September 9th, 2010
06:00 AM ET

How did dengue fever get to the U.S.?

As a feature of CNNhealth.com, our team of expert doctors will answer readers' questions. Here's a question for Dr. Gupta.

From: Rob, Bellport, New York

"Dengue fever in Florida, in a high tourist area. So how did that get here?"


Rob, thanks for your question. CNN has reported that cases of dengue fever have been reported this year in Florida, including several among Key West residents.

The simple answer to how dengue fever got to the United States is “mosquitoes.” Dengue fever is spread by mosquitoes infected with one of four dengue viruses. A mosquito becomes infected when it bites a human who is infected with the virus, and then the mosquito spreads the virus to other uninfected humans when it bites them. Dengue cannot be spread from human to human, according to the Centers for Disease Control and Prevention.

People infected with dengue fever experience a high fever, severe headaches, along with pain behind the eyes, in the joints, muscles and bones, a rash, and they can experience mild bleeding of the nose, gums, and easy bruising. Younger children and those with their first dengue infection tend to get a milder version of the illness compared with older children and adults.

A more severe form of the virus is called dengue hemorrhagic fever. It’s caused by the same virus as dengue fever but DHF can be fatal if it’s not identified and treated properly and quickly. In addition to the fever and pain symptoms of dengue fever, patients will experience vomiting, abdominal pain, and sometimes difficulty breathing after their fever subsides. The victim then experiences a 24- to 48-hour period where the blood vessels become “leaky,” which can lead to circulatory failure and can cause death if not treated quickly.

There’s no specific medicine or treatment for dengue fever or DHF but patients should use acetaminophen-containing pain relievers, and avoid aspirin, which can increase the risk of bleeding. Rest, drinking plenty of fluids, and consulting a medical professional is also advised. If vomiting or abdominal pain develops after the fever subsides, the CDC advises that people should go immediately to the hospital for evaluation. Fluid replacement therapy benefits patients with DHF, and hospitalization is often required for treatment.

Many scientists believe that global warming is increasing subtropical weather patterns, raising public health concerns about diseases transmitted by mosquitoes – such as malaria, dengue fever, yellow fever and several kinds of encephalitis, according to an article by Dr. Paul R. Epstein, associate director of the Center for Health and Global Environment at Harvard Medical School. “Mosquito-borne disorders are projected
to become increasingly prevalent because their insect carriers, or 'vectors,' are very sensitive to meteorological conditions," Epstein explains. "Cold can be a friend to humans, because it limits mosquitoes to seasons and regions where temperatures stay above certain minimums.” Warmer temperatures allow dangerous pests to thrive and multiply, raising public health concerns.

Fighting mosquitoes is the best way to prevent dengue fever. When I was recently in Pakistan covering their flooding disaster, we were very careful to use mosquito repellents and to cover our arms and legs to prevent exposing skin to biting insects. It’s important to use a product that contains 20 to 30 percent DEET as the active ingredient. Wearing long-sleeved clothing and pants can also decrease your exposure to mosquito bites. Running air conditioning, and using screens in windows and doors can help prevent mosquitoes from coming indoors.

Mosquitoes breed by laying eggs in water, so it’s important to eliminate outdoor sources of standing water, including pet water dishes and flower pots.

While dengue fever is fairly unusual in the continental United States, you might be surprised to learn that as many as 100 million people are infected globally each year, according to the CDC. Dengue is most common in tropical and subtropical regions, including popular tourist destinations including Puerto Rico, Latin America and Southeast Asia, so remember your mosquito protection when you travel to those areas.

soundoff (61 Responses)
  1. Kurt

    FYI, I have a friend who contracted Dengue while in Florida last month. He never went below Tampa and has not been out of the country recently.

    September 9, 2010 at 08:25 | Report abuse | Reply
    • Guy Smith

      DDT will KILL the disease carrying mosquitoes. Long sleeves? Repelant?? You must kill the insects so they don't breed. DDT is effective during Health Emergency and it's justified. DDT must be allowed for vector control

      September 9, 2010 at 12:09 | Report abuse |
    • Yaya

      Florida is a good place to get AIDS too. Will DDT help?

      September 10, 2010 at 17:39 | Report abuse |
  2. Twigsz

    Ive lived in Florida all my life...dengue is extremely rare to get. Just use your bug spray!

    September 9, 2010 at 10:03 | Report abuse | Reply
  3. RedondoBeach

    Many years ago I read an article in New West magazine (as I recall) that stated that dengue fever first came to the US in a shipload of automobile tires from Brazil. It had been raining at the Brazilian port and water collected in the tires. Dengue-bearing mosquitoes laid their eggs in the water, the ship set sail for Florida and voila.

    September 9, 2010 at 10:20 | Report abuse | Reply
  4. zana

    go chemical free... use a SansBug mosquito net tent.

    September 9, 2010 at 10:37 | Report abuse | Reply
    • Knowledgeabout bug

      Zana...chemical free does not work when all it takes is one bite to kill you. A bug tent is only good as long as you are in it. When you are walking around, u need deet

      September 9, 2010 at 10:56 | Report abuse |
    • Guy Smith

      Use DDT. Kill the insects so they don't breed. DDT not Deet.

      September 9, 2010 at 12:07 | Report abuse |
  5. domino57

    Dengue occasionally occurs in deep south texas and across the border in larger cities after prolonged rain. Ponding of water and water in old tires is often a source of mosquito breeding.

    September 9, 2010 at 10:50 | Report abuse | Reply
  6. Guy Smith

    DDT should be allowed to apply for vector control because this could become a Health Emergency. DDT will kill most and contain the rest. DDT works. This WILL justify the use of DDT.

    September 9, 2010 at 11:59 | Report abuse | Reply
    • Capt. NoDuh

      My memory needs refreshing. Why was DDT banned in the first place?

      September 9, 2010 at 17:01 | Report abuse |
    • Greed trumps reason in the 21st

      You must be a stockholder, your support of this lovely, harmless chemical is so vehement. The bald eagle's totally support it too.

      September 10, 2010 at 17:37 | Report abuse |
  7. Phearis

    It was meeeeeee!! I brought it to the US!! WAH-HA-HA-HA-HA!!!

    September 9, 2010 at 12:14 | Report abuse | Reply
  8. Debbie

    if we just went back to using DDT, which has NEVER been proven to harm humans, only mosquitoes, the world would not have this problem. Since teh erradication of the use of DDt, more than 500,000,000.00 people have died from Malaria and Dengue Fever.

    September 9, 2010 at 12:45 | Report abuse | Reply
    • Mig

      That's right, it was PROVEN harmful to animals, particularly those who lay eggs. But who cares about animals, right? We are the only big dumb animal that matters.

      September 10, 2010 at 17:32 | Report abuse |
  9. miker

    yes DDT is great no mosquitoes or birds of prey. screw ddt and that stupid comment

    September 9, 2010 at 13:20 | Report abuse | Reply
    • Guy Smith

      Screw birds of Prey. They can adapt to the chemical. DDT RULES! Besides, DDT did NOT eradicate ANY birds. It simply thinned their eggshells.

      September 9, 2010 at 18:03 | Report abuse |
    • Guy Smith

      Rachel Carson's book was a 'Feel Good' piece that irrationally vilafied DDT use in the U.S. DDT eradicated Malaria and BEDBUGS. DDT needs to be revisited for use agains these two public health emergencies.

      September 9, 2010 at 18:14 | Report abuse |
  10. KMH

    DDT is used in 3rd world countries for the express purpose of combating public health emergencies such as malaria. In fact, 37% or so of mosquitos caught in South Africa near populations are thought to be resistant to DDT. But South Africa still uses DDT along with 11 or so other countries. In fact, WHO lists DDT as recommended for anti-malaria. The US 'total' ban does not affect the rest of the world. The "worldwide ban" does not apply to vector control and public health use is exempt completely.

    September 9, 2010 at 13:58 | Report abuse | Reply
    • ADiff

      Technically yes. But in practice the U.S. ban resulted in the widespread end of most DDT application programs, regardless whether the cessation was mandatory or not. Cost and availability changes, as well as funding alterations and abandonment of such programs by very many donor organizations, along with the inevitable herd mentality effect, pretty much ended widespread DDT programs for decades following our hasty and ill-considered ban. The resurgence and persistence of malaria is directly tied to these arbitrary policy changes, at least as much as resistance. The single most effective weapon against malaria in the 3rd world was DDT application inside buildings, and regardless formal regulation, the effect of the ban was to generally end these. It's pretty much impossible not to conclude from the evidence that our (essentially 'feel-good') ban on DDT has resulted in tens or millions of avoidable human deaths, and untold economic and material damages.

      September 9, 2010 at 14:58 | Report abuse |
    • Guy Smith

      Resistant means that the mosquitoes don't die IMMEDIATELY but they still DIE. Also the resistance of mosquitoes is "Avoidance Resistant" meaning that the mosquitoes AVOID sprayed areas in a vector conrol use of DDT which elimates the diseased insects just as well. DDT is needed at once.

      September 9, 2010 at 18:10 | Report abuse |
  11. ADiff

    It's pretty cold at the Arctic National Wildlife Refuge. During the summer there it has about the worst mosquitos anywhere. Malaria was once endemic in Manchuria, Korea, the United States & Canada, there were outbreaks in the mid 19th Century in New York City, Paris, London, Versailles, Japan....hardly warm places. The common factor is open water, marshlands. Not warmth! The widest spread of malaria was at a time long before any of the warming of the 20th Century. It's hard to see how 'global warming', whatever that is, would "spread" Dengue any more than it would "spread" malaria...which history makes perfectly clear it won't. About all that warming could do is expand the areas where infections could occur year round, as opposed to where they would be seasonal. A good case in point for this is Al Gore's claim that 'global warming' has spread malaria to parts of Kenya...when even a rudimentary review of the history of the area reveals that malaria was endemic there long, long before any such thing, and had only disappeared through the use of DDT. And it was the end of DDT use that brought the malaria back, not any purported "global warming" impact.

    September 9, 2010 at 14:52 | Report abuse | Reply
  12. dave

    It bought a plane ticket, how the freak do ya think!

    September 9, 2010 at 16:25 | Report abuse | Reply
  13. stanton cummings


    September 9, 2010 at 17:14 | Report abuse | Reply
    • Guy Smith

      Hey 'stanton cummings'! It got here thousands of years ago. Only until the use of DDT was dengue fever eradicated. It has simply returned to this country.

      September 9, 2010 at 19:22 | Report abuse |
    • jenycuco

      and what necessary shots and papers would protect you from dengue, genious?? did you not read the part about it not being spead human to human?

      September 9, 2010 at 22:36 | Report abuse |
  14. me in GA

    We went to Costa Rica and I picked it up there. By the time I got home, I really thought I was dying. Went to local hospital where I was told "there is no way you can have that, it comes from Austrilia!!" (wrong) They had never seen anything like it and TOTALLY misdiagnosed me and sent me home. I have a friend who works for the CDC–she told me what I had over the phone. We were 7 on our trip and I was the only one who got it. The morning I went to the hospital, I couldn't hardly move my body, every muscle and bone hurt. It ran through it's course in a about 6-8 few days.

    September 9, 2010 at 19:37 | Report abuse | Reply
  15. harold Bissonette (pronounced Bissonay)

    Maybe all the tax cuts that went to million and billionaires could have been used for programs of mosquito eradication or public health awareness or development of underprivileged sections of the U.S. Instead our nation is becoming a very large Haiti. Soon we'll be eating dirt pancakes like the real Haiti.

    September 9, 2010 at 21:07 | Report abuse | Reply
  16. jenycuco

    i am an american living in puerto vallarta, mexico and dengue is bad here-i've gotten it twice in the last year and it's a horrible sickness. i'd never heard of it so i researched it on the internet and read that it is spread by black/white mosquitos that only bite during the day, so watch out for those (if, of course, that is true)

    September 9, 2010 at 22:33 | Report abuse | Reply
  17. leikela

    My husband got Dengue in the Pacific. Dengue outbreaks happen in Hawaii because people who are infected (w/o knowing it) come and get bitten by local mosquitoes and spread it that way. With all the tourists that come into FL, it is not unlikely the disease would follow.

    September 9, 2010 at 22:37 | Report abuse | Reply
  18. Sean

    Oh, of course. It's "global warming" again. Everyone knows that twenty years ago Florida was an arctic zone. Whatever they can do to infuse this into the collective subconscious. I'm so sorry everyone is being taken in by it. People should read what was just leaked to Fox News at the following web address, and how it is revealed that the evil elite Bilderberger plan is to "make global redistribution of wealth the real basis of that climate agenda". They'll do that by preying on everyone's fears and using propaganda. They might even stage disasters to make it happen. Don't believe me? Read about it here: foxnews.com/world/2010/09/08/years-setbacks-looks-world-leader/

    September 10, 2010 at 00:38 | Report abuse | Reply
  19. Sarah Anderson

    There are 5 kinds of dengue. Only 1 will kill you (hemoragic). You get one, you won't get that specific one again. The absolute #1 cause of dengue outbreaks is standing water in urban areas. Get rid of that, you will get rid of the outbreaks. The NIH is working on a vaccine, and they are not far away from the final version. So, it is very simple. Wear bug spray, get rid of all standing water, all of it. Wear longer clothing. Not hard. It really isn't. Just pay attention, be vigilent and be smart.

    September 10, 2010 at 00:43 | Report abuse | Reply
  20. Joe Smith

    I like how the article skirts the fact, someone with dengue came to the US.

    September 10, 2010 at 02:19 | Report abuse | Reply
  21. Joe Smith

    DDT accumulates and concentrates in animals, it is a persistent organic pollutant, it doesn't just go away. people are at the top of the food chain, so DDT accumulates in us! Humans store DDT in fat cells for as long as 10 YEARS. It concentrates in mothers milk. Anyway iIt softens the eggs of birds causing them to crack, birds eat mosquitoes , less birds more mosquitoes. Even though it is banned in the US in the 70's in 2005 EVERY PERSON TESTED by the CDC had DDT in them!!! Those proposing DDT use shout READ ABOUT DDT before posting!

    September 10, 2010 at 02:29 | Report abuse | Reply
  22. Bite Me

    One thing the article fails to mention is that, once a person contracts Dengue Fever, they do NOT develop an immunity to it, but in fact the exact opposite happens: they become much more susceptible to contracting the more serious forms of Dengue, including DHF, which kills tens of thousands of people each year. Speaking as someone who contracted Dengue in the South Pacific, I can attest that it is not a pleasant experience. When your eyeballs begin to bleed, and your skin looks like its about to seep blood, you know that you are dealing with a serious disease.

    September 10, 2010 at 07:24 | Report abuse | Reply
  23. Lynn

    Why dont they tell the truth! the last time dengue fever was here was yrs ago! ( research & will be verified) Was when the MILITARY dumped it upon the people of AVON PARK FLA.. putting approx 100 mosquitos in brown bags and dropped em on the public as a EXPERIMENT upon the people!!!

    September 10, 2010 at 08:19 | Report abuse | Reply
  24. Fred Duffy

    Someone is using this picture and making defamatory remarks about people in Pawtucket, RI. I think they are using the Doctor's picture ?? thats not right !! The site is on Facebook (http://www.facebook.com/dongrebien)(http://www.facebook.com/profile.php?id=100001409726789)

    September 14, 2010 at 17:33 | Report abuse | Reply
  25. SAM

    The 40 Million IMMIGRANTS whom are not SCREENED WHATSOEVER

    September 23, 2010 at 12:51 | Report abuse | Reply
  26. Benjamin Frazier

    DDT is banned and there is a reason for that. Death is just another part of life. If you transcend with Dengue fever than accept it. Dont get so hung up on living in this world that you ruin it for everyone else by poisioning the future.

    September 30, 2010 at 15:23 | Report abuse | Reply
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