- - Wanna share this article in order for us to be aware. . . it's all about the "DENGUE FEVER" since now a days, we really encountered heavy rains. Have time to read...
The onset of the rainy season in the Philippines brings with it a variety of mosquito-borne diseases that pose a serious threat to the health of all Filipinos. One of these diseases is dengue fever.
Because the environment’s wet conditions are a perfect breeding ground for these insects, each year the Department of Health sets up preventive guidelines in order to stop the spread of the disease. However, every year, the number of cases continues to increase.
Part of the problem is because there is little information disseminated to the public about the insidious mosquito responsible for the spread of dengue, namely Aedes aegypti. It is only by understanding the mosquito’s lifecycle that we can take measures to prevent an unwary populace from contracting the dreaded dengue fever.
Mosquitoes are particularly prevalent in tropical and subtropical regions of the world. Although there are many species of mosquitoes, the three main groups are Culex, Anopheles and Aedes.
Culex is the vector of the parasites that cause filariasis (an inflammation of the lymphatic circulation). Anopheles is the vector responsible for the spread of malaria.
There are two species of mosquito in the Aedes group that pose a serious health threat to human beings. The first is Aedes albopictus, the known vector of yellow fever. Our bigger concern, however, are the four arboviruses of dengue fever which are transmitted by Aedes aegypti.
Compared with other mosquitoes, Aedes aegypti is small, around three to four millimeters long, excluding the length of its legs. Totally black, it is distinctly marked with white spots on the head and body with white rings on its legs. There is a white lyre or harp-shaped design on its thorax, the “chords” of which are two dull yellow lines. Aedes aegypti has translucent wings, bordered with scales.
When at rest, the hind legs turn in a curve. These legs usually rub against each other; one leg crossed over the other, or are alternately raised and lowered.
Breeding and growth patternsMost species of mosquitoes lay their eggs in dirty or polluted water. Aedes, however, lays its eggs in clean water that does not contain other living species. While most mosquitoes lay their eggs in a cluster or “raft” formation, Aedes lays its eggs separately. The eggs are spread throughout the water’s surface, if environmental conditions permit. In this way, the eggs have a greater chance of survival. The eggs are white when freshly laid, but later turn black.
As they grow into larvae, Aedes feeds on bacteria present in the water and soon shed off their skins. Within a few weeks, the larvae progress to the pupal stage. A very short stage, the pupae rise to the surface of the water. As the top of its case pops open like a can lid, the adult Aedes mosquito emerges.
The male Aedes mosquito thrives on fruit. It is the female that bites animals and humans for blood, needed to hasten the maturity of its eggs.
Aedes, unlike other mosquitoes, has adapted itself to a life with man, its primary source of nourishment. It never lives more than ninety meters from human dwellings to ensure steady meals. While other mosquitoes produce an irritating humming sound. Aedes is able to reduce the hum so it can approach man undetected. A daytime feeder, it never flies toward a person’s face. It attacks from below and behind, usually from underneath tables and chairs, striking at the feet and ankles.
Read the entire article at The Manila Times!
