Dengue is a sudden specific fever of about seven days duration,and characterized by pains in all over the body.a rash and a raise in temperature,by the cause of a specific filterable virus.Man is the reservoir of infection.The Aedes mosquito which has acquired infection from a case is the immediate source of infection.
The virus multiplies in the stomach of the female mosquito of Aedes and its transmission occurs to man through its bite about 10 days after taking a blood meal from a case of dengue during its infective period.The most Important vector species in India is Aedes aegypti which bites man in day and night.The incubation period is normally 4 to 7 days and can limit from two to fifteen days.
A case is infective to mosquitoes during the first 3 days of the illness,and the mosquito remains infective for the whole of its life period of 3-4 weeks after it becomes infective. Man possess no natural immunity,but an attack confers considerable immunity.Second or third attack may occur occasionally,but they are much milder than the first attack. In an endemic area local people enjoy
almost complete immunity.The new comers from non-infected areas are particularly susceptible and among them the disease occur with suddenness affecting large numbers.
Dengue has a wide distribution in tropical and sub-tropical areas and mainly in coastal region and and the deltas of great rivers.it is a disease of towns rather than of the villages of the country,In the tropics the disease is always onset of the monsoon rise.In the sub-tropics the incidence occur in summer and autumn.In India Dengue occurs in the eastern side of the country mainly north east and less in south east.It is also occurs in epidemic form in north-west India.In Bengal the highest disease occurs in August and September and also it may occur in epidemics.In Kerala also endemic cases occur during rainy season.
Though the disease is with no mortality,it is important as it may affect a number of people when occurring in epidemic form.
Prevention and control of the disease.
The only preventive measure of dengue is the control of the vector mosquito i.e .Aedes aegypti. This
mosquito has limited power of infiltration so that its breeding places to be eliminated from human habitations and places of working areas.This is effective in controlling dengue in epidemic areas.Use of repellents and protective clothing and mosquito nets come under personal protective measures.The use of insecticides are very important during epidemics. The patient should be treated under a mosquito net during day and night,as the vector Aedes aegypti mosquito is active in day and night.For attendants and contacts no action is essential.
pm kutty
very good,
ReplyDeleteuseful and informative.