BY DR. MUDAMA PRECIOUS (M.B.B.S., BENIN) THE FEVER CALLED LASSA BY DR. MUDAMA PRECIOUS (M.B.B.S., BENIN)

OUTLINE INTRODUCTION EPIDEMIOLOGY MODE OF TRANSMISSION SIGNS AND SYMPTOMS DIAGNOSIS MANAGEMENT PREVENTION DISCUSSION CONCLUSION 20/09/2018

INTRODUCTION Lassa fever is a zoonotic viral haemorrhagic fever, first described in 1950. The animal reservoir, or host, of Lassa virus is a rodent called “multimammate rat” (Mastomys natalensis). Rats infected with Lassa virus do not become ill, but they can shed the virus in their urine and faeces. 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. Early supportive care with rehydration and symptomatic treatment improves survival. 20/09/2018

EPIDEMIOLOGY 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 overall case-fatality rate is 1%. Observed case-fatality rate among patients hospitalized with severe cases of Lassa fever is 15%. As of 9 June 2017, a total of 501 suspected cases including 104 deaths have been reported since the onset of the current Lassa fever outbreaks season in December 2016. Of the reported cases, 189 have been further classified, 175 laboratory- confirmed including 59 deaths and 14 probable cases (all dead). 20/09/2018

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MODE OF TRANSMISSION Mainly zoonotic: Infected faeces and body fluids (hand-to- mouth). Person-to-person: Same as above (within 1m of reach). Health care setting: Same as above, including contaminated instruments. Sexual transmission: Few reported cases, especially among homosexuals and drug addicts. 20/09/2018

SIGNS AND SYMPTOMS The incubation period of Lassa fever ranges from 6–21 days. Phase 1: Fever, general weakness, and malaise. Phase 2: Headache, sore throat, muscle pain, chest pain, nausea, vomiting, diarrhoea, cough, and abdominal pain. Phase 3: Facial swelling, fluid in the lung cavity, bleeding from the mouth, nose, vagina or gastrointestinal tract, proteinuria and hypotension. Phase 4: Shock, seizures, tremor, disorientation, deafness, coma, and death (within 2 weeks in severe case). 20/09/2018

SIGNS AND SYMPTOMS OF LASSA… 20/09/2018

DIAGNOSIS Laboratory specimens may be hazardous and must be handled with extreme care. Lassa virus infections can only be diagnosed definitively in reference laboratories using the following tests: Reverse transcriptase polymerase chain reaction (RT-PCR) assay Antibody enzyme-linked immunosorbent assay (ELISA) Antigen detection tests Virus isolation by cell culture. 20/09/2018

MANAGEMENT History Findings on physical examination Early detection and prompt use of Ribavirin Contact tracing and isolation of contacts SIGNS AND SYMPTOMS CURE + PREVENT COMPLICATIONS PREVENT SPREAD 20/09/2018

PREVENTION PRIMORDIAL PRIMARY SECONDARY TERTIARY 20/09/2018

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DISCUSSION A 35year old pregnant woman in 3rd trimester of pregnancy, presents in and ambulance, through the emergency unit of the referring hospital with sudden onset bleeding and abdominal pain. A diagnosis of abruptio placenta was made at the referring hospital, and the request form states that an obstetric USS for fetal viability and well-being should be done. DISCUSS (porter, nurses, radiographers, janitors). A 30year old man presents at the reception with history suggestive of malaria. Has been vomiting for 2days (vomited at the reception) and has been on drip as a result. A look at his exposed hand shows areas of bleeding under the skin. His doctor requests MP/Widal, FBC, serology, SEUCr, plain abdominal xray (erect/supine), and abdominopelvic USS. DISCUSS (GROs, porter, janitors, laboratory scientists, nurses, radiographers). 20/09/2018

CONCLUSION Knowing what to do is good but knowing when to do what is to be done, is better. Lassa fever is deadly, but much deadlier is ignorance of its strengths and weaknesses. Early detection and prompt response, improves the chances of survival. But in all, PREVENTION IS BETTER THAN CURE!!! 20/09/2018

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THANKS FOR LISTENING! !! 20/09/2018