{"id":98,"date":"2023-05-22T19:59:20","date_gmt":"2023-05-22T18:59:20","guid":{"rendered":"https:\/\/microregistrar.com\/?p=98"},"modified":"2023-06-25T09:34:47","modified_gmt":"2023-06-25T08:34:47","slug":"lassa-fever","status":"publish","type":"post","link":"https:\/\/microregistrar.com\/?p=98","title":{"rendered":"Lassa fever"},"content":{"rendered":"\n
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What is Lassa fever?<\/h2>\n\n\n\n

Lassa fever is a zoonosis, an acute viral illness transmitted to humans from rats (multimammate rat \u2013 Mastomys natalensis<\/em>).<\/p>\n\n\n\n

Lassa fever was first discovered in 1969 from a case in Lassa, Nigeria.<\/p>\n\n\n\n

It is endemic in West African countries like- Benin, Ghana, Guinea, Liberia, Mali, Sierra Leone, Togo, Nigeria. However, it probably exists in other West African countries as well.<\/p>\n\n\n\n

It has been estimated that about 100,000 to 300,000 infections of Lassa fever occur annually. This number could be an underestimate as many cases may not get reported.<\/p>\n<\/div>\n\n\n\n

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Mastomys natalensis<\/em>, Kelly, et al
https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC3562201\/<\/a><\/figcaption><\/figure>\n<\/div>\n<\/div>\n\n\n\n

How severe is Lassa fever?<\/h2>\n\n\n\n

Over 80% of people infected with Lassa fever never develop symptoms and recover spontaneously. Lassa fever accounts for 10%-16% of hospitalisation in endemic countries. Although the overall case fatality rate is low (1%), it could be 15% in severe hospitalised cases.<\/p>\n\n\n\n

In perspective, the case fatality rate for COVID-19 was usually around two, but at the peak of the epidemic, it went up to 14-16% in some countries. You can get an idea here \u2013 https:\/\/ourworldindata.org\/grapher\/deaths-covid-19-vs-case-fatality-rate?time=2022-02-10<\/a><\/p>\n\n\n\n

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Distribution of Lassa fever<\/figcaption><\/figure>\n<\/div>\n\n\n\n
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What is the Lassa virus?<\/h2>\n\n\n\n

Lassa virus or Lassa mammarenavirus (LMV) belongs to the arenavirus family. It is an enveloped, single-stranded, bi-segmented RNA virus.<\/p>\n\n\n\n

Unlike other enveloped viruses, LMV uses a clathrin-independent endocytosis process to enter the cell. The receptor for these viruses is alpha-dystroglycan (alpha-DG). The virus replication and transcription occur in the cytoplasm. The newly formed virus exits the infected cells by budding.<\/p>\n\n\n\n

This virus has a high degree of genetic variability, and seven clades of this virus are circulating in West Africa.<\/p>\n\n\n\n

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How is Lassa fever transmitted?<\/h2>\n\n\n\n

The main reservoir of LMV is the rat. Once infected, the rat excretes the virus for a prolonged period, often lifelong.<\/p>\n\n\n\n

These rats live in the close vicinity of humans. Humans may get infected by eating food\/water contaminated with rat excretion, inhaling the dust particles from soil contaminated with rat excretion and occasionally by direct contact with the rat, e.g., handling or eating a rat.<\/p>\n\n\n\n

Person-to-person infections and laboratory transmission can also occur. It is usually after exposure to the virus in the blood, tissue, secretions, or excretions of a Lassa virus-infected individual. This is more common in healthcare when appropriate personal protective equipment is not used.<\/p>\n\n\n\n

Casual exposure, like shaking hands or exposure without exchanging body fluids, does not transmit Lassa fever.<\/p>\n\n\n\n

What are the symptoms of Lassa fever?<\/h2>\n\n\n\n

The incubation period takes about 1 \u2013 3 weeks after exposure to develop the infection. 80% of the individuals either develop mild or no symptoms.<\/p>\n\n\n\n

Patients usually present with fever and malaise (disproportionate to fever). After a few days, headache, body ache, arthralgia, sore throat, cough, nausea, vomiting and diarrhoea could be seen.<\/p>\n\n\n\n

1 in 5 cases may develop severe symptoms, which are<\/p>\n\n\n\n