Lassa Fever: Symptoms, Treatment, and Recent US Case – What You Need to Know

Lassa Fever: Recently, an eastern Iowa resident in the United States who had travelled to West Africa died after contracting Lassa fever, as reported by the Iowa Department of Health and Human Services. State officials confirmed that preliminary tests were presumptively positive, and the Centers for Disease Control and Prevention (CDC) is working to verify the diagnosis. Lassa fever, a disease in the same hemorrhagic fever category as Ebola, spreads mainly through rodent exposure and person-to-person contact under limited conditions.

What is Lassa Fever?

Lassa Fever is a viral hemorrhagic illness caused by the Lassa virus, primarily found in West Africa. This disease, named after the Nigerian town where it was first identified in 1969, typically spreads through contact with food or household items contaminated by the urine or feces of infected rodents, particularly the Mastomys rat. Lassa fever is endemic in countries like Nigeria, Liberia, Sierra Leone, and Guinea, though it may occur in other parts of West Africa as well.

How is it transmitted?

The virus is zoonotic, meaning it transmits from animals to humans. Most cases arise from exposure to infected rodent waste. In rare cases, it can spread from person to person through direct contact with bodily fluids, particularly in healthcare settings without proper infection controls. This highlights the importance of preventive measures in high-risk areas.

When do Symptoms appear?

Usually, people don't become contagious before symptoms appear and cannot transmit the infection via casual contact like hugging, shaking hands, or sitting near someone who is infected. Mainly, symptoms appear in one to three weeks after exposure. 

What are the Symptoms of Lassa Fever?

Lassa fever's incubation period ranges from 6 to 21 days, and symptoms vary significantly. Around 80% of cases are asymptomatic or mild, but others experience severe, life-threatening symptoms. Early symptoms include:

• Fever
• General malaise
• Headache
• Sore throat
• Muscle and chest pain
• Nausea and vomiting

If left untreated, symptoms can progress to more severe issues like:

• Abdominal pain
• Respiratory distress
• Facial swelling
• Fluid accumulation in the lungs
• Bleeding from the mouth, nose, or gastrointestinal tract
• Neurological issues, such as seizures or disorientation

In critical cases, Lassa fever can lead to multi-organ damage, including liver and kidney impairment.

Diagnosis of Lassa Fever

Diagnosing Lassa fever can be challenging due to its similarity to other illnesses like malaria and typhoid. Accurate diagnosis often requires specialized laboratory tests in facilities equipped for high-level biosafety measures. Early detection is critical for effective treatment and controlling potential outbreaks.

Lassa Fever: Treatment

As per NIH and various other registered organisations, the antiviral drug Ribavirin has shown effectiveness, especially when administered early. Treatment typically includes supportive care to manage symptoms, such as:

• Hydration
• Pain management
• Monitoring for organ function

For severe cases, hospitalization and close monitoring may be necessary. Immediate isolation of patients helps prevent transmission to others, especially in healthcare settings.

Preventive Measures to Lassa Virus

According to Africa CDC Preventing Lassa fever primarily involves reducing contact with rodents in endemic areas. Key prevention strategies include:

• Storing food securely and keeping homes clean to deter rodents
• Using protective gear like gloves, masks, and gowns for healthcare providers
• Educating communities on risks and protective actions

In healthcare settings, implementing rigorous infection control protocols is vital to protect medical staff and other patients.

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