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Dengue fever

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					                              Dengue fever
Symptoms
Signs and symptoms of dengue fever usually begin four to seven days after you've been
bitten by a mosquito carrying a dengue virus. These signs and symptoms can vary,
depending on the form of the disease. More severe forms of the disease usually begin the
same way as the mild form (dengue fever), then become worse after several days.

Dengue fever signs and symptoms typically include:

      High fever, up to 105 F
      A rash over most of your body, which may subside after a couple of days and then
       reappear
      Severe headache, backache or both
      Pain behind your eyes
      Severe joint and muscle pain
      Nausea and vomiting

Dengue fever rarely causes death, and symptoms usually get better after five to seven
days.

Dengue hemorrhagic fever — a more severe form of the disease — can also cause:

      Significant damage to your blood and lymph vessels
      A decrease in the number blood cells that help your blood clot (platelets)
      Bleeding from the nose, mouth and under the skin, creating the appearance of
       bruising
      Death

Dengue shock syndrome — the most severe form of the disease — may also cause:

      Blood vessel fluid (plasma) leakage
      Heavy bleeding
      A sudden drop in blood pressure (shock)
      Death

These signs and symptoms usually appear between the third and seventh day of illness,
after fever has improved. They may be preceded by severe abdominal pain, frequent
vomiting and disorientation. Two percent to 5 percent of those with a severe form of the
disease die. Modern supportive hospital care decreases this risk.

Recovery from dengue fever may include a long period of listlessness, fatigue and even
depression.
Causes
Dengue fever is caused by any one of four dengue viruses spread by the Aedes aegypti

Mosquito. These mosquitoes thrive in and near human habitations where they breed in

even the cleanest water.




                                    Aedes aegypti mosquito


Mosquitoes transmit the virus back and forth between humans. When a mosquito bites a
person infected with a dengue virus, the virus enters the mosquito's bloodstream. It then
circulates before settling in the salivary glands. When the infected mosquito then bites
another person, the virus enters that person's bloodstream, where it may cause the serious
illness.

You can become infected with dengue fever more than once. This happens when you're
exposed to a different one of the four dengue viruses than one to which you were
previously exposed. Infection a second time is typically what causes the more severe
form of the disease — dengue hemorrhagic fever.




                                      Dengue Virus
Tests and diagnosis
Diagnosing dengue fever can be difficult. That's because its signs and symptoms can be
easily confused with those of other diseases, such as malaria, leptospirosis and typhoid
fever. Still, diagnosis of dengue fever is typically done by evaluating your signs and
symptoms along with your medical and travel history. To diagnose your condition, your
doctor will likely ask about these. In addition, your blood may be tested for evidence of a
dengue virus.

Medical history
your doctor will likely ask about your medical and travel history and any exposure to
mosquitoes. Be sure to describe international trips in detail, including the countries you
visited and the dates, as well as any contact you may have had with mosquitoes.

Blood tests
Laboratory tests, usually using a sample of your blood, are needed to confirm a diagnosis
of dengue fever. If you have dengue fever, your blood may reveal the virus itself. If not,
blood tests known as hemagglutination inhibition (HI) assay, enzyme-linked
immunosorbent assay (ELISA) and reverse transcriptase-polymerase chain reaction (RT-
PCR) also can detect antigens, antibodies or nucleic acids specific to the viruses. These
tests may take several days.




Treatments and drugs
No specific treatment for dengue fever exists.

If you have a mild form of the disease, your doctor will recommend making sure to
drink enough fluids to avoid dehydration from vomiting and high fever. You can also
take acetaminophen (Tylenol, others) for pain and fever. Avoid aspirin or other
nonsteroidal anti-inflammatory drugs, such as ibuprofen (Advil, Motrin, others) and
naproxen sodium (Aleve). These can increase the risk of bleeding complications.

If you have a more severe form of the disease, treatment consists of supportive care in
a hospital. Such care includes intravenous fluids and electrolyte replacement, maintaining
adequate blood pressure and replacing blood loss.

If you have any form of dengue fever, you may also be kept away from mosquitoes, to
avoid transmitting the disease to others.

				
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posted:12/30/2010
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