Haemorrhagic fevers caused by viruses (VHFs) are usually transmitted by rodents, ticks or mosquitos, but are also transmissible from person to person. Their zoonotic character, however, makes them primarily viral diseases of tropical areas in populations with limited facilities for diagnosis, medical care or treatment. Four fevers Lassa, Ebola, Marburg and CongoÑCrimean Haemorhagic (CCHF) have major potential for hospital spread with high mortality where there is inadequate disinfecfion, indiscriminate use of needles or inadvertent surgery. Though rapid internationa! travel has increased the potential range of geographic spread by humans of these viruses, outside endemic areas human infection has only been documented for Marburg, Ebola and Lassa viruses.
Many of the fears and myths of the early 1970s should now be dissipated. Much has changed in international medicine. More aggressive and successful intensive care techniques combined with effective antiviral therapy now give the physician, few of whom would choose to work within the constraints of a patient isolator, the obligation to offer his/her patient the care to survive the few critical hours or days of circulation collapse. To deny this care to the patient in a Western hospital, may deny fundamental human rights.
The 1988 CDC Guidelines for the Management of Patients with VHFs recommends routine patient isolation in a single room, preferably but not necessarily with negative air pressure gradient from the hallway, through an anteroom to the patient room. Use of gloves, gowns, masks and rigorous disinfection with fresh liquids completes the structures. Contacts are graded such that high risk is only associated with direct contact with blood or body fluids. This approach was validated in 1989. Vaccines are not yet available, but post-exposure prophylaxis with tribavirin is a reasonable approach.
The documented history of the VHFs is of nosocomial outbreaks associated with gross violation of the principles of barrier nursing techniques, and no secondary cases associated with their efficient and consistent practice. Most experts consider the policies outlined by CDC in its guide-lines for the haemorrhagic fever viruses to be adequate, and to offer the best opportunity for the health and safety of patients and staffalike. Where in the past, a cavalier attitude to blood spills and accidents might have been a problem, AIDS has had a major impact on the quality of sfaff protection by hospitals and laboratories. The recommendations issued to deal with human immmunodefiency virus are certainly also adequate for VHFs, and their extension to VHF containmenk would be the simplest and most consistent approach for all countries. The 1985 WHO guidelines or managing patients with VHFs are now woefully out of date, and an inappropriate burden to less wealthy nations. They should be revised to reflecf the international consensus on the appropriate handling of patients with blood borne viruses in a humanitarian fashion.