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Lassa Virus Facts

Lassa Virus Facts
Lassa virus is a virus that causes a viral hemorrhagic fever called Lassa hemorrhagic fever in some primates and in humans. Lassa virus is considered to be biological agent requiring a Biosafety Level 4 containment, the highest level containment because of its potential to cause severe to fatal disease in humans. Lassa virus is considered to be an emerging virus that first appeared in 1969 when a missionary nurse became ill in Lassa, Nigeria. It was first described in the 1950s but not yet identified as Lassa virus. It was later discovered that the multimammate rat in West Africa carried the virus. Lassa virus can result in no symptoms to infected humans or it may present with symptoms such as weakness, fever, muscle pains, vomiting, and headaches. In severe cases bleeding from the gastrointestinal tract and mouth may occur. Roughly 1% of cases are fatal.
Interesting Lassa Virus Facts:
Lassa virus is named after the region in Nigeria where the first infection was identified in 1969. It was known to have occurred a decade earlier but it had only been described.
A missionary nurse names Laura Wine contracted the virus from a patient and was transported to Jos, Nigeria. She died but the virus was passed to two more people.
Lassa virus was identified at Yale University after samples were sent there following the infections in Nigeria.
The incubation period once infected with the Lassa virus is between 6 to 21 days before symptoms appear.
Once infected Lassa virus can result in an acute hemorrhagic fever that can last anywhere from 2 to 21 days.
Symptoms of Lassa fever includes the gradual onset of weakness and fever, followed by muscle pains, a sore throat, headaches, coughing, vomiting, abdominal pain and chest pain. If it becomes severe symptoms can include swelling of the face, bleeding from the nose and mouth, and from the gastrointestinal tract.
In fatal cases death usually occurs with two weeks.
Lassa virus is transmitted to humans when they come into contact with the urine or feces of an infected rodent.
Transmission of Lassa virus can also occur from human to human contact when infection prevention is not adequate or control measures are not followed properly.
Lassa virus has been identified in many countries but it known to be endemic in Nigeria, Sierra Leone, Mali, Liberia, Guinea, Ghana, and Benin.
The fatality rate is 1% in those infected with Lassa virus.
The fatality rate of those infected with Lassa virus that require hospitalization as a result is approximately 15%.
Treatment for Lassa virus and Lassa fever involves symptomatic treatments and rehydration.
There is no known cure or vaccine for Lassa virus or Lassa fever.
Lassa fever is considered to be zoonotic, which means it transmits to humans from infected animals.
The host of Lassa virus is the multimammate rat. These rats do not become sick but the infection is shed in their feces and urine and the virus is then able to transmit to humans when they come into contact with contaminated surfaces.


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