1. Dealing With Dengue Laura Sadowski, MPH Student Walden University
PUBH
Instructor: Dr. Jalal Ghaemghami
Fall 2009
Hello fellow community members, neighborhood administrators and staff from the International School. I thank you for coming today to learn about an important health topic that affects us all. This presentation about Dengue Fever in our neighborhood and how we can best prevent it will take about 20 minutes. We will have time for questions at the end.

2. Purpose…. To prevent Dengue Fever through community participation
Our main purpose for this presentation is to prevent the transmission and infection of Dengue Fever in our community. As you know or as you can guess from this slide, mosquito control is the major method of prevention.

3. Expect To Have These Questions Answered……
What is Dengue Fever?
How common is it?
What causes it ?
How is it transmitted?
What are the symptoms?
Can we treat it?
What can be done to prevent it?
Before I get to prevention though, I will be speaking about these other topics first. I will provide basic information on what Dengue Fever is and what causes it. You will learn about how often it occurs and what countries are at risk. I will talk about the symptoms of dengue fever and how to treat it and then we will get to the methods of prevention.

4. What is Dengue Fever?
Dengue Fever is a virus. There are 4 strains of dengue virus. People can get dengue fever more than once because they can be infected by a different strain each time.
Second infection can lead to DHF
WHO. (2009). Dengue. WHO Regional Office for South East Asia. Retrieved on October 15, 2009 from
So let’s get started with the basics…dengue fever is a virus. There are 4 strains of this virus.
Having been infected with one dengue fever strain gives you immunity to that strain. However, one can get dengue fever another time with another strain and the prior immunity has a potentiating effect. In other words, the second infection tends to be worse and can lead to the more serious Dengue hemorrhagic fever.

5. The Cause of Dengue Fever
The mosquito Aedes aegypti transmits the virus.
National Environment Agency. (2005). Campaign against dengue. Retrieved on October 20, 2009 from
Dengue Fever is a mosquito borne virus, which means that the mosquito carries the virus and infects people through bites. Some facts about this mosquito…the average life span for a mosquito is 2 weeks and female mosquitoes, the only ones that bite, can lay eggs 3 times in their life. About 100 eggs are laid each time.

6. How is it transmitted?
The mosquito bites an infected person and carries the virus to the next person.
National Environment Agency. (2005). Campaign against dengue. Retrieved on October 20, 2009 from
So, like I said, the female mosquito bites an infected person. It then takes about 7 days for the virus to replicate, mature, and then reach the mosquitoes salivary glands. At this point it is now able to infect another person.

7. More About the Mosquito
Peak biting is dusk and dawn
From egg to larva to pupa to adult is about 7 days.
National Environment Agency. (2005). Campaign against dengue. Retrieved on October 20, 2009 from
This type of mosquito that transmits dengue fever tends to be a day time biter (dengue=daytime), so the mosquitoes biting at dusk and dawn are the ones to beware of.
The time period from when the egg is laid in standing water to when an adult mosquito emerges is about 7 days.
These facts are important to remember when we discuss prevention…but for now, let’s move on and talk about who and how many people are at risk…

8. Who Gets It
50 million infants, children, and adults annually in over 100 countries
400,000 cases of the more severe DHF with 22,000 deaths
WHO. (2009). The impact of Dengue. Retrieved on October 20, 2009 from
The WHO estimates that 50 million cases of dengue fever occur annually. The number of countries reporting cases has greatly increased over the past 30 years with now over 100 countries reporting infections. As a comparison, in 1970, as few as 9 countries had cases of dengue fever.
The more severe DHF occurs in about 400,000 people every year and 22,000 people, mostly children, die. In fact, in some Southeast Asian countries, DHF is a leading cause of childhood mortality.

9. Countries at Risk for Transmission
It occurs in tropical and sub tropical areas in South East Asia, Africa, and Central and South America. It is predominantly transmitted among people living in urban and semi urban areas.
WHO. (2009). The impact of Dengue. Retrieved on October 20, 2009 from

10. Situation in Thailand
Until 2003 Thailand had the highest number of cases in Southeast Asia
Currently in 2nd place after Indonesia and has 23% of all cases in region-about 50,000
Less than 1% mortality rate
WHO. (2009). The impact of Dengue. Retrieved on October 20, 2009 from
According to the WHO, Thailand had the highest annual rates of dengue fever until 2003 when Indonesia then became the leader. Thailand now has about 50,000 cases per year.
A positive thing to mention…Even though the incidence rates have been rising, the numbers of deaths remain low- at less than 1%.

11. Symptoms of Dengue Fever
Sudden onset of high fever
Severe headache
Pain behind the eyes
Body aches and joint pains
Nausea and vomiting
Skin rash example
National Institute of Health. (2007). Dengue fever: Symptoms. Retrieved on October 22, 2009 from
So, now that I have gone over how dengue fever is transmitted and how common it is, I will now move on to talk about the symptoms of the disease…
Within 4-7 days of being bitten by an infected mosquito, patients will have a very high fever which can last up to a week. Patients can experience headaches and pain behind the eyes as well as joint and body aches. Nausea and vomiting may also occur. About 3-4 days after the fever starts, a rash usually appears over most of the body. It usually subsides after 1-2 days.. sometimes the rash appears a second time.
As noted before, Dengue fever can lead to the serious, sometime fatal dengue hemorrhagic fever…

12. Dengue Hemorrhagic Fever
Includes all of the symptoms of Dengue Fever
plus:
Bleeding from nose, gums, under the skin-purple bruises
Severe abdominal pain
Can lead to Dengue Shock Syndrome:
Massive bleeding
Low blood pressure
National Institute of Health. (2007). Dengue fever: Symptoms. Retrieved on October 22, 2009 from
DHF can occur in the second or third infection. It includes all of the classic Dengue fever symptoms plus bleeding and bruising. It can lead to Dengue Shock Syndrome and it is sometimes fatal, usually to children

13. Treatment No vaccine Bed rest Plenty of fluids
Medicine for fever, avoid aspirin, ibuprofen
Patients usually recover within two weeks
Early medical care can prevent complications and death from DHF
National Institute of Health. (2007). Dengue fever: Symptoms. Retrieved on October 22, 2009 from
There is no specific treatment or vaccine for Dengue Fever. But with bed rest, fluids, fever medication, patients usually get better after 2 weeks. Aspirin and Ibuprofen should be avoided because of the tendencies for bleeding. If any symptoms occur suggesting DHF-bleeding, bruising, abdominal pain, patients should be immediately brought to the hospital for fluid and electrolyte replacement and monitoring.

14. Basic Facts Spread by the bite of a mosquito
Symptoms begin 4-7 days after bite
Mosquito rests indoors or outdoors
Lays eggs in water containers outside near houses, schools, buildings
Barrels, buckets, vases, plant saucers, anywhere that rain water collects
So, let’s review some of the basic facts about dengue fever…This virus is the most common mosquito borne virus in the world. It is spread by a mosquito that bites during the day and seeks places to breed in urban and suburban areas wherever water is trapped. Knowing these things can help us prevent transmission in our neighborhood…

15. Prevent Mosquito Bites
Wear clothing to cover the skin
Mosquito repellent, local brand Jaico works well
Use mosquito coils to keep mosquitoes away
Use nets to protect babies
Use nets around a patient infected with dengue
WHO. (2009). Dengue. WHO Regional Office for South East Asia. Retrieved on October 15, 2009 from
Since the dangerous mosquitoes bite during the day, try to keep skin covered at peak biting times. This is difficult in Thailand where it is very warm. So mosquito repellents work well. The local brand comes in a roll-on and is called Jaico, but OFF, an American brand, is also available here. Mosquito coils are very effective to keep mosquitoes away. Nets, especially pesticide treated nets, can be used to protect babies and should also be used for people who have dengue fever, since a mosquito who bites an infected person then passes it on when it bites another person.

16. Prevent Mosquito Breeding
Drain water from anywhere that it collects
Remove plant saucers from indoor and outdoor plants
Remove water from refrigerator drip pans
Discard solid containers that might collect water
WHO. (2009). Dengue. WHO Regional Office for South East Asia. Retrieved on October 15, 2009 from
The mosquito that transmits dengue fever searches for water in which to lay its eggs. Removing standing water can prevent dengue fever….

17. Places Mosquitoes Breed
Anyplace where water collects…
Anyplace where water collects will be used by these mosquitoes. Indoors, this could be refrigerator drip pans and plant saucers, toilets and sinks that are not used often. Outdoors, especially during the rainy season, water can collect in any receptacle and attract mosquitoes. Air conditioner trays, roof gutters, holes in trees, and lawn ornaments. It is important to check and drain these areas often, at least every other day.

18. What Else Can We Do As a Community?
Inform neighbors
Be vigilant of common areas
When going on vacation, arrange for someone to remove any standing water that may accumulate.
So as a community, you can see that there are ways we can prevent dengue fever. Some other things we can do include informing and educating our neighbors about the dangers of mosquitoes. We should be aware of the common areas in the neighborhood as well as our own property and make sure that anything that can be a receptacle for water should be drained, turned over, or thrown away. In our community, many people leave their homes for weeks at a time for home leave or vacation. During those times, it is important that someone is watching the property and ensuring that water is not accumulating in any areas.

19. Neighborhood Administrators
Educate homeowners
Inform newcomers
Ensure gardeners/grounds keepers are removing standing water
Larvicide/Pesticide fumigation
WHO. (2006). Dengue Fever/DHF Frequently asked questions. Retrieved on October 24, 2009 from
The office people who help run the neighborhood and who are responsible for renting the properties and taking care of the common areas have a responsibility as far as dengue fever is concerned. They are in the perfect position to educate homeowners as well as newcomers renting the properties. They should be educating the groundskeepers and landscapers to remove receptacles that could be collecting water and they should periodically use larvicide and pesticide to fumigate some of the neighborhoods. Fumigating or “fogging” is done to kill the adult mosquitoes and is truly not an effective prevention because it must be done about every 4 days to work…and this is not feasible..

20. School Educate grounds keepers about standing water
Encourage staff to be vigilant
Periodic fumigation during school breaks
Ensure school nurse knows signs and symptoms of dengue fever in order to facilitate early diagnosis and treatment
The school in the center of our community must also be a part of the solution. Employees including teachers, staff and grounds keepers must be aware of the threat of mosquito breeding areas. School nurses should know the symptoms of dengue fever and encourage early diagnosis and treatment.

21. In Closing….
The WHO states that “the community is the key to prevention” of dengue fever
The main strategy of prevention is mosquito reduction
Every household can prevent the collection of standing water
Let’s work together!
WHO. (2006). Dengue Fever/DHF Frequently asked questions. Retrieved on October 24, 2009 from
In closing…let’s remember that as a community there are simple ways we can work together to make our neighborhood dengue free…

22. For more information…. Visit the CDC Dengue information webpage:
Singapore’s Campaign Against Dengue
National Institute of Allergy and Infectious Diseases
Dengue Fever research
If you are interested in more information, these three websites are very accessible and can provide the latest news about Dengue fever research, prevention, and control.

23. References
National Environment Agency. (2005). Campaign against dengue. Retrieved on October 20, 2009 from
National Institute of Health. (2007). Dengue fever: Symptoms. Retrieved on October 22, 2009 from .htm
WHO. (2006). Dengue Fever/DHF Frequently asked questions. Retrieved on October 24, 2009 from
WHO. (2009). Dengue. WHO Regional Office for South East Asia. Retrieved on October 15, 2009 from
WHO. (2009). The impact of Dengue. Retrieved on October 20, 2009 from

24. Questions?
I thank you all for coming and I will be here to answer any questions you might have.

25. Thank you