Dengue Fever
Dengue (Fever) is a mosquito-transmitted febrile illness that is caused by any one of four subtypes of a group of 4 similar viruses (DEN-1, DEN-2, DEN-3, and DEN-4). Dengue Fever and these viruses are endemic in more than 100 countries in tropical and subtropical regions of the world and causes an estimated 50 million infections annually worldwide.
Although mild Dengue disease and Dengue Fever contributes more than half of the total public health burden of Dengue-associated illness, the more serious manifestations of Dengue Hemorrhagic Fever and Dengue Shock Syndrome provide the major impetus for efforts to prevent infection. Studies have shown that the greatest risk factor for the development of one of these more serious syndromes of Dengue virus infection is a second infection with a different dengue serotype from the original infecting virus. Thus, severe disease occurs primarily in patients who reside in hyperendemic areas where multiple serotypes circulate simultaneously. Viet Nam as a whole is considered a hyperendemic area, especially in the south of Viet Nam.
Dengue virus infection is a risk for anyone living in or traveling in Viet Nam. Dengue virus transmission can occur year-round, however, the risk of infection tends to be seasonal and can be expected to be highest during the wet or rainy season. The objectives of programs to prevent dengue infections differ depending upon whether local residents or visitors are targeted. There is no direct antiviral therapy available against these dengue viruses, which increases the importance of prevention.
PREVENTION; The greatest risk for dengue virus infection is in individuals residing in endemic areas and not in travelers, but many travelers have the potential to become infected. The mosquito which transmits the Dengue viruses is the Aedes aegypti mosquito, which are most active in houses and residences during the daytime hours. Avoidance of exposure to infected A. aegypti mosquitoes is the primary approach to prevention of dengue virus infections in travelers. These mosquitoes predominantly live in urban areas in and around houses. Thus, travelers to major cities are at risk for exposure to A. aegypti. Bed netting is of little use since these particular mosquitoes are most active during the daytime. Remaining in well-screened or air-conditioned buildings during the day can reduce the risk of exposure but many travelers are unwilling or unable to comply. When outside during the day, travelers wishing to avoid dengue should wear covering clothing that reduces the amount of exposed skin and should use an effective mosquito repellent, such as N,N-diethyl-metatoluamide (DEET). There are several formulations of DEET and these formulations primarily are categorized by how long after application (from 2-12 hours) that the mosquito repellent is present and active.
Most people who live in endemic areas and are not travelers, will not find it practical to apply mosquito repellent every day of the year, or be able to take measures when going out.
Mosquito control - Mosquito control is the most effective community-level approach to the prevention of Dengue Fever virus transmission.
Large scale insecticide spraying, in response to dengue outbreaks, is not highly effective against A. aegypti mosquitoes, which frequently breed inside houses. Community-based approaches involving education of the population in efforts to reduce breeding sites, such as discarded tires and other containers that accumulate standing water, have shown some promise.
In a study within Viet Nam, a comprehensive community and governmental control program and strategy included the seeding of water vessels with copepods (small water crustaceans) that feed on mosquito larvae, was successful in eliminating A. aegypti and dengue transmission in 32 communities in rural areas of Vietnam. However, this strategy is much more difficult to apply in larger cities where breeding sites are different and community participation is harder to sustain.
Vaccination - Research is occuring into a Dengue Fever vaccine, which would mean persons are vaccinated against all 4 of the subtypes that cause Dengue Fever infections. These vaccines are in development but are not available or tested as yet.
Most travelers from non-endemic countries are at exceedingly low risk for the more complicated syndromes of Dengue Virus infections because they lack previous exposure to dengue viruses (exceptions however are returning Viet Kieu travelers who now live in non-edemic regions and then return to Viet Nam for visiting, such persons would have a higher risk for a more serious infection).
Dengue Fever Infection used to go by the name “Break Bone Fever” and so severe body and bony aches occur with the infection, high-spiking fevers, diarrhea can occur, and even some upper respiratory symptoms (sore throat, cough) can occur, and a rash can occur in about 50% of infections. A full discussion of Dengue Fever cannot be made here. If you feel you may be having a Dengue Fever virus infection, it is best to be seen as early as possible in the course of the symptoms by an experienced physician.
The physicians at the Stamford Medical Clinic are experienced with the evaluating, treating, and diagnosing Dengue Fever presentations.
Dengue (Fever) is a mosquito-transmitted febrile illness that is caused by any one of four subtypes of a group of 4 similar viruses (DEN-1, DEN-2, DEN-3, and DEN-4). Dengue Fever and these viruses are endemic in more than 100 countries in tropical and subtropical regions of the world and causes an estimated 50 million infections annually worldwide.
Although mild Dengue disease and Dengue Fever contributes more than half of the total public health burden of Dengue-associated illness, the more serious manifestations of Dengue Hemorrhagic Fever and Dengue Shock Syndrome provide the major impetus for efforts to prevent infection. Studies have shown that the greatest risk factor for the development of one of these more serious syndromes of Dengue virus infection is a second infection with a different dengue serotype from the original infecting virus. Thus, severe disease occurs primarily in patients who reside in hyperendemic areas where multiple serotypes circulate simultaneously. Viet Nam as a whole is considered a hyperendemic area, especially in the south of Viet Nam.
Dengue virus infection is a risk for anyone living in or traveling in Viet Nam. Dengue virus transmission can occur year-round, however, the risk of infection tends to be seasonal and can be expected to be highest during the wet or rainy season. The objectives of programs to prevent dengue infections differ depending upon whether local residents or visitors are targeted. There is no direct antiviral therapy available against these dengue viruses, which increases the importance of prevention.
PREVENTION; The greatest risk for dengue virus infection is in individuals residing in endemic areas and not in travelers, but many travelers have the potential to become infected. The mosquito which transmits the Dengue viruses is the Aedes aegypti mosquito, which are most active in houses and residences during the daytime hours. Avoidance of exposure to infected A. aegypti mosquitoes is the primary approach to prevention of dengue virus infections in travelers. These mosquitoes predominantly live in urban areas in and around houses. Thus, travelers to major cities are at risk for exposure to A. aegypti. Bed netting is of little use since these particular mosquitoes are most active during the daytime. Remaining in well-screened or air-conditioned buildings during the day can reduce the risk of exposure but many travelers are unwilling or unable to comply. When outside during the day, travelers wishing to avoid dengue should wear covering clothing that reduces the amount of exposed skin and should use an effective mosquito repellent, such as N,N-diethyl-metatoluamide (DEET). There are several formulations of DEET and these formulations primarily are categorized by how long after application (from 2-12 hours) that the mosquito repellent is present and active.
Most people who live in endemic areas and are not travelers, will not find it practical to apply mosquito repellent every day of the year, or be able to take measures when going out.
Mosquito control - Mosquito control is the most effective community-level approach to the prevention of Dengue Fever virus transmission.
Large scale insecticide spraying, in response to dengue outbreaks, is not highly effective against A. aegypti mosquitoes, which frequently breed inside houses. Community-based approaches involving education of the population in efforts to reduce breeding sites, such as discarded tires and other containers that accumulate standing water, have shown some promise.
In a study within Viet Nam, a comprehensive community and governmental control program and strategy included the seeding of water vessels with copepods (small water crustaceans) that feed on mosquito larvae, was successful in eliminating A. aegypti and dengue transmission in 32 communities in rural areas of Vietnam. However, this strategy is much more difficult to apply in larger cities where breeding sites are different and community participation is harder to sustain.
Vaccination - Research is occuring into a Dengue Fever vaccine, which would mean persons are vaccinated against all 4 of the subtypes that cause Dengue Fever infections. These vaccines are in development but are not available or tested as yet.
Most travelers from non-endemic countries are at exceedingly low risk for the more complicated syndromes of Dengue Virus infections because they lack previous exposure to dengue viruses (exceptions however are returning Viet Kieu travelers who now live in non-edemic regions and then return to Viet Nam for visiting, such persons would have a higher risk for a more serious infection).
Dengue Fever Infection used to go by the name “Break Bone Fever” and so severe body and bony aches occur with the infection, high-spiking fevers, diarrhea can occur, and even some upper respiratory symptoms (sore throat, cough) can occur, and a rash can occur in about 50% of infections. A full discussion of Dengue Fever cannot be made here. If you feel you may be having a Dengue Fever virus infection, it is best to be seen as early as possible in the course of the symptoms by an experienced physician.
The physicians at the Stamford Medical Clinic are experienced with the evaluating, treating, and diagnosing Dengue Fever presentations.