Lassa fever is an acute viral haemorrhagic illness caused by Lassa virus, a member of the arenavirus family of viruses.
Humans usually become infected with Lassa virus through exposure to food or household items contaminated with urine or faeces of infected Mastomys rats. The disease is endemic in the rodent population in parts of West Africa.
Once a Mastomys rat is infected with the virus, it can excrete the virus in its feces and urine, potentially for the rest of its life.
As a result, the virus can spread easily, especially as the rats breed rapidly and can inhabit human homes.
Diagnosis
The symptoms of Lassa fever vary widely, and diagnosis can be difficult.
Clinically, the disease can resemble other viral hemorrhagic fevers, including the Ebola virus, malaria, and typhoid.
The only definitive tests for Lassa fever are laboratory-based, and the handling of specimens can be hazardous. Only specialized institutions can conduct these tests.
Lassa fever is generally diagnosed by using enzyme-linked immunosorbent serologic assays (ELISA). These detect IgM and IgG antibodies and Lassa antigens.
Reverse transcription-polymerase chain reaction (RT-PCR) can also be used in the early stages of the disease.
Prevention
The main focus of prevention is “community hygiene,” to control the rat population.
This includes:
- regular hand-washing
- storing foods in rodent-proof containers
- keeping garbage away from the home
- keeping pet cats
- avoiding blood and other bodily fluids when caring for sick relatives
- following safe burial procedures
- using protective equipment in a healthcare setting, including masks and eyewear
The Mastomys rat is so widespread that it cannot realistically be eradicated. As a result, the main aim is to avoid these rodents and prevent them from sharing human habitation.
