Yellow Fever Prophylaxis

Yellow Fever General Information

Yellow Fever is the generic medical term given to an acute viral disease causing hemorrhagic fever. Despite the use of a very effective vaccine, this affection is still a great threat to individuals that live or travel in endemic areas, such as regions from Africa and South America. Apart from fever and jaundice (the two main symptoms that have given the disease its name), patients infected with the virus may also experience headaches, nausea and vomiting. However, in many cases the disease progresses rapidly and affects the heart, liver and kidneys, causing serious complications and internal bleeding. The mortality rate is as high as 50% in patients affected by severe forms of the disease.

The Yellow Fever virus is spread to humans primarily by mosquitoes. Until the means of transmission had been understood and until an effective vaccine had been developed, this disease causes a number of devastating epidemics, leading to thousands of deaths during each outbreak. Currently, despite the use of the vaccine, it is estimated that over 200,000 individuals contract the disease each year, and from these over 30,000 die because of it. Unfortunately, there is no specific, generalized treatment for this affection at this time. Efforts are made to develop curative solutions however, at this time, the best option to fight the disease is prevention.

Yellow Fever Prophylaxis

As part of the Yellow Fever Prophylaxis, a vaccine has been developed in 1937 to prevent infection with this virus. Since then, this vaccine has proven its effectiveness and safety offering the vaccinated individuals a 10 year immunity and causing remarkably few side effects in the millions of individuals that have been vaccinated and obtaining immunity after the first dose in over 90% of the cases. In people that develop side effects, these are mild and may include low grade fever, fatigue, headaches, muscle aches and soreness at the location of the injection, and will subside within 5 to 10 days. In patients under 9 months of age or over 60 years of age, more severe reactions may appear. Affections similar to the disease itself, encephalitis (an inflammation of the brain) and death have been reported. In situations where the vaccine needs to be administered to infants or elderly patients, a specialized health care professional needs to assess the situation, outweighing the benefits and the risks involved in vaccination prior to giving the injection.

Apart from elderly patients and infants, most cases of side effects occur in patients that present an egg allergy or have a weakened immune system either due to medication or medical conditions. Pregnant women may also be at risk of developing complications. These patients should not normally be vaccinated as part of Yellow Fever Prophylaxis, but they should consult a specialized health care professional in order to determine the possibilities for them to receive protection against the disease.

Apart from vaccination, as the virus is spread to humans primarily by mosquitoes, proper protection against them is also part of the Yellow Fever Prophylaxis. It is recommended to avoid outdoor activities at dawn, dusk and during early evening as these are the periods during which mosquitoes are most active. At the same time, ensuring a safe indoor environment through screening the house and providing air conditioning is also important.

Wearing proper clothing is also part of Yellow Fever Prophylaxis. Shirts with long sleeves and long pants should be worn, and generally clothing that covers as much of the body as possible. Certain repellent substances for clothing should also be used, primarily products containing Permethrin, in order to further boost the protection offered by clothing, shoes, bed nettings and camping gear. Repellent products for the skin are also available, and you should use those with a proper concentration of DEET (products with 10% concentration offer protection for around two hours, higher concentrations protect for longer). However, as chemical products may be toxic, it is advised that prolonged use is avoided, and these products may not be suitable for children.

Yellow Fever Treatment

Currently, there is no efficient means to treat Yellow Fever. Antiviral medication has yielded no results in fighting the disease, and as such supportive care is the only therapy that may be employed for patients affected by this disease. The patient is kept under medical observation, and is provided with fluids and oxygen as needed. The blood pressure is monitored and maintained, and when needed the lost blood is replaced through transfusions. Dialysis is performed in case of kidney failure. It is possible to treat collateral infections, and generally symptomatic treatment is available. If needed, plasma transfusions may also be performed in order to replace blood proteins and improve blood clotting.

Patients affected by Yellow Fever should also be properly protected from mosquitoes, in order to prevent the disease from spreading to other individuals. The same methods apply; apart from ensuring proper air conditioning and building screening, the patient should be dressed in clothing that covers as much of the body as possible, and application of repellents on both the clothing and bed netting is advised. Chemical repellents may also be applied to the patient’s skin, however the medical personnel must ensure that this does not in any way cause any reactions with the patient’s organism, and no toxic substances may enter the patient’s body.