Current management of patients with Viral Haemorrhagic Fevers in the United Kingdom

➤ des personnes ayant eu des contacts rapprochés avec le patient deux jours avant l’apparition des symptômes ou durant la maladie, de même que le personnel de laboratoire. La méthode ELISA ou le test d’immunofluorescence n’ont identifié aucun anticorps anti-Ebola chez les 74 contacts (3). On peut souligner que le patient souffrait d’une infection relativement aiguë, avec diarrhée, vomissements et atteinte du système nerveux central, mais sans aucun signe ou symptôme hémorragique, et qu’aucune procédure de laboratoire spéciale n’avait été mise en place. Cependant il n’y a pas eu d’autre contamination (3).


Gestion actuelle des patients atteints de fièvres hémorragiques virales au Royaume-Uni
In the UK, suspected and confirmed cases of viral haemorrhagic fever are currently managed according to the 1996 Guidance of the Advisory Committee on Dangerous Pathogens, which describes an approach to the risk categorisation of suspected cases.It also provides guidance on patient management including transfer, laboratory investigations, infection control, and monitoring of contacts based on the risk assessment.Confirmed cases are managed in bed isolators ("Trexler units"), two of which are available in high security infectious disease units in the UK.This guidance is under review and may change.Recent experience has shown that communication and reassurance for health care workers and the public are major tasks in managing such cases.

Aspects microbiologiques
Le paludisme doit être exclu par les procédures habituelles mais les autres analyses microbiologiques doivent être suspendues en attendant le diagnostic.Chez les patients pour qui le diagnostic de paludisme n'est pas confirmé, des ➤ I n the UK, suspected and confirmed cases of viral haemorrhagic fever (VHF) are managed according to the document produced by the Advisory Committee on Dangerous Pathogens (ACDP) called the "Management and Control of Viral Haemorrhagic Fevers" which was published in 1996 (1).As the name suggests, these are comprehensive guidelines.The ACDP is currently reviewing the UK guidance in the light of the experience gained from recent European cases to ensure that safety is maintained while optimising provision of modern medical care for such patients (2).

Transfer of patients from endemic areas into UK
People suffering from VHF should be treated in the endemic area if the medical facilities in that country are favourable.However, instances do arise when it becomes necessary to transport a confirmed or suspected case to a non-endemic area and contingency plans exist for this procedure.Air ambulances carrying suspected cases of VHF (eg febrile patients from an endemic area) are required to inform the port health authority at the airport before arriving in the UK.Similarly, when patients become ill on a passenger flight into the UK, port health should be informed.Patients suspected of being at high risk of having a VHF should ideally be transported in the aeroplane in a high security isolator and received into a high security ambulance on arrival in the UK before transfer to an infectious diseases unit with provision for high security isolation.There are two high security infectious disease units (HSIDU) in the UK.One is at Coppett's Wood Hospital in London.The other is located at Newcastle General Hospital in the north of England, to serve cases arriving in Scotland, the north England and Northern Ireland.On average, less than one patient per year is managed in such a unit.The highest volumes of air traffic occur between endemic areas and London, so the most likely points of arrival are Gatwick and Heathrow airports.In addition, London has several infectious disease units to which such patients may be referred for investigation of undiagnosed fever.

Categorisation of risk
Pending confirmation of diagnosis, patients are categorised as low, moderate, and high risk (table 1).The risk categorisation changes as more information, or results of tests become available.All high risk patients should be referred immediately to a HSIDU.Problems have been identified with the case definitions since the guidance was developed (3).As HSIDUs are not overwhelmed with referrals, it seems that most clinicians do not follow the guidance exactly and many front-line clinicians may not be aware of them.The case definitions may be simplified following the current review of UK guidance.

Investigation of patients
Laboratory investigation should be minimised until the diagnosis is established.The priority is to examine samples for malaria as this is the likeliest diagnosis.Safe methods to conduct these investigations are described in the memorandum.

Management of confirmed cases of VHF
UK guidance is that confirmed cases should be managed in a high security isolator bed (Trexler unit).This requirement is based on UK interpretation of European legislation on the control of such dangerous pathogens (category 4) though Control of Substances Hazardous to Health legislation.It is an engineering solution which contains all infectious material by containing the patient (as well as waste and other potential infectious materials).Such a unit therefore protects everyone, in contrast to suited units which offer personal protection to the wearer of the suit only.All personnel who would be expected to use the facility should received regular training in its use (every 3 months is suggested).Use of containment measures which provide only personal protection is acceptable under current legislation only if there is no alternative way of managing a particular patient.

Laboratory aspects
Malaria should be ruled out using normal procedures but other laboratory investigations should be postponed awaiting the diagnosis.In

Management of contacts
At the point where the diagnosis of VHF is suspected, the physician must notify the designated local public health doctor who is the proper officer for notification (generally the consultant in communicable disease control or consultant in public health medicine in Scotland).She/he will start to identify all the contacts awaiting establishment of the diagnosis and organise provision of information.Contacts should be categorised by level of risk (table 2).Only contacts in categories 1 and 2 require monitoring if VHF is confirmed.They should be monitored by taking their temperature twice daily for 21 days from the date of last contact with the patient and reporting it to their safety officer.The ACDP guidance does not mention use of ribavirin prophylaxis, but this was offered to Category 1 contacts of the patient with Lassa fever managed in England during 2000.

Communication
For public health officials and press officers, communication is the greatest task.This takes place in the context of greater access to information through media such as the Internet.Each confirmed case of VHF generates tremendous anxiety in healthcare workers and in the public and press briefings need to be prepared.Contacts of the patient need full information about their risk.Local, regional and national public health authorities, the Department of Health, the ministry of health of the country in which the patient contracted the infection, any organisations that transported the patient, the European Commission and the World Health Organization all should be notified and have information about the case.

Lessons learnt from recent cases
Many lessons are learnt following each case of VHF (2,5).Firstly, it is clear that UK guidance on risk assessment of cases is not always followed.As found in other countries, if the diagnosis of VHF is not considered then diagnosis will be delayed, however detailed are the case definitions.VHF cases are very rare, so it is a challenge to maintain awareness amongst clinicians.In interpreting safety legislation, the ACDP needs to find the right balance between exacting standards of safety in management of an individual VHF case and practicability for clinicians managing many febrile patients who have travelled to endemic regions (3).
Communication is a vital task for clinicians and public health specialists.It requires robust systems to ensure that information reaches staff when large numbers working long shifts become involved with caring for a patient.Safety officers need dedicated time for this communication role.
The Trexler unit is popular amongst staff trained in its use and it is probably more congenial for patients to see their carers' faces than to be surrounded by staff in protective suits.Protective suits limit the time staff can work to four hours, which means that more staff are required to care for the patient.This presents a significant problem for the UK National Health Service.However, providing modern intensive care within a Trexler unit also presents a challenge.

Conclusions
VHF is rarely diagnosed in the UK, with two confirmed cases between 1997 and 2000.The potential for such patients to come to the UK is always present because tourists, aid workers and troops travel regularly to and from the UK to endemic areas of the world.In addition, VHF are amongst the agents that have potential to be weaponised.Events since September 11 have underlined the importance of national preparedness to contain and manage the deliberate release of infectious diseases such as VHF.■

Evaluation des risques pour une FHV Risk category Minimum
patients in whom malaria diagnosis is not confirmed, blood or serum samples should be sent to the Central Public Health Laboratory (CPHL) at Colindale or ➤ Ne se sont pas rendus dans des régions endémiques avant l'apparition de la maladieOuSe sont rendus dans des régions endémiques (ou en contact avec une source connue ou suspecte de FHV) mais chez lesquels la maladie est survenue plus de 21 jours après leur dernier contact avec une source possible d'infectionModéréPatients fiévreux qui : Se sont rendus dans des régions endémiques au cours des 21 jours précédant la survenue de la maladie mais qui ne présentent aucun facteur de risque supplémentaire pouvant les placer dans la catégorie à haut risque Ou Ne se sont pas rendus dans une région endémique connue, mais ont pu visiter des régions ou pays proches au cours des 21 jours précédant la survenue de la maladie, et qui présentent une maladie grave avec un organe déficient et/ou une hémorragie pouvant être due à une FHV, et pour laquelle aucun diagnostic alternatif n'est évident Been in endemic area during the 21days before the onset of illness, but who have none of the additional risk factors which would place him or her in the high risk category Or Not been in a known endemic area but who may have been in adjacent areas or countries during the 21 days before the onset of illness, and who have evidence of severe illness with organ failure and/or a haemorrhage which could be due to a VHF, and for which no alternative diagnosis is currently evident OuOnt participé aux soins de malades fiévreux, connus ou fortement suspectés d'avoir une FHV, ou ont été en contact avec des liquides organiques, tissus ou corps décédés de tels patients Ou Sont des personnels de laboratoire, de santé ou autre et ont été probablement en contact avec des liquides organiques, tissus ou corps humain ou animal, identifié ou fortement suspecté d'avoir une FHV Ou Qui ont été d'abord classés comme risque modéré mais qui présentent un organe déficient et/ou une hémorragie Ou patients fièvreux qui n'ont pas visité de région endémique mais qui au cours des trois semaines avant la maladie : Ont soigné un patient ou animal connu ou fortement suspecté d'avoir une FHV , ou ont eu un contact avec des liquides organiques, tissus ou corps décédé d'un tel patient ou animal Ou Ont manipulé des échantillons, tissus ou cultures de laboratoire connus ou fortement suspectés de contenir un agent de FHV Tableau 1 -Febrile patients who have: Not been in known endemic areas before the onset of illness Or Been in endemic areas (or in contact with a known or suspected source of VHF) but in whom the onset of illness was definitely more than 21 days after their last contact with any potential source of infection Moderate Febrile patients who have: Or Are a laboratory, health or other worker who has, or has been likely to have come into contact with the body fluids, tissues or the body of a human or animal known or strongly suspected to have a VHF Or Who were previously categorised as moderate risk but who have developed organ failure and/or haemorrhage Or febrile patients who have not been in an endemic area but during the three weeks before the illness they: Cared for a patient or animal known or strongly suspected to have a VHF, or came into contact with the body fluids, tissues or dead body of such a patient or animal Or Handled clinical specimens, tissues or laboratory cultures known or strongly suspected to contain the agent of a VHF

Table 1 -Risk categorisation for VHF ➤
the Special Pathogens Unit at the Centre for Applied Microbiological Research (CAMR) for rapid molecular diagnosis (PCR).Usually PCR results are available within 24 hours (4).Virological confirmation of PCR results by serology and/ or viral isolation may take up to one week.Laboratories and clinical centres sending samples for VHF diagnosis are required to inform the receiving laboratory (CPHL/ CAMR) prior to the dispatch of samples.Details on handling, collection and transport of specimens are given in the guidance.

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Il est essentiel pour les médecins et les spécialistes de santé publique de communiquer.Ceci exige des systèmes solides pour assurer la circulation des informations quand plusieurs équipes effectuant de longues gardes sont ➤ Catégorie 2 / Category 2 Contact direct avec le patient ou les prélèvements du patient, mais pas de contact direct avec les liquides organiques/sang et application des mesures préventives appropriées / Direct contact with the patient or specimens from the patient but no direct contact with blood/bodily fluids and appropriate precautions taken Catégorie 3 / Category 3 A passé du temps dans les mêmes lieux que le patient, mais sans contact physique avec le patient / liquides organiques / prélèvements / Spent time in areas where the patient had been, but no physical contact with patient/ bodily fluids / specimens Catégorie 4 / Category 4 A partagé le même espace public que le patient / Shared the same public space as the patient Catégorie 5 / Category 5 Les personnes en contact avec celles des catégories 1 et 2 / People who were in contact with those in categories 1 and 2.Tableau /