LASSA FEVER

Introduction:

Lassa fever is an acute viral hemorrhagic illness that occurs in West Africa. It was first discovered in 1969, Borno state, Nigeria where two missionary nurses died. The cause of the illness was found to be Lassa virus, named after the town in Borno state where its first cases originated.

Causive Organism:

Lassa fever is causes by Lassa virus; a single-stranded RNA virus which is zoonotic (animal-borne). It is hosted in the bodies of Natal Multimammate mice (mastomys ntalensis) from the sub Saharan Africa.

Mode of Transmission:

Lassa virus can be spread through direct contact with the droppings, urines, or excretions of these mastomys rodents through touch, or eating food contaminated with these materials. The virus can also be spread through inhalation of tiny particles in the air contaminated with the rodent’s excretions. This mode is known as Aerosol (air-borne transmission). It can also be spread through consumption of these rodents as food materials. Lassa virus can also be spread via person to person contact. This involves contact with blood, tissues, or excretions of an infected person.

It should be noted that Lassa virus cannot be spread through casual contact.

Symptoms:

Symptoms of Lassa fever occur from 1 to 3 weeks after contact with the virus.

They include:

• Fever
• Restosternal pain (pain behind the chest wall)
• Sore throat
• Back pain
• Cough
• Abdominal pain
• Vomiting
• Diarrhea
• Conjunctivitis
• Facial swelling
• Proteinuria (protein in urine)
• Mucosal bleeding

Neurological symptoms have also been described including hearing loss, tremors, and encephalitis.

Treatment

Ribervin, an antiviral drug has proved helpful in treating Lassa fever patients. However, it is most effective when administered during the early course of the illness.