The transmission of Lassa fever from rats to humans occurs through ingestion or inhalation.
Lassa fever is an animal-borne viral illness that spreads through rats. It is an endemic that majorly affects people living in western Africa.
About 300,000 cases of Lassa fever are identified, out of which about 5000 deaths are recorded, yearly. The disease can have mild symptoms but, sometimes, could be life-threatening.
The disease was first identified in a Nigerian town called Lassa. The name was given in 1969 after the death of two nurses in the Nigerian town, of Lassa.
How does Lassa fever transmit?
A multimammate rat type hosts the Lassa virus in its urine or feces. These rats are found in West, Central, and East Africa. They tend to live in houses, usually in the pantry, where food is stored.
The transmission from rats to humans occurs through ingestion or inhalation. These rats shed their feces and urine on objects or foods. The virus usually affects humans by entering the body through open cuts or sores.
Person-to-person transmission can occur via blood feces but not via touch, shaking hands, or hugging. Furthermore, the virus can be spread by sharing needles. A few cases of the virus being transmitted sexually have been reported.
Who are at a high risk of Lassa fever?
The following people are at risk of getting Lassa fever:
- Visit endemic regions of West, Central, and East Africa
- Come in contact with the urine or feces of infected rats
- Eat rats as food
- Breathe a few airborne particles contaminated with rat's urine or feces
Lassa infection may lead to the following in infected individuals:
- About 20 percent of the cases of Lassa fever may result in hospitalization
- Pregnant women with Lassa fever are more likely to have miscarriages, which increases the risk of death in the later stages of pregnancy
- Most people with Lassa infection may end up with deafness as a complication
- Death may occur two weeks after the onset of symptoms due to multiorgan failure
What are the signs and symptoms of Lassa fever?
Once infected with the Lassa virus, the person may show the symptoms in one to three weeks. Mostly, the symptoms are mild, and sometimes, they can be severe and life-threatening.
Mild symptoms include:
Severe complications include:
Bowel regularity means a bowel movement every day.
How to diagnose Lassa fever
The symptoms may resemble other hemorrhagic virus infections, such as Ebola virus, malaria, and typhoid, which makes the diagnosis difficult. One of the best methods to diagnose Lassa fever is enzyme-linked immunosorbent serologic assays (ELISA). This test identifies Lassa antigens and immunoglobulin M and immunoglobulin G antibodies.
In the early stages of infection, swab tests may help diagnose the condition.
How to treat Lassa fever
The treatment could be effective in the early stages of infection. Ribavirin, an antiviral, is the most effective drug to treat Lassa viral infection. Ribavirin can be administered orally as a pill or intravenously.
When the symptoms are severe, you may require hospital care and monitoring.
Your healthcare provider helps:
- Stay hydrated
- Maintain fluid and electrolyte balance
- Monitor blood pressure
- Administer oxygen therapy if required
- Treat other underlying health issues
How to prevent Lassa virus infection
The infection can be prevented in the following ways:
- Stay away from rats
- Wash your hands frequently
- Keep your surroundings clean
- Take precautions while caring for sick individuals
- Foods should be covered properly in tight or rat-proof containers
- Set up rat traps if you notice any rats around you
- Do not cook or eat rats
Reviewed on 12/2/2022
Image Source: iStock image
What Is Lassa Fever? https://www.webmd.com/a-to-z-guides/lassa-fever-overview
Lassa Fever. https://www.cdc.gov/vhf/lassa/symptoms/index.html
Viral hemorrhagic fevers. https://www.mayoclinic.org/diseases-conditions/viral-hemorrhagic-fevers/symptoms-causes/syc-20351260