Dengue fever is a vector borne disease caused due to transmission of dengue virus from patients to new victims by Aedes mosquitoes. The occurrence of Dengue has increased in the past decade due to increased vector host interactions. The principle vector of dengue is Aedes aegypti. Female aedes mosquitoes feed on bloods of human and mammals to develop eggs. Aedes mosquitoes develop in stagnant water present indoors as well as outdoors. Aedes mosquitoes can breed in varieties of habitat ranging from water collected in the Air conditioners, flower vas, refrigerators, rain water collected in coconut shells, water collected in the crevices of trees, etc. Aedes mosquitoes are active in both day and night and will cause biting nuisance entire 24 hours. Aedes mosquitoes are short fliers and hence can't fly long distance. Therefore breeding place of aedes mosquitoes will be close to human dwellings. The important feature of aedes mosquitoes is that the eggs can withstand desiccations/drought. The female aedes mosquitoes lay eggs on the surfaces above water where moisture is present. The eggs if the water is dried won't die but will hatch when water is filled later. This unique phenomenon makes control of aedes mosquitoes much difficult. Aedes mosquitoes unlike other mosquitoes doesn't require full blood meal to produce eggs, rather female aedes will develop eggs proportionate to amount of blood ingested. This biology of aedes mosquitoes makes it efficient in multiplying in short duration.
Dengue fever is associated with fever, joints pain, headache and rashes. The joints pain observed in dengue fever is the most cause of concern as it is reported that the many patients struggles to move their joints for few days and it takes months to reduce the pain of joints and do normal activities. Dengue hemorrhagic fever is the more severe form of dengue if not treated properly, results in the internal bleedings and organ damages leading to death of patients. Dengue is caused by flavi-virus that is divisible in to four serotypes as DV1, DV2, DV3 and DV4. Dengue virus belongs to the single stranded RNA type of virus with genome size of near 11Kb. The genome codes for a single open reading frame (ORF), containing structural and non-structural proteins with highly organized 5' and 3' flanking untranslated sequences.
Dengue illness is classified into three phases as fever, critical and recovery phases. Most of the Dengue patients recover from fever, but in few the situations might get complicated. There is no proper treatment for dengue except monitoring and fluid replacement. The Dengue hemorrhagic patients have to be carefully monitored and if required body fluid should be balanced, so that the patients can recover within few days. Patients with serious hemorrhagic or very low platelet counts are transfused with platlets. If not properly monitored Dengue hemorrhagic becomes fatal, the blood capillaries ruptures causing internal bleeding in the organs, which might leads to organ failure leading to death of patient.
The vector management is the best remedy for controlling Dengue as there no proper medicines or vaccines. The surroundings of the human dwelling should be cleaned and the empty containers like tyres, pots, coconut shells, empty bottles etc., should be removed. Inside house, care should be taken to remove water collected in Air conditioners, refrigerators once in three days as the aedes mosquitoes has the capacity to grow in few ml of waters collected in these appliances. The aedes mosquitoes larvae can develop into adult within a week, hence open water tanks should be cleaned once in a week. The aedes mosquitoes are small and difficult to control through bed nets or window screens and they are active in both nights and days. Hence source reduction is the best method in controlling aedes mosquitoes than other conventional methods like insecticides or bed nets. The frequencies of dengue increases in rainy seasons as the mosquitoes multiply rapidly due to availability of more breeding place. Therefore in rainy season care should be taken to remove collected rain waters in waste containers.
Community participation in the vector control program is the proper remedy for vector borne diseases such as dengue. The breeding place of the aedes mosquito vector if controlled, will results in less mosquitoes nuisance and also reduced chance of vector host contact and also vector virus contact, which will culminates in less Dengue cases.
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An enthuiastic author from India