RISK GROUP CLASSIFICATION:
Risk Group 4(22)
. CONTAINMENT REQUIREMENTS: Containment Level 4 facilities, equipment, and operational practices for work involving infectious or potentially infectious materials, animals, and cultures.
Who is most at risk for Lassa fever?
Individuals at greatest risk of Lassa virus infection are those who live in or visit endemic regions, including Sierra Leone, Liberia, Guinea, and Nigeria and
have exposure to the multimammate rat
. Risk of exposure may also exist in other west African countries where Mastomys rodents exist.
What type of virus is Lassa?
Lassa fever is
an acute viral haemorrhagic illness
caused by Lassa virus, a member of the arenavirus family of viruses. Humans usually become infected with Lassa virus through exposure to food or household items contaminated with urine or faeces of infected Mastomys rats.
What is the mortality rate of the Lassa virus?
Approximately 15%-20% of patients hospitalized for Lassa fever die from the illness. However,
only 1% of all Lassa virus infections result in death
. The death rates for women in the third trimester of pregnancy are particularly high.
Where is Lassa virus most common?
Lassa fever is an animal-borne, or zoonotic, acute viral illness. It is endemic in parts of
West Africa including Sierra Leone, Liberia, Guinea and Nigeria
. Neighboring countries are also at risk, as the animal vector for Lassa virus, the “multimammate rat” (Mastomys natalensis) is distributed throughout the region.
Is there a cure for Lassa?
Ribavirin, an antiviral drug
, has been used with success in Lassa fever patients. It has been shown to be most effective when given early in the course of the illness.
Is Lassa fever a pandemic?
Like many potentially pandemic diseases, Lassa fever
is spread by a virus carried by animals
– in this case, rats – and in West Africa where it is endemic it can be as dangerous as Ebola or COVID-19.
What are the symptoms of Lassa virus?
For the majority of Lassa fever virus infections (approximately 80%), symptoms are mild and are undiagnosed. Mild symptoms include
slight fever, general malaise and weakness, and headache
.
How long can Lassa virus survive outside the body?
SURVIVAL OUTSIDE HOST: The virus is stable as an aerosol, particularly at low relative humidity (30 % RH). The biological half-live at both 24°C and 32°C ranges from
10.1 to 54.6 minutes
(20).
Do all rats cause Lassa fever?
Lassa fever is a
viral infection carried by
the multimammate rat Mastomys natalensis (M. natalensis). This is one of the most common rodents in equatorial Africa, found across much of sub-Saharan Africa. Lassa fever mainly occurs in Sierra Leone, Liberia, Guinea, and Nigeria.
Is Lassa fever airborne?
Contact with the virus may also occur when a person inhales tiny particles in the air contaminated with infected rodent excretions. This aerosol or
airborne transmission
may occur during cleaning activities, such as sweeping.
How is Lassa fever diagnosed?
Lassa fever is most often diagnosed by using
enzyme-linked immunosorbent serologic assays (ELISA)
, which detect IgM and IgG antibodies as well as Lassa antigen. Reverse transcription-polymerase chain reaction (RT-PCR) can be used in the early stage of disease.
Is Lassa fever still in Nigeria?
Lassa fever
remains a neglected tropical disease
, despite the virus being discovered more than 50 years ago in Nigeria. It is endemic in West Africa, but very little research has been conducted to date against this disease, for which there is no vaccine.
How can I protect myself from Lassa fever?
Primary transmission of the Lassa virus from its host to humans can be prevented by
avoiding contact with Mastomys rodents
, especially in the geographic regions where outbreaks occur. Putting food away in rodent-proof containers and keeping the home clean help to discourage rodents from entering homes.
Can a rat bite make you sick?
Rat bites aren’t always serious, but
they can become infected or cause a condition
called rat-bite fever.
What is the biggest risk factor for infection with Ebola?
Among the postprimary case-patients, the most important risk factor was
direct repeated contact with a sick person’s body fluids
, as occurs during the provision of care. As expected, the risk was higher when the exposure took place during the late stage of the disease at home.
