Here's some Lassa Fever info from wiki. It looks

Here's some Lassa Fever info from wiki. It looks like the 23% death rate Doc was speaking of are among those who have to be hospitalized for the virus. According to this, the overall death rate is 1%. There's some conflicting info on wiki also.

https://en.wikipedia.org/wiki/Lassa_fever

Lassa fever, also known as Lassa hemorrhagic fever (LHF), is a type of viral hemorrhagic fever caused by the Lassa virus.[1] Many of those infected by the virus do not develop symptoms.[1] When symptoms occur they typically include fever, weakness, headaches, vomiting, and muscle pains.[1] Less commonly there may be bleeding from the mouth or gastrointestinal tract.[1] The risk of death once infected is about one percent and frequently occurs within two weeks of the onset of symptoms. [1] Among those who survive about a quarter have hearing loss, which improves within three months in about half of these cases.[1]

The disease is usually initially spread to people via contact with the urine or feces of an infected multimammate mouse.[1] Spread can then occur via direct contact between people.[1] Diagnosis based on symptoms is difficult.[1] Confirmation is by laboratory testing to detect the virus's RNA, antibodies for the virus, or the virus itself in cell culture.[1] Other conditions that may present similarly include Ebola, malaria, typhoid fever, and yellow fever.[1] The Lassa virus is a member of the Arenaviridae family of viruses.[1]

There is no vaccine.[3] Prevention requires isolating those who are infected and decreasing contact with the mice.[1] Other efforts to control the spread of disease include having a cat to hunt vermin, and storing food in sealed containers.[1] Treatment is directed at addressing dehydration and improving symptoms.[1] The antiviral medication ribavirin has been recommended,[1] but evidence to support its use is weak.[4]

Descriptions of the disease date from the 1950s.[1] The virus was first described in 1969 from a case in the town of Lassa, in Borno State, Nigeria.[1][5] Lassa fever is relatively common in West Africa including the countries of Nigeria, Liberia, Sierra Leone, Guinea, and Ghana.[1][2] There are about 300,000 to 500,000 cases which result in 5,000 deaths a year. [2][6]

Signs and symptoms
Onset of symptoms is typically 7 to 21 days after exposure.[7] In 80% of those who are infected little or no symptoms occur. [7][8] These mild symptoms may include fever, tiredness, weakness, and headache.[7] In 20% of people more severe symptoms such as bleeding gums, breathing problems, vomiting, chest pain, or dangerously low blood pressure may occur.[7] Long term complications may include hearing loss.[7] In those who are pregnant, miscarriage may occur in 95%.[7]

In cases in which death occurs, this typically occurs within 14 days of onset.[7] About 1% of all Lassa virus infections result in death.[7] Approximately 15%-20% of those who have required hospitalization for Lassa fever die .[7] The risk of death is greater in those who are pregnant.[7] A "Swollen baby syndrome" may occur in newborns, infants and toddlers with pitting edema, abdominal distension and bleeding.[9]