Lassa Fever: Recently, one of the three persons diagnosed with Lassa fever in the United Kingdom (UK) has died on February 11, 2022.

Key facts:

• The cases have been linked to travel to west African countries.
• The Lassa virus is named after a town in Nigeria where the first cases were discovered.
• The death rate associated with this disease is low, at around one per cent.
• However, death rate is higher for certain individuals, such as pregnant women in their third trimester.
• According to the European Centre for Disease Prevention and Control, about 80% of the cases are asymptomatic and therefore remain undiagnosed.
• Some patients may need to be hospitalized and develop severe multi-system disease.
• 15% of the hospitalized patients may die.
• It was first discovered in Lassa, Nigeria in 1969.
• This disease was discovered when two nurses died in Nigeria.

What is Lassa fever?

• Lassa fever also known as Lassa hemorrhagic fever (LHF) is a type of viral hemorrhagic fever caused by the Lassa virus.
• Lassa fever is an animal-borne (zoonotic) virus.
• The virus is commonly carried by rats.
• It is endemic in parts of West Africa — mainly in the regions of Ghana, Mali, Togo, Benin, Sierra Leone, Guinea, Liberia, and Nigeria.

How does it spread?

• According to the WHO, a person can become infected, when they come in contact with food items contaminated with urine or faces of an infected rat.
• People who catch and prepare the rats as food and who may breathe in tiny airborne particles infected with the rats’ faeces are also at risk.
• In rare cases, it can also spread, if a person comes in contact with infected bodily fluids of sick person or through mucous membranes like eyes, nose or the mouth.
• Person-to-person transmission is common in healthcare settings.

Symptoms:

• Symptoms of Lassa fever typically occur 1-3 weeks after the patient is exposed to the virus.
• Mild symptoms include slight fever, fatigue, weakness and headache.
• More serious symptoms include bleeding, difficulty breathing, vomiting, facial swelling, pain in the chest, back, and abdomen and shock.
• Neurological problems may also occur including hearing loss, tremors, and encephalitis. Multi-organ failure may cause death within two weeks of symptom onset.
• Most common complication associated with it is deafness.
• The key to improving the survival rate is early supportive care with rehydration and symptomatic treatment.

How to prevent Lassa fever?

Primary transmission of the Lassa virus from its host to humans can be prevented by:

• Avoiding contact with rats.
• Storing food in rodent-proof containers.
• Maintaining hygiene by keeping the house clean and keeping food in rat-proof containers.
• Further human-to-human transmission can be avoided with preventive precautions against contact with patient secretions and proper sterilization.
• Patients should be isolated and PPE kits should be used.