Lassa fever is an acute, viral disease carried by a type of rat that is common in West Africa. It can be life-threatening. It is a hemorrhagic virus, which means it can cause
bleeding
, although 8 out of every 10 people with the virus have no symptoms. If it affects the liver, kidneys, or spleen, it can be fatal.
Does Lassa fever have a cure?
Lassa fever is a rodent-borne zoonosis that clinically manifests as an acute hemorrhagic fever. It is
treated using ribavarin
. Surviving Lassa fever without receiving the antiviral drug ribavarin is rare. Only few cases have been documented to date.
What part of the body does Lassa fever affect?
About 80% of people who become infected with Lassa virus have no symptoms. 1 in 5 infections result in severe disease, where the virus affects several organs such as
the liver, spleen and kidneys
.
Is there a cure for Lassa?
Ribavirin, an antiviral drug
, has been used with success in Lassa fever patients. It has been shown to be most effective when given early in the course of the illness.
How does Lassa fever enter the body?
Transmission of Lassa virus to humans occurs most commonly through
ingestion or inhalation
. Mastomys rodents shed the virus in urine and droppings and direct contact with these materials, through touching soiled objects, eating contaminated food, or exposure to open cuts or sores, can lead to infection.
How long can Lassa virus survive outside the body?
SURVIVAL OUTSIDE HOST: The virus is stable as an aerosol, particularly at low relative humidity (30 % RH). The biological half-live at both 24°C and 32°C ranges from
10.1 to 54.6 minutes
(20).
How can I protect myself from Lassa fever?
Primary transmission of the Lassa virus from its host to humans can be prevented by
avoiding contact with Mastomys rodents
, especially in the geographic regions where outbreaks occur. Putting food away in rodent-proof containers and keeping the home clean help to discourage rodents from entering homes.
Do all rats cause Lassa fever?
Lassa fever is a
viral infection carried by
the multimammate rat 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.
Is Lassa fever a pandemic?
Like many potentially pandemic diseases, Lassa fever
is spread by a virus carried by animals
– in this case, rats – and in West Africa where it is endemic it can be as dangerous as Ebola or COVID-19.
Is Lassa fever contagious?
Lassa fever facts
Unlike Ebola virus,
Lassa fever is not as contagious person to person
, nor as deadly. Lassa virus is typically transmitted by the urine or feces of Mastomys rats to humans. Health workers may be infected by direct contact with blood, body fluids, urine, or stool of a patient with Lassa fever.
What are the symptoms of Lassa?
For the majority of Lassa fever virus infections (approximately 80%), symptoms are mild and are undiagnosed. Mild symptoms include
slight fever, general malaise and weakness, and headache
.
How is Lassa fever diagnosed?
Lassa fever is most often diagnosed by using
enzyme-linked immunosorbent serologic assays (ELISA)
, which detect IgM and IgG antibodies as well as Lassa antigen. Reverse transcription-polymerase chain reaction (RT-PCR) can be used in the early stage of disease.
When was the first outbreak of Lassa fever in Nigeria?
Lassa fever was first discovered in
1969
in Nigeria following the death of two missionary nurses in Lassa town, Borno State [6]. The disease is endemic in West Africa countries of Sierra-Leone, Liberia, Guinea and Nigeria where about 300,000 to 400,000 cases occur annually with approximately 5,000 deaths [7].
What causes Lassa virus?
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.
Where is Lassa fever most common?
Lassa fever is an animal-borne, or zoonotic, acute viral illness. It is endemic in parts of
West Africa including Sierra Leone, Liberia, Guinea and Nigeria
.
What is the mortality rate of the Lassa virus?
Approximately 15%-20% of patients hospitalized for Lassa fever die from the illness. However,
only 1% of all Lassa virus infections result in death
. The death rates for women in the third trimester of pregnancy are particularly high.
