The Mosquito Coast
By Collin Myers, Technical Writer/Marketing Assistant
I grew up in a small Maryland town smack dab between two rivers – the Severn and the Magothy. During the insufferable months of summer, when the humidity is so thick that it can make everyone’s breathing sound asthmatic and laborious, I remember constantly being under attack by mosquitoes. In Maryland, our major insectile nemesis is the Japanese Tiger Mosquito. These mosquitoes are larger in size than any other mosquito I’ve ever seen – they have long black legs and their backs are covered in white spots. Nowadays, in the evenings, I have a habit of wearing jeans all summer long as a defense against the little vampires.
A friend of mine from Miami, Florida, who says that there are a lot of similarities between our two home states: humid, boiling summers, heat storms, and close proximity to numerous bodies of water – lakes, rivers, and bays. I often joke that as a resident of Maryland, we’re living in a pseudo-Amazonian swamp. And of course the other similarity between our home states: both are infested with bloodthirsty mosquitoes.
In 2009, officials in Florida identified nearly 30 cases of Dengue Fever, a disease carried by infected mosquitoes. Outbreaks have also been found in Central America (Puerto Rico recorded around 5,000 infections in the year 2012 alone), as the number of mosquito-borne illnesses continues to increase. Dengue Fever causes a range of symptoms including fever, vomiting, headache, nausea, skin rashes, and joint and muscle pain. These symptoms are often confused with influenza and other viral infections. For a small percentage of those who are infected, the illness can be extremely painful and excruciating, and in some cases can cause death. Dengue often shows no serious symptoms, and physicians have not yet grown accustomed in their respected practices at accounting for Dengue Fever as a serious threat to their patients’ health. One physician in Florida actually laughed at one of his patients when she suggested that she feared she might have contracted Dengue (it was later discovered that this patient did in fact have the virus).
Prior to World War II, Dengue Fever actually held endemic status in the United States, but the US Army managed to eliminate most cases of the disease as a result of determined efforts to curb malaria infections among troops. But unlike malaria, there are no drugs proven to cure or suppress Dengue, and until recently, attempts to create an effective vaccine have failed.
Sanofi Pasteur, an American affiliate of the French firm, Sanofi, will begin applying for licenses as early as 2015 to gain the authority to produce a vaccine for chimeric yellow fever (CYD). According to vice president Guillaume Leroy, Sanofi has been attempting to quietly develop a useful vaccine for nearly 20 years. So far a candidate vaccine has shown to be effective against only certain Dengue serotypes, but a larger additional study is planned involving 20,000 children in countries like Mexico, Brazil, and Puerto Rico.
The World Health Organization (WHO) estimates that there are between 50 and 100 million Dengue infections each year, and cases have been reported in multiple states in the US, including Hawaii, Texas, and Florida. The disease is still considered very minor in the US when compared to the number of estimated infections found worldwide – WHO recently revised its estimates to show that more than 390 million people may harbor the disease (though many only sustain very minor symptoms). The disease causes an average of 12,000 deaths per year. A majority of the worldwide cases of Dengue are found in Central and South America, central Africa, and southeast Asia.
There are two species of mosquito that can carry Dengue. The most prominent is known as Aedes aegypti, also known as the “yellow fever mosquito??? found in a number of tropical countries around the world. Aedes aegypti originated in Africa and is also a potential carrier of both yellow fever and Chikungunya. Females always bite humans because they require blood to mature their eggs and reproduce. These mosquitoes are highly attracted to man-made chemicals including ammonia, carbon dioxide, lactic acid, and octenol. The Asian Tiger mosquito, also known as Aedes albopictus, is characterized by its black and white striped body and legs. This species of mosquito became more widespread due to an increase in international shipping and transportation. The Asian Tiger Mosquito was responsible for the first ever Chikungunya epidemic, which struck Italy in the summer of 2007, infecting over 200 people.
Recent reports from the Florida Department of Health state that 24 separate cases of Dengue fever have been confirmed. Each infected patient had recently traveled to the Caribbean and contracted the virus. In some views, viruses are traveling more rapidly now due to the frequency of international plane travel, cruise ships, and the ever expanding world population. The more human hosts available to contract a virus, the more likely the virus will spread.
As Dengue continues to spread, epidemics have broken out in Venezuela and Honduras. Dengue is also endemic to northern Mexico and southern Texas. Infections can also cause complications characterized by high fevers, hemorrhagic phenomena, convulsions, and circulatory failure. Contracting the virus multiple times greatly increases the severity of these symptoms, and symptoms are often intensified in immunocompromised individuals and the elderly.
Certain pain relievers have shown to calm milder symptoms. Normal treatment methods include rest, drinking fluids, and visiting a physician. The best method of precaution, however, may be to defend against mosquitoes using insect repellent, staying indoors, running air conditioners, and keeping windows closed, avoiding outdoor activities in late afternoon hours when mosquitoes are most active. In the meantime, the showdown between science and nature will continue, as humans race to discover a cure to this pesky disease.