What Is Yellow Fever? Symptoms, Causes, Treatment, and Prevention
Yellow fever is a potentially life-threatening viral disease transmitted by infected mosquitoes. It primarily affects people living in or traveling to parts of Africa and South America, where the virus is endemic. Named for the jaundice (yellowing of the skin and eyes) that occurs in severe cases, yellow fever remains a significant public health concern, despite the availability of an effective vaccine.
In this article, we’ll explore the causes, symptoms, treatment, and prevention of yellow fever.
What Causes Yellow Fever?
Yellow fever is caused by the yellow fever virus, a member of the Flavivirus family. It is spread through the bite of infected Aedes or Haemagogus mosquitoes. Once bitten, the virus enters the bloodstream and begins to multiply, sometimes leading to serious complications.
Key Symptoms of Yellow Fever
Yellow fever symptoms usually appear 3 to 6 days after infection and can range from mild to severe. The disease has two phases:
Initial (Acute) Phase
- Sudden high fever
- Headache
- Chills
- Back pain
- Muscle aches (especially in the knees and back)
- Nausea and vomiting
- Loss of appetite
- Dizziness
Most people recover after this phase. However, about 15% of infected individuals enter a toxic phase, which is much more dangerous.
Toxic Phase (Severe Yellow Fever)
- Return of fever after short recovery
- Yellowing of skin and eyes (jaundice)
- Abdominal pain
- Bleeding from the nose, mouth, or eyes
- Blood in vomit or stool
- Organ failure (especially liver and kidneys)
- Delirium or coma
This phase can be fatal in up to 50% of cases without medical attention.
How Is Yellow Fever Diagnosed?
Diagnosis is usually based on:
- Recent travel history to endemic regions
- Symptoms
- Blood tests to detect the virus or antibodies
Laboratory confirmation is important because yellow fever shares symptoms with diseases like malaria, dengue, and hepatitis.
Is There a Cure for Yellow Fever?
There is no specific antiviral treatment for yellow fever. Management focuses on supportive care, which includes:
- Rest and hydration
- Pain relievers (avoid aspirin and NSAIDs due to bleeding risk)
- Hospitalization for severe cases
Patients in the toxic phase may need intensive care, including dialysis or blood transfusions.
Yellow Fever Prevention: The Vaccine Works
The best protection against yellow fever is vaccination. The yellow fever vaccine is:
- Safe and effective
- Usually given as a single dose
- Required for travel to certain countries
Most people develop lifelong immunity after one dose.
Other preventive measures include:
- Using insect repellents containing DEET
- Wearing long-sleeved clothing
- Sleeping under mosquito nets
- Staying in air-conditioned or screened-in areas
Who Needs the Yellow Fever Vaccine?
- Travelers to countries where yellow fever is common
- Residents of affected regions
- People working in forests or rural areas in endemic zones
Some countries require proof of vaccination (yellow card) for entry, especially if you’re coming from or going to an at-risk country.
Final Thoughts
Yellow fever is preventable, yet still causes thousands of deaths each year due to lack of vaccination and awareness. If you’re traveling to a yellow fever zone, consult your doctor well in advance to get vaccinated and take appropriate precautions.
