Forty three participants came from Germany, Switzerland, the Netherlands or the United Kingdom. The speakers presented the clinical laboratory and public health aspects of four cases which had been managed in Europe in 1999-2000. There was a marked difference in approaches to the infection control, management of contacts and use of ribavirin prophylaxis in the different countries represented, and current policies vary widely. Several issues for further consideration were identified.

Late diagnosis

A common feature of all cases discussed was late diagnosis. The consequences were that ribavirin treatment of the patients started later, more staff were in contact with the patient and contacts were at a greater level of exposure to the patient than necessary.

Health care workers who work both in infectious and tropical medicine and general medicine need to be aware that the clinical features of Lassa fever are often non-specific. General practitioners and accident and emergency departments also need to have better awareness of the diagnosis and the infection control issues. Some late diagnoses may occur in the UK because according to current guidance the suspicion of the diagnosis is enough to lead to patients being put into medium or high risk category and at that point they must be transferred to a high security infectious disease unit [1]. This makes clinicians reluctant to request laboratory investigations unless they strongly suspect the diagnosis.

There was consensus that there should be a lower threshold for carrying out investigations for viral haemorrhagic fevers to exclude the diagnosis. It is preferable to exclude a diagnosis of Lassa fever by transporting specimens than to transport patients who are sometimes very sick to specialised units before commencing investigations and appropriate treatment. There is very little risk to stuff using modern automated equipment for testing of samples from patients with viral haemorrhagic fevers, and laboratory safety issues should not prevent clinicians from investigating patients more readily.

For this to happen, the current availability of polymerase chain reaction (PCR) diagnostic services needs to be disseminated and rapid PCR results should be obtainable in all countries. PCR diagnosis may need to be more widely available. European liaison may be required to improve the rapidity of and availability of diagnosis, as there is no uniformity currently.

Airlines may be able to provide information leaflets to travellers to and from endemic areas to raise their awareness of the risk of Lassa fever.

Management of patients

Here there was the most divergence in approaches. The Netherlands used a negative pressure room, and universal precautions but no additional forms of protection for staff. The German model is for staff to wear suits. In the management of a recent case in Germany it was found that three hours was the maximum work period that could be sustained by staff whilst wearing a suit. The implications for staffing of units are considerable. The UK model is to manage patients within a plastic bubble which encloses the patient in his bed (the "Trexler Unit") which has invaginated sleeves with which health care workers reach the patient. This has advantages in allowing the staff to work longer shifts. However, the specialists in intensive care took the view that with the current arrangements it was not possible to provide an adequate standard of intensive care in such a unit. Whether suits or a sealed unit were used, these must be adapted to meet the requirements of modern intensive care.

There was general consensus that although more evidence is required about infectivity and route of transmission, mild Lassa fever infection does not pose a great infection control hazard. Patients could be managed according to the severity of their clinical state so that a confirmed case of Lassa fever can be managed in negative pressure room or medium security isolation. Nevertheless, clinicians from Germany and the UK felt that such patients should always be managed in a hospital where they could be transferred immediately into a high security isolation facility should their clinical state deteriorate. Preferably this should be in a specialised centre. The transfer of a sick patient to another hospital could jeopardise their clinical outcome.

Management of contacts

Monitoring contacts

The Netherlands’ model was to encourage contacts of cases to monitor their own temperature, but not to report regularly to authorities. This approach relies upon individuals complying with their recommendations. In the UK, all contacts were required to report their temperatures daily to a safety officer. This resulted in a considerable task for public health ‰ ‰ authorities of little obvious benefit and at great opportunity cost. It was agreed that low risk contacts could be encouraged to self monitor and that active reporting to public health authorities, only recommended for contacts at highest risk, who had been directly exposed to a patient’s body fluids, blood etc. [category 1 exposure].

Ribavirin prophylaxis

The use of ribavirin prophylaxis is variable in Europe. In Germany and the UK this has been offered to category 1 contacts. In the Netherlands where a case was confirmed late in the illness, it was not offered. Contacts who took ribavirin in the UK and Germany had numerous problems tolerating the prophylaxis. The optimum dosage of ribavirin is probably 1g per day in two divided doses. Examination of the evidence base for the use of ribavirin prophylaxis shows it to be very limited in this context. It was agreed that full and frank information should be given to contacts in a higher risk category including an explanation that there is a possible benefit, but also that there are hazards of taking ribavirin. Once fully informed, contacts should be allowed to make up their own mind.

Communication

Dialogue should be started with airlines and air ambulances on procedures for the repatriation of suspected cases from endemic areas and contacts of cases. These aspects apply to all viral haemorhagic fevers, not just Lassa fever. International aid agencies should have better awareness of such illnesses and develop procedures for repatriation of their employees. A pan-European approach may be helpful.

The PHLS will liaise with International Health Exchange as a representative of aid agencies in the UK. There may be a need for European legislation and for a European approach to improving the awareness in aid agencies. Travellers should be informed of the risks as well through information on relevant websites and through bulletins.

Hospitals in endemic areas and air ambulance services which arrange for a patient to be medically evacuated to a European country with a possible viral haemorrhagic fever should communicate this fact to the relevant authorities. The role of ministries such as the Foreign Office in the UK should be clarified and may no longer be relevant or useful. European member states should issue alerts for suspected cases of Lassa fever if there are implications for other member states, such as exposure of other nationals on commercial airlines.

Medical insurance for travellers or expatriate employees is an important issue. Insurance companies should be aware of these diseases and the necessity to medically evacuate patients when they become unwell.

If cover for such diagnoses is excluded this must be made explicit to travellers. People should be wary of travelling with insurance that excludes VHF if they are travelling to endemic areas and undertaking activities that may put them at risk. Aid agencies should also check their insurance packages.

Conclusion

Participants agreed that the proceedings of the meeting should be put into the public domain and made available to relevant authorities including the Advisory Committee on Dangerous Pathogens in the UK and the European Network Committee. A long term aim would be to produce European consensus on how patients with Lassa Fever should be managed and how their contacts should be followed-up.