Natural History

Dengue/dengue hemorrhagic fever is an acute viral disease caused by four closely related, but distinct viruses. It is primarily an urban disease of the tropics. The viruses are maintained in large urban centers in a cycle that involves humans and Aedes aegypti mosquitoes. Aedes aegypti mosquitoes are highly adapted to humans. They prefer to feed on humans during the day and spend most of their lifetimes in human habitations. This intimate association makes Aedes aegypti a highly efficient epidemic vector of dengue viruses.

Children Suffer Most

Infections with dengue viruses can produce a spectrum of clinical illness, ranging from mild, nonspecific viral syndrome to severe and fatal hemorrhagic disease. The severe form of disease, dengue hemorrhagic fever, is primarily a disease of children under the age of 15 years, but it also can occur in adults. Dengue hemorrhagic fever is a confusing disease for physicians because in the

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early acute state of illness, signs and symptoms are nonspecific. It is difficult to distinguish from other common viral and some bacterial and parasitic illnesses. Lack of proper diagnosis and treatment can result in high mortality.

Dramatic Increase

The past 15 years has seen a dramatic increase in the incidence of dengue hemorrhagic fever both in frequency of epidemics and geographic distribution of viruses and mosquito vectors. Three main factors are responsible for the changing disease pattern:

• uncontrolled urbanization increases mosquito densities
• increased air travel transports viruses worldwide
• deteriorating public health infrastructure cannot control mosquito-borne disease

Dengue viruses and their mosquito vector have a worldwide distribution in the tropics. Dengue hemorrhagic fever is a leading cause of hospitalization and death among children in many tropical countries.

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Since 1981 dengue hemorrhagic fever has emerged in many western hemisphere countries

• 2.5 billion people live in areas of high risk
• 50-100 million cases of dengue fever annually
• 500 thousand cases of dengue hemorrhagic fever annually
• Dengue/Dengue hemorrhagic fever can devastate a community

Why Rotary International

• Rotary in more than 155 countries
• 28, 134 Rotary Clubs
• 1.2 million Rotarians
• Service above self
• Focus on community ownership and long-term self-help
• Strong emphasis on school children and other youth groups
• Benefit over 2.5 billion people worldwide
• Very defined role for Rotary International
• Funds provided by Rotary International can leverage support from local communities, thus creating true community responsibility for their health destiny.

The Next Challenge: After Polio Plus

In 1985 Rotary accepted the challenge to eradicate polio from the world by the year 2005. The unanticipated success of the Polio Plus program demonstrated the power and influence of

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Rotary International in prevention and control of global public health problems. Polio now has been eradicated from the Americas and disease incidence is decreasing rapidly in other regions of the world. The $250 million donated by Rotarians to purchase and distribute vaccines and the time and resources volunteered by Rotarians have been two of the important contributing factors in the World Health Organization's (WHO) successful polio eradication program.

With polio eradication a near reality, Rotary International should begin to plan now for its next major health challenge: to eliminate dengue hemorrhagic fever as a global public health problem.

- Provide resources and expertise on social marketing of disease prevention and control

- Create community ownership and participation in disease prevention

- Help clean up the environment to control Aedes aegypti mosquitoes

- Help convince citizens of a community to assume responsibility for their own health destiny

- Use Matching Grants to initiate Prevention Programs

For more information contact:

Dr. Duane J. Gubler, Director

Center for Disease Control

Division of Vector Borne

Infectious Diseases

PO Box 2087

Fort Collins, CO 80522-2087

Telephone: 970-221-6428
Fax: 970-221-6476
E-mail: djg2@cdc.gov