I have what? Dengue? How did that happen? Well, the answer is that dengue is the most rapidly spreading mosquito-borne viral disease in the world. An estimated 50 million dengue infections occur annually according to the World Health Organization (WHO). So it’s shouldn’t be such a surprise for someone who spends significant amounts of time in South East Asia.
In early March, while I was in Bangkok for many weeks, I became very sick. I assumed it was a bad flu, that’s what it felt like. I had some pretty typical symptoms and some more unusual ones. For example, I had splitting headaches – something I don’t usually suffer from. After a few days, I still wasn’t feeling any better, so I saw a physician. He treated me as if I had the flu.
About a week or so later, still not feeling like I was back to normal, and suffering with some lingering flu like symptoms – most notably a very annoying cough – I sought further medical attention. After ruling out pneumonia and bronchitis they did some further testing which revealed the Dengue virus.
Dengue, also called Dengue Fever, is caused by any of four dengue viruses, and is transmitted by mosquitoes. Dengue is a major public health problem in the tropics and subtropics, which includes Puerto Rico and the U.S. Virgin Islands, where thousands of U.S. citizens develop dengue every year.
There are two classifications of Dengue, Dengue and Severe Dengue. Historically Severe Dengue was called Dengue Hemorrhagic Fever. The WHO no longer calls it that and the term Severe Dengue has been adopted instead. It is important to note that you cannot pass Dengue from Human to Human. It is only passed from mosquito to human.
Dengue is leading cause of fever in travelers returning from Asia, the Caribbean and Latin America. Transmission has occasionally occurred in the continental United States in areas where Aedes mosquitoes are found.
So what is Dengue?
(All information compiled from the Center for Disease Control (CDC) and WHO)
Dengue virus is a small single-stranded RNA virus comprising four distinct serotypes or strains known as Dengue 1 – 4. The various strain of the dengue virus are transmitted to humans through the bites of infected Aedes mosquitoes. This mosquito is a tropical and subtropical species widely distributed around the world, mostly between latitudes 35 N and 35 S.
Humans are the main host of the virus. Dengue virus circulating in the blood of an infected human (someone is infectious for 24-48 hours after being bitten) is ingested by female mosquitoes during feeding. The virus then infects the mosquito over an incubation period of 8–12 days. After the 8-12 day incubation period, the virus can be transmitted to other humans during subsequent feeding. Thereafter the mosquito remains infective for the rest of its life.
If you get it:
Infection by any of the four virus strain can produce a wide spectrum of illness within a patient. However, patients surviving the infection are thought to have a lifelong protective immunity to the infecting strain. Individuals suffering an infection are protected from becoming ill with a different strain within 2–3 months of the primary infection but there is no known long-term protective immunity, which means you can become infected from a different strain in the future.
Individual risk factors and the specific strain determine the severity of disease. Risk factors include: secondary infection, age, ethnicity and possibly chronic diseases like bronchial asthma, sickle cell anemia and diabetes. Young children in particular may be less able than adults to compensate and are consequently at greater risk. Dengue 2 is known to be one of the more serious strains and is responsible for many deaths in the tropics.
Prevention and Treatment
There are no vaccines to prevent dengue and no medicines specifically approved to treat the disease, however, timely medical care can greatly reduce the possibility of death. Doctors focus on treating any secondary infections and chronic conditions to ensure that the patient’s immune system can fight the Dengue virus.
Before you travel, determine the risk level for the area you’re traveling to. You can visit the WHO or CDC website. The CDC recommends taking precautions like using repellent and killing visible mosquitoes. The CDC recommends repellents containing DEET, picaridin, oil of lemon eucalyptus or IR3535 as the active ingredient. Repellent can be applied to exposed skin and/or clothing. Some spatial repellent/insecticide products (mosquito coils, plug-in or butane powered devices), may assist in reducing the risk of mosquito around you.
Mosquitoes are active at all times, but especially around dusk. I was bitten two times while I was in Thailand in early March; one time in a car in the early morning and one time in an un-air-conditioned bathroom mid-day. They occurred within 24 hours of each other so I have no idea which one was the one that infected me.
Symptoms of dengue include high fever, severe headache, severe pain behind the eyes, joint pain, muscle and bone pain, rash and mild bleeding involving the nose or gums, flu-like symptoms, cough, and easy bruising. Severe infections can result in hemorrhage, shock, and death.
How to Care for the Patient While They Have a Fever:
- Bed rest. Let patient rest as much as possible.
- Control the fever.
- Give acetaminophen or paracetamol (Tylenol) every 6 hours (maximum 4 doses per day). Do not give ibuprofen (Motrin, Advil) aspirin, or aspirin containing drugs.
- Prevent dehydration which occurs when a person loses too much fluid (from high fevers, vomiting, or poor oral intake). Give plenty of fluids and watch for signs of dehydration.
Bring patient to clinic or emergency room if any of the following signs develop:
- Decrease in urination (check number of wet diapers or trips to the bathroom)
- Few or no tears when child cries
- Dry mouth, tongue or lips
- Sunken eyes
- Listlessness or overly agitated or confused
- Fast heart beat (more than 100/min)
- Cold or clammy fingers and toes
Watch for warning signs as temperature declines 3 to 7 days after symptoms began. Return IMMEDIATELY to clinic or emergency department if any of the following warning signs appear:
- Severe abdominal pain or persistent vomiting
- Red spots or patches on the skin
- Bleeding from nose or gums
- Vomiting blood
- Black, tarry stools
- Drowsiness or irritability
- Pale, cold, or clammy skin
- Difficulty breathing
Severe dengue should be considered if the patient is from an area of dengue risk and has a fever of 104 or higher for 3–7 days plus any of the following features:
- There is evidence of plasma leakage, such as:
- high or progressively rising haematocrit (can be determined through a blood test)
- Fluid in the abdomen or that region
- circulatory compromise or shock
- weak or undetectable pulse
- There is significant bleeding
- There is an altered level of consciousness (lethargy or restlessness, coma, convulsions).
- There is severe or persistent vomiting, increasing or intense abdominal pain
- There is severe organ impairment such as liver failure
Complications of Dengue
The complications associated with Dengue will vary depending on what strain you have, your immune system, secondary infections and other factors. Both hyperglycemia and hypoglycaemia may occur following infection, even in the absence of diabetes. Electrolyte and acid-base imbalances are also common. People infected with Dengue are instructed not to take any blood thinners (without physician supervision) for 3-6 months after infection; to avoid unnecessary surgeries or activities that could cause severe bleeding for up to 12 months following infection. For several weeks following infection patients can feel fatigued or tired. There are no known long-term side effects and most people feel “normal”within 2-4 weeks.
For me, personally, I was pretty sick for about 4 days and then felt flu-like symptoms for 6 days. I had a cough that lingered for a few weeks.
What’s new with Dengue?
Despite formidable challenges to developing dengue vaccines, significant progress has been made in recent years. WHO officials are hopeful that they will have a first generation dengue vaccine licensed within the next five to seven years. The search for dengue antivirals is a new endeavor that is gaining momentum due to both increased interest in dengue and substantial progress in the structural biology of dengue virus
Dengue is very common around the world and infects somewhere between 50-100 million people worldwide. For people with strong immune systems who have access to medical care, dealing with Dengue is no more challenging than dealing with the flu. For those people in areas without good medical care or for those at high risk, dealing with Dengue can be much more challenging and more serious.
In 2011, only .02% of the people in Thailand who contracted Dengue died. That’s a huge decrease in the death rate and goes to show how effectively the Thai people and doctors deal with Dengue. In 2009, there was an outbreak in Key West, Florida. No one died. Currently (as of April 20 2013) Paraguy is facing its worst Dengue outbreak ever with with more than 65,000 infected so far in 2013 – 45% more people than in all of 2012 – with 12,000 hospitalized and 50 in critical condition.
So no matter where you are, you could be at risk, the key is ensuring that you take precautions and get treatment if you become sick. Personally when I return to Bangkok next month I will wear repellent at all times and use the Off Clip-On or coils when I’m in a non-air conditioned room.
The lesson I learned is that you don’t have to freak out if you get Dengue, you just have to take care of yourself.