Dengue Fever: Who, Where, and When

Dear, Auntie:

Today you asked me What Causes Dengue and How is it Transmitted? This is the study of epidemiology.

Dengue is transmitted from person to person by the Aedes aegypti and Aedes albopictus mosquitoes.[1] These mosquitoes are known as "vectors" because they pass the Dengue virus from one person to another. Many people distinguish the mosquitoes which transmit malaria from the mosquitoes which transmit Dengue by the white stripes on the legs.

Figure 1. This is the Aedes albopictus mosquito which is
responsible for infecting people with the Dengue virus. 

In order to pass the virus from person to person, the mosquito must bite the Dengue infected person while they are showing signs of Dengue infection and the mosquito will be able to infect other humans about 8 days after biting the infected person.[1] It usually takes a week after a mosquito bite to start showing signs of Dengue infection and the illness lasts about 3-10 days.[1]

Dengue Fever is endemic (or common) in tropical or subtropical places like Guyana and other South American countries. However, in the United States it is not common, despite the tropical weather in some Southern states and the closeness to Mexico, simple because of infrequent exposure to Dengue infected persons in the US.[1,2]

Figure 2. The countries in orange are those who had reported cases of Dengue in 2010 according to the World Health Organization. As you can see, most of these areas are just North and South of the equator where the climate is tropical.[2]

References:
1. Epidemiology: Transmission of the Dengue Virus. Centers for Disease Control and Prevention Web site. Updated. Jun 9, 2014. Accessed on: April 6, 2015. Accessed From: http://www.cdc.gov/dengue/epidemiology/
2. Murray NE, Quam MB, Wilder-Smith A. 2013. Epidemiology of dengue: past, present, and future propects. Clin Epidemiol 5: 299-309. doi: 10.2147/CLEP.S34440. 

Dengue Fever: "Ah, Lawd! Me bones bun an bruk."

Dear, Auntie:

You asked me to tell you more about Dengue Fever, known as Break-Bone Fever in many parts of the world. So I decided to write you a whole, interactive blog about it!

I am sure you have seen Dengue fever in action - the terrible fever and the pain in the joints and bones that makes the illness feel almost unbearable. Guyana joins one-third of the world's population in living in an area where dengue fever is common [1]. Auntie, if you are interested in learning more about Dengue around the world, click here!

Here is a summary of the important points you should keep in mind as we learn more about Dengue together [2]:
 - Humans get sick with Dengue from a virus carried by mosquitoes
 - People with Dengue have flu-like symptoms: fever, bone/joint pain, etc.
 - Dengue is found in tropical climates (like Guyana)
 - There is no specific treatment for Dengue, but most people will not die from Dengue is they seek early treatment.
 - Controlling mosquitoes is the most effective way to guard yourself against Dengue.

Here is a cool video to help you understand a little more about Dengue, but we will talk more about it over the next few weeks.

References:
1. Dengue. Centers for Disease Control and Prevention (CDC). Web site. Accessed online from: http://www.cdc.gov/Dengue/
2. Dengue and Severe Dengue. The World Health Organization (WHO). Web site. Accessed online from: http://www.who.int/mediacentre/factsheets/fs117/en/.