Yellow Fever: More Dangerous Than Zika

The yellow fever virus is found in tropical and subtropical areas in South America and Africa. The virus is transmitted to people by the bite of an infected mosquito. Illness ranges in severity from a self-limited febrile illness to severe liver disease with bleeding.

There's a separate outbreak of about seven cases in rural areas of Uganda. In Angola, the latest figures show 2,267 suspected cases of yellow fever, with 293 deaths. About a third, 696 cases, have been confirmed by laboratory tests.

What is more worrisome are the rapidly depleting yellow fever vaccine supplies and the infections that have already occurred in China, Kenya, Mauritania, and the Democratic Republic of the Congo. There are currently 20 reported cases of yellow fever in Peru, a significant increase from their reported average. The Peru cases are not thought to be tied to the Angolan outbreak.

Some 41 cases have been lab-confirmed in the Democratic Republic of Congo, most imported from Angola. As well, 11 yellow fever cases imported from Angola have been reported in China, and two in Kenya.
Yellow fever, which is carried by the same mosquito that carries dengue, Zika, and Chikungunya, has caused trouble for humans since the first yellow fever epidemic was reported in 1648. In 1793, a yellow fever outbreak killed 10 percent of the population of Philadelphia. Annually, yellow fever kills 30,000 people globally. 
 
Preventative steps are outlined below:
Avoid Mosquito Bites

• Use insect repellent. When you go outdoors, use an EPA-registered insect repellent such as those containing DEET, picaridin, IR3535, or oil of lemon eucalyptus on exposed skin. Even a short time outdoors can be long enough to get a mosquito bite.

• Wear proper clothing to reduce mosquito bites. When weather permits, wear long-sleeves, long pants and socks when outdoors. Mosquitoes may bite through thin clothing, so spraying clothes with repellent containing permethrin or another EPA-registered repellent will give extra protection. Clothing pretreated with permethrin is commercially available. Mosquito repellents containing permethrin are not approved for application directly to skin.

• Be aware of peak mosquito hours. The peak biting times for many mosquito species is dusk to dawn. However, Aedes aegypti, one of the mosquitoes that transmits yellow fever virus, feeds during the daytime. Take extra care to use repellent and protective clothing during daytime as well as in the evening and early morning. Staying in accommodations with screened or air-conditioned rooms, particularly during peak biting times, will also reduce risk of mosquito bites.

Get Vaccinated If Recommended

• Yellow fever vaccine is recommended for people ages nine months and older who are traveling to or living in areas at risk for yellow fever virus transmission.

Yellow fever vaccine may be required for entry into certain countries. Yellow fever vaccination requirements and recommendations for specific countries are available on the CDC’s Travelers' Health page located in the link below:
 CDC Travelers' Health page.
 
Signs and Symptoms
The majority of people infected with yellow fever virus have no symptoms or only mild symptoms.

• In people who develop symptoms, the incubation period (time from infection until illness) is typically three to six days.

• The initial symptoms include sudden onset of fever, chills, severe headache, back pain, general body aches, nausea, and vomiting, fatigue, and weakness. Most persons improve after the initial presentation.

• After a brief remission of several hours to a day, roughly 15 percent of cases progress to develop a more severe form of the disease. The severe form is characterized by high fever, jaundice, bleeding, and eventually shock and failure of multiple organs.

 
Sources:
http://www.medpagetoday.com
www.cdc.gov
http://www.who.int/en/