Mosquitoes are number one human killer in the world. Aside from malaria, another disease that is wrecking havoc over tropical and sub-tropical countries is the dengue fever. And today, the disease is spreading throughout the world. World Health Organization (WHO) estimates that between 50 and 100 million people around the world falls victim to this disease? A large portion of the victims are mainly children and those that have a poor immune system. Even though the mortality rate is low at 2.5 %, just imagine how many people died out of 50 million victims.
The dengue fever is an illness thatis being transmitted to humans through a bite of certain mosquito species. To date, there had been four kinds of virus strains known to medicine that causes dengue fever. Dengue fever had been known to science for more than 200 years already to which its original name was called a “break-bone” fever. The term given because of the severe joint and muscle pains symptoms associated with the disease to which the patient fells like his bone are breaking inside.
The disease is being carried off by a certain species of mosquitoes – the Aedes aegypti. One of the major characteristic of this species is that they only bite during daytime and propagate in clean waters. These mosquitoes often bites the elbow area as well was below the knee. Recent studies show that another mosquito species can be also a prominent carrier of the dengue virus – the Asiantiger mosquito (Aedes albopictus). This secondary dengue carrier is now spreading to colder climate countries such as North America and Europe. The Asian tiger mosquito is more adaptable to colder temperatures and is able to tolerate freezing temperatures, thus having the ability to propagate and spread to larger area.
These two mosquito species are not able to breed if the temperature falls under 16 degrees C. But in tropical countries, this temperature rarely reached this mark; therefore the danger of dengue fever is a year-round problem. But the peak occurs during rainy season to which there is lots of free water to breed at. While in colder climates, there had been known cases of dengue fever encountered during winter.
But how does these mosquito species transmit the dengue virus to humans? Female mosquitoes needed blood in order to breed. And often times, these mosquitoes doesn’t mind if the blood is contaminated with the disease as they are not affected by it. Once a female mosquito bites a person with dengue, they become a carrier of the disease. Later, when they bite a healthy person, they had also transmitted the virus. There had been no reported cases that the dengue virus can be transmitted from person to person. Therefore, it needs a mosquito as the transitional vector of the disease.