Lassa Fever-West Africa

Lassa fever is an animal-borne or zoonotic acute viral illness. It has been proven to be endemic in some countries in West Africa such as Sierra Leone, Liberia, Guinea and Nigeria. There is a high risk of the virus spreading in neighboring countries; also, the animal vector for the virus “multimammate rat” (Mastomys natalensis) can be distributed throughout the region (“Lassa Fever | CDC,” 2019).

 The virus was unidentified until the year 1969. The virus is a single-stranded RNA virus belonging to its family “Arenaviridae”.  An estimate of 80% of people who were infected by the virus do not present with the symptoms. About 1 in 5 infections can cause other medical complications as the virus affects other various organs that include liver, spleen and kidneys. Although the virus cannot be contaminated by air, it can be contagious through urine/faeces of the affected person or rat. It has been discovered that it is difficult to detect the virus in affected people because the clinical course of the virus is variable(World Health Organization, 2017).

 Nigeria, Sierra Leone, Liberia, and Ghana have the majority of outbreak of the virus. The environment can also be at risk as a result of the population of rat in West and East Africa. There are 100,000-300,000 cases of Lassa fever each year around the world. Sierra Leone and Liberia are impacted the most with an estimate of 5,000 deaths in both countries and 10-16% of hospital admission per year. Children are more prone to the threat. Compared to Ebola Virus of 70% cases, Lassa fever has a fatality rate of 1% to a severe rate of 15%. “An unusually intense outbreak developed in early 2018 in Nigeria with over 300 confirmed positive cases reported in the month of March. Cases were reported in Bauchi, Plateau, Edo, Ondo, and Ebonyi States. Sixteen health workers, at least four of whom died, were diagnosed as of Mar. 4, 2018. Along with high numbers, case fatality rates for this outbreak exceeded 20%. A Weekly Epidemiological Report has been maintained by the Nigeria Centre for Disease Control.” The Nigerian Minister of Health, Professor Isaac Adewale, announced that vaccine against Lassa virus would be arriving by the end of 2018. Dr. Chikwe Ihekweazu, CEO of the Nigeria Centre for Disease Control, has stressed the important advances of improved awareness and expanded ability to test for Lassa fever virus in recent years. Dr. Ihekweazu has encouraged improved adherence to infection prevention measures and community sanitation efforts to control current and future outbreaks of Lassa fever. Lassa fever has rarely been diagnosed in the U.S. There have been only six diagnosed cases since 1969. The last case was diagnosed in May 2015, in New Jersey in a patient traveling from Liberia. U.S. cases have involved international travelers or immigrants who arrived with the infection after exposure to rodents in West Africa(Sandra Gonzalez Gompf, MD, 2019).

References

Lassa Fever | CDC. (2019). Retrieved January 27, 2020, from https://www.cdc.gov/vhf/lassa/index.html

Sandra Gonzalez Gompf, MD, F. (2019). (No Title).

World Health Organization. (2017). Lassa fever. Retrieved January 27, 2020, from https://www.who.int/news-room/fact-sheets/detail/lassa-fever