Dengue Fever Facts: All You Need to Know Before Planning Your Trip
Nowadays, over 100 countries around the globe are affected by Dengue. Annually, about 400 million individuals are exposed to this disease, which results in more than 22,000 deaths worldwide.1 During the last 5 decades, the number of infected people has been increase 30 times.2 Tourists from all around the world are recommended to know the high-risk regions for Dengue infection and be aware of preventive tools before traveling.
About the Disease
What is Dengue Fever?
Dengue is a viral illness transmitted by specific Aedes species mosquito. These mosquitos are also known to spread other infections such as the Zika virus and Chikungunya. 1 There are 4 serotypes of Dengue viruses. All of them are capable to cause serious (sometimes deadly) health complications.3
What are the risk factors of Dengue Fever?
As it has been mentioned before, Dengue is transmitted through mosquitos. This mosquitos are mostly present in tropical and subtropical regions of the world. So, by visiting those areas, a person automatically increase his/her risk of Dengue acquisition. There are some additional risk factors of getting Dengue virus such as:
- Being previously infected with other serotype of Dengue
- Spending a lot of time outdoors
- Not using insect repellents
What is the incubation period of Dengue Fever?
Infected individuals develop symptoms 3-14 days after being exposed to the Dengue virus (being bitten by an infected mosquito). 4
What are the symptoms of Dengue fever?
Dengue manifestation may be mild and severe. Usually, those individuals who have never been exposed to the Dengue virus have milder symptoms. When the mild form of the disease often does not result in any serious health problems and might even be confused with the flu, the severe Dengue might be life-threatening. The table below summarizes the main signs and symptoms for both mild and severe Dengue cases. 4, 5, 6
| For of the Disease | Start of the Symptoms | Dengue Symptoms |
|---|---|---|
Mild form of the disease |
4-10 days after being bitten by mosquito |
|
Severe form of the disease |
3-7 days after the first symptoms of the disease |
|
What are the chances of dying from Dengue Fever for young and healthy individuals?
About 2.5% of people with severe Dengue die from disease-related complications. However, with the help of early diagnosis and effective medical care, the number of fatal cases may be decreased to 1%. 6
How common is Dengue Fever?
Dengue map
Dengue is mostly found in tropical and subtropical regions of the world. The later include Africa, the Mediterranean regions, Asia, and the Americas. 7 The following Dengue map presents updated information on high-risk areas and recent outbreaks of the disease.
How common is Dengue Fever?
The number of infected people varies between countries and regions. The table below shows the total number of Dengue cases for the majority of high-risk areas.
| Asia | |
| Country | Number of Cases |
| Cambodia | 65,000 (2019 estimates) |
| Bangladesh | 101,354 (2019 estimates) |
| The Maldives | 4,984 (2019 estimates) |
| Malaysia | 127,407 (2019 estimates) |
| Vietnam | 320,702 (2019 estimates) |
| Thailand | 86,418 (2019 estimates) |
| Philippines | 420,453 (2019 estimates) |
| Singapore | 16,003 (2019 estimates) |
| Sri Lanka | 103,924 (2019 estimates) |
| Africa | |
| Country | Number of Cases |
| Tanzania | 6,873 (2019 estimates) |
| Angola | 550 (2019 estimates) |
| South Africa | 176 (2010-2016 estimates) |
| Region of the Americas | |
| Country | Number of Cases |
| Brazil | 2,226,914 (2019 estimates) |
| Costa Rica | 9,400 (2019 estimates) |
| Mexico | 268,458 (2019 estimates) |
| Honduras | 112,788 (2019 estimates) |
| Panama | 9,225 (2019 estimates) |
| Guatemala | 50,432 (2019 estimates) |
| Argentina | 3,220 (2019 estimates) |
| Venezuela | 16,015 (2019 estimates) |
| Belize | 8,302 (2019 estimates) |
| Peru | 17,143 (2019 estimates) |
| Nicaragua | 186,173 (2019 estimates) |
| Colombia | 127,553 (2019 estimates) |
| Bolivia | 16,193 (2019 estimates) |
| Uruguay | 0 (2019 estimates) |
| Chile | 29 (2019 estimates) |
| Paraguay | 11,811 (2019 estimates) |
| Puerto Rico | 30 (2019 estimates) |
| Cuba | 3,259 (2019 estimates) |
| Dominican Republic | 20,183 (2019 estimates) |
| Virgin Islands (US) | 0 (2019 estimates) |
| Curacao | 0 (2019 estimates) |
| Haiti | 93 (2019 estimates) |
| Bermuda | 2 (2019 estimates) |
| Ecuador | 8,416 (2019 estimates) |
| Bahamas | 27 (2019 estimates) |
| Saint Lucia | 20 (2019 estimates) |
| Barbados | 44 (2019 estimates) |
| Trinidad and Tobago | 416 (2019 estimates) |
| Jamaica | 7,555 (2019 estimates) |
| Virgin Islands (UK) | 78 (2019 estimates) |
| Australia and Polynesia | |
| Country | Number of Cases |
| Australia | 1,419 (2019 estimates) |
| French Polynesia | 3,137 (2019 estimates) |
| New Caledonia | 3,914 (2019 estimates) |
| Europe | |
| Country | Number of Cases |
| France | 9 (2019 estimates) |
| Spain | 2 (2019 estimates) |
What is the chance of being infected with Dengue?
There is about a 1% per month chance of getting Dengue while being in a high-risk location. However, the probability of getting the infection depends on various factors such as:6
- The region (up to 70% of infected travelers return from tropical areas)
- The length of the stay (the longer they stay- the higher the chance of being infected)
- The time of the day (people are more likely to be bitten in early morning or early evening)
- The seasonality (more people get infected during the rainy and warm months).
How to Prevent Dengue Fever?
What should be done to prevent Dengue Fever?
In general, 3 main things should be done to prevent Dengue, namely, maintain personal protection, get vaccinated, and prevent mosquito bites. All of them are explained in the table below. 3
| Preventive Method | Options of the Preventive Method |
| Personal protection |
|
| Mosquito Control |
|
| Vaccination (is not recommended for travelers) |
|
What if you get sick with Dengue fever?
When to see a doctor?
People who have symptoms of severe Dengue such as the nose and/or gum bleeding blood in the stool and/or vomiting blood, and severe pain in the abdomen, should immediately go to the nearest healthcare facility. 9 Also, everyone who has visited risky area and has any dengue-related signs and symptoms is required to see a doctor for further diagnosis and treatment.
What treatment is available?
The treatment strategy is decided based on the form of the disease (mild or severe). The figure below describes the possible treatment options for each of them. 5
What is the average recovery time?
In case of the mild Dengue, a patient will recover after 7 days from the onset of the symptoms. 5 Severe Dengue recovery period depends on the overall health condition of the patient and the treatment strategy.
Testing upon Arrival
Is it customary to get tested upon arrival?
The Dengue testing is required for only those travelers who have Dengue-related symptoms. 8
Which tests are available?
There are 2 available tests for Dengue: 6
- Serological tests (detect the antibodies for Dengue in the blood during the period of 1 week to 3 months after exposure)
- PCR tests (detect the RNA of the virus from the first day of the onset of the symptoms)
Patients who have symptoms for less than a week, need to undergo both Serological and PCR testing. For those who have symptoms for more than a week, the serological testing is enough for Dengue detection and diagnosis. 8
Which tests do we perform?
In our clinic we perform both a PCR testing and Serological testing for Dengue virus.
Conclusion
Dengue is a potentially deadly infection which is widespread in tropical and subtropical regions of the globe. Tourists from all around the world should take preventive measures in order to protect themselves from the disease and probable negative outcomes.
References
- About Dengue: What You Need to Know | Dengue | CDC.
- TREATMENT, PREVENTION AND CONTROL TREATMENT, PREVENTION AND CONTROL 2O12-2O2O.;
- Dengue virus infection: Prevention and treatment - UpToDate.
- Dengue fever - including symptoms, treatment and prevention :: SA Health.
- Symptoms and Treatment | Dengue | CDC.
- Dengue and severe dengue.
- Prevention and Control Strategies to Counter Dengue Virus Infection.
- Testing Guidance | Dengue | CDC.
- Dengue fever - Diagnosis and treatment - Mayo Clinic.