication with staff, the public, and national and international colleagues is the largest task facing teams managing cases of VHF imported into industrialised countries. Experts in virology, public health, field epidemiology, infectious diseases, and communication need to work together to produce a European capacity to respond to such incidents, including possible biological attack. Although each speciality has an important perspective to offer, multidisciplinary working has not been a strong feature of European networks. Perhaps this is something towards which we should now be working.
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- McCormick JB, Webb PA, Krebs JW, Johnson KM, Smith ES. A prospective study of the epidemiology and ecology of Lassa fever. J Infect Dis 1987 Mar;155(3):437-44
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- Management of Patients With Suspected Viral Hemorrhagic Fever. MMWR February 26, 1988 / 37(S-3);1-16
- to Readers Update: Management of Patients with Suspected Viral Hemorrhagic Fever - United States. MMWR June 30, 1995 / 44(25);475-479