What is Dengue Fever?
A. aegypti and dengue viruses are endemic in many countries throughout the world. The risk for exposure to A. aegypti is often higher in urban areas. Many tourist facilities present a lower risk than local residential areas because of air conditioning, grounds keeping, elevation, or combinations of these.
The prevalence of Dengue has been broken down based on the part of the world.
Dengue Fever in Asia
Southeast Asia — A. aegypti mosquitoes are found throughout the region, extending to southern China and the south of the island of Taiwan, and all countries in the region are affected by dengue virus infection. Epidemic dengue reemerged in China during the 1980s and the 1990s after an absence of several decades and was associated with the first occurrence of DHF in that country. Nepal had the first cases detected in 2004. Over one-hundred and forty cases of dengue were detected in Japan in 2014, representing the first occurrence of transmission in that nation since World War II. More than 80 percent of cases have been linked with a single location in Tokyo, and A. albopictus is the apparent vector in this outbreak. More than 200,000 cases of DHF were reported from the region each year from 2012 with the exception of 2011 (177,500 cases); Indonesia and Thailand accounted for the majority of cases in each of these years.
South Asia — A. aegypti are widely distributed in India, Pakistan, and Sri Lanka. Dengue virus transmission increased substantially during the 1980s and 1990s. Over 50,000 cases were reported from India in 2012, more than twice the average over the previous decade. Pakistan has reported several outbreaks since 2011.
Dengue Fever in Western Pacific Islands
Western Pacific islands — A. aegypti mosquitoes are present in most of the region. Transmission of all four dengue serotypes is present in Malaysia and the Philippines. Other islands experience frequent dengue outbreaks; high incidence rates were reported from 14 island nations for 2009, including American Samoa, Cook Islands, French Polynesia, New Caledonia, and Tonga.
Dengue Fever in Australia
Australia — A. aegypti mosquitoes are present in the northeastern corner of Australia. Dengue viruses are not endemic to the continent, but periodic introduction of dengue viruses from neighboring islands has led to epidemics in urban areas of north Queensland.
Dengue Fever in Africa and Eastern Mediterranean
Africa and Eastern Mediterranean — A. aegypti mosquitoes are present in much of sub-Saharan Africa and the Middle East. Documented infections in visitors to the area indicate that there is ongoing dengue virus transmission. Several outbreaks were reported from Central Africa, East Africa, and the Middle East during the 1990s and 2000s.
Dengue Fever in Europe
Europe — A. albopictus is present across much of southern Europe. Most dengue cases reported from the region have been acquired during travel to endemic countries. However, local transmission of dengue virus was documented in both southern France and Croatia in 2010. In 2012, an outbreak of dengue was reported on Madeira Island (Portugal), associated with the presence of A. aegypti.
Dengue Fever in North America
North America — A. aegypti mosquitoes are present in most areas of Mexico and in the southeastern United States. A. albopictus is also present in these areas, but its range extends further north, nearly to the Great Lakes. Dengue virus transmission is seasonal, with peak activity in late summer and fall. In 2013, over 230,000 cases of dengue infection were reported from Mexico, including more than 18,000 cases of severe dengue and 104 deaths.
In 2010, dengue fever was reported in 28 residents of Key West, Florida, who had not traveled abroad and a serological survey of 240 residents in Key West found that 5 percent had evidence of recent dengue infection. Local transmission of dengue virus continues to occur in south Florida but appears limited in scope. Of 543 cases reported across the United States in 2013, 24 were locally acquired.
Dengue Fever in Central America
Central America — A. aegypti mosquitoes and transmission of all four dengue virus serotypes are present throughout the region. The region experienced a major outbreak in 2013; Nicaragua and Costa Rica reported among the highest numbers of cases of dengue (77,000 and 49,000, respectively) and incidence rates (over 1000 cases per 100,000 population) that year. However, all of these countries have had one or more years of heavy dengue activity during the past five years.
Dengue Fever in the Caribbean
Caribbean — A. aegypti mosquitoes are present throughout the region. Hyperendemic circulation of dengue virus serotypes 1, 2, and 4 has been present on the larger islands (other than Cuba) for several decades and dengue virus serotype 3 has been present since 1998. In Puerto Rico, peak dengue virus transmission usually occurs between October and December; over 21,000 cases of dengue virus infection were reported there in 2010, representing the largest outbreak ever recorded. The Dominican Republic (16,000 cases), French Guiana (16,000 cases), Guadeloupe (12,000 cases), Martinique (7,000 cases), and St. Martin (3,000 cases) all reported major outbreaks in 2013. Other islands have experienced periodic dengue epidemics.
Dengue Fever in South America
South America — A. aegypti mosquitoes are present in every South American country except Chile. Circulation of all four dengue virus serotypes has been present in the north of the continent since the reintroduction of dengue virus serotype 3 was detected in Brazil and Venezuela during 2000. Brazil, Venezuela, and Colombia have reported the largest number of dengue cases. Low-level, year-round transmission has been observed, but most cases follow an epidemic pattern; in Brazil, peak dengue transmission occurs between February and May. Brazil experienced a major outbreak in 2013, with nearly 1.5 million cases nationwide, including almost 7,000 cases of severe dengue. Colombia (127,000 cases) and Paraguay (144,000 cases) also reported major dengue outbreaks in 2013.
Treatment of Dengue Fever
As of today, there is no treatment for Dengue, and vaccinations currently under investigation have demonstrated only moderate protection.