A recent article on Medical News Today discussed Dengue Fever as the fastest growing vector-borne disease in the world. Dengue is a viral illness that is spread by the bite of infected Aedes mosquitoes. This illness, once confined to SE Asia has now become more common in Latin America, Asia, Africa, North America and even Australia. Dengue, nicknamed “breakbone fever” due to the wracking muscle cramping it causes, has no specific treatment and carries a case fatality rate of 40-50% if left untreated and progresses to the dreaded Dengue Hemorrhagic Fever (DHF).
Dengue fever is a flavivirus that is classified into 4 different strains, named Dengue 1, 2, 3 and 4. All four strains can be present in the same geographic area, at the same time. Once a person is infected with a specific strain of Dengue, they are believed to be immune to that strain for life. The problem occurs when a person who has been previously infected with one strain acquires a second and different strain; This second infection increases the likelihood that a person will acquire Dengue Hemorrhagic Fever (DHF), characterized by uncontrolled bleeding from the gums, intestinal tract, skin rash and fevers. The increased risk of progression to DHF with each subsequent infection is exactly one of the reasons why producing a successful vaccine has been so difficult.
Symptoms of Dengue fever can be as mild as a slight fever, head and muscle aches, rash and nausea/vomiting. Often, the first case of Dengue gets undiagnosed by a person who believes they simply have a bad cold and then go on to make a full recovery. This has now made their body a candidate for DHF should they become infected a second or even third time.
The World Health Organization estimates that there are roughly 50 million Dengue infections per year and 2.5 billion people live in areas at risk. That's 2/5 of the world’s population. In 1970, there were only 9 countries with Dengue fever and at present that list has grown to 100 countries. With the Aedes Mosquito acting as the vector or carrying agent, one can clearly see the explosive growth the mosquito species has had as well.
Researchers are attempting to link increased global temperatures and rainfall with the increased Dengue activity. The idea that warmer weather leads to increased mosquitoes and mosquito breeding grounds are nothing new, especially combined with standing water which allows the mosquitoes to have an ideal breeding ground.
Prevention of Dengue fever by travellers centers around several key points. First, knowing that one is traveling in a potential Dengue area should raise alerts and prompt you to be cautious.
Second, prevention of mosquito bites should become a way of life. Using DEET sprays, permethrin treated clothing, bed nets and long sleeves and pants are vital steps to help keep mosquitoes away from your skin.
Lastly, be cautious of areas with standing water such as upturned canisters, flower pots, tires that may contain water and lakes or large puddles. Public Health campaigns center on the destruction of these standing water breeding grounds, trying to eliminate of at least decrease the Aedes mosquito population.
Travellers headed to areas with Dengue activity should travel prepared. Caution should also be used when looking at the time of year, especially during rainy seasons. Dengue should not be going away anytime soon and savvy travelers need to be aware of it and start getting used to taking proper precautions.