Dengue virus (DENV) is an arthropod-borne single stranded RNA
virus infecting around 100 million people every year and owes its complexity
due to its existence as distinct serotypes (DENV1, DENV2, DENV3 and DENV4). The
genome size of all DENV serotypes is approximately 11 kb consisting of 5′ UTR,
a single polyprotein sequence which codes for three structural proteins and seven
non-structural proteins and a 3′ UTR. DENV infections increase health and
economic burden mainly due to complications of this infection such as dengue
haemorrhagic fever and dengue shock syndrome (2 & 3). These four viruses are called
serotypes because each has different interactions with the antibodies in human
blood serum. The four dengue viruses are similar — they share approximately 65%
of their genomes — but even within a single serotype, there is some genetic
variation. Despite these variations, infection with each of the dengue
serotypes results in the same disease and range of clinical symptoms.
days after feeding on blood, the mosquito lays her eggs inside a container just
above the water line. Eggs are laid over a period of several days, are
resistant to desiccation and can survive for periods of six or more months.
When rain floods the eggs with water, the larvae hatch. The entire immature or
aquatic cycle (from egg to adult) can occur in as little as 7-8 days. The life
span for adult mosquitos is around three weeks. Aedes aegypti genome contains ?1376 million (1.376
billions) base pairs, which is about 5 times the size of the genome of the
malaria vector Anopheles gambiae (12).
larvae feed upon small aquatic organisms, algae and particles of plant and
animal material in water filled containers. The adult feed on nectar. On the
other hand female need blood to produce eggs, and that is why female of
mosquito is responsible for the transmitting the viruses not the male.
aegypti is a small,
dark mosquito with white lyre shaped markings and banded legs. This species is
most active for approximately two hours after sunrise and several hours before
sunset, but it can bite in well-lit areas. The mosquito bites humans, dogs, and
other domestic animals, mostly mammals. These mosquitos can use natural
locations or habitats; such as tree holes and plant axils, and artificial
containers with water to lay their eggs. They lay eggs during the day in water
containing organic materials (decaying leaves, algae, etc.) in containers with
wide opening and prefer dark colored containers located in the shade.