What is Lassa Fever?
Lassa fever is an acute viral hemorrhagic illness caused by the Lassa virus, a member of the
Arenaviridae family. It is endemic in parts of West Africa, with Nigeria, Sierra Leone, Liberia, and Guinea being the most affected countries. The disease is named after the town of Lassa in Nigeria, where it was first identified in 1969.
How is Lassa Fever Transmitted?
Lassa fever is primarily spread to humans via contact with food or household items contaminated with urine or feces of infected
Mastomys rats, commonly known as multimammate rats. These rodents are the natural reservoir of the virus. Human-to-human transmission can also occur through exposure to the blood, tissue, secretions, or excretions of an infected individual. It's important to note that the disease can spread in healthcare settings where proper infection control practices are not followed.
What are the Symptoms of Lassa Fever?
Symptoms of Lassa fever typically appear 1 to 3 weeks after exposure. The illness usually starts with non-specific symptoms such as fever, general weakness, and malaise. As the disease progresses, more severe symptoms like headache, sore throat, muscle pain, chest pain, nausea, vomiting, diarrhea, cough, and abdominal pain may develop. In severe cases, patients may experience facial swelling, fluid in the lung cavity, bleeding from the mouth, nose, or other body parts, and shock. The disease can be fatal, with a case-fatality rate of about 1%, but severe cases can have a mortality rate of up to 15%.
How is Lassa Fever Diagnosed?
Diagnosing Lassa fever can be challenging due to its non-specific initial symptoms, which are similar to those of other febrile illnesses. Laboratory confirmation is essential and can be done through a variety of tests, including
enzyme-linked immunosorbent serologic assays (ELISA), reverse transcription-polymerase chain reaction (RT-PCR), and virus isolation by cell culture. Early diagnosis is crucial for effective management and reducing transmission risk.
What are the Treatment Options for Lassa Fever?
The mainstay of Lassa fever treatment is supportive care, which involves maintaining hydration, treating symptoms, and managing complications. The antiviral drug
ribavirin has been shown to be effective if administered early in the course of the disease. However, its efficacy diminishes if treatment is started later. In addition, healthcare workers need to employ rigorous infection control measures to prevent nosocomial transmission.
How Can Lassa Fever be Prevented?
Prevention of Lassa fever focuses on promoting good community hygiene to discourage rodents from entering homes. This includes storing food in rodent-proof containers, disposing of garbage far from homes, and maintaining clean living environments. In healthcare settings, strict
infection control practices are vital, including the use of personal protective equipment (PPE) and proper decontamination procedures. Currently, there is no vaccine available for Lassa fever, though research is ongoing.
What is the Public Health Impact of Lassa Fever?
Lassa fever is a significant public health concern in endemic regions due to its high morbidity and potential for outbreaks. It poses a threat to healthcare workers and can overwhelm healthcare systems. Addressing Lassa fever requires a multifaceted approach involving surveillance, early detection, prompt treatment, and community education. Efforts to develop a vaccine and improve diagnostic and treatment options are ongoing, which could significantly mitigate the disease's impact in affected communities.
