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Dengue fever can stick it to you!

By: invivo

Female Aedes feeding*

Female Aedes feeding*

Newspapers, radio, and television won’t stop talking about it: dengue. And it’s important they keep it up because we should really worry about it. In recent years, this illness has cropped up all over Brazil and even set off epidemics in some states (an epidemic is when many people get sick all at once).

Do you know someone who’s had dengue? Do you know what it feels like to catch it? Do you know what dengue really is?

Dengue fever is caused by a virus that is transmitted by the Aedes aegypti mosquito—a small, black, harmless-looking insect with white stripes on its body and legs.

Although dengue is only one disease, classic dengue can worsen and turn into hemorrhagic dengue. An infected person may have fever, aches and pains in their body, headache, vomiting, and, in the case of hemorrhagic dengue, bleeding. When not treated properly, dengue can even lead to death.

Dengue virus (2)

Dengue virus (2)

How do you catch dengue?

Anyone can catch dengue. The mosquito that transmits the illness is common in places with dense concentrations of people. It’s actually only the female that feeds off our blood and transmits the virus by biting us. The mosquito needs this blood to produce her eggs.

There are four types of dengue virus: Den-1, Den-2, Den-3, and Den-4. All four can cause dengue.

The mosquito generally needs to bite someone who has the disease in order to pick up the virus. But sometimes female mosquitoes will transmit it directly to their young. Once infected with the virus, the female mosquito keeps on transmitting dengue until she dies. During her 30-day life cycle, she will lay more than one thousand eggs and can bite and infect many people.

Since you might not even notice if an Aedes aegypti bites you and it doesn’t leave a mark on your skin, people often don’t realize they’ve been attacked by the mosquito, which is the only way to catch dengue. You can’t get dengue by having contact with infected people or from sources like water or food.

Dengue rash disappears under pressure (3)

Dengue rash disappears under pressure (3)

How do I know if I have dengue?

The first symptoms of dengue are: a sudden, high fever; headache; achy muscles, bones, and joints; a reddish rash; fatigue; vomiting; nausea; loss of appetite; diarrhea; and pain behind the eyes.

If dengue should worsen and turn into the hemorrhagic form, new symptoms may appear: intense pain in the abdominal region; intense vomiting; pale, cold, moist skin; bleeding from the mouth, gums, or nose; weak pulse; difficulty breathing; dry mouth; intense thirst; and loss of consciousness.

And how do I treat it?

If you catch dengue or think you might have it, see a doctor right away. Do not take any medications on your own, because some medicine may have side effects or can even make the dengue worse. Drugs containing acetylsalicylic acid, like Aspirin®, Anacin®, Advil®, or Alka-Seltzer Plus®, for example, can increase your risk of bleeding.

Hemorrhagic dengue (4)

Hemorrhagic dengue (4)

There is no specific treatment for dengue. The first symptoms, like fever, headache, and body aches, should be treated using medicine prescribed by your doctor. It’s also important to rest and drink lots of fluids.

Patients with hemorrhagic dengue should be extra careful. Treatment should also include oral rehydration, but in this case the doctor must keep a much closer eye on the patient. A drop in the number of platelets may lead to a loss of fluid in the blood flow, in turn causing such a significant drop in blood pressure that it can lead to death.

How can I keep from catching dengue?

There is no vaccine against dengue. The pesticide trucks that drive around spraying insecticides really do little good. They only kill the adult mosquitoes, and even then they’re not very successful at it. Other methods, like plug-in mosquito repellants or sprays, also promise to wipe out the disease transmitter but none of them are effective enough. It’s extremely hard to get rid of so many bugs.

A. aegypti eggs. Photo: CDC

A. aegypti eggs. Photo: CDC

The best way to fight dengue is to wipe out the insect’s breeding grounds, that is, the places where it lays its eggs and reproduces. The Aedes aegypti mosquito doesn’t leave its eggs just any place: the female lays her eggs in the moist or wet areas of almost any recipient containing clean water. When the eggs make contact with the water, they eclode, forming larvae.

Do you have any idea where these containers of water might be found? A lot closer than you might think...

The mosquito that transmits dengue lives right inside our homes, hidden under chairs and tables, inside closets—all over the place That means they lay their eggs near our homes as well: in bird baths, rain barrels, drip plates underneath house plants, buckets, laundry tubs, vases of flowers, empty cans, discarded tires, eaves troughs… Up close and personal. That’s why we can all help combat the mosquito.

Check out these easy tips on how to fight the dengue mosquito:

Foto: Portal Governo/DF.

Foto: Portal Governo/DF.

# Keep your rain barrel or other water reservoirs tightly sealed.

# If you can’t get rid of the drip plates under your plants, place sand in them instead of water.

# Scrub all water basins or containers with a brush and soap and then cover them up tight with a lid or screen.

# Always put the lid down on the toilet.

# Store empty bottles and buckets upside down.

# Recycle your old tires or store them in a covered place.

# Seal garbage bags well and keep the lid on your trash can closed tightly too.

# Every week, check any trays in your refrigerator or air conditioning units that catch water.

# Don’t let water build up at the bottom of elevator shafts.

# Change the water once a week on any plants that tend to accumulate water, like bromeliads.

# Throw any useless objects that might trap water into the trash.

# Make sure all the drains in your house have been disinfected, and cover up any you don’t use.

# When you get a new supply of water for your cooler, be sure to clean the stand well.

# If you have any decorative or other objects in your yard or garden that might collect water, fill any empty spaces with sand.

# Wash your pet’s water dish at least once a week using a scrub brush, soap, and running water.

Photo: Carol Garcia. Gov-BA

Photo: Carol Garcia. Gov-BA

Changing our behavior is the main way to prevent dengue. Do you want to combat this disease? Now you know how. Do your part and pass these tips along to your family, friends, and neighbors.
In Brazil, if you or your friends find a place that might be a breeding ground for mosquitoes but you know you can’t fight the Aedes aegypti there, report it!



(1)Photo: James Gathany/CDC.

(2)Photo: Sanofi Pasteur (Electron Microscopy).

(3)Photo: Kleber Luz/Portal Saúde

(4)Photo: Kleber Luz/Portal Saúde

Consultancy/Technical Review: Anthony Érico Guimarães (Head of the Diptera Laboratory - Entomology/IOC-Fiocruz

See also:

Fact and fiction about dengue

Acetylsalicylic acid medications


Ministério da Saúde

Rio contra a Dengue

World Health Organization - Dengue


In English

Visit the virtual exhibit on dengue


Life cycle of the mosquito

Dengue in the Americas timeline

Leaflet and educational material

Comic on Dengue


In Portuguese

Take a quiz to test your knowledge of dengueOswaldo Cruz Institute

Dengue Special

Video: The macro and micro world of Aedes aegypti

Leaflet and educational material - Combat dengue!

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