DENGUE FEVER
Disease
Dengue is a mosquito-transmitted acute, infectious
tropical disease characterized by a combination of fever,
muscle and bone pain (sometimes extremely severe), rash,
headache, nausea and vomiting, fatigue, and swollen
lymph nodes. Because of the sudden onset and severity
of the disease, it is known by various other names,
i.e., break-bone fever, 7-day fever. The disease is
transmitted by the bite of a mosquito (Aedes aegypti),
lasts about 7-10 days, and is frequently followed by
weakness and depression. It may occur as soon as 3 days
after a bite, but usually occurs about 4-7 days later.
The diagnosis is frequently difficult to make because
the symptoms of dengue closely mimic the symptoms of
malaria, influenza, and numerous other infectious diseases.
The incidence of the disease has increased significantly
over the past decade in the Caribbean, Mexico, and South
and Central America. Because cases of dengue continue
in travelers returning to the U.S., the diagnosis of
dengue should be considered in all patients with a fever
and a recent (i.e., within 3 weeks) history of travel
to the tropics.
Prevention
There is no vaccine available. The cornerstone of prevention
is the avoidance of mosquito bites. The mosquitoes that
transmit dengue bite during the day, especially indoors,
in shady areas, or during overcast periods. General
recommendations for preventing mosquito bites (to prevent
dengue or malaria) include the following:
- Apply insect repellents containing DEET
- Wear long-sleeved shirts and long pants whenever
possible when you are outdoors
- Spray your clothing with repellents containing
permethrin
- Use mosquito netting over the bed if your bedroom
is not screened or air-conditioned
- Spray permethrin or a similar insecticide in your
bedroom before going to bed.
Treatment
There is no specific therapy. Non-specific treatment
should include acetaminophen products (not aspirin or
ibuprofen!) for pain and fever, bedrest, and plenty
of fluids. Because of the prolonged weakness and fatigue,
a two-week period of convalescence is not unusual. The
patient should be closely observed for signs of complications,
i.e., dengue hemorrhagic fever (see below).
Complications
Although most cases are mild and resolve over 1-2
weeks, infection in some cases can result in the complication
of dengue hemorrhagic fever (DHF). DHF is a severe form
of the disease that may proceed to dengue shock syndrome,
and even death. The signs of DHF are bleeding nose or
gums, tendency to bruise easily or other types of skin
hemorrhages, and possibly internal bleeding. DHF carries
a mortality as high as 44%.
Based
on CDC,
Health Information for International Travel 2000-2001,
DHHS, Atlanta, GA, 2001; WHO,
International Travel and Health, 2002, Geneva.
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