How is Lassa virus transmitted: Lassa virus is transmitted to humans through contact with the urine or feces of infected multimammate rats (Mastomys natalensis), which are the natural reservoirs of the virus.
The rats can shed the virus in their excreta without showing any symptoms and can contaminate food, water, or household items. Humans can also get infected by inhaling aerosols or dust containing the virus, or by direct contact with the blood or tissues of infected rats.
What causes Lassa fever?
Lassa fever is a severe viral hemorrhagic fever caused by Lassa virus infection. The virus belongs to the family Arenaviridae, genus Mammarenavirus, and has a single-stranded RNA genome that encodes four proteins: Z, L, NP, and GP. The GP protein is cleaved into two subunits, GP1 and GP2, which mediate the attachment and entry of the virus into host cells via the alpha-dystroglycan receptor. The NP protein binds to the viral RNA and forms the ribonucleoprotein complex with the L protein, which is the RNA-dependent RNA polymerase that replicates and transcribes the viral genome. The Z protein is a zinc finger protein that regulates the viral transcription and replication.
How is Lassa fever transmitted from person to person?
Lassa fever can be transmitted from person to person through contact with the blood, body fluids, or tissues of infected individuals. The virus can also be transmitted through contaminated medical equipment, such as needles or syringes, or through sexual contact. The incubation period of Lassa fever ranges from 6 to 21 days, and the symptoms include fever, headache, sore throat, cough, chest pain, nausea, vomiting, diarrhea, abdominal pain, and bleeding from various sites. Lassa fever can cause severe complications such as shock, organ failure, deafness, and death.
Is Lassa fever like Ebola?
Lassa fever and Ebola are both viral hemorrhagic fevers that can cause severe illness and death in humans. However, they are caused by different types of viruses and have different epidemiological patterns. Ebola is caused by filoviruses that belong to the order Mononegavirales, while Lassa is caused by arenaviruses that belong to the order Bunyavirales. Ebola outbreaks occur sporadically and unpredictably in Central and West Africa, while Lassa is endemic in West Africa and causes regular outbreaks. Ebola has a higher case fatality rate than Lassa (about 50% vs 15%), but Lassa has a higher transmission rate than Ebola (about 20% vs 2%). Ebola has no specific treatment or vaccine available, while Lassa can be treated with antiviral drugs such as ribavirin and has several vaccine candidates under development.
Is Lassa fever in Ghana?
The Ghana Health Service (GHS) says 12 more cases of Lassa Fever have been recorded in Ghana.
The cases were revealed after the GHS traced 56 contacts of the initial two cases confirmed on Sunday, February 26, 2023.
The active cases of Lassa Fever in Ghana now stands at 13.
One person has so far died from the disease.
“This brings to 14 the total number of confirmed cases for the outbreak… One death has so far been recorded. All 13 cases are alive and in stable condition and are being managed in designated health facilities. A total of 97 contacts have been identified and efforts are underway to identify more contacts,” , a statement dated February 28, 2023, and signed by Director General of GHS, Dr Patrick Kuma-Aboagye said.
He added that “a probable case has been reported from Central Region and contacts are being identified and monitored while we await confirmation. Psychological support is being provided for all cases and contacts.”
How is Lassa fever treated?
Lassa fever is treated with supportive care and antiviral therapy. Supportive care includes fluid and electrolyte replacement, oxygen therapy, blood transfusion, treatment of secondary infections, and management of complications such as shock or bleeding. Antiviral therapy consists of administering ribavirin intravenously as soon as possible after the onset of symptoms. Ribavirin is an nucleoside analogue that inhibits the viral RNA polymerase and reduces viral replication. Ribavirin has been shown to reduce mortality and morbidity in Lassa fever patients if given early in the course of infection.
