Yellow Fever - know the symptoms

It is the sound that makes me mad. If they could keep quiet, things would be so much easier for them. I would be able to tolerate them hovering over me at night, admiring my sleeping body and gentle, innocent smile. It would even be acceptable for them to extract some body fluids, leaving a little red welt and then leaving the room. But no. It is that incessant buzzing, the high pitched whining, the ceaseless zzzzzzzzzzzzzzznnning like a miniature flying hairdryer that makes me resort to wet towel measures.

Mosquitos, I dislike them. Much.

They are even more loathed as you head deeper into Africa where they can cause an array of rather ugly diseases such as yellow fever and malaria. Yellow fever is a viral infection spread by mosquitoes and common in sub-Saharan Africa. Malaria is also spread by mosquitos¬ and occurs more in the tropics. Anyone can contract yellow fever, but old people are more at risk. Not only are they likely to be slower to slap the bloody insect with a wet towel but they have a higher risk of severe infection. A simple injection in the upper arm, leaving a little red welt without the buzzzing, is all it takes to make you immune to the nasty but exotic-sounding yellow fever.

There are three possible methods of transmitting the yellow fever virus: sylvatic (jungle), intermediate and urban.
- Jungle yellow fever mainly affects monkeys and is rare in humans.  Infected monkeys can pass the virus on to other mosquitoes that feed on them. These infected "wild" mosquitoes can contaminate humans living or walking in the forest.
- Intermediate yellow fever can cause small-scale epidemics in Africa when ‘semi-domestic’ mosquitoes infect monkeys and humans.
- Urban yellow fever is spread by Aedesaegypti mosquitoes. These mosquitoes gets infected by biting infected people. Large epidemics can occur when migrant workers introduce the virus into cities.
- Yellow fever cannot be transmitted between humans.


Symptoms may develop 3 - 6 days later after been bitten by an infected mosquito and include the following nice surprises:

Sudden fever
Nausea and vomiting
Muscle aches
Yellow skin and eyes (jaundice)
Red eyes, face and tongue
Decreased urination
Irregular heartbeats (arrhythmias)
Bleeding (may progress to haemorrhage)

Yellow fever has three stages:

1 - Infection stage:

 Symptoms include headache, muscle and joint aches – especially back ache, fever, blushing (red tongue), loss of appetite, vomiting and jaundice (yellow skin and eyes) are common. Symptoms subside after about three or four days.

2 - Remission stage:  
Fever may subside and other symptoms will go away. Most people will recover now, but about 15% of cases may get worse within 24 hours.

3 - Intoxication stage:
Problems with many organs occur. It could be heart, liver and kidney failure.
Bleeding disorders, seizures, coma and delirium may follow.


Vaccination is effective against yellow fever.
Consult your doctor about two weeks before you depart on your trip. This effective vaccine lasts for 10 years and provides protection within a week.
You will be provided with a yellow fever certificate which you need to show immigration officials.

While visiting a yellow fever area make sure you:
1 - Apply mosquito repellent
2 - Wear clothes that cover bare skin
3 -Sleep in a mosquito-protected room with screens or mosquito nets.

Contact your doctor if you experience any symptoms within a week after your return.
Mild yellow fever, characterized by fever, headache, malaise may resemble other arboviral infections and flu. Diagnosis is made by serology – blood tests.
Symptoms are treated and generally include rehydration and pain relief with paracetamol.
Drink lots of fluid and rest.
Stay away from mosquitos, they might get infected if they bite you and can further spread the disease.
Dehydrated patients might need intravenous fluids to also treat low blood pressure and low blood sugar.
In severe cases, dialysis will assist with kidney failure and blood transfusions could be usedin cases of bleeding disorders

The majority of infected persons will not show symptoms or have mild disease with complete recovery.
After you have recovered you may feel weak and tired for several months.
Death can occur in 20% - 50% of cases that develop severe disease.
You will be immune against possible subsequent yellow fever infections.

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