The current outbreak of the viral disease, Lassa fever, in Nigeria has resulted in some 53 fatalities in 10 states and the Federal Capital Territory (FCT) since December, according to UN health officials Friday.

Nigeria map divided by states/United Nations
Nigeria map divided by states/United Nations

Lassa fever outbreak is a yearly occurrence during the dry season in Nigeria but, this year’s outbreak is more widespread with 10 states, 140 suspected and 30 confirmed cases. The case fatality rate (CFR) is significantly high at 53 or 37.9% of all cases.

The outbreak is so far affecting Bauchi, Nasarawa, Niger, Taraba, Kano, Rivers, Edo, Oyo, Plateau states and the FCT, with Niger being the most affected with 48 cases and 16 deaths. Epidemiological link between the outbreaks of the different states has so far not been established.

The Honourable Minister of Health, Professor Isaac Adewole, declared an outbreak and reiterated the Federal Government’s commitment to quickly contain it. He assured the public that “Nigeria has the capability to diagnose Lassa fever” and that “all confirmed cases were diagnosed by the country’s laboratories”. However, because the symptoms of Lassa fever are so varied and non-specific, clinical diagnosis is often difficult, especially early in the course of the disease.

Professor Adewole also directed all health facilities in the country to emphasize routine infection prevention and control measures and ensure all patients are treated free. Furthermore, he advised family members and health care workers to always be careful to avoid contact with blood and body fluids while caring for sick persons.

Related: Lassa fever: 20 percent of cases could be due to human-to-human transmission, Cambridge study

Lassa fever is a significant cause of morbidity and mortality. While Lassa fever is mild or has no observable symptoms in about 80% of people infected with the virus, the remaining 20% have a severe multisystem disease.

The animal host of Lassa virus is a rodent known as the “multimammate rat” of the genus Mastomys. Humans get infected with Lassa through aerosol or direct contact with excreta from the rodent. Laboratory infections do occur primarily through contaminated needles.

The symptoms of Lassa fever typically occur 1-3 weeks after the patient comes into contact with the virus. These include fever, retrosternal pain (pain behind the chest wall), sore throat, back pain, cough, abdominal pain, vomiting, diarrhea, conjunctivitis, facial swelling, proteinuria (protein in the urine), and mucosal bleeding. Neurological problems have also been described, including hearing loss, tremors, and encephalitis.