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.
