Yellow fever


In 1881, Carlos Juan Finlay, a physician in Havana, first proposed that yellow fever was a mosquito-borne illness, which subsequently was proven by Walter Reed and colleagues. 

U.S. Army doctor Discovered the Cause of Yellow Fever August 27, 1900.

Walter Reed, M.D., (1851-1902) was an American Army surgeon who led the team which proved the theory first set forth in 1881 by the Cuban doctor and scientist Dr. Carlos Finlay that yellow fever is transmitted by mosquitoes rather than direct contact. The risky but fruitful research work was done with human volunteers, including some of the medical personnel such as Clara Maass and surgeon Jesse W. Lazear Walter Reed Medal winner who allowed themselves to be deliberately infected and died of the virus. All this lead to the elimination of Yellow Fever from Cuba and allowed the final construction of the Panama Canal. 

Yellow fever has caused many terrible epidemics over the history of the word! It is fascinating to discover the world of yellow fever, and the devastation!



Yellow fever is an acute viral infectious disease that is transmitted to humans through the bite of infected mosquitoes. Though many cases of yellow fever are mild and self-limiting, yellow fever can also be a life-threatening disease causing hemorrhagic fever and hepatitis (hence the term "yellow" from the jaundice it can cause.  

Yellow fever is an infectious disease caused by the yellow fever virus. It is transmittted to humans by the bite of infected mosquitoes. It is endemic in areas of Africa and South America.

  • The symptoms of yellow fever include fever, headache, and muscle aches, with some patients going on to develop life-threatening complications
  • Yellow fever is diagnosed clinically, with laboratory confirmatory testing available.
  • The treatment for yellow fever is supportive.
  • Yellow fever can be prevented by vaccination and mosquito-control measures. 

The history of yellow fever

This viral disease occurs in tropical areas of Africa and South America, and each year there are an estimated 200.000 cases of yellow fever worldwide, leading to approximately 30,000 deaths. An  increase in the number of cases of yellow fever in the last few decades has led to campaigns aimed at improving public awareness and disease prevention for this re-emerging infectious disease.   

Yellow fever is thought to have originated in Africa and was likely brought to the Americas on ships during the slave trade. Several significant yellow fever outbreaks have occurred throughout history, with the first documented outbreak occurring in the Yucatan peninsula during the 17th century. During the late 18th century, a severe yellow fever outbreak struck New England and several North American port cities. The city of Philadelphia is thought to have lost about one-tenth of its population during the 1793 yellow fever epidemic, causing many notable figures in American politics to flee the city. The last major yellow fever outbreak in North America occurred in New Orleans in 1905.

The theory that yellow fever is transmitted by a mosquito was first introduced by a Cuban physician, Dr. Carlos Finlay, in the late 19th century. It was not until 1900, using earlier research from Dr. Finlay as a foundation, that U.S. Army Major Dr. Walter Reed and his team proved that yellow fever was in fact transmitted by mosquitoes. This groundbreaking idea was instrumental in leading to the subsequent control of yellow fever in various regions. The virus responsible for yellow fever was later isolated in the late 1920s, and this breakthrough discovery allowed Max Theiler to later develop the first vaccine against yellow fever in the 1930s. This successful vaccine helped control and eliminate yellow fever from various countries in Africa and South America during the mid-20th century.

How does yellow fever attack the bodies of its victims?

Yellow fever is caused by infection with a flavivirus. This virus replicates in the blood and tissues, potentially damaging the body's vita organs. The liver is often affected. When liver function declines, The skin and eyes become yellow, a condition known as jaundice, and the body's ability to form blood clots is compromised. Difficult-to-control bleeding may occur from areas such as the intestines. Damage to the heart, brain, and other vital organs. It can also cause shock, coma and increased susceptibility to bacteral infections. If a person survives a sever infection, it may take several months to fully recover.   Honor sociaty of Nursing (STTI)

Signs and symptoms of yellow fever

Once contracted, the virus incubates in the body for 3 to 6 days, followed by infection that can occur in one or two phases. The first, "acute", phase usually causes fever, muscle pain with prominent backache, headache, shivers, loss of appetite, and nausea or vomiting. Most patients improve and their symptoms disappear after 3 to 4 days. However, 15% of patients enter a second, more toxic phase within 24 hours of the initial remission. High fever returns and several body systems are affected. The patient rapidly develops jaundice and complains of abdominal pain with vomiting. Bleeding can occur from the mouth, nose, eyes or stomach. Once this happens, blood appears in the vomit and faeces. Kidney function deteriorates. Half of the patients who enter the toxic phase die within 10 to 14 days, the rest recover without significant organ damage.

Yellow fever is difficult to diagnose, especially during the early stages. It can be confused with severe malaria, dengue hemorrhagic fever, leptospirosis, viral hepatitis (especially the fulminating forms of hepatitis B and D), other hemorrhagic fevers (Bolivian, Argentine, Venezuelan hemorrhagic fevers and others flavivirus as West Nile, Zika virus etc) and other diseases, as well as poisoning. Blood tests can detect yellow fever antibodies produced in response to the infection. Several other techniques are used to identify the virus in blood specimens or liver tissue collected after death. These tests require highly trained laboratory staff and specialized equipment and materials.

Do you think you know a lot about this awful disease? Well, here you have many quizzes, try to do your best in your own evaluation. Good luck!    

For more information related to this topic click on each link:

  • Ref : Monitoring the mosquito Aedes aegypti: A novel surveillance method and newentomological indices using the gravid trap MosquiTRAP. and a synthetic oviposition attractant (AtrAedes.)
  • Ref: Aedes aegypti survey of Chennai* Port/Airport, India
  • Manson’s tropical disease – 21st edition

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