Dengue is a febrile viral infection caused by four dengue virus (DEN) serotypes (1–4) that are transmitted by Aedes mosquitoes (mainly Aedes aegypti and Aedes albopictus) 3-5
In countries where dengue is endemic, infections have increased in incidence by a factor of 30 over the last 50 years 2,6
According to the WHO, dengue is currently the fastest spreading mosquito-borne viral disease in the world 4
Approximately 3.9 billion people around the globe – half of the world’s population – are at risk of dengue 4,7
Dengue is now endemic in more than 100 countries and causes an estimated 390 million infections and more than 20,000 deaths globally each year 3, 4, 6
Dengue can circulate year-round in affected areas and is highly correlated with temperature, rainy season, and vector fluctuation with seasonality 4,6
The potential effects of dengue infection could disrupt travellers' itineraries and result in unplanned financial costs13
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In countries where dengue is endemic, infections have increased in incidence by a factor of 30 over the last 50 years 2,6
-
According to the WHO, dengue is currently the fastest spreading mosquito-borne viral disease in the world 4
-
Approximately 3.9 billion people around the globe – half of the world’s population – are at risk of dengue 4,7
-
Dengue can circulate year-round in affected areas and is highly correlated with temperature, rainy season, and vector fluctuation with seasonality 4,6
-
The potential effects of dengue infection could disrupt travellers' itineraries and result in unplanned financial costs13
Dengue is now endemic in more than 100 countries and causes an estimated 390 million infections and more than 20,000 deaths globally each year 3, 4, 6
In countries where dengue is endemic, infections have increased in incidence by a factor of 30 over the last 50 years 2,6
According to the WHO, dengue is currently the fastest spreading mosquito-borne viral disease in the world 4
Approximately 3.9 billion people around the globe – half of the world’s population – are at risk of dengue 4,7
Dengue is now endemic in more than 100 countries and causes an estimated 390 million infections and more than 20,000 deaths globally each year 3, 4, 6
Dengue can circulate year-round in affected areas and is highly correlated with temperature, rainy season, and vector fluctuation with seasonality 4,6
The potential effects of dengue infection could disrupt travellers' itineraries and result in unplanned financial costs13
-
In countries where dengue is endemic, infections have increased in incidence by a factor of 30 over the last 50 years 2,6
-
According to the WHO, dengue is currently the fastest spreading mosquito-borne viral disease in the world 4
-
Approximately 3.9 billion people around the globe – half of the world’s population – are at risk of dengue 4,7
-
Dengue can circulate year-round in affected areas and is highly correlated with temperature, rainy season, and vector fluctuation with seasonality 4,6
-
The potential effects of dengue infection could disrupt travellers' itineraries and result in unplanned financial costs13
Dengue is now endemic in more than 100 countries and causes an estimated 390 million infections and more than 20,000 deaths globally each year 3, 4, 6
How does dengue spread?
Dengue is transmitted by female mosquitoes, mainly Aedes aegypti and Aedes albopictus 4
Vertical transmission of dengue virus to mosquito eggs has been documented for both Aedes species, which could play a key role in maintaining DENV circulation in the mosquito vector population 9
Aedes aegypti is well adapted to urban environments and thrives in close proximity to humans 5,6
Once infectious, a mosquito can transmit dengue virus for the rest of its life, to multiple individuals 4,5
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Dengue is transmitted by female mosquitoes, mainly Aedes aegypti and Aedes albopictus 4
-
Vertical transmission of dengue virus to mosquito eggs has been documented for both Aedes species, which could play a key role in maintaining DENV circulation in the mosquito vector population 9
-
Aedes aegypti is well adapted to urban environments and thrives in close proximity to humans 5,6
-
Once infectious, a mosquito can transmit dengue virus for the rest of its life, to multiple individuals 4,5
Dengue is transmitted by female mosquitoes, mainly Aedes aegypti and Aedes albopictus 4
Vertical transmission of dengue virus to mosquito eggs has been documented for both Aedes species, which could play a key role in maintaining DENV circulation in the mosquito vector population 9
Aedes aegypti is well adapted to urban environments and thrives in close proximity to humans 5,6
Once infectious, a mosquito can transmit dengue virus for the rest of its life, to multiple individuals 4,5
-
Dengue is transmitted by female mosquitoes, mainly Aedes aegypti and Aedes albopictus 4
-
Vertical transmission of dengue virus to mosquito eggs has been documented for both Aedes species, which could play a key role in maintaining DENV circulation in the mosquito vector population 9
-
Aedes aegypti is well adapted to urban environments and thrives in close proximity to humans 5,6
-
Once infectious, a mosquito can transmit dengue virus for the rest of its life, to multiple individuals 4,5
Travellers at risk
Travellers include workers, tourists and migrants – all these people can be at risk of infection with dengue if they travel to countries with outbreaks 3
This means travellers can be at risk of dengue infection in these areas, according to data from Centers for Disease Control and Prevention: 10
Figure adapted from Centers for Disease Control and Prevention (CDC). Dengue around the world. Last reviewed January 2023. Available at: https:www.cdc.gov/dengue/areaswithrisk/around-the-world.html. (Accessed October 2023)
Dengue can infect people of all nationalities and ages 4,7,11
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Meet Hugo*Engineering Student,20Denmark*This is a fictional patient case
Dengue history
Hugo has no history of dengue infection, having never travelled outside of Northern Europe. Now he is taking a month off his studies to explore South East Asia, from the busy cities to the rural countryside.
Impact of dengue
Shortly after arriving in Vietnam, Hugo was bitten by a mosquito while having breakfast and was infected with the dengue virus. A few days later he became unwell. A fever, severe headache and vomiting meaning he was unable to leave his room for a week. Luckily, Hugo made a full recovery and was able to continue with his trip, but was constantly worried he would become sick again.
It is scary becoming ill in an unfamiliar place, I missed out on a lot of activities I had carefully planned and may not get a chance to do again.
I thought I was only at risk in the evening?
Due to the behaviors of the 2 most important mosquito vectors (Aedes aegypti and Aedes albopictus), travellers are at risk of being bitten both indoors and outdoors at all times during the day, with peak mosquito activity in the morning and afternoon 4,12
Meet Hugo**This is a fictional patient case
Engineering Student,20DenmarkIt is scary becoming ill in an unfamiliar place, I missed out on a lot of activities I had carefully planned and may not get a chance to do again.Dengue history
Hugo has no history of dengue infection, having never travelled outside of Northern Europe. Now he is taking a month off his studies to explore South East Asia, from the busy cities to the rural countryside.
Impact of dengue
Shortly after arriving in Vietnam, Hugo was bitten by a mosquito while having breakfast and was infected with the dengue virus. A few days later he became unwell. A fever, severe headache and vomiting meaning he was unable to leave his room for a week. Luckily, Hugo made a full recovery and was able to continue with his trip, but was constantly worried he would become sick again.
I thought I was only at risk in the evening?
Due to the behaviors of the 2 most important mosquito vectors (Aedes aegypti and Aedes albopictus), travellers are at risk of being bitten both indoors and outdoors at all times during the day, with peak mosquito activity in the morning and afternoon 4,12
-
Meet Chloé and Louis*Couple approaching retirement,late 50sFrance*This is a fictional patient case
Dengue history
Chloé and Louis have no history of dengue infection, however Louis has heart problems and high blood pressure. They want to celebrate their early retirement by taking a river cruise in Northern Africa.
Impact of dengue
Both Chloé and Louis were bitten by mosquitos after sunbathing by the pool in the afternoon. After a few days both became ill with nausea, muscle pain and a fever. While Chloé recovered within a few days, Louis worsened, developing severe abdominal pain, rapid breathing and fatigue. Being too unwell to fly home, Louis was admitted to a local hospital for emergency treatment.
We want to enjoy the sights of Africa, but we’re not as young as we used to be so don’t want to get too close to the action.
I thought I was safe if I stayed indoors?
Due to the behaviors of the 2 most important mosquito vectors (Aedes aegypti and Aedes albopictus), travellers are at risk of being bitten both indoors and outdoors 12
Meet Chloé and Louis**This is a fictional patient case
Couple approaching retirement,late 50sFranceWe want to enjoy the sights of Africa, but we’re not as young as we used to be so don’t want to get too close to the action.Dengue history
Chloé and Louis have no history of dengue infection, however Louis has heart problems and high blood pressure. They want to celebrate their early retirement by taking a river cruise in Northern Africa.
Impact of dengue
Both Chloé and Louis were bitten by mosquitos after sunbathing by the pool in the afternoon. After a few days both became ill with nausea, muscle pain and a fever. While Chloé recovered within a few days, Louis worsened, developing severe abdominal pain, rapid breathing and fatigue. Being too unwell to fly home, Louis was admitted to a local hospital for emergency treatment.
I thought I was safe if I stayed indoors?
Due to the behaviors of the 2 most important mosquito vectors (Aedes aegypti and Aedes albopictus), travellers are at risk of being bitten both indoors and outdoors 12
-
Meet the Singh Family*Anil (35) and Lakshmi (33) with their children, Jyoti (4) and Maya (7)UK*This is a fictional patient case
Dengue history
Anil and Lakshmi have family in Mumbai who they visit every year. Lakshmi and Jyoti became ill after returning home from Mumbai last year and both were diagnosed with dengue.
Impact of dengue
While planning their trip this summer, Lakshmi’s GP informs her that, while they will now be immune to one serotype of dengue, she and her daughter are at an increased risk of developing severe dengue if they are infected with one of the other serotypes. The GP also tells her that severe dengue can occasionally be life-threatening.
We are always so careful with mosquito bites, but if we were bitten last year what is to say we won’t be bitten again? I am afraid to put myself and my family through that risk.
I have family out there; I’m going to be ok, right?
Dengue can infect people of all ethnicities, ages, and socioeconomic status. All four dengue serotypes circulate in many endemic countries, 4 and travellers who have had a prior dengue infection are at a higher risk of developing severe dengue than travellers with no previous exposure 4,7,11,13
Meet the Singh Family**This is a fictional patient case
Anil (35) and Lakshmi (33) with their children, Jyoti (4) and Maya (7)UKWe are always so careful with mosquito bites, but if we were bitten last year what is to say we won’t be bitten again? I am afraid to put myself and my family through that risk.Dengue history
Anil and Lakshmi have family in Mumbai who they visit every year. Lakshmi and Jyoti became ill after returning home from Mumbai last year and both were diagnosed with dengue.
Impact of dengue
While planning their trip this summer, Lakshmi’s GP informs her that, while they will now be immune to one serotype of dengue, she and her daughter are at an increased risk of developing severe dengue if they are infected with one of the other serotypes. The GP also tells her that severe dengue can occasionally be life-threatening.
I have family out there; I’m going to be ok, right?
Dengue can infect people of all ethnicities, ages, and socioeconomic status. All four dengue serotypes circulate in many endemic countries, 4 and travellers who have had a prior dengue infection are at a higher risk of developing severe dengue than travellers with no previous exposure 4,7,11,13
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Meet Sonya*Businesswoman,41Sweden*This is a fictional patient case
Dengue history
Sonya’s job requires that she travels on a regular basis. She contracted dengue a few years ago in Malaysia, and is now attending an IT conference in Guadalajara, Mexico.
Impact of dengue
During some evening drinks with her conference colleagues, Sonya is bitten by a mosquito. After returning home to Sweden, she begins to feel ill with nausea, vomiting and swollen glands. After a few days her symptoms worsen, leading to restlessness, persistent vomiting with blood and bleeding gums. After going to the emergency clinic she is diagnosed with severe dengue and hospitalised.
International travel is part of my job, so I now realise how important it is that I protect myself from illness.
I’m only travelling for a few days, so I’m not at risk.
The dengue virus is transmitted to humans via the bite of an infected mosquito. This can happen anywhere the mosquito vectors are present, even if only visiting the at-risk area for a short time 4
Meet Sonya**This is a fictional patient case
Businesswoman,41SwedenInternational travel is part of my job, so I now realise how important it is that I protect myself from illness.Dengue history
Sonya’s job requires that she travels on a regular basis. She contracted dengue a few years ago in Malaysia, and is now attending an IT conference in Guadalajara, Mexico.
Impact of dengue
During some evening drinks with her conference colleagues, Sonya is bitten by a mosquito. After returning home to Sweden, she begins to feel ill with nausea, vomiting and swollen glands. After a few days her symptoms worsen, leading to restlessness, persistent vomiting with blood and bleeding gums. After going to the emergency clinic she is diagnosed with severe dengue and hospitalised.
I’m only travelling for a few days, so I’m not at risk.
The dengue virus is transmitted to humans via the bite of an infected mosquito. This can happen anywhere the mosquito vectors are present, even if only visiting the at-risk area for a short time 4
*This is a fictional patient case
Dengue history
Hugo has no history of dengue infection, having never travelled outside of Northern Europe. Now he is taking a month off his studies to explore South East Asia, from the busy cities to the rural countryside.
Impact of dengue
Shortly after arriving in Vietnam, Hugo was bitten by a mosquito while having breakfast and was infected with the dengue virus. A few days later he became unwell. A fever, severe headache and vomiting meaning he was unable to leave his room for a week. Luckily, Hugo made a full recovery and was able to continue with his trip, but was constantly worried he would become sick again.
I thought I was only at risk in the evening?
Due to the behaviors of the 2 most important mosquito vectors (Aedes aegypti and Aedes albopictus), travellers are at risk of being bitten both indoors and outdoors at all times during the day, with peak mosquito activity in the morning and afternoon 4,12
*This is a fictional patient case
Dengue history
Hugo has no history of dengue infection, having never travelled outside of Northern Europe. Now he is taking a month off his studies to explore South East Asia, from the busy cities to the rural countryside.
Impact of dengue
Shortly after arriving in Vietnam, Hugo was bitten by a mosquito while having breakfast and was infected with the dengue virus. A few days later he became unwell. A fever, severe headache and vomiting meaning he was unable to leave his room for a week. Luckily, Hugo made a full recovery and was able to continue with his trip, but was constantly worried he would become sick again.
I thought I was only at risk in the evening?
Due to the behaviors of the 2 most important mosquito vectors (Aedes aegypti and Aedes albopictus), travellers are at risk of being bitten both indoors and outdoors at all times during the day, with peak mosquito activity in the morning and afternoon 4,12
*This is a fictional patient case
Dengue history
Chloé and Louis have no history of dengue infection, however Louis has heart problems and high blood pressure. They want to celebrate their early retirement by taking a river cruise in Northern Africa.
Impact of dengue
Both Chloé and Louis were bitten by mosquitos after sunbathing by the pool in the afternoon. After a few days both became ill with nausea, muscle pain and a fever. While Chloé recovered within a few days, Louis worsened, developing severe abdominal pain, rapid breathing and fatigue. Being too unwell to fly home, Louis was admitted to a local hospital for emergency treatment.
I thought I was safe if I stayed indoors?
Due to the behaviors of the 2 most important mosquito vectors (Aedes aegypti and Aedes albopictus), travellers are at risk of being bitten both indoors and outdoors 12
*This is a fictional patient case
Dengue history
Chloé and Louis have no history of dengue infection, however Louis has heart problems and high blood pressure. They want to celebrate their early retirement by taking a river cruise in Northern Africa.
Impact of dengue
Both Chloé and Louis were bitten by mosquitos after sunbathing by the pool in the afternoon. After a few days both became ill with nausea, muscle pain and a fever. While Chloé recovered within a few days, Louis worsened, developing severe abdominal pain, rapid breathing and fatigue. Being too unwell to fly home, Louis was admitted to a local hospital for emergency treatment.
I thought I was safe if I stayed indoors?
Due to the behaviors of the 2 most important mosquito vectors (Aedes aegypti and Aedes albopictus), travellers are at risk of being bitten both indoors and outdoors 12
*This is a fictional patient case
Dengue history
Anil and Lakshmi have family in Mumbai who they visit every year. Lakshmi and Jyoti became ill after returning home from Mumbai last year and both were diagnosed with dengue.
Impact of dengue
While planning their trip this summer, Lakshmi’s GP informs her that, while they will now be immune to one serotype of dengue, she and her daughter are at an increased risk of developing severe dengue if they are infected with one of the other serotypes. The GP also tells her that severe dengue can occasionally be life-threatening.
I have family out there; I’m going to be ok, right?
Dengue can infect people of all ethnicities, ages, and socioeconomic status. All four dengue serotypes circulate in many endemic countries, 4 and travellers who have had a prior dengue infection are at a higher risk of developing severe dengue than travellers with no previous exposure 4,7,11,13
*This is a fictional patient case
Dengue history
Anil and Lakshmi have family in Mumbai who they visit every year. Lakshmi and Jyoti became ill after returning home from Mumbai last year and both were diagnosed with dengue.
Impact of dengue
While planning their trip this summer, Lakshmi’s GP informs her that, while they will now be immune to one serotype of dengue, she and her daughter are at an increased risk of developing severe dengue if they are infected with one of the other serotypes. The GP also tells her that severe dengue can occasionally be life-threatening.
I have family out there; I’m going to be ok, right?
Dengue can infect people of all ethnicities, ages, and socioeconomic status. All four dengue serotypes circulate in many endemic countries, 4 and travellers who have had a prior dengue infection are at a higher risk of developing severe dengue than travellers with no previous exposure 4,7,11,13
*This is a fictional patient case
Dengue history
Sonya’s job requires that she travels on a regular basis. She contracted dengue a few years ago in Malaysia, and is now attending an IT conference in Guadalajara, Mexico.
Impact of dengue
During some evening drinks with her conference colleagues, Sonya is bitten by a mosquito. After returning home to Sweden, she begins to feel ill with nausea, vomiting and swollen glands. After a few days her symptoms worsen, leading to restlessness, persistent vomiting with blood and bleeding gums. After going to the emergency clinic she is diagnosed with severe dengue and hospitalised.
I’m only travelling for a few days, so I’m not at risk.
The dengue virus is transmitted to humans via the bite of an infected mosquito. This can happen anywhere the mosquito vectors are present, even if only visiting the at-risk area for a short time 4
*This is a fictional patient case
Dengue history
Sonya’s job requires that she travels on a regular basis. She contracted dengue a few years ago in Malaysia, and is now attending an IT conference in Guadalajara, Mexico.
Impact of dengue
During some evening drinks with her conference colleagues, Sonya is bitten by a mosquito. After returning home to Sweden, she begins to feel ill with nausea, vomiting and swollen glands. After a few days her symptoms worsen, leading to restlessness, persistent vomiting with blood and bleeding gums. After going to the emergency clinic she is diagnosed with severe dengue and hospitalised.
I’m only travelling for a few days, so I’m not at risk.
The dengue virus is transmitted to humans via the bite of an infected mosquito. This can happen anywhere the mosquito vectors are present, even if only visiting the at-risk area for a short time 4
-
Meet Hugo*Engineering Student,20Denmark
*This is a fictional patient case
Dengue history
Hugo has no history of dengue infection, having never travelled outside of Northern Europe. Now he is taking a month off his studies to explore South East Asia, from the busy cities to the rural countryside.
Impact of dengue
Shortly after arriving in Vietnam, Hugo was bitten by a mosquito while having breakfast and was infected with the dengue virus. A few days later he became unwell. A fever, severe headache and vomiting meaning he was unable to leave his room for a week. Luckily, Hugo made a full recovery and was able to continue with his trip, but was constantly worried he would become sick again.
It is scary becoming ill in an unfamiliar place, I missed out on a lot of activities I had carefully planned and may not get a chance to do again.
I thought I was only at risk in the evening?
Due to the behaviors of the 2 most important mosquito vectors (Aedes aegypti and Aedes albopictus), travellers are at risk of being bitten both indoors and outdoors at all times during the day, with peak mosquito activity in the morning and afternoon 4,12
Meet Hugo**This is a fictional patient case
Engineering Student,20DenmarkIt is scary becoming ill in an unfamiliar place, I missed out on a lot of activities I had carefully planned and may not get a chance to do again.Dengue history
Hugo has no history of dengue infection, having never travelled outside of Northern Europe. Now he is taking a month off his studies to explore South East Asia, from the busy cities to the rural countryside.
Impact of dengue
Shortly after arriving in Vietnam, Hugo was bitten by a mosquito while having breakfast and was infected with the dengue virus. A few days later he became unwell. A fever, severe headache and vomiting meaning he was unable to leave his room for a week. Luckily, Hugo made a full recovery and was able to continue with his trip, but was constantly worried he would become sick again.
I thought I was only at risk in the evening?
Due to the behaviors of the 2 most important mosquito vectors (Aedes aegypti and Aedes albopictus), travellers are at risk of being bitten both indoors and outdoors at all times during the day, with peak mosquito activity in the morning and afternoon 4,12
-
Meet Chloé and Louis*Couple approaching retirement,late 50sFrance
*This is a fictional patient case
Dengue history
Chloé and Louis have no history of dengue infection, however Louis has heart problems and high blood pressure. They want to celebrate their early retirement by taking a river cruise in Northern Africa.
Impact of dengue
Both Chloé and Louis were bitten by mosquitos after sunbathing by the pool in the afternoon. After a few days both became ill with nausea, muscle pain and a fever. While Chloé recovered within a few days, Louis worsened, developing severe abdominal pain, rapid breathing and fatigue. Being too unwell to fly home, Louis was admitted to a local hospital for emergency treatment.
We want to enjoy the sights of Africa, but we’re not as young as we used to be so don’t want to get too close to the action.
I thought I was safe if I stayed indoors?
Due to the behaviors of the 2 most important mosquito vectors (Aedes aegypti and Aedes albopictus), travellers are at risk of being bitten both indoors and outdoors 12
Meet Chloé and Louis**This is a fictional patient case
Couple approaching retirement,late 50sFranceWe want to enjoy the sights of Africa, but we’re not as young as we used to be so don’t want to get too close to the action.Dengue history
Chloé and Louis have no history of dengue infection, however Louis has heart problems and high blood pressure. They want to celebrate their early retirement by taking a river cruise in Northern Africa.
Impact of dengue
Both Chloé and Louis were bitten by mosquitos after sunbathing by the pool in the afternoon. After a few days both became ill with nausea, muscle pain and a fever. While Chloé recovered within a few days, Louis worsened, developing severe abdominal pain, rapid breathing and fatigue. Being too unwell to fly home, Louis was admitted to a local hospital for emergency treatment.
I thought I was safe if I stayed indoors?
Due to the behaviors of the 2 most important mosquito vectors (Aedes aegypti and Aedes albopictus), travellers are at risk of being bitten both indoors and outdoors 12
-
Meet the Singh Family*Anil (35) and Lakshmi (33) with their children, Jyoti (4) and Maya (7)UK
*This is a fictional patient case
Dengue history
Anil and Lakshmi have family in Mumbai who they visit every year. Lakshmi and Jyoti became ill after returning home from Mumbai last year and both were diagnosed with dengue.
Impact of dengue
While planning their trip this summer, Lakshmi’s GP informs her that, while they will now be immune to one serotype of dengue, she and her daughter are at an increased risk of developing severe dengue if they are infected with one of the other serotypes. The GP also tells her that severe dengue can occasionally be life-threatening.
We are always so careful with mosquito bites, but if we were bitten last year what is to say we won’t be bitten again? I am afraid to put myself and my family through that risk.
I have family out there; I’m going to be ok, right?
Dengue can infect people of all ethnicities, ages, and socioeconomic status. All four dengue serotypes circulate in many endemic countries, 4 and travellers who have had a prior dengue infection are at a higher risk of developing severe dengue than travellers with no previous exposure 4,7,11,13
Meet the Singh Family**This is a fictional patient case
Anil (35) and Lakshmi (33) with their children, Jyoti (4) and Maya (7)UKWe are always so careful with mosquito bites, but if we were bitten last year what is to say we won’t be bitten again? I am afraid to put myself and my family through that risk.Dengue history
Anil and Lakshmi have family in Mumbai who they visit every year. Lakshmi and Jyoti became ill after returning home from Mumbai last year and both were diagnosed with dengue.
Impact of dengue
While planning their trip this summer, Lakshmi’s GP informs her that, while they will now be immune to one serotype of dengue, she and her daughter are at an increased risk of developing severe dengue if they are infected with one of the other serotypes. The GP also tells her that severe dengue can occasionally be life-threatening.
I have family out there; I’m going to be ok, right?
Dengue can infect people of all ethnicities, ages, and socioeconomic status. All four dengue serotypes circulate in many endemic countries, 4 and travellers who have had a prior dengue infection are at a higher risk of developing severe dengue than travellers with no previous exposure 4,7,11,13
-
Meet Sonya*Businesswoman,41Sweden
*This is a fictional patient case
Dengue history
Sonya’s job requires that she travels on a regular basis. She contracted dengue a few years ago in Malaysia, and is now attending an IT conference in Guadalajara, Mexico.
Impact of dengue
During some evening drinks with her conference colleagues, Sonya is bitten by a mosquito. After returning home to Sweden, she begins to feel ill with nausea, vomiting and swollen glands. After a few days her symptoms worsen, leading to restlessness, persistent vomiting with blood and bleeding gums. After going to the emergency clinic she is diagnosed with severe dengue and hospitalised.
International travel is part of my job, so I now realise how important it is that I protect myself from illness.
I’m only travelling for a few days, so I’m not at risk.
The dengue virus is transmitted to humans via the bite of an infected mosquito. This can happen anywhere the mosquito vectors are present, even if only visiting the at-risk area for a short time 4
Meet Sonya**This is a fictional patient case
Businesswoman,41SwedenInternational travel is part of my job, so I now realise how important it is that I protect myself from illness.Dengue history
Sonya’s job requires that she travels on a regular basis. She contracted dengue a few years ago in Malaysia, and is now attending an IT conference in Guadalajara, Mexico.
Impact of dengue
During some evening drinks with her conference colleagues, Sonya is bitten by a mosquito. After returning home to Sweden, she begins to feel ill with nausea, vomiting and swollen glands. After a few days her symptoms worsen, leading to restlessness, persistent vomiting with blood and bleeding gums. After going to the emergency clinic she is diagnosed with severe dengue and hospitalised.
I’m only travelling for a few days, so I’m not at risk.
The dengue virus is transmitted to humans via the bite of an infected mosquito. This can happen anywhere the mosquito vectors are present, even if only visiting the at-risk area for a short time 4
*This is a fictional patient case
Dengue history
Hugo has no history of dengue infection, having never travelled outside of Northern Europe. Now he is taking a month off his studies to explore South East Asia, from the busy cities to the rural countryside.
Impact of dengue
Shortly after arriving in Vietnam, Hugo was bitten by a mosquito while having breakfast and was infected with the dengue virus. A few days later he became unwell. A fever, severe headache and vomiting meaning he was unable to leave his room for a week. Luckily, Hugo made a full recovery and was able to continue with his trip, but was constantly worried he would become sick again.
I thought I was only at risk in the evening?
Due to the behaviors of the 2 most important mosquito vectors (Aedes aegypti and Aedes albopictus), travellers are at risk of being bitten both indoors and outdoors at all times during the day, with peak mosquito activity in the morning and afternoon 4,12
*This is a fictional patient case
Dengue history
Hugo has no history of dengue infection, having never travelled outside of Northern Europe. Now he is taking a month off his studies to explore South East Asia, from the busy cities to the rural countryside.
Impact of dengue
Shortly after arriving in Vietnam, Hugo was bitten by a mosquito while having breakfast and was infected with the dengue virus. A few days later he became unwell. A fever, severe headache and vomiting meaning he was unable to leave his room for a week. Luckily, Hugo made a full recovery and was able to continue with his trip, but was constantly worried he would become sick again.
I thought I was only at risk in the evening?
Due to the behaviors of the 2 most important mosquito vectors (Aedes aegypti and Aedes albopictus), travellers are at risk of being bitten both indoors and outdoors at all times during the day, with peak mosquito activity in the morning and afternoon 4,12
*This is a fictional patient case
Dengue history
Chloé and Louis have no history of dengue infection, however Louis has heart problems and high blood pressure. They want to celebrate their early retirement by taking a river cruise in Northern Africa.
Impact of dengue
Both Chloé and Louis were bitten by mosquitos after sunbathing by the pool in the afternoon. After a few days both became ill with nausea, muscle pain and a fever. While Chloé recovered within a few days, Louis worsened, developing severe abdominal pain, rapid breathing and fatigue. Being too unwell to fly home, Louis was admitted to a local hospital for emergency treatment.
I thought I was safe if I stayed indoors?
Due to the behaviors of the 2 most important mosquito vectors (Aedes aegypti and Aedes albopictus), travellers are at risk of being bitten both indoors and outdoors 12
*This is a fictional patient case
Dengue history
Chloé and Louis have no history of dengue infection, however Louis has heart problems and high blood pressure. They want to celebrate their early retirement by taking a river cruise in Northern Africa.
Impact of dengue
Both Chloé and Louis were bitten by mosquitos after sunbathing by the pool in the afternoon. After a few days both became ill with nausea, muscle pain and a fever. While Chloé recovered within a few days, Louis worsened, developing severe abdominal pain, rapid breathing and fatigue. Being too unwell to fly home, Louis was admitted to a local hospital for emergency treatment.
I thought I was safe if I stayed indoors?
Due to the behaviors of the 2 most important mosquito vectors (Aedes aegypti and Aedes albopictus), travellers are at risk of being bitten both indoors and outdoors 12
*This is a fictional patient case
Dengue history
Anil and Lakshmi have family in Mumbai who they visit every year. Lakshmi and Jyoti became ill after returning home from Mumbai last year and both were diagnosed with dengue.
Impact of dengue
While planning their trip this summer, Lakshmi’s GP informs her that, while they will now be immune to one serotype of dengue, she and her daughter are at an increased risk of developing severe dengue if they are infected with one of the other serotypes. The GP also tells her that severe dengue can occasionally be life-threatening.
I have family out there; I’m going to be ok, right?
Dengue can infect people of all ethnicities, ages, and socioeconomic status. All four dengue serotypes circulate in many endemic countries, 4 and travellers who have had a prior dengue infection are at a higher risk of developing severe dengue than travellers with no previous exposure 4,7,11,13
*This is a fictional patient case
Dengue history
Anil and Lakshmi have family in Mumbai who they visit every year. Lakshmi and Jyoti became ill after returning home from Mumbai last year and both were diagnosed with dengue.
Impact of dengue
While planning their trip this summer, Lakshmi’s GP informs her that, while they will now be immune to one serotype of dengue, she and her daughter are at an increased risk of developing severe dengue if they are infected with one of the other serotypes. The GP also tells her that severe dengue can occasionally be life-threatening.
I have family out there; I’m going to be ok, right?
Dengue can infect people of all ethnicities, ages, and socioeconomic status. All four dengue serotypes circulate in many endemic countries, 4 and travellers who have had a prior dengue infection are at a higher risk of developing severe dengue than travellers with no previous exposure 4,7,11,13
*This is a fictional patient case
Dengue history
Sonya’s job requires that she travels on a regular basis. She contracted dengue a few years ago in Malaysia, and is now attending an IT conference in Guadalajara, Mexico.
Impact of dengue
During some evening drinks with her conference colleagues, Sonya is bitten by a mosquito. After returning home to Sweden, she begins to feel ill with nausea, vomiting and swollen glands. After a few days her symptoms worsen, leading to restlessness, persistent vomiting with blood and bleeding gums. After going to the emergency clinic she is diagnosed with severe dengue and hospitalised.
I’m only travelling for a few days, so I’m not at risk.
The dengue virus is transmitted to humans via the bite of an infected mosquito. This can happen anywhere the mosquito vectors are present, even if only visiting the at-risk area for a short time 4
*This is a fictional patient case
Dengue history
Sonya’s job requires that she travels on a regular basis. She contracted dengue a few years ago in Malaysia, and is now attending an IT conference in Guadalajara, Mexico.
Impact of dengue
During some evening drinks with her conference colleagues, Sonya is bitten by a mosquito. After returning home to Sweden, she begins to feel ill with nausea, vomiting and swollen glands. After a few days her symptoms worsen, leading to restlessness, persistent vomiting with blood and bleeding gums. After going to the emergency clinic she is diagnosed with severe dengue and hospitalised.
I’m only travelling for a few days, so I’m not at risk.
The dengue virus is transmitted to humans via the bite of an infected mosquito. This can happen anywhere the mosquito vectors are present, even if only visiting the at-risk area for a short time 4
Dengue can infect people of all nationalities and ages 4,7,11
-
Meet Hugo*Engineering Student,20Denmark
*This is a fictional patient case
Dengue history
Hugo has no history of dengue infection, having never travelled outside of Northern Europe. Now he is taking a month off his studies to explore South East Asia, from the busy cities to the rural countryside.
Impact of dengue
Shortly after arriving in Vietnam, Hugo was bitten by a mosquito while having breakfast and was infected with the dengue virus. A few days later he became unwell. A fever, severe headache and vomiting meaning he was unable to leave his room for a week. Luckily, Hugo made a full recovery and was able to continue with his trip, but was constantly worried he would become sick again.
It is scary becoming ill in an unfamiliar place, I missed out on a lot of activities I had carefully planned and may not get a chance to do again.
I thought I was only at risk in the evening?
Due to the behaviors of the 2 most important mosquito vectors (Aedes aegypti and Aedes albopictus), travellers are at risk of being bitten both indoors and outdoors at all times during the day, with peak mosquito activity in the morning and afternoon 4,12
Meet Hugo**This is a fictional patient case
Engineering Student,20DenmarkIt is scary becoming ill in an unfamiliar place, I missed out on a lot of activities I had carefully planned and may not get a chance to do again.Dengue history
Hugo has no history of dengue infection, having never travelled outside of Northern Europe. Now he is taking a month off his studies to explore South East Asia, from the busy cities to the rural countryside.
Impact of dengue
Shortly after arriving in Vietnam, Hugo was bitten by a mosquito while having breakfast and was infected with the dengue virus. A few days later he became unwell. A fever, severe headache and vomiting meaning he was unable to leave his room for a week. Luckily, Hugo made a full recovery and was able to continue with his trip, but was constantly worried he would become sick again.
I thought I was only at risk in the evening?
Due to the behaviors of the 2 most important mosquito vectors (Aedes aegypti and Aedes albopictus), travellers are at risk of being bitten both indoors and outdoors at all times during the day, with peak mosquito activity in the morning and afternoon 4,12
-
Meet Chloé and Louis*Couple approaching retirement,late 50sFrance
*This is a fictional patient case
Dengue history
Chloé and Louis have no history of dengue infection, however Louis has heart problems and high blood pressure. They want to celebrate their early retirement by taking a river cruise in Northern Africa.
Impact of dengue
Both Chloé and Louis were bitten by mosquitos after sunbathing by the pool in the afternoon. After a few days both became ill with nausea, muscle pain and a fever. While Chloé recovered within a few days, Louis worsened, developing severe abdominal pain, rapid breathing and fatigue. Being too unwell to fly home, Louis was admitted to a local hospital for emergency treatment.
We want to enjoy the sights of Africa, but we’re not as young as we used to be so don’t want to get too close to the action.
I thought I was safe if I stayed indoors?
Due to the behaviors of the 2 most important mosquito vectors (Aedes aegypti and Aedes albopictus), travellers are at risk of being bitten both indoors and outdoors 12
Meet Chloé and Louis**This is a fictional patient case
Couple approaching retirement,late 50sFranceWe want to enjoy the sights of Africa, but we’re not as young as we used to be so don’t want to get too close to the action.Dengue history
Chloé and Louis have no history of dengue infection, however Louis has heart problems and high blood pressure. They want to celebrate their early retirement by taking a river cruise in Northern Africa.
Impact of dengue
Both Chloé and Louis were bitten by mosquitos after sunbathing by the pool in the afternoon. After a few days both became ill with nausea, muscle pain and a fever. While Chloé recovered within a few days, Louis worsened, developing severe abdominal pain, rapid breathing and fatigue. Being too unwell to fly home, Louis was admitted to a local hospital for emergency treatment.
I thought I was safe if I stayed indoors?
Due to the behaviors of the 2 most important mosquito vectors (Aedes aegypti and Aedes albopictus), travellers are at risk of being bitten both indoors and outdoors 12
-
Meet the Singh Family*Anil (35) and Lakshmi (33) with their children, Jyoti (4) and Maya (7)UK
*This is a fictional patient case
Dengue history
Anil and Lakshmi have family in Mumbai who they visit every year. Lakshmi and Jyoti became ill after returning home from Mumbai last year and both were diagnosed with dengue.
Impact of dengue
While planning their trip this summer, Lakshmi’s GP informs her that, while they will now be immune to one serotype of dengue, she and her daughter are at an increased risk of developing severe dengue if they are infected with one of the other serotypes. The GP also tells her that severe dengue can occasionally be life-threatening.
We are always so careful with mosquito bites, but if we were bitten last year what is to say we won’t be bitten again? I am afraid to put myself and my family through that risk.
I have family out there; I’m going to be ok, right?
Dengue can infect people of all ethnicities, ages, and socioeconomic status. All four dengue serotypes circulate in many endemic countries, 4 and travellers who have had a prior dengue infection are at a higher risk of developing severe dengue than travellers with no previous exposure 4,7,11,13
Meet the Singh Family**This is a fictional patient case
Anil (35) and Lakshmi (33) with their children, Jyoti (4) and Maya (7)UKWe are always so careful with mosquito bites, but if we were bitten last year what is to say we won’t be bitten again? I am afraid to put myself and my family through that risk.Dengue history
Anil and Lakshmi have family in Mumbai who they visit every year. Lakshmi and Jyoti became ill after returning home from Mumbai last year and both were diagnosed with dengue.
Impact of dengue
While planning their trip this summer, Lakshmi’s GP informs her that, while they will now be immune to one serotype of dengue, she and her daughter are at an increased risk of developing severe dengue if they are infected with one of the other serotypes. The GP also tells her that severe dengue can occasionally be life-threatening.
I have family out there; I’m going to be ok, right?
Dengue can infect people of all ethnicities, ages, and socioeconomic status. All four dengue serotypes circulate in many endemic countries, 4 and travellers who have had a prior dengue infection are at a higher risk of developing severe dengue than travellers with no previous exposure 4,7,11,13
-
Meet Sonya*Businesswoman,41Sweden
*This is a fictional patient case
Dengue history
Sonya’s job requires that she travels on a regular basis. She contracted dengue a few years ago in Malaysia, and is now attending an IT conference in Guadalajara, Mexico.
Impact of dengue
During some evening drinks with her conference colleagues, Sonya is bitten by a mosquito. After returning home to Sweden, she begins to feel ill with nausea, vomiting and swollen glands. After a few days her symptoms worsen, leading to restlessness, persistent vomiting with blood and bleeding gums. After going to the emergency clinic she is diagnosed with severe dengue and hospitalised.
International travel is part of my job, so I now realise how important it is that I protect myself from illness.
I’m only travelling for a few days, so I’m not at risk.
The dengue virus is transmitted to humans via the bite of an infected mosquito. This can happen anywhere the mosquito vectors are present, even if only visiting the at-risk area for a short time 4
Meet Sonya**This is a fictional patient case
Businesswoman,41SwedenInternational travel is part of my job, so I now realise how important it is that I protect myself from illness.Dengue history
Sonya’s job requires that she travels on a regular basis. She contracted dengue a few years ago in Malaysia, and is now attending an IT conference in Guadalajara, Mexico.
Impact of dengue
During some evening drinks with her conference colleagues, Sonya is bitten by a mosquito. After returning home to Sweden, she begins to feel ill with nausea, vomiting and swollen glands. After a few days her symptoms worsen, leading to restlessness, persistent vomiting with blood and bleeding gums. After going to the emergency clinic she is diagnosed with severe dengue and hospitalised.
I’m only travelling for a few days, so I’m not at risk.
The dengue virus is transmitted to humans via the bite of an infected mosquito. This can happen anywhere the mosquito vectors are present, even if only visiting the at-risk area for a short time 4
*This is a fictional patient case
Dengue history
Hugo has no history of dengue infection, having never travelled outside of Northern Europe. Now he is taking a month off his studies to explore South East Asia, from the busy cities to the rural countryside.
Impact of dengue
Shortly after arriving in Vietnam, Hugo was bitten by a mosquito while having breakfast and was infected with the dengue virus. A few days later he became unwell. A fever, severe headache and vomiting meaning he was unable to leave his room for a week. Luckily, Hugo made a full recovery and was able to continue with his trip, but was constantly worried he would become sick again.
I thought I was only at risk in the evening?
Due to the behaviors of the 2 most important mosquito vectors (Aedes aegypti and Aedes albopictus), travellers are at risk of being bitten both indoors and outdoors at all times during the day, with peak mosquito activity in the morning and afternoon 4,12
*This is a fictional patient case
Dengue history
Hugo has no history of dengue infection, having never travelled outside of Northern Europe. Now he is taking a month off his studies to explore South East Asia, from the busy cities to the rural countryside.
Impact of dengue
Shortly after arriving in Vietnam, Hugo was bitten by a mosquito while having breakfast and was infected with the dengue virus. A few days later he became unwell. A fever, severe headache and vomiting meaning he was unable to leave his room for a week. Luckily, Hugo made a full recovery and was able to continue with his trip, but was constantly worried he would become sick again.
I thought I was only at risk in the evening?
Due to the behaviors of the 2 most important mosquito vectors (Aedes aegypti and Aedes albopictus), travellers are at risk of being bitten both indoors and outdoors at all times during the day, with peak mosquito activity in the morning and afternoon 4,12
*This is a fictional patient case
Dengue history
Chloé and Louis have no history of dengue infection, however Louis has heart problems and high blood pressure. They want to celebrate their early retirement by taking a river cruise in Northern Africa.
Impact of dengue
Both Chloé and Louis were bitten by mosquitos after sunbathing by the pool in the afternoon. After a few days both became ill with nausea, muscle pain and a fever. While Chloé recovered within a few days, Louis worsened, developing severe abdominal pain, rapid breathing and fatigue. Being too unwell to fly home, Louis was admitted to a local hospital for emergency treatment.
I thought I was safe if I stayed indoors?
Due to the behaviors of the 2 most important mosquito vectors (Aedes aegypti and Aedes albopictus), travellers are at risk of being bitten both indoors and outdoors 12
*This is a fictional patient case
Dengue history
Chloé and Louis have no history of dengue infection, however Louis has heart problems and high blood pressure. They want to celebrate their early retirement by taking a river cruise in Northern Africa.
Impact of dengue
Both Chloé and Louis were bitten by mosquitos after sunbathing by the pool in the afternoon. After a few days both became ill with nausea, muscle pain and a fever. While Chloé recovered within a few days, Louis worsened, developing severe abdominal pain, rapid breathing and fatigue. Being too unwell to fly home, Louis was admitted to a local hospital for emergency treatment.
I thought I was safe if I stayed indoors?
Due to the behaviors of the 2 most important mosquito vectors (Aedes aegypti and Aedes albopictus), travellers are at risk of being bitten both indoors and outdoors 12
*This is a fictional patient case
Dengue history
Anil and Lakshmi have family in Mumbai who they visit every year. Lakshmi and Jyoti became ill after returning home from Mumbai last year and both were diagnosed with dengue.
Impact of dengue
While planning their trip this summer, Lakshmi’s GP informs her that, while they will now be immune to one serotype of dengue, she and her daughter are at an increased risk of developing severe dengue if they are infected with one of the other serotypes. The GP also tells her that severe dengue can occasionally be life-threatening.
I have family out there; I’m going to be ok, right?
Dengue can infect people of all ethnicities, ages, and socioeconomic status. All four dengue serotypes circulate in many endemic countries, 4 and travellers who have had a prior dengue infection are at a higher risk of developing severe dengue than travellers with no previous exposure 4,7,11,13
*This is a fictional patient case
Dengue history
Anil and Lakshmi have family in Mumbai who they visit every year. Lakshmi and Jyoti became ill after returning home from Mumbai last year and both were diagnosed with dengue.
Impact of dengue
While planning their trip this summer, Lakshmi’s GP informs her that, while they will now be immune to one serotype of dengue, she and her daughter are at an increased risk of developing severe dengue if they are infected with one of the other serotypes. The GP also tells her that severe dengue can occasionally be life-threatening.
I have family out there; I’m going to be ok, right?
Dengue can infect people of all ethnicities, ages, and socioeconomic status. All four dengue serotypes circulate in many endemic countries, 4 and travellers who have had a prior dengue infection are at a higher risk of developing severe dengue than travellers with no previous exposure 4,7,11,13
*This is a fictional patient case
Dengue history
Sonya’s job requires that she travels on a regular basis. She contracted dengue a few years ago in Malaysia, and is now attending an IT conference in Guadalajara, Mexico.
Impact of dengue
During some evening drinks with her conference colleagues, Sonya is bitten by a mosquito. After returning home to Sweden, she begins to feel ill with nausea, vomiting and swollen glands. After a few days her symptoms worsen, leading to restlessness, persistent vomiting with blood and bleeding gums. After going to the emergency clinic she is diagnosed with severe dengue and hospitalised.
I’m only travelling for a few days, so I’m not at risk.
The dengue virus is transmitted to humans via the bite of an infected mosquito. This can happen anywhere the mosquito vectors are present, even if only visiting the at-risk area for a short time 4
*This is a fictional patient case
Dengue history
Sonya’s job requires that she travels on a regular basis. She contracted dengue a few years ago in Malaysia, and is now attending an IT conference in Guadalajara, Mexico.
Impact of dengue
During some evening drinks with her conference colleagues, Sonya is bitten by a mosquito. After returning home to Sweden, she begins to feel ill with nausea, vomiting and swollen glands. After a few days her symptoms worsen, leading to restlessness, persistent vomiting with blood and bleeding gums. After going to the emergency clinic she is diagnosed with severe dengue and hospitalised.
I’m only travelling for a few days, so I’m not at risk.
The dengue virus is transmitted to humans via the bite of an infected mosquito. This can happen anywhere the mosquito vectors are present, even if only visiting the at-risk area for a short time 4
Dengue around the world
cases reported from 2017-2020, principally due to imported cases3
most common cause of fever in travellers returning from endemic countries4
most common cause of hospitalisations due to febrile illness after return from abroad3
Dengue in Europe
cases reported from 2017-2020, principally due to imported cases3
most common cause of fever in travellers returning from endemic countries4
most common cause of hospitalisations due to febrile illness after return from abroad3
16%
of febrile illness in returning travellers, was due to dengue (from 2009-2010). In general, around 3% of travellers reported a febrile illness upon their return 15,16
In a US study,
40%
(2176) of reported dengue cases were hospitalised, most of whom (2119; 97%) were travellers 14
From 2000- 2011
studies reported dengue as being the leading cause of febrile illness among ill travellers returning from Southeast Asia, Latin America and the Caribbean 17
In a US study,
~1%
(46/5009) of travel-associated dengue cases developed severe dengue, and it was fatal in 0.4% (18/5009) of these cases 14
16%
of febrile illness in returning travellers, was due to dengue (from 2009-2010). In general, around 3% of travellers reported a febrile illness upon their return 15,16
In a US study,
40%
(2176) of reported dengue cases were hospitalised, most of whom (2119; 97%) were travellers 14
From 2000- 2011
studies reported dengue as being the leading cause of febrile illness among ill travellers returning from Southeast Asia, Latin America and the Caribbean 17
In a US study,
~1%
(46/5009) of travel-associated dengue cases developed severe dengue, and it was fatal in 0.4% (18/5009) of these cases 14
Incidence of dengue
Compared to other diseases that are regularly vaccinated against, the incidence of dengue is relatively high amongst travellers 15,18
ESTIMATE MONTHLY INCIDENCE OF VACCINE-PREVENTABLE DISEASES IN NON-IMMUNE TRAVELLERS 21
Figure adapted from Steffen R, et al. J Travel Med. 2018;25(1):1-3
* Diseases positioned by Prof Steffens personal assessment. Dengue incidence per month calculated as per Ratnam I, et al. Journal of Travel Medicine. 2013;20(6):384–393, by dividing 1,000 person-months by 1,000 (study period 1991-2010).
Symptoms of dengue
Symptoms range from a non-specific febrile illness to life-threatening fever and shock, or death in rare cases 4,6,7
*Depending on the study, between 2% to 57% of individuals may experience persistent dengue-related symptoms for several weeks or months after the acute phase of dengue infection 7,24-26
- Approximately 1 in 4 infections are symptomatic 4
- Symptoms usually last 2-7 days, but can persist for months or years after infection 4,23
- Dengue can cause both physical and mental distress 6,24-26
- There is no cure: Medication and supportive care can only control the symptoms 4,6
-
Persistent symptoms can include post-infection fatigue, muscle weakness, and variable neurological abnormalities 24,26
Many travellers might not be aware that, according to the World Health Organization (WHO), those presenting with a high fever and any of the below symptoms could have a dengue infection:6
-
Approximately 5% of symptomatic dengue cases progress to severe dengue 20,21, a potentially lethal complication of dengue infection 4
-
The risk of severe dengue is greater in those who have had a previous dengue infection with a different serotype 7,27
-
Two variants of severe dengue exist – dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS) 3
-
People who develop DHF have a 5% chance of death, but this can be as high as 40% if DSS develops
-
-
Early detection of disease progression associated with severe dengue, and access to proper medical care lowers fatality rates of severe dengue to below 1%. 4
Many travellers might not be aware that, according to the WHO, individuals who are infected for the second time are at a greater risk of severe dengue and that severe dengue symptoms often come after the the fever has gone away: 4
Dengue symptoms
- Approximately 1 in 4 infections are symptomatic 4
- Symptoms usually last 2-7 days, but can persist for months or years after infection 4,23
- Dengue can cause both physical and mental distress 6,24-26
- There is no cure: Medication and supportive care can only control the symptoms 4,6
-
Persistent symptoms can include post-infection fatigue, muscle weakness, and variable neurological abnormalities 24,26
Many travellers might not be aware that, according to the World Health Organization (WHO), those presenting with a high fever and any of the below symptoms could have a dengue infection:6
Severe dengue symptoms
-
Approximately 5% of symptomatic dengue cases progress to severe dengue 20,21, a potentially lethal complication of dengue infection 4
-
The risk of severe dengue is greater in those who have had a previous dengue infection with a different serotype 7,27
-
Two variants of severe dengue exist – dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS) 3
-
People who develop DHF have a 5% chance of death, but this can be as high as 40% if DSS develops
-
-
Early detection of disease progression associated with severe dengue, and access to proper medical care lowers fatality rates of severe dengue to below 1%. 4
Many travellers might not be aware that, according to the WHO, individuals who are infected for the second time are at a greater risk of severe dengue and that severe dengue symptoms often come after the the fever has gone away: 4
Risks factors for dengue
Risk factors for travellers are linked to conditions of their destinations, with the following being important collective risk factors: 4,12,28
Mosquitos are active in both urban (Aedes aegypti) and rural (Aedes albopictus) areas
Areas with high population density
Areas with inadequate sanitation standards
Warmer ambient temperatures (especially 26–29°C)
Areas with high rainfall and those subject to periods of drought
Travellers are at risk of being bitten by mosquitos indoors and outdoors at all times during the day, with peak mosquito activity in the morning and afternoon
-
Mosquitos are active in both urban (Aedes aegypti) and rural (Aedes albopictus) areas
-
Travellers are at risk of being bitten by mosquitos indoors and outdoors at all times during the day, with peak mosquito activity in the morning and afternoon
Mosquitos are active in both urban (Aedes aegypti) and rural (Aedes albopictus) areas
Areas with high population density
Areas with inadequate sanitation standards
Warmer ambient temperatures (especially 26–29°C)
Areas with high rainfall and those subject to periods of drought
Travellers are at risk of being bitten by mosquitos indoors and outdoors at all times during the day, with peak mosquito activity in the morning and afternoon
-
Mosquitos are active in both urban (Aedes aegypti) and rural (Aedes albopictus) areas
-
Travellers are at risk of being bitten by mosquitos indoors and outdoors at all times during the day, with peak mosquito activity in the morning and afternoon
It is possible to be infected with dengue more than once 4
Travellers who plan to enter dengue-endemic regions more than once in their lifetime are at a greater risk of contracting a secondary infection and, potentially, severe dengue4
- Dengue virus has 4 serotypes which are circulating worldwide in varying frequency 4
- This means a person can be infected more than once with different serotypes of the dengue virus 4
- Secondary infection with a different dengue virus serotype increases the risk of severe dengue 7,27
▼ This medicinal product is subject to additional monitoring.
GB & NI: Adverse Events should be reported. Reporting forms and information can be found at: www.mhra.gov.uk/yellowcard.
ROI: Adverse Events should be reported to the Pharmacovigilance Unit at the Health Products Regulatory Authority. Reporting forms and information can be found at: www.hpra.ie.
GB, NI and ROI: Adverse Events should also be reported to Takeda UK Ltd at: AE.GBR-IRL@takeda.com
- QdengaTM Summary of Product Characteristics
- Biswal S, et al. NEJM. 2019;381(21):2009-2019 and supplementary appendix.
- Mathis A and Schaffner F. et al. Lancet Infect Dis 2014; 14:1271-80.
- World Health Organization. Dengue and severe dengue. 17 March 2023. Available at: https://www.who.int/news-room/fact-sheets/detail/dengue-and-severe-dengue. Last accessed: October 2023.
- Bäck AT, et al. Infect Ecol Epidemiol. 2013;doi:10.3402/iee.v3i0.19839.
- Guzman MG, et al. Nat Rev Dis Primers. 2016;2:16055.
- Jing Q and Wang M. Glo Health J. 2019;3(2):37-45.
- Bhattacharya MK, et al. Int J Biomedical Science. 2013;9(2):61-67.
- Ferreira-de-Lima V & Lima-Camara TN. Parasit Vectors. 2018;11:77.
- Centers for Disease Control and Prevention Dengue around the world. Available at: https://www.cdc.gov/dengue/areaswithrisk/around-the-world.html. Last accessed: October 2023.
- Mulligan K, et al. Pathog Glob Health. 2015;109(1):10-18.
- World Health Organization. Dengue guidelines for diagnosis, treatment, prevention and control. New edition 2009. Available at: https://apps.who.int/iris/handle/10665/44188. Last accessed: October 2023.
- Wilder-Smith A, et al. Curr Infect Dis Rep. 2018;20(12):50.
- Rivera A, et al. MMWR Morb Mortal Wkly Rep. 2020;69:149–154.
- Ratnam I, et al. Journal of Travel Medicine. 2013;20(6):384–393.
- Ryan ET, et al. N Engl J Med. 2002;347(7):505-516.
- Tozan Y, et al. Am. J. Trop. Med. Hyg. 2019;100(6):1525-1533
- Steffen R, et al. J Travel Med. 2018;25(1):1-3.
- European Centre for Disease Prevention and Control. Factsheet about dengue. https://www.ecdc.europa.eu/en/dengue-fever/facts/factsheet. Last accessed: October 2023.
- Centers for Disease Control and Prevention. Yellow book 2024: infectious diseases. https://www.nc.cdc.gov/travel/yellowbook/2024/infections-diseases/dengue. Last accessed: October 2023.
- Centers for Disease Control and Prevention. Clinical Presentation. https://www.cdc.gov/dengue/healthcare-providers/clinical-presentation.html. Last accessed: October 2023.
- Duong V, et al. Proc Natl Acad Sci U S A. 2015;112(47):14688-14693.
- Garcıa G, et al. International Journal of Infectious Diseases. 2011;15(1):e38-43.
- Elson WH, et al. PLoS Neg. Trop Dis. 2020;14(7):e0008477.
- Martelli CMT, et al. Am J Trop Med Hyg. 2011;85(4):732-738.
- Tran BX, et al. Int J Environ Res Public Health. 2018;15(6):1174.
- Katzelnick LC, et al. Proc Natl Acad Sci U S A. 2016;113:728–33.
- Lowe R, et al. Lancet Planet Health. 2021;5:e209-19.
DEN, dengue virus; DHF, dengue hemorrhagic fever; DSS, dengue shock syndrome; WHO, World Health Organization.
C-APROM/GB/DENV/0075 | Date of preparation: December 2023