Lassa fever

About Lassa fever-

• It is an acute viral haemorrhagic illness caused by Lassa virus, a member of the arena-virus Family of viruses. 
• The Lassa virus is named after a town in Nigeria where the first cases were discovered in 1969.
• The virus is a single-stranded RNA virus belonging to the virus family Arenaviridae.
• The fever is spread by rats and is endemic in the rodent population in parts of West Africa – Benin, Ghana, Guinea, Liberia, Mali, Sierra Leone, Togo and Nigeria.
• Symptoms typically appear 1-3 weeks after exposure. 
• Mild symptoms include slight fever, fatigue, weakness and headache and more serious symptoms include bleeding, difficulty breathing, vomiting, facial swelling, pain in the chest, back, and abdomen and shock.
• Death can occur from two weeks of the onset of symptoms, usually as a result of multi-organ failure. 

• Humans usually become infected with Lassa virus through exposure to food or household items contaminated with urine or faeces of infected Mastomys rats.
• It can also be spread, though rarely, if a person comes in contact with a sick person’s infected bodily fluids or through mucous membranes such as the eyes, nose or the mouth.
• Person-to-person infections and laboratory transmission can also occur, particularly in health care settings in the absence of adequate infection prevention and control measures.
• The overall case-fatality rate is 1%. Among patients who are hospitalized with the severe clinical presentation of Lassa fever, case-fatality is estimated at around 15%.
• Early supportive care with rehydration and symptomatic treatment improves survival.
• 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.