On 27 August 1977, the BMJ published an editorial on an outbreak the previous year in Southern Sudan and Zaire of a severe haemorrhagic infectious disease, raising the question of the implications for control and containment of future infections.
Lassa fever took its name from a small village in Nigeria, where a mysterious outbreak in a mission hospital in 1969 led to the three mission nurses becoming infected. Two died, but the third survived and was evacuated to the Colombia Presbyterian Hospital in New York.
Twenty one outbreaks were recorded worldwide between 1969 and 1983 and the Department of Health published a memorandum on Lassa in 1976. Some cases were spread by rodents, others by monkeys. A number of related viruses were responsible for a range of similar illnesses; the death rate could be high, as was the infectivity. In Zaire in 1976, 211 out of 237 patients infected with Ebola virus died. But many cases were mild and in endemic areas the overall death rate could be as low as 1%.
The risk that people might travel by air during the incubation period led to plans for high-security infectious disease units. Travellers returning to Britain with a temperature were sometimes suspected of Lassa fever, though the diagnosis was rarely confirmed. A laboratory worker at Porton Down accidentally pricked his thumb while working with Ebola virus and six days later became ill and was transferred to an infectious disease unit at Coppetts Wood Hospital in north London where a plastic isolator, developed by Trexler, was available for use. A permanent high-security unit was planned for Coppetts Wood but was delayed interminably while there were public protests and arguments about the design. The hospital was next to an infants’ school and the area medical officer said that the proper place for swamp fevers was swamps - not Haringey.
One of the prime research workers himself died. On 17 March 2004, while treating a patient, Dr Conteh pricked himself with a needle and died as a result. Lassa may have been the cause of public anxiety in the 1970s. Other greater threats such as AIDs followed.