Yellow fever

Description

Yellow fever is a viral infection that is spread by several species of mosquitoes. The disease is most common in Africa, South Africa and affects tourists and residents of these areas.

In milder cases, the viral infection causes an increase in body temperature, headache, nausea and vomiting.

But it is possible that the disease can cause complications such as heart, liver and kidney damage accompanied by hemorrhages. Up to 50% of people who develop complications die.

There is no specific treatment for the disease. But getting vaccinated before visiting areas where the disease is endemic is a way to protect against infection.

What are the symptoms?

For the first 3-6 days after exposure to the virus, you will not experience any symptoms. After that, the infection enters an acute phase, and subsequently, in some of the infected, into a toxic phase, which can threaten their lives.

Acute phase

• Fever;
• Headache;
• Muscle aches, especially in the back and knees;
• Sensitivity to light;
• Nausea, vomiting or both;
• Loss of appetite;
• Dizziness;
• Redness of the eyes, face or tongue;

These signs and symptoms subside after a few days.

Toxic phase

Although the signs and symptoms of the acute phase disappear in a few days, in some of those infected the disease enters a toxic phase.

In this phase, the clinical manifestations of the acute recur as more aggravated and those that are life-threatening such as:

• Yellowing of the skin and the whites of the eyes – jaundice;
• Acute abdominal pain and vomiting, sometimes accompanied by blood;
• Decreased frequency of urination and the amount of urine excreted;
• Bleeding from the nose, mouth and eyes;
• Slowed heart rate – bradycardia;
• Liver and kidney failure;

The toxic phase can be fatal.

When should you seek medical attention?

4 or 5 weeks before traveling to a region where the viral infection is endemic, make an appointment with your GP to to discuss whether you need a vaccine.

If you don’t have that much time, still call your doctor, as immunity against the virus builds up 3-4 weeks after the vaccine is administered. In addition, the doctor will give you recommendations for prevention and against other diseases that you could acquire during your visit to these regions.

Seek emergency medical care if you develop symptoms of the toxic phase of the virus after traveling to a country known to have sick people. Also see a doctor if you develop mild clinical signs of the infection after returning from an endemic area.

What are the causes?

The disease is caused by infection with an Arbovirus, part of the family Flaviviridae, which is spread by mosquitoes:

• Aedes aegypti, Aedes simpsaloni and Aedes africanus in continental Africa;
• genus Haemagogus in South America;
• genus Sabethes in France;

Treatment of yellow fever

Antiviral preparations are not an effective treatment. Therefore, the treatment consists in supportive therapy in a hospital setting.

This method of treatment includes infusion of fluids intravenously, in case of breathing difficulties additional amounts of oxygen are provided; normal blood pressure is maintained; blood transfusions are performed to restore blood lost from the body due to hemorrhages; if kidney failure develops, the patient is put on dialysis and any other possible infections that develop as a result of the weakened immune system are treated.

Some patients may need a plasma transfusion to replace the proteins that improve blood clotting.

After being cured of the disease, a person acquires immunity for the rest of his life.