Frequently Asked Questions About Dengue Fever
What is dengue fever? Dengue and Dengue Haemorrhagic Fever (DHF) are caused by four closely related viral strains. The virus is transmitted to humans through the bites of infected mosquitoes (Aedes aegypti and Aedes albopticus). Infection with one of the viral strains does not guarantee immunity from the other three. When a person who has already fought one strain of the disease contracts another of the viral strains, it can cause severe forms of DHF or Dengue Shock Syndrome (DSS). Who is infected with dengue fever? The global prevalence of Dengue has risen dramatically, and is now endemic in more than 100 countries in Africa, the Americas, and the Eastern Mediterranean. The most serious outbreaks are found in Southeast Asia and the Western Pacific. The World Health Organization (WHO) estimates that 50 million cases occur each year, requiring 500,000 hospitalizations. Approximately two fifths of the world’s population is at risk for Dengue.1 Since 1986, the incidence of DHF has quadrupled. Where is dengue fever endemic? The disease occurs mainly in tropical Asia, Africa and the Caribbean, and is most common during rainy seasons in areas infested with infected mosquitoes. A global pandemic of dengue began in Southeast Asia after World War II and has intensified during the last 15 years. Most cases occur at low altitudes in urban areas. Epidemics are most common in countries lacking effective mosquito control, or that have inadequate water, sewage, and waste-management problems. The denguetransmitting mosquitoes Aedes aegypti and Aedes albopticus , are on the increase and have been detected in Mexico and South Texas during the last 10 years. What are the symptoms? Dengue fever is characterized by the sudden onset of fever, lethargy, painful headaches, nausea and vomiting, eye, joint, and muscle pain, and rash, leading to the nickname “break-bone fever”. The onset of symptoms begins about five to six days after the mosquito bite occurs, and symptoms generally last between one to two weeks. DHF is a potentially lethal complication. Patients will develop a sudden rise in temperature accompanied with internal bleeding, and hypovolaemic shock. The average fatality rate for DHF is five percent.2 Why is this a recent epidemic? According to the Centers for Disease Control and Prevention, in most countries, the public health infrastructure has deteriorated. Funds are allocated only for emergency responses to epidemics, rather than for the development of programs to prevent epidemic transmission, such as detection programs. As a result, an epidemic has often reached or passed transmission before it is detected. It is believed that rapid urbanization, increased travel and trade, and the lack of effective mosquito control efforts contribute to the spread of the disease. Are there any available treatments? While there are no specific treatments for dengue available yet, supportive treatments include bed rest, fluid administration and analgesia. There is no available vaccine for dengue, although vaccines are currently in development. What is the Singapore Dengue Consortium? The Singapore Dengue Consortium consists of six organizations, including the NITD, focused on research into dengue fever. These organizations have signed a collaboration of understanding with the intention of exploring ways to better understand and manage the dengue infection.
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World Health Organization: www.who.int/health_topics/en/#D. Centers for Disease Control and Prevention: www.cdc.gov/ncidod/dvbid/dengue/index.htm.