Lujo is a bisegmented RNA virus—a member of the family Arenaviridae—and a known cause of viral hemorrhagic fever (VHF) in humans.

Its name was suggested by the Special Pathogens Unit of the National Institute for Communicable Diseases of the National Health Laboratory Service (NICD-NHLS) by using the first two letters of the names of the cities involved in the 2008 outbreak of the disease, Lusaka (Zambia) and Johannesburg (Republic of South Africa).

All four patients in which infection proved fatal first showed signs of improvement and then went into respiratory distress, displayed neurological problems, and had circulatory issues that resulted in collapse.

Almost two weeks later, the paramedic that nursed the patient on the flight to South Africa also fell ill and was also brought to Johannesburg for medical treatment.

This was corroborated by full genome sequencing that was conducted by the NICD-NHLS, CDC and collaborators from Columbia University in New York.

[8] In-depth research into Lujo virus and its treatment have been difficult because of the lack of economic and cultural stability of the regions where the only known cases have occurred.

The fifth case was treated with ribavirin early after onset of clinical disease (was detected through active contact tracing), an antiviral drug which is effective in treating Lassa fever, and survived; however, complete ribavirin's effectiveness against Lujo virus remains unknown but may be useful as adjunctive therapy.