http://id.wikipedia.org/wiki/Demam_berdarah
Dengue fever (pronounced UK: /ˈdɛŋɡeɪ/, US: /ˈdɛŋɡiː/) and dengue
hemorrhagic fever (DHF) are acute febrile diseases transmitted by
mosquitoes, which occur in the tropics, can be life-threatening, and
are caused by four closely related virus serotypes of the genus
Flavivirus, family Flaviviridae.[1] It was identified and named in 1779.
It is also known as breakbone fever, since it can be extremely
painful. Unlike malaria, dengue is just as prevalent in the urban
districts of its range as in rural areas. Each serotype is sufficiently
different that there is no cross-protection and epidemics caused by
multiple serotypes (hyperendemicity) can occur.
Dengue is transmitted to humans by the Aedes (Stegomyia) aegypti
or more rarely the Aedes albopictus mosquito. The mosquitoes that
spread dengue usually bite at dusk and dawn but may bite at any time
during the day, especially indoors, in shady areas, or when weather
is cloudy.[2]
The WHO says some 2.5 billion people, two fifths of the world's
population, are now at risk from dengue and estimates that there
may be 50 million cases of dengue infection worldwide every year.
The disease is now endemic in more than 100 countries.[3]
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Signs and symptoms
The disease manifests as fever of sudden onset associated with
headache, muscle and joint pains (myalgias and arthralgias —
severe pain that gives it the nickname break-bone fever or
bonecrusher disease), distinctive retro-orbital pain, and rash.[4]
The classic dengue rash is a generalised maculopapular rash with
islands of sparing. A hemorrhagic rash of characteristically bright
red pinpoint spots, known as petechiae can occur later during the
illness and is associated with thrombocytopenia. It usually appears
first on the lower limbs and the chest; in some patients, it spreads
to cover most of the body.
There may also be severe retro-orbital pain, (a pain from behind
the eyes that is distinctive to Dengue infections), and gastritis with
some combination of associated abdominal pain, nausea, vomiting
coffee-grounds-like congealed blood, or severe diarrhea.
Some cases develop much milder symptoms which can be mis-
diagnosed as influenza or other viral infection when no rash or
retro-orbital pain is present. Febrile travelers from tropical areas
may transmit dengue inadvertently to previously Dengue free
populations of Aedes (Stegomyia) aegypti mosquitoes, having
not been properly diagnosed for Dengue. Patients only transmit
Dengue when they are febrile and bitten by Aedes (Stegomyia)
aegypti mosquitoes, or (much more unusually) via blood products.
The classic dengue fever lasts about two to seven days, with
a smaller peak of fever at the trailing end of the disease (the
so-called "biphasic pattern"). Recovery may be associated with
prolonged fatigue and depression.[5] Clinically, the platelet
count will drop until after the patient's temperature is normal.
Cases of DHF also show higher fever, variable hemorrhagic
phenomena including bleeding from the eyes, nose, mouth,
ear, into the gut, and oozing of blood from skin pores,
thrombocytopenia, and hemoconcentration.
When Dengue infections proceed to DHF symptoms, DHF causes
vascular leak syndrome which includes fluid in the blood vessels
leaking through the skin and into spaces around the lungs and
abdomen. This fluid loss and severe bleeding can cause blood
pressure to fall; then Dengue Shock Syndrome (DSS) sets in,
which has a high mortality rate.
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Prevention
There is no tested and approved vaccine for the dengue flavivirus.
There are many ongoing vaccine development programs. Among
them is the Pediatric Dengue Vaccine Initiative set up in 2003 with
the aim of accelerating the development and introduction of dengue
vaccine(s) that are affordable and accessible to poor children in
endemic countries.[19]
Thai researchers are testing a dengue fever vaccine on 3,000–5,000
human volunteers after having successfully conducted tests on animals
and a small group of human volunteers.[20] A number of other vaccine
candidates are entering phase I or II testing.[21] As of July 2010,
the National Institutes of Health reported on their ClinicalTrials.Gov
Web site that there were 11 vaccines undergoing testing or recruiting
for participants.[22]
Because exposure to one of dengue's four serotypes provides
no immunity against infection by the other types, and may make
the patient susceptible to more severe disease symptoms, testing
vaccines must be performed carefully, and usually not in areas
where the disease is endemic for fear that even attenuated virus
vaccines may cause severe reactions.[23]
In 1998, scientists from the Queensland Institute of Medical
Research (QIMR) in Australia and Vietnam's Ministry of Health
introduced a scheme that encouraged children to place a water
bug, the crustacean Mesocyclops, in water tanks and discarded
containers where the Aedes aegypti mosquito was known to thrive.[24]
This method is viewed as being more cost-effective and more
environmentally friendly than pesticides, though not as effective,
and requires the continuing participation of the community.[25]
Even though this method of mosquito control was successful in rural
provinces, not much is known about how effective it could be if
applied to cities and urban areas. The Mesocyclops can survive and
breed in large water containers but would not be able to do so in
small containers that most urban dwellers have in their homes. Also,
Mesocyclops are hosts for the guinea worm, a pathogen that causes a
parasite infection, and so this method of mosquito control cannot be
used in countries that are still susceptible to the guinea worm.
The biggest dilemma with Mesocyclops is that its success
depends on the participation of the community. This idea
of a possible parasite-bearing creature in household water
containers dissuades people from continuing the process of
inoculation and, without the support and work of everyone
living in the city, this method will not be successful.[26]
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Treatment
The mainstay of treatment is timely supportive therapy to
tackle circulatory shock due to hemoconcentration and bleeding.
Close monitoring of vital signs in the critical period (up to 2 days
after defervescence - the departure or subsiding of a fever) is
critical. Oral rehydration therapy is recommended to prevent
dehydration in moderate to severe cases.
Supplementation with intravenous fluids may be necessary to
prevent dehydration and significant concentration of the blood
if the patient is unable to maintain oral intake. A platelet transfusion
may be indicated if the platelet level drops significantly (below
20,000) or if there is significant bleeding. The presence of melena
may indicate internal gastrointestinal bleeding requiring platelet
and/or red blood cell transfusion.
Aspirin and non-steroidal anti-inflammatory drugs should be avoided as
these drugs may worsen the bleeding tendency associated with some of
these infections. All kinds of Intramuscular injections are contraindicated.
Patients may receive paracetamol, acetaminophen, preparations
to deal with these symptoms if dengue is suspected.[27]