So, Yellow Like a Lemon? What Exactly is Yellow Fever?

It is a disease that is caused by a virus and is spread to humans by the bite of an infected mosquito. It is found in tropical and subtropical areas in South America and Africa and is endemic in a total of forty-four countries. Though it is a very rare cause of illness in U.S. travelers to these areas, it is a major cause of death for the local population of these areas.  According to the World Health Organization (WHO), up to 50% of severely affected persons without treatment will die from yellow river.

Endemic Zones in Africa

Endemic Zones in South America

The number of yellow fever cases has actually increased over the past two decades despite the fact that an effective vaccine is available as a preventative measure against yellow fever.  A large-scale push for vaccination in Africa during the 1930s and 1960s reduced yellow fever incidence for several decades but subsequent low vaccination coverage allowed for resurgence of the disease in the area. In South American, the rate of transmission of yellow fever is lower than that of Africa due to higher vaccine coverage and more aggressive immunization campaigns following yellow fever outbreaks.

In addition to declining population immunity to infection as a result of low vaccination overage, raising yellow fever cases are also related to deforestation, urbanization, population movements, and climate change.

As of 2006, there have been efforts to accumulate funding for large preventative mass vaccination campaigns in the most affected countries of Africa to control for future outbreaks and manage current disease burdens. Recent research published in 2014 by PLOS Medicine estimate that as a result of mass yellow fever vaccination campaigns from 2006-2012, there has been a 27% drop in the number of cases of yellow fever and deaths across Africa in 2013. 

Why is it called “yellow” fever?

The “yellow” in the name refers to the jaundice caused by hepatitis (inflammation of the liver) that affects some patients.

Why should you care?

As mentioned above, although it is rare for U.S. travelers in these areas to be infected by this disease, there have been cases where it does occur. It will be important for you to be informed of what yellow fever is, especially if you intend to travel to areas at risk for yellow fever transmission. Proof of yellow fever vaccination may be required for entry into certain countries, and reading up on what the vaccine is, its effectiveness, recommendations, and potential side effects will allow you to be an informed consumer.

In the following posts, we will delve more into yellow fever as a disease topic and talk about the epidemiology of the disease (who it affects, where is it most prevalent), the pathophysiology of the disease (how is the virus transmitted), how the disease is diagnosed, what are the signs and symptoms of the disease, prevention and treatment options, nursing care of individuals with the disease, and nursing diagnoses related to this disease.  

See you next week!


References

Barnett, E. D. (2007). Yellow fever: epidemiology and prevention. Clinical Infectious Diseases, 44(6), 850-856. doi:10.1086/511869

Centers for Disease Control and Prevention. (2011). Yellow fever. Retrieved from: http://www.cdc.gov/yellowfever/

Garske, T., Van Kerkhove, M. D., Yactayo, S., Ronveaux, O., Lewis, R. F., Staples, J. E., ... Feruson, N. M. (2014). Yellow fever in africa: estimating the burden of disease and impact of mass vaccination from outbreak and serological data. PLOS Medicine, 11(5). doi:10.1371/journal.pmed.1001638

World Health Organization. (2014). Yellow fever (Fact sheet No. 100). Retrieved from: http://www.who.int/mediacentre/factsheets/fs100/en/