Dengue: What factors make you vulnerable?

7 mins
Dengue fever a leading cause of illness for those living in dengue mosquito areas
Travelling with a pre-existing condition increases risk of dengue fever and more severe dengue symptoms
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The threat of dengue needs to be taken seriously

Dengue is the world’s most common and fastest spreading mosquito-transmitted infection.1,2 The last 50 or so years alone have seen a 30-fold rise in the incidence of dengue.3 It is often a leading cause of illness in areas with risk.4

“Each year, an estimated 400 million people are infected with dengue virus, 100 million become ill with dengue, and 21,000 deaths are attributed to dengue.”

 

– Centers for Disease Control and Prevention.5

Although many infections are mild and or result in no symptoms, dengue can be really dangerous for some people.6 Infections can have severe complications, such as shock and organ damage, which can lead to hospitalization and even death in some cases.6-8

 

Unfortunately, it is not a level playing field when it comes to dengue, some people are at greater risk of developing severe complications and outcomes than others.7,9,10

Read on to find out if you may be at greater risk and if so, what you can do to help keep yourself safe from this potentially life-threatening disease...6

 

Upping the stakes: Certain pre-existing conditions can increase the risk of dengue severity

Some pre-existing conditions can increase the risk of severity of dengue.7,9-10 These pre-existing conditions are also known as comorbidities if the person has the condition at the same time as they also have another disease (such as a dengue infection). Certain comorbidities can compromise the immune system as well as the lining of the blood vessels.7,10-12 Scientists think this could be partly behind why comorbidities can lead to poorer outcomes in dengue – although the exact reasons are still being researched.7,10-12 So, what are these pre-existing conditions and how might they worsen dengue in some people?

 

Some of the main culprits

Diabetes

Heart/blood circulation disorders

Diabetes increases risk of dengue fever and more severe dengue symptomsHeart disorders increase the risk of dengue fever and more severe dengue symptoms

  • Having diabetes can increase the risk of dengue severity and possibility of death. This may partly be due to the disruption caused to the immune system and linings of the blood vessels by diabetes.10

  • A study in Brazil found that for patients in hospital with dengue, diabetes increased the risk of death about 10 times compared to patients without it.13

  • High blood pressure can increase the progression to severe dengue in infected adults. One of the reasons for this may be the disruption caused to the immune system and linings of the blood vessels by high blood pressure.11

  • High blood pressure has been linked to a higher risk of hospitalization and death among people infected with dengue.10

Lung conditions

Kidney conditions

Lung conditions increase the risk of dengue fever and more severe dengue symptomsKidney conditions increase the risk of dengue fever and more severe dengue symptoms

  • A study in Singapore found dengue patients with pre-existing asthma were about twice as likely as dengue patients without asthma to have severe organ involvement.7

  • For patients, already in hospital with dengue, a study in Brazil found that certain pre-existing lung conditions can increase the risk of death up to about 10 times more compared to patients without these conditions.14

  • Chronic kidney disease can increase the risk of severe or fatal dengue outcomes compared to people without it. This may in part be due to disruption of the immune system caused by dengue.10,14

  • For patients already in hospital with dengue, a study in Brazil found that kidney comorbidities can increase the risk of death up to about 10 times more compared to patients without these conditions.13

Obesity or Overweight

 

Being overweight increases the risk of dengue fever and more severe dengue symptoms

 

  • People considered to be overweight may be 1.5 times more at risk of developing severe dengue than people within the normal weight range. Obesity is known to impair the immune system though it is not yet clear if this is the reason for the increased risk.12

  • Obesity has also been linked to longer hospital stays for patients with dengue.15

 

There may be other comorbidities besides the ones mentioned here, as this is an area scientists continue to research. Please contact your physician if you have any concerns about your own risk.

 

Adding up the risks: more comorbidities can mean more problems

Unfortunately, for those with more than one comorbidity, the risk may add up when it comes to dengue.7 This means that the combined effect of multiple comorbidities increases the risk of dengue further than compared to a single pre-existing comorbidity.7 For example, study in Singapore found that patients were more at risk to experience severe organ impairment as a result of dengue if they had both diabetes and hypertension than compared to if they just had one of these comorbidities alone.7

 

A higher risk in the elderly

Old age can increase the risk of severe dengue and death.7,10 Research has shown that people over 60 years had about a three times higher risk for severe organ impairment than those aged 12–29 years old.7 The risk associated with age may partly be down to the gradual decline of the immune system function that occurs naturally with advancing years.7 Unfortunately, being elderly is linked with a higher chance of having a number of chronic conditions16 – many of which can increase the risk of poor dengue outcomes in their own right.10

 

Stacking the odds against dengue in your favor

Related content

References

  1. Yang X, et al. J Travel Med. 2021;28(8):taab146.

  2. Bouri N, et al. Public Health Rep. 2012;127(3):259-66.

  3. World Health Organization. Available at: https://www.who.int/news-room/questions-and-answers/item/dengue-and-severe-dengue Accessed December 2023.

  4. Centers for Disease Control and Prevention. Available at: https://www.cdc.gov/dengue/areas-with-risk. Accessed December 2023.

  5. Centers for Disease Control and Prevention. https://www.cdc.gov/dengue/training/cme/ccm/page51440.html. Accessed December 2023.

  6. World Health Organization. Available at: https://www.who.int/news-room/fact-sheets/detail/dengue-and-severe-dengue Accessed December 2023.

  7. Pang J, et al. Sci Rep. 2017;7:39872.

  8. Calderón-Peláez MA et al. Front Microbiol. 2019;10:1435.

  9. Sangkaew S, et al. Lancet Infect Dis. 2021;21(7):1014-1026.

  10. Fonseca-Portilla R, et al. Int J Infect Dis. 2021;110:332-336.11.

  11. Ng WY, et al. PLoS One. 2022;17(9):e0273071.

  12. Chen CY, et al. BMC Infect Dis. 2023;23(1):502.

  13. Werneck GL, et al. Mem Inst Oswaldo Cruz. 2018;113(8):e180082.

  14. Lien CE, et al. Am J Trop Med Hyg. 2021;105(6):1544-1551.

  15. Tan VPK, et al. PLoS One. 2018;13(7):e0200698.

  16. Divo MJ, et al. Eur Respir J. 2014;44(4):1055-68.

  17. Herman J, et al. 2018;46(1):59-65.

Are you visiting a dengue endemic region as an elderly traveler or with a pre-existing medical condition? Take vital steps ahead of time…

Advanced age and/or certain long-term medical conditions can increase a traveler’s risk of complications (including death) from dengue if they catch it.7,9-10 Such travelers can be at risk from the adverse impacts of dengue – both during their travels (where they can originally be infected) and after they return (at which point they still may be experiencing symptoms of dengue).17

 

This means there are a few extra steps you may want to take before going abroad to areas at risk of dengue. Fortunately, careful planning can help you minimize the threat of dengue abroad. Here’s what you need to know…

 

Preparation is key: Check in with your doctor

Arranging a health check-up before you travel can help the doctor see how well-controlled your comorbidity is.17 If you take medication for your condition, you should plan ahead to make sure you take an adequate supply with you. It can be helpful to take a list of your medications with you, this is something your doctor can help with.17 Your doctor can also advise you on your individual risk of dengue when visiting the destination.17

 

Aside from seeing your doctor, another important thing to do before you fly is to enquire about a comprehensive insurance plan which covers your underlying condition(s).17

 

Things to consider about your destination

It is a good idea to check, ahead of travel, if and where your medication will be available at your destination.17 Consider too, how well-set up the local hospitals or health centers are for treatment of your condition. For instance, if they are likely to have the right equipment needed for treatment.17 One of the most important things you can do when you arrive at your destination is to make sure you take all the measures you can to avoid being bitten by mosquitoes in the first place.6

 

Make your holiday memorable the right reasons

Related content

References

  1. Yang X, et al. J Travel Med. 2021;28(8):taab146.

  2. Bouri N, et al. Public Health Rep. 2012;127(3):259-66.

  3. World Health Organization. Available at: https://www.who.int/news-room/questions-and-answers/item/dengue-and-severe-dengue Accessed December 2023.

  4. Centers for Disease Control and Prevention. Available at: https://www.cdc.gov/dengue/areas-with-risk. Accessed December 2023.

  5. Centers for Disease Control and Prevention. https://www.cdc.gov/dengue/training/cme/ccm/page51440.html. Accessed December 2023.

  6. World Health Organization. Available at: https://www.who.int/news-room/fact-sheets/detail/dengue-and-severe-dengue Accessed December 2023.

  7. Pang J, et al. Sci Rep. 2017;7:39872.

  8. Calderón-Peláez MA et al. Front Microbiol. 2019;10:1435.

  9. Sangkaew S, et al. Lancet Infect Dis. 2021;21(7):1014-1026.

  10. Centers for Disease Control and Prevention. Available at: https://www.cdc.gov/dengue/is-it-dengue-or-covid.html. Accessed December 2023.

  11. Fonseca-Portilla R, et al. Int J Infect Dis. 2021;110:332-336.11.

  12. Ng WY, et al. PLoS One. 2022;17(9):e0273071.

  13. Chen CY, et al. BMC Infect Dis. 2023;23(1):502.

  14. Werneck GL, et al. Mem Inst Oswaldo Cruz. 2018;113(8):e180082.

  15. Lien CE, et al. Am J Trop Med Hyg. 2021;105(6):1544-1551.

  16. Tan VPK, et al. PLoS One. 2018;13(7):e0200698.

  17. Divo MJ, et al. Eur Respir J. 2014;44(4):1055-68.

  18. Herman J, et al. 2018;46(1):59-65.

It’s time to talk about dengue

With dengue cases rising and no specific cure available, prevention is key1,2

 

Learn how to help protect yourself from mosquito bites and from dengue.

 

Contact your local health expert to talk about how to help prevent dengue.

Analogue alarm clock with mosquito on the edge
Analogue alarm clock with mosquito on the edge
  1. World Health Organization. Available at: https://www.who.int/news-room/fact-sheets/detail/dengue-and-severe-dengue. Accessed February 2024.
  2. World Health Organization. Available at: https://www.who.int/emergencies/disease-outbreak-news/item/2023-DON498#. Accessed February 2024.

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Learn how dengue has impacted the lives of some patients and families

 

Watch & Listen

Mother and daughter sitting side by side looking concerned
Mother and daughter sitting side by side looking concerned

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Aedes aegypti mosquito

Test your knowledge of dengue!

Can bites from male or female dengue-carrying mosquitoes infect humans?

Male bites
Female bites

Correct

 

Male mosquitoes feed on flower nectar and fruit juices and not blood.1 Only female mosquitoes feed on hosts such as humans, whose blood provides the protein they need to help their eggs develop.1

 

Contact your healthcare provider immediately if you suspect you have symptoms of dengue or have questions about your risk.

 

Learn more about dengue.

  1. The National Environment Agency. Vector Borne Diseases. Available at: https://www.nea.gov.sg/corporate-functions/resources/research/wolbachia-aedes-mosquito-suppression-strategy/male-mosquitoes-do-not-bite. Accessed January 2024.

Incorrect

 

Diseases such as dengue are not spread to humans by the bites of male Aedes mosquitoes; in fact, they don’t even bite humans.1 Only female mosquitoes feed on hosts such as humans, whose blood provides the protein they need to help their eggs develop.1

 

Contact your healthcare provider immediately if you suspect you have symptoms of dengue or have questions about your risk.

 

Learn more about dengue or try again!

  1. The National Environment Agency. Vector Borne Diseases. Available at: https://www.nea.gov.sg/corporate-functions/resources/research/wolbachia-aedes-mosquito-suppression-strategy/male-mosquitoes-do-not-bite. Accessed January 2024.

Survey Question 7

Test your knowledge of dengue!

By about how much has the number of reported dengue cases increased in the last two decades?

8-fold
4-fold

Correct

 

The number of reported dengue cases has increased over eightfold in the last two decades, from 505,430 cases in 2000 to over 4.2 million in 2019.1

 

Contact your healthcare provider promptly if you have questions about your risk.

 

Learn more about dengue.

 

  1. Zeng Z, et al. EClinicalMedicine. 2021;32:100712.

Incorrect

 

The number of reported dengue cases has increased over eightfold in the last two decades, from 505,430 cases in 2000 to over 4.2 million in 2019.1

 

Contact your healthcare provider promptly if you have questions about your risk.

 

Learn more about dengue or try again!

 

  1. Zeng Z, et al. EClinicalMedicine. 2021;32:100712.

Survey Question 8

Test your knowledge of dengue!

By what other name is dengue sometimes referred to?

Breakbone fever
Brittle bone fever

Correct

 

Dengue is also known as ‘breakbone fever’ due to the severe muscle and joint pain that can occur in some symptomatic patients.1

 

Contact your healthcare provider promptly if you have questions about your risk.

 

Learn more about dengue.

 

  1. 8. Whitehorn J and Farrar J. British Medical Bulletin. 2010; 95:161-173.

 

Dengue has historically been known as ‘breakbone fever’, due to the severe muscle and joint pain that can occur in some symptomatic patients.1

 

Contact your healthcare provider promptly if you have questions about your risk.

 

Learn more about dengue or try again!

 

  1. Whitehorn J and Farrar J. British Medical Bulletin. 2010; 95:161-173.

Survey Question 9

Test your knowledge of dengue!

Is there a specific cure or treatment available for dengue?

Yes
No

Correct

 

There is no specific treatment for dengue – the focus is on managing the symptoms. Most cases of dengue fever can be treated at home, however, for those who develop severe dengue, hospitalization is often needed.1

 

Contact your healthcare provider immediately if you suspect you have symptoms of dengue.

 

Learn more about dengue.

 

  1. World Health Organization [WHO]. Available at: https://www.who.int/news-room/fact-sheets/detail/dengue-and-severe-dengue. Accessed May 2024.

Incorrect

 

There is no specific treatment for dengue – the focus is on managing the symptoms. Most cases of dengue fever can be treated at home, however, for those who develop severe dengue, hospitalization is often needed.1

 

Contact your healthcare provider immediately if you suspect you have symptoms of dengue.

 

Learn more about dengue or try again!

 

  1. World Health Organization [WHO]. Available at: https://www.who.int/news-room/fact-sheets/detail/dengue-and-severe-dengue. Accessed May 2024.

Explore our resources to learn more about the risk of dengue and how you could help protect yourself and your loved ones

 

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Father and daughter sitting side by side smiling while looking at mobile phone screen

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