lassa fever – an old curse stages a comeback

- February 7, 2020

Origin of the Name Lassa Fever

I am sure many Nigerians may not know the source of the name given to the viral hemorrhagic disease that goes by the name, Lassa Fever. The name is derived from the sleepy town in Borno State from where the first set of isolates were taken and discovered in 1969. 

The MultiMate Ratmouse

An Old Curse

Though first described in the 1950s, the virus causing Lassa disease was not identified until 1969. The virus is a single-stranded RNA virus belonging to the virus family Arenaviridae.

About 80% of people who become infected with Lassa virus have no symptoms. 1 in 5 infections result in severe disease, where the virus affects several organs such as the liver, spleen and kidneys.

The clinical course of the disease can take many forms, detection of the disease in affected patients has been difficult. When presence of the disease is confirmed in a community, however, prompt isolation of affected patients, good infection prevention and control practices, and rigorous contact tracing can help to stem the outbreak.

                              Lassa Fever virus

Here are the Basic Facts Concerning Lassa Fever

  • Lassa fever is an acute viral hemorrhagic illness of 2-21 days duration that occurs in most part of West Africa.
  • The Lassa virus is transmitted to humans via contact with food or household items contaminated with rat urine or feces.
  • Person-to-person infections and laboratory transmission can also occur, particularly in hospitals that lack adequate infection prevention and control measures.
  • Lassa fever is known to be endemic in Benin, Ghana, Guinea, Liberia, Mali, Sierra Leone, and Nigeria, but probably exists in other West African countries as well.
  • The virus causing Lassa fever is in the same family as that causing Ebola, but it is not as deadly.
  • The overall case-fatality rate is 1%. Observed case-fatality rate among patients hospitalized with severe cases of Lassa fever is 15%.
  • Early supportive care with rehydration and symptomatic treatment improves chances of survival.

West Africa – Endemic area for Lassa Fever

The Most Recent Outbreak – Coming Back with a Vengeance

The Federal Ministry of Health and the Lagos State Commissioner of Health have notified the public of another outbreak of Lassa Fever since December 2019.

About 29 deaths were reported in December 2019.

As at 24th of January 2020, 195 confirmed cases and 29 deaths had been reported in eleven states,” the Nigeria Centre for Disease Control (NCDC) said in a statement recently.

A national emergency operations centre had been activated to coordinate the response “to the increasing number of Lassa fever cases” across the country.

Nigeria declared an outbreak of Lassa fever a year ago and around 170 people died from the virus in 2019.

Almost 90 percent of the recent confirmed cases have been in Edo, Ondo and Ebonyi state in southern Nigeria, but there have also been reports of deaths in the north. Hard figures are still hard to come by.

The NCDC said that compared to the same period last year the fatality rate had dropped from 23.4 percent to 14.8 percent. This is could be due to a combination of early detection and better – case management in the facilities.

Treatment and prophylaxis

The use of Ribavirin, an antiviral agent has been reported to be effective if treatment is started early at the onset of the disease. There is currently no vaccine that protects against Lassa fever.

Written by Medicals