Lassa fever is an acute viral hemorrhagic infection that is rapidly causing the death of many especially in West Africa.
The Lassa fever is carried by a rodent Mastomys natalensis (M. natalensis). This is one of the most common rodents in equatorial Africa, found across much of sub-Saharan Africa. Lassa fever mainly occurs in Sierra Leone, Liberia, Guinea, and Nigeria. However, the Mastomys rat is common in neighboring countries, so these areas are also at risk.
Lassa fever was first discovered in Nigeria, when two missionary nurses became ill with the virus in 1969. It’s name is derived from the village of Lassa, where it was first documented.
Cause of Lassa Fever
Lassa fever occurs once a Mastomys rat is infected with the virus, it can excrete the virus in its feces and urine, as a result, the virus can spread easily especially as the rats breed rapidly and can live in human homes.
Mode of Transmission
– Consuming or inhaling rat urine and feces.
– Exposure to food or household items contaminated with urine or feces of infected Mastomys rat
– Person to Person infections and laboratory transmission can also occur especially in health care setting.
Symptoms in Humans
About 80 percent of who become infected with Lassa virus do not produce significant symptoms, although there maybe a general malaise, headache and slight fever.
In the remaining 20 percent of cases, Lassa fever becomes serious.
– Bleeding in the gums, nose and eyes
– Difficulty in breathing
– vomiting and diarrhea
– Difficulty in swallowing
– abnormal heart rhythm
– High / Low blood pressure
In around 1 percent of all cases, Lassa fever is fetal and around 15-20 percent of all hospitalization for the disease will end in death. Death can occur within 2- Weeks after onset of symptoms due to multiple organ failure.
It is particularly dangerous for women in their third trimester of pregnancy. Spontaneous loss of pregnancy occurs in around 95 percent of pregnancies.
The symptoms of Lassa fever vary widely, hence difficult to diagnose.
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 using enzyme – linked Imunosorbent serologic assays (ELISA), which detect IgM and IgG antibodies and Lassa antigens.
Prevention of the Disease
The definitive focus for prevention is ‘community hygiene’ to control the rat population.
– Storing food in rodent proof containers
– Regular Hand – Washing
– Keeping garbage away from home
– Ensuring clean households
– Keeping Cats
– Avoiding contact with blood and bloody fluids while caring for sick persons