Type: Viral

Geography: Americas, Africa, Middle East, Southeast Asia, Pacific Islands

Fatality rate: 1%

Cases per year: 100 to 400 million

First discovered: 1943 in Japan by Ren Kimura and Susumu Hotta

Dengue is spread to people through the bite of an infected mosquito. It is common in more than 100 countries around the world, and about 40% of the world’s population (3 billion people) live in areas with a risk of dengue. There are 4 types of dengue virus, so people could become infected up to 4 times in their lifetime. Dengue epidemics peak during and after rainy seasons due to the increase in mosquito population levels, precipitation and humidity, and air temperatures.

3 out of 4 people infected with dengue do not get sick, but travelers should take precautions. The most common symptom of dengue is fever along with any of the following: nausea and vomiting, rash, aches and pains (bone, joint, muscle, behind the eyes, or headache). Symptoms usually last 2 to 7 days and most people recover after about a week. About 1 in 20 people infected will develop severe dengue, with symptoms such as: stomach pain or tenderness, vomiting, bleeding from the nose or gums, vomiting blood or blood in the stool, and feeling tired or restless. Severe dengue can result in shock, internal bleeding, and even death, and typically appears 24 to 48 hours after the fever has gone away.

Protection against dengue includes protecting oneself from mosquito bites by using the correct insect repellent, wearing long pants and long sleeves, and using mosquito netting when sleeping. Once a person has already been infected with dengue virus, they can receive the vaccine.

Photo: Dengue virus – Electron micrograph