Explained: What is Lassa Fever, its Symptoms, and Treatment?

Lassa Fever: The United Kingdom is facing another health risk that is majorly linked to travellers from Western African countries and the disease is named Lassa fever. On 11 February, one out of three persons was diagnosed with Lassa fever. It is said that the death rate is one percent now but in certain individuals such as pregnant women in their third trimester, the risks are high.

As per the European Centre for Disease Prevention and Control, around 80 percent of the cases are asymptomatic and therefore remain undiagnosed. Some of the patients may need to be hospitalised and develop the various multi-system disease. 15% of hospitalised patients may die.

What is Lassa Fever?

As per CDC, 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. In 1969, it was first discovered in Lassa, Nigeria. The disease was discovered after two nurses died in Nigeria. Lassa fever is spread by rats. The animal vector for the Lassa virus is the "multimammate rat” (Mastomys natalensis). 

How is it transmitted?

Lassa virus transmission to occurs to humans mainly through ingestion or inhalation. The infection occurs when Mastomys rodents shed the virus in urine, droppings, and through direct contact with these materials, via touching soiled objects, eating contaminated food, or exposure to open cuts. Rarely, it can spread, if a person comes in contact with a sick person's infected bodily fluids via mucous membranes including the eyes, nose, or mouth. It is said that person-to-person transmission is more common in healthcare settings.

Sometimes Mastomys rodents are consumed as a food source and infection may occur when rodents are caught and prepared. A person also gets contacted with the virus when he or she inhales tiny particles in the air contaminated with infected rodent excretions. During cleaning activities, this aerosol or airborne transmission may occur like sweeping.

When do Symptoms appear?

Usually, people don't become contagious before symptoms appear and cannot transmit the infection via casual contact like hugging, shaking hands, or sitting near someone who is infected. Mainly, symptoms appear in one to three weeks after exposure. 

What are the Symptoms of Lassa Fever?

Mild symptoms are:

Slight fever

General malaise and weakness

Headache.

Serious symptoms include;

Hemorrhaging in gums, eyes, or nose, as examples.

Respiratory distress

Repeated vomiting

Facial swelling

Pain in the chest, back, and abdomen

Shock, etc.

Neurological problems may also occur including;

Hearing loss

Tremours and 

Encephalitis

Within two weeks, death can also occur after symptom onset due to multi-organ failure.

Most common complication of this fever is deafness. It may develop in mild as well as in severe cases.

Lassa Fever: Treatment

As per CDC, Ribavirin which is an antifungal drug has been used in Lassa fever patients. If it is given early, it will be effective in the course of illness. With the treatment, the patient should take some supportive care including appropriate fluid, electrolyte balance, oxygenation, etc. Also, treatment of any other complicating infections. 

_{Source: cdc}

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