Lujo virus is a member of the Arenaviridae family, a group of viruses known to cause hemorrhagic fever. It is responsible for a severe and often fatal illness in humans, but it is exceptionally rare. The virus gained recognition following a single, contained outbreak that resulted in a high case-fatality rate. As an arenavirus, it is related to more well-known viruses like Lassa virus.
Discovery and Origin of the Virus
The history of Lujo virus is traced to a single outbreak in the fall of 2008. The first patient, a travel agent from Lusaka, Zambia, fell ill and was medically evacuated to Johannesburg, South Africa. This initial case led to a small but deadly cluster of infections and remains the only documented outbreak of the disease.
The virus derives its name from the locations associated with the outbreak: Lusaka (Lu) and Johannesburg (Jo). Its identification was carried out by South Africa’s National Institute for Communicable Diseases in collaboration with the U.S. Centers for Disease Control and Prevention.
Symptoms and Disease Progression
Lujo hemorrhagic fever (LUHF) begins with non-specific symptoms that can make it difficult to distinguish from other febrile illnesses. The onset is abrupt, starting with fever, malaise, muscle pain, and headache. Within a few days, patients develop a sore throat, chest pain, and gastrointestinal issues like diarrhea. These symptoms appeared 7 to 13 days after exposure in the known cases.
As the disease progresses, more severe symptoms emerge. A characteristic rash may appear on the face and torso, with swelling of the face and neck. Patients may also exhibit redness in the whites of the eyes and minor bleeding. Despite its classification as a hemorrhagic fever, major bleeding was not a prominent feature in the 2008 outbreak.
In fatal cases, a brief period of apparent improvement was followed by a rapid decline. This deterioration was marked by respiratory distress, neurological signs, and circulatory collapse. The illness advanced to multi-organ system failure, leading to death between 10 and 13 days after symptoms first appeared. The case-fatality rate in the outbreak was 80%, with four of the five infected individuals dying.
Transmission and Prevention
The natural source of Lujo virus has not been identified, but a rodent is strongly suspected. This is based on its relation to other arenaviruses, which are spread to humans through contact with the urine, droppings, or saliva of infected rodents. The first patient lived on a peri-urban farm, increasing the likelihood of wildlife exposure, though studies have not yet isolated the virus from local animals.
The 2008 outbreak provided clear evidence of human-to-human transmission in a healthcare setting. A paramedic, two nurses, and a hospital cleaner became infected after contact with the first patient. This highlights the risk to healthcare workers when infection control measures are not in place.
Prevention for individuals in affected regions focuses on avoiding contact with rodents and their waste. In healthcare facilities, strict infection control protocols are necessary. This includes the use of personal protective equipment (PPE) for anyone caring for a patient with a suspected or confirmed viral hemorrhagic fever.
Diagnosis and Treatment
Diagnosing Lujo virus requires specialized laboratory capabilities. Confirmation relies on molecular tests like polymerase chain reaction (PCR) to detect the virus’s genetic material or on isolating the live virus from patient samples. During the 2008 outbreak, diagnosis was complex and delayed until an epidemiological link between patients was established.
There is no specific cure for Lujo hemorrhagic fever. Treatment is supportive, focusing on managing the patient’s symptoms and supporting failing organ systems. This can include maintaining fluid and electrolyte balance, managing blood pressure, and providing respiratory support.
During the 2008 outbreak, the antiviral drug ribavirin was administered. The single survivor received intravenous ribavirin early in her illness, which suggests it may be effective. However, the small number of cases makes it impossible to draw firm conclusions about its efficacy, as the survivor’s treatment also included other therapies.