Dengue, Zika and Chikungunya: What are they?

19 January 2020

We constantly hear about mosquito-borne diseases in the news, but do you know what dengue, zika and chikungunya actually are?

Travel, global trade, and climate change, amongst other causes, have unfortunately led to the global spread of these diseases. Travelers should be well informed about the risks, and how to mitigate these risks, before traveling to another country.

Volyse has an app-based travel clinic with a team of experts ready to help you with all of your needs.

In the meantime, we wanted to share with you some key information about dengue, zika and chikugunya, the regions in the world where they pose risk, and where can you travel if you wish to completely avoid risk of infection.

 

Mosquito-borne disease: a bit of general information

These three different infections are usually transmitted by the same mosquito, which makes them hard to distinguish. This mosquito belongs to a family called Aedes spp, which is present in tropical and subtropical areas. 1,10,11 There is also a species of this mosquito present in regions further north, such as southern Europe.

12 Dengue is now present in over 100 countries, with over 400 million cases worldwide every year!148

Mosquitoes carrying these infectious diseases usually bite during the day. Make sure to use appropriate prevention methods to avoid bites!

 

How to know if you have dengue, zika or chikungunya?

As mentioned, these infections are transmitted by the same type of mosquito. Also, the diseases caused by these infections often display no symptoms. Meaning, you don’t really feel anything different, yet you are infected (and you can potentially transmit the disease to others – see more about this below). Depending on the infection, the data shows that only one out of four or five travelers will display symptoms.

Not only is the percentage of travelers who show symptoms small, but the symptoms of these three diseases are very similar and often very difficult to distinguish when only based on clinical symptoms. These infections often co-circulate in different countries and areas, making it harder to know. Usually, when you suspect an infection, doctors will proceed with extra tests to find out which of these diseases has infected you. 

 

A few tips to avoid mosquito bites:

  • High altitude: Mosquitoes that transmit dengue, zika and chikungunya usually don’t live in places higher than 6500 feet (1982 meters). 
  • Avoid the rainy season: The transmission of mosquitoes-borne viruses is highest in the rainy season.
  • AC: Book your stays with air conditioning.
  • Higher is better: When booking your accommodation, try to select rooms on higher floors (if possible).

 

Everything you need to know about zika, dengue and chikungunya


DengueZikaChikungunya
Where is the virus present?Mexico, Central and South America, Central Africa, Asia, Philippines, East side of the USA (such as Florida state),United States, Mexico, Central America, South East Asia (India, Bangladesh, Laos, Vietnam, Malaysia, Cambodia, Laos, Indonesia, Philippines, Maldives, Papua New Guinea, Fiji Islands, Maynmar) , South America, Central Africa (Senegal, Ethiopia, Uganda, Angola, Cameroon, Nigeria, Ivory Coast, Burkina Faso), FranceUnited States, Mexico, Central America, South America (Except Chile and Uruguay), South East Asia, Central and South Africa, Italy, France
A few examples of destinations/areas where the transmission of these viruses has not yet been reported (as of December 2019)?Where to travel without dengue: Chile (except Easter Island); some countries in Europe such as: Spain, Italy, Croatia, Portugal, Switzerland, Austria, Russia, Netherlands, Sweden, Norway, Czech Republic, Greece); some countries in arab africa such as: Morocco, Algeria. Tunisia, Turkey; Japan, South Africa, Canary Islands, New Zealand, Azores, Canada, Iceland, Ocean and Pacific IslandsWhere to travel without zika: Morocco, Bermuda, Canary Islands, New Zealand, Mauritius, Azores, Seychelles, Canada, Australia, Iceland, Spain, Italy, Greece, Poland, Sweden, Norway, Ukraine, Romania, Mongolia, Japan, Ocean and Pacific IslandsWhere to travel without chikungunya: Morocco, Algeria, Turkey, Tunisia, Australia, Canada, Spain and other countries of Europe except Italy and France, Iceland, Ocean and Pacific Islands, Japan
Symptoms1 out of 4 will develop symptoms (25%).Flu-like symptoms, high fever, headache, nausea, vomiting, skin rash, pain behind the eyes, muscle and joint pain.
1 out of 5 will develop symptoms (20%). Often no symptoms. Moderate fever, muscular pain, nausea, rash, inflammation of the conjonctiva50% to 97% may develop non-specific symptoms.
Chikunguyna symptoms are described as: sudden fever, pink eye (without pus), articular and muscular pain. Sometimes associated with headaches, fatigue, nausea and a skin rash. 
Incubation period (time from the infection (mosquito bite) to the time the disease appears/develops)3 to 14 days3 to 12 days3 to 12 days
Sexually transmittable?Cannot be excluded, but not of major significance.Yes WOMEN should wait 2 months after coming back from a country at risk before conceiving.
MEN should wait 3 months between a possible zika infection and conception. The use of condoms or abstinence from intercourse for the whole pregnancy is also advised. *
Cannot be excluded, but not of major significance.
Risk for pregnant womenSevere complications and pregnancy related diseases. Does not seem related to congenital malformations. Severe complications, including microcephaly.Not associated with an increased risk of complications in pregnant women.42
Pregnant women are still at risk of complications, just like everyone else, from dengue and long-term sequelae. Also, there is a risk of perinatal transmission at the time of labour and significant consequences for the newborn. 
Available treatmentNone – symptomatic support only.None – symptomatic support only.None – symptomatic support only.

*Since only 1 out of 5 people infected with zika will show symptoms, you may be infected and not be aware of it. Considering the detrimental consequences for newborns, it’s important to not have sex or use condoms for the time indicated above when returning from a country at risk, especially if you want to conceive. At the moment, there is no test typically conducted for zika asymptomatic people (when you don’t have any symptoms). Some procedures may be taken by your healthcare provider if you are hoping to conceive. 

 

Is there any vaccine against mosquito-borne viruses?

No vaccine or medication currently exists to prevent zika or chikungunya. Consulting a travel health expert or the Volyse travel clinic will help provide you with proper advice to protect you from mosquito bites, and inform you about the appropriate bug repellent and/or protective clothing. 

Dengue vaccine: A new vaccine, called Dengvaxia(r), has been developed against dengue; a few other vaccines are under development. Dengvaxia is only available in a handful of countries and can only be given to people who are already infected with dengue. Currently, Dengvaxia is not available in canadian travel clinics. 

 

Find more tips about how to protect yourself from mosquito bites through the Volyse mobile APP: iOS  | Android

 
 

Sources:

  • Rossi Ashley, Do Travelers Still Need to Worry About the Zika Virus in 2019? SmartTraveler, [Online], June 24th 2019 https://www.smartertravel.com/traveler-information-zika-virus-2019/
  • Wilder-Smith A, Ooi E-E, Horstick O, Wills B. Dengue. Lancet Lond Engl  2019; 393:350–63.
  • Weaver SC, Lecuit M. Chikungunya virus and the global spread of a mosquito-borne disease. N Engl J Med  2015; 372:1231–9.
  • Baud D, Gubler DJ, Schaub B, Lanteri MC, Musso D. An update on Zika virus infection. Lancet Lond Engl  2017; 390:2099–109.
  • Kraemer MU, Sinka ME, Duda KA et al.  The global distribution of the arbovirus vectors Aedes aegypti and Ae. albopictus. Elife  4. 
  • Centers for Disease Control and Prevention. Dengue Virus. Published online. Jan  2019; 15. https://www.cdc.gov/dengue/index.html .
  • Hunsperger E., Peeling R., Gubler DJ., Dengue pre-vaccination serology screening for the use of Dengvaxia®, Journal of Travel Medicine, Volume 26, Issue 8, 2019.
  • Vouga M., Chiu Y-C., Pomar L., V de Meyer S., Masmejan S., Genton B., Musso D., Baud D., Stojanov M. Dengue, Zika and chikungunya during pregnancy: pre- and post-travel advice and clinical management. Journal of Travel Medicine, Volume 26, Issue 8, 2019
  • Center for Disease Control and Prevention. Statistics and Maps, dengue cases in the US. Online information – December 2019. 
  • Masyeni S, Yohan B, Somia IKA, Myint KSA, Sasmono RT. Dengue infection in international travellers visiting Bali, Indonesia. J Travel Med  2018; 25. 
  • CATMAT. Zika Virus Prevention and Treatment Recommendations. 2019; published online May 2. https://www.canada.ca/en/public-health/services/publications/diseases-conditions/zika-virus-prevention-treatment-recommendations.html#tb1.
  • WHO. WHO guidelines for the prevention of sexual transmission of Zika virus: executive summary. 2019. https://apps.who.int/iris/bitstream/handle/10665/311026/WHO-RHR-19.4-eng.pdf?ua=1.

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