Monday, December 7, 2009

Dengue Alert

What is dengue?

Dengue fever is a relatively common problem in Asia and periodically reaches epidemic proportions in some countries like Indonesia, Philippines and others, usually every 4-5 years. Rarely fatal in fit adults, the patient is often left debilitated and requires considerable time for convalescence. Dengue Fever is most common during the rainy season (November - May) as the mosquito requires clean standing water to reproduce.

Dengue occurs due to infection by a flavivirus which is transmitted by the bite of the Aedes mosquito. (Unlike malaria, this disease occurs in greater Jakarta - urban dengue occurs in nearly all tropical countries like I said it before).


Certainly in the aboriginal stages of illness, dengue fever is difficult if not impossible to distinguish clinically from the many other possible causes of similar symptoms and signs.


The deposit of the dengue virus in the skin by the bite, there is an incubation period of 2 - 14 (usually 4 - 8) days.

Thereafter onset of symptoms is usually abrupt, coinciding with viremia (the virus multiplying in the bloodstream) with chills, headache, backache, weakness, pain behind the eyes, flushing of the face, muscle and joint pain, and lassitude. The joint and back pains can be very bad indeed; hence the older name 'breakbone fever'.

The temperature rapidly rises, often to 40°C (104°F), and there is a low heart rate (compared to the degree of, and other causes of, high fever). The blood pressure is often low also. A transient rash which blanches under pressure may be seen during the first 24 hours of fever.

During the 2nd to 6th day of fever, nausea and even vomiting may occur, and the patient may develop one or more of the following; skin hypersensitivity, generalized swelling of regional lymph nodes, swelling of the palms, changes in taste sensation, loss of appetite, constipation, anxiety and depression.

Within 2 to 4 days a temporary improvement can occur with a sudden drop in temperature and subjective improvement - for 24 hours until there is a second rapid temperature rise. A generalized morbilliform (“measles-like”) rash appears a characteristic rash on the trunk, limbs, palms and soles especially. (This second febrile phase does not invariably occur). This rash usually disappears in 1-5 days, the skin in these areas turn bright red and may peel. The temperature should fall back to normal and the infectious episode is effectively over.

Epistaxis (“nose bleeds”), petechiae (“red skin spots”) and purpuric skin lesions (“purple skin spots / bruises”) can occur at any stage of the disease, varying with age, sex, and type of dengue virus. Bleeding from the gastrointestinal tract, and excessive vaginal bleeding if menstruating can also occur, but do not usually occur in most cases.


A fever occurs in nearly all dengue infections in children; the other most common symptoms are a red throat, a (usually mild) runny nose, cough, and mild gastrointestinal symptoms which of course may present similar to pharyngitis, influenza, and upper respiratory infections.

The presentation of dengue in the younger child is much less characteristic than in the older child and adult as above.


It has no particular cure for the infectious caused by dengue virus in dengue fever or DHF / DSS. The complications can and should be treated, and in the rare cases of DSS, treatment for shock as well as a low platelet count is both essential and available including fresh blood and / or platelet transfusion but there is no medicine or vaccine anywhere available that can act specifically against the virus.

It has been suggested that DHF is more likely if the patient has previously had an attack of dengue within the last calendar year (generally within the last eight-twelve months), and that the occurrence of DHF relates to this previous "sensitization". Previous exposure may raise the incidence of subsequent DHF, presumably (as experiments have shown) by the antibody elicited in response to the first infection, being capable of enhancing the infection due to the virus found in the second episode.

Uncontrolled bleeding distinguishes this from uncomplicated dengue fever. Bleeding can occur from the gums, nose, intestine, or under the skin as bruises or spots of blood especially under a tourniquet this test should be employed if there is any suspicion. The liver is often enlarged.

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