Yellow Fever

Yellow fever is a viral infection which is spread by a particular type of mosquito. It most commonly occur in Africa and south America. In mild cases, it results in fever, headache and vomiting. However, heart, liver and kidney problems can also occur in serious infections.

More than 50% of people die with the severe form of yellow fever. Only symptomatic treatment can be given and vaccination is recommended before travelling to yellow fever prone areas.

Signs and symptoms of yellow fever vary depending on its phase.

Symptoms of acute phase include:

• Fever
• Headache
• Muscle ache
• Sensitivity to light
• Nausea
• Vomiting
• Loss of appetite
• Dizziness and Redness

They usually improve with in several days. Symptoms of more severe forms include:

• Yellowing of skin and mucus membranes
• Abdominal pain
• Decreased urination
• Blood in vomit
• Bleeding from nose mouth and eyes
• Slow heart rate
• Liver failure
• Kidney failure
• Brain dysfunction leading to coma

People from acute case may enter into severe case but many people heal with in several days.

Cause of yellow fever is a virus that is spread by Aedes aegypti mosquito. These mosquitoes thrive near humans and can breed in cleanest water. They transmit the virus back and forth between monkeys and humans. The virus enters blood stream when a mosquito bites a human.

Diagnosis of yellow fever can be challenging because acute phase of this disease is similar to that of malaria, typhoid, dengue fever and other viral hemorrhagic fever.

Doctor starts diagnosis by asking questions about medical history and travel history.

He or she may collect blood sample for identifying specific antibodies against virus.

Antiviral drugs do not work against yellow fever. Therefore, treatment consists of supportive care in the hospital which includes:

• Providing fluids
• Oxygen supply
• Maintaining blood pressure
• Replacing lost blood
• Dialysis and Treating any infection that develops

Some people may also receive hem transfusions to replace clotting factors. The person with yellow fever remains immune to this disease for the rest of his or her life.

The following preventive methods are available for yellow fever:

• Vaccine - a safe and highly effective vaccination is available it should be taken at least 10 days before trip begins.
• Mosquito protection - reducing exposure to mosquitoes by avoiding unnecessary outdoor activity, wearing long sleeved shirts and long pants, staying in well screened houses and using bed nets.
• Using repellants -  repellants which are applied to clothing shoes, camping gear and bed netting are called non skin repellants. Permethrin is present in them. Repellent applied to the skin containing DEET, IR3535 and picaridin are called skin repellants.  They can cause some side effects.

There are no alternative or homeopathic remedies to treat yellow fever.

According to centers for disease control and prevention, oil of lemon eucalyptus offers the same protection as DEET. It is a more natural product with less side effects. It must be used with caution in children.

There are several risks and complications associated with yellow fever.

Travelling to areas like sub-Saharan Africa and tropical south America is the major risk factor of this disease. A yellow fever vaccination should be done before travelling. Older people are at greater risk of acquiring this disease. 20-50% of people with severe disease die. Other complications include:

• Kidney failure
• Liver failure
• Jaundice
• Secondary bacterial infections
• Delirium and Coma