Dengue Fever and

Posted on 8:02 AM | By Gonks ^_^ | In , ,

Dengue fever disease is very scary world. Especially in Indonesia. This disease is even a seasonal disease and always repeated in the rainy season. Let us find out about dengue fever disease ranging from small children to adult who contracted.

fever is a relatively common problem in Indonesia and periodically reaches epidemic proportions in Jakarta and other parts of Indonesia, 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).
SYMPTOMS
Certainly in the first stages of illness, dengue fever is difficult if not impossible to clinically distinguish from the many other possible causes of similar symptoms and signs.

IN ADULTS:

Following the deposit of the dengue virus in the skin by the bite, there is a 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 turns 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 the majority of cases.

IN CHILDREN:

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.
CONFIRMING THE DIAGNOSIS

There are no immediately useful tests for dengue fever which are unequivocally accurate. However the laboratory can be used to aid confirmation of a clinically suspicious case:

    * The white cell count is often low unlike in bacterial causes of fever.
    * The dengue blot test can give both false positive and false negative results, especially in the first week of the disease.
    * The diagnosis will in a large proportion of cases be based on clinical presentation and a characteristic
      drop of platelets in the blood (platelets are often low - normal is 150,000 - 400,000).

Definite confirmation of the diagnosis of dengue infection can be made by sophisticated tests, but the results are not available for two weeks or more after the onset of the illness (because two separate blood samples need to be tested (by the same lab) for dengue antibody levels, the first as soon as possible after the onset of the illness, the second 10-14 days later).

Convalescence can take weeks, and bed rest and antipyretics and analgesics are required. An attack produces immunity for a year or more, but only to the one of the four flavivirus strains responsible for the intial illness.
DENGUE HAEMORRHAGIC FEVER / DENGUE SHOCK SYNDROME

A rare complication of dengue fever, dengue haemorrhagic fever, can occur, most often in small children and elderly adults. This can sometimes be a serious illness. If DHF / DSS occurs it will usually do so by day 3-5 of the fever.

IN CHILDREN

In children, the progression of disease is not always characteristic. A relatively mild first phase with an abrupt onset of fever, malaise, vomiting, headache anorexia and cough is succeeded 2-5 days later by weakness and, sometimes, physical collapse. Frequently, spots appear on the forehead, arms and legs, along with spontaneous bruises and bleeding from punctures where blood was taken. The more ill child may breathe rapidly and often effortfully; the pulse may be weak, rapid, and thready. Almost always patients have a positive “tourniquet test” (where a tourniquet i.e. a blood pressure cuff is applied and the skin demonstrates petechiae and / or bruising).

The WHO criteria for DHF are a platelet count of less than 100,000 and a haematocrit 20% greater then normal. Such children need to be hospitalized and watched for potential DSS. Such shock can be a mortal illness and requires rapid and careful in-hospital management with assiduous correction and replacement of fluid, electrolytes, plasma and sometimes fresh blood / platelet transfusions. The most useful laboratory test in suspected DHF is estimation of thrombocytes (platelets) which will be very low. In contrast to uncomplicated dengue fever the white cell count is more often high. Mortality ranges from 5 - 30% (in untreated native populations) and the highest risk is to infants under 1 year.
TREATMENT

There is no specific treatment for the infectious cause - the dengue virus - in either dengue fever or DHF / DSS. The symptoms 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 8-12 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.
TO AVOID GETTING DENGUE YOU MUST AVOID BEING BITTEN

In an epidemic, the emergency control measure is insecticide applied outside by vehicle-mounted or portable ultra-low-volume generators for a minimum 2 applications at 10 day intervals. The uncontrolled use of residual and space insecticides especially where inappropriate and possibly toxic materials are used, is to be avoided.

Do not allow indiscriminate use of insecticides around work sites or dwellings unless possible risks of their use are clearly understood. Know what you are doing and / or what chemical is being used.
PREVENTIVE MEASURES AGAINST MOSQUITOES

All varieties of mosquitoes breed in or near water that is stagnant or slow moving. The importance of mosquitoes in transmission of disease makes adequate control of mosquito-breeding sites very important, especially those close to human habitation.

In the long term community education and participation are necessary to eliminate mosquito breeding sites, especially those close to human habitation as mosquitoes usually fly less than one kilometer from where they are hatched. Over 50 important diseases can be transmitted by the bite of infected female mosquitoes - among these are malaria, dengue, Japanese B encephalitis, yellow fever, and a variety of forest and jungle fevers. Urban mosquitoes breed in any pools of standing water such as empty tin cans, old tires and water filled tire tracks, coconut shells, and the saucers under domestic pot plants. Rural mosquitoes breed in rice paddies, stagnant ponds and slow moving streams. So destroy mosquitoes and their larvae (young) by:

    * Clearing the neighborhood of ponds and pits.
    * Covering all water containers and any objects that can trap rain water (tires, pots, etc.). Invert any used buckets and containers that can trap water, and ensure roof gutters are not clogged.
    * Filling in or draining areas of stagnant water except for swimming pools and ornamental pools if they are aerated by a pump or fountain or similar.
    * Use of larvicides or mosquito larvae-eating fish in waters that cannot be drained.
    * In endemic mosquito areas, insist owners, employers and landlords supply screens on doors and windows and mosquito nets on beds.
    * Changing water in flower pots once a week and washing them thoroughly. Do not let plants stand in trays containing water. Scrub trays weekly to get rid of any mosquito eggs.
    * Fill tree holes with sand or cement and plug the tops of bamboo fences.
    * Remove and destroy old tires.
    * Installing mosquito screens on doors and windows and mosquito nets on beds.
    * Avoid the uncontrolled use of residual and space insecticides, and the use of toxic materials. Do not allow indiscriminate use of insecticides unless possible risks of their use are clearly understood. Know what you are doing and / or what chemical is being used.

Personal protective measures can greatly reduce the risk of being bitten. The use of mosquito deterrents in bedrooms is effective to reduce the number of mosquitoes in the room, but it does not prevent mosquito bites all together. The chemical deterrent is released through an electronically heated impregnated pad or gel, and its effectiveness depends largely on the size and ventilation of the room.

Other personal protection methods include:

    * Use of mosquito coils and "knockdown spray" (containing pyrethoids)
      - spray insecticide in cool dark places where mosquitoes lurk.
    * Avoid use of dark colored clothing, perfumes and colognes in the
      evening and at night, as all these attract mosquitoes.
    * Use of an effective mosquito repellent on exposed skin and clothing.
      DEET (diethylmethylbenzamide) is an effective safe component of good
      repellents. The actual concentration of DEET varies widely between
      different manufacturers, and can be as high as 90% (too high for safety).
      Choose a repellent with between 30-45% DEET and take the following
      precautions against adverse reactions:
      a. apply sparingly and only to exposed skin
      b. never apply high concentrations to skin (use those for clothing)
      c. do not inhale / swallow repellent or get in eyes or mucous membranes
      d. do not apply to hands that may touch eyes or mouth
      e. do not apply to wounds, rashes, or abrasions
      f. wash repellent off after coming indoors to stay
      g. if skin starts to burn, wash repellent off and seek medical advice
      DEET-based repellents should last for up to 4 hours.

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