1. Dengue: A Global Threat
Audience: United States International Travelers
Arkia Blackman, MPH student
Walden University
PUBH Environmental Health
Instructor: Dr. Donald Goodwin
Spring, 2010
The audience that is the target of this presentation are United States international travelers.
My presentation will present data on dengue, the characteristics, the impact and possible prevention and treatments.

2. Agenda Definition Modes of Transmission Serotypes Classification
Contributing factors
Statistics
Prevention
Treatment
Tips for travelers
Blood transfusion
Here are the following agenda items will be covering in the following presentation.

3. Definition What is Dengue?
Dengue is a virus consisting of a single-stranded Ribonucleic Acid (RNA) (Thomas, John & Kanish, 2010).
The virus genetic makeup consist of a lipid envelope protein that enables it to transport and bind in possible hosts (Teo, Ng & Lam, 2009).
Let us define Dengue

4. Modes of Transmission Vector borne transmission Mosquito
Non vector borne transmission
Mother to child (Wiwanitki, 2010).
Blood transfusion (Wiwanitki, 2010).
Organ transplantation (Wiwanitki, 2010).
There are various modes of transmission to contract Dengue and it can be separated into two categories vector borne and non vector borne.

5. Aedes Aegypti (Teo et al., 2009)
Mode of Transmission
Aedes Aegypti (Teo et al., 2009)
Aedes albopictus (Teo et al., 2009)
Aedes polynesiensis (Teo et al., 2009)
Mosquitoes is a vector borne modes of transmission. There are three types of mosquito families that can contribute to Dengue infection.

6. Modes of Transmission
Dengue is transmitted primarily by the mosquito family Aedes Aegypti (Teo et al., 2009).
Dengue can also be transmitted by mosquito family Aedes albopictus and Aedes polynesiensis (Teo et al., 2009).
A female mosquito bite leads to an infection of Dengue then is transmitted into other victims in a constant cycle.
The incubation period of the infection varies 7-14 days (Teo et al., 2009).
The mosquito biting period occurs primarily in the dawn and at dusk (Teo et al., 2009).

7. Modes of Transmission Mother to child transmission
Can occur during a woman’s late term of their pregnancy through the placenta (Wiwanitki, 2010).
Transmission through transfusion of blood and blood products (Wiwantiki, 2010).
Transplantation of Dengue infected organs (Wiwantiki, 2010).
Non vector transmission can be a threat to the blood supply as far as eligible donors and unsuitable blood products.

8. Serotypes There are four serotypes of dengue (Teo et al., 2009). Den-1
Infection of one serotype does not ensure immunity against the other serotypes (Teo et al., 2009).
The serotypes are independent of each other (Teo et al., 2009).

9. Classification Dengue fever
Classified as individuals with symptoms such as headache, rash, leukopenia or myalgia along with the serological confirmation or in an area with similar cases (Thomas et al., 2010).
Dengue hemorrhagic fever
Classified by a previous or current fever lasting 2-7 days, bleeding such as hematemesis, a high thrombocytopenia count, and evidence of plasma leakage (Thomas et al., 2010).
Dengue shock syndrome
Classified as having all the symptoms of dengue hemorrhagic fever and failure to the circulatory system (Thomas et al., 2010).
Three different clinical illnesses can occur due to dengue infection which are dengue fever (DF), dengue shock syndrome (DSS) and dengue hemorrhagic fever (DHF) (Thomas et al., 2010). Here are the characteristics that describe each illness.

10. Contributing Factors Population growth (Teo et al., 2009)
Ineffective mosquito control (Teo et al., 2009)
Global travel (Teo et al., 2009)
Poor water management (Teo et al., 2009)
The contributing factors listed are some of the reasons why dengue infections are on the rise. These factors can increase breeding grounds for the mosquitoes and spread the disease to larger populations and across greater distances than just surrounding communities of endemic countries.

11. Statistics 2.5 billion individuals are at risk globally (CDC, 2010).
100 million individuals become affected with dengue fever annually (CDC, 2010)
Children make up the majority of the
500,000 cases of the fatal dengue hemorrhagic fever (CDC, 2010).
Here are some statistics to show the significance of dengue fever globally.

12. Statistics
Dengue is the second highest disease among travelers hospitalized after travel to tropical areas (Tomashek, 2009)
Individuals that travel to dengue-endemic countries suffer an infection rate of 2.9% to 8% (Tomashek, 2009)
Dengue is the number one disease for individuals that travel to South Central Asia, Southeast Asia, Caribbean and South America (Tomashek, 2009).
Dengue has had an impact on countries not endemic to this disease due to international travel. Here are some statistics to show the impact on travelers that travel to endemic countries.

13. Prevention
Environmental control involves reducing or eliminating breeding grounds for mosquitoes by properly managing solid waste in a community or country (Gurugama, Garg, Perera, Wijewickrama & Seneviratne, 2010).
Chemical control involves the use of insecticides to target the larvae state of mosquito lifecycle or thermal fogging which is a form of spraying in the household (Gurugama et al., 2010).
Here are some prevention methods

14. NO VACCINE AVAILABLE
No vaccine is currently available for dengue infection.

15. Treatment Dengue without warning signs
Treatment include proper bed rest, replenishment of fluids and proper dosage of the drug Paracetamol (World Health Organization [WHO], 2009).
Dengue with warning signs
Treatment include fluid therapy as prescribed by medical personnel (WHO, 2009).
Severe Dengue
Treatment consist of fluid resuscitation with isotonic crystalloid solutions (WHO, 2009).
The treatment for Dengue in individuals can vary according to the severity of the disease.

16. Prevention
Vaccines are being created and are in clinical studies so that they can be tested and researched for safety and effectiveness (Guzman, Vazquez & Kouri, 2009)
Some issues with creating vaccines include the differences between the four serotypes which may require different types of vaccine instead of one and the lack of an animal research subject (Guzman et al. 2009)

17. Tips for Travelers Sleeping accommodations
Travelers should ensure they are staying in accommodations that have air conditioning available and windows are appropriately screened (Tomashek, 2009).
Clothing
Travelers should wear clothing that protects exposed areas such as legs and arms to ensure mosquitoes do not have easy access to bite and transmit the dengue virus (Tomashek, 2009).
Insect Repellant
Repellant is very important and necessary when traveling to areas that are endemic to dengue. The repellant should be used on clothes and areas of the skin (Tomashek, 2009).
Travelers need to reduce the risk of getting dengue by taking some safety precautions recommended by the Center for Disease Control.

18. Blood Transfusions Donor qualification
Due to the rise of dengue infection in endemic countries and among travelers the individuals can be deferred from donating blood to prevent the risk of transfusion related transmission of dengue (Teo et al., 2009).
In various countries blood donors are being deferred for 6 months and 2-3 weeks and this diminishes the number of blood donations available for emergency and routine use (Teo et al., 2009).
NAT testing
The cost of NAT testing for dengue will be expensive and necessary to detect dengue in blood donations to ensure there is a safe blood supply (Teo et al., 2009).

19. Summary Dengue is a virus transmitted by vector and non vector methods
There are 3 types of dengue disease, dengue fever, dengue hemorrhagic fever and dengue shock syndrome
Travelers need to protect themselves when traveling to prevent infection of dengue
No vaccine is available for use currently
Blood donations are at risk
Dengue is a emerging disease that is on the rise and is a threat to endemic countries and non endemic countries due to international travelers. Vector control is the main source of prevention and there are barriers due to poor water management and population growth and travel. The blood supply may be at a potential risk because of international travel and stricter guidelines for donating blood if a person is at risk for dengue due to travel. Various vaccines are being created to protect the spread of this disease and bringing the incidence rate down and decrease morbidity and mortality among dengue infected individuals.

20. Questions
Please let me know if there are any questions? Thank you.

21. References Center for Disease Control. (2010). Dengue-A
Worldwide Threat. The Dengue Update. Volume 1.
Retrieved on April 24, 2010, from
Gurugama, P., Garg, P., Perera, J., Wijewickrama, A., &
Seneviratne S. L. (2010). Dengue Viral Infections. Indian
Journal of Dermatology, 55(1), DOI: /0019
Guzman M. G., Vazquez, S. & Kouri, G. (2009). Dengue:
where are we today? Malaysian Journal of Medical Sciences,
16(3), Retrieved from Academic Search Complete Database
Teo D., Ng L. C., & Lam, S. (2009). Is dengue a threat to the
blood supply? Transfusion Medicine, 19, doi:
10.111/j x

22. References
Thomas E. A., John, M., & Kanish B. (2010).
Mucocutaneous Manifestations of Dengue Fever.
Indian Journal of Dermatology, 55(1), DOI: /
Tomashek, K. M. (2009). Dengue Fever (DF) and
Dengue Hemorrhagic Fever (DHF). Retrieved April
25, 2010, from
Wiwanitkit, V. (2010). Non vector-borne transmission
modes of dengue. Journal of Infection In Developing
Countries, 4(1), Retrieved from Academic Search
Complete Database.

23. References World Health Organization. (2009). Dengue
Guidelines for Diagnosis,Treatment, Prevention and Control.
Retrieved April 24, 2010, from
_eng.pdf

24. Sources to Read
For information on insect repellants such as how to use them, when to use and why to use them check out the following site
Centers for Disease Control and Prevention. Insect Repellent
Use and Safety; [updated 2008 May 14; cited 2008 Nov 29]. Available from:
For additional information on insect repellants and which ones are registered and unregistered and alternative preventative measures please visit this site on the U.S. Environmental Protection Agency
U.S. Environmental Protection Agency. How to Use Insect
Repellents Safely; [updated 2007 July 5; cited 2008 Nov 29]. Available from:

25. Sources to Read
For information on the research being conducted to create a vaccine and the progress and challenges of this effort please read the following article
Swaminathan, S. & Khanna, N. (2010). Dengue vaccine
current progress and challenges. Current Science. 98(3):