This increase is believed to be due to a combination of urbanization, population growth, increased international travel, and global warming. The geographical distribution is around the equator. Of the 2.5 billion people living in areas where it is common 70% are from the WHO Southeast Asia Region and Western Pacific Region. An infection with dengue is second only to malaria as a diagnosed cause of fever among travelers returning from the developing world. It is the most common viral disease transmitted by arthropods, and has a disease burden estimated at 1,600 disability-adjusted life years per million population. The World Health Organization counts dengue as one of seventeen neglected tropical diseases.Like most arboviruses, dengue virus is maintained in nature in cycles that involve preferred blood-sucking vectors and vertebrate hosts. The viruses are maintained in the forests of Southeast Asia and Africa by transmission from female Aedes mosquitos—of species other than A. aegypti—to their offspring and to lower primates. In towns and cities, the virus is primarily transmitted by the highly domesticated A. aegypti. In rural settings the virus is transmitted to humans by A. aegypti and other species of Aedes such as A. albopictus. Both these species had expanding ranges in the second half of the 20th century. In all settings the infected lower primates or humans greatly increase the number of circulating dengue viruses, in a process called amplification. One projection estimates that climate change, urbanization, and other factors could result in more than 6 billion people at risk of dengue infection by 2080.
Genetic testing can be utilized to ensure an proper diagnosis for which the correct treatment can be applied. Treatment
At present there is no treatment for Stargardt Disease. However, ophthalmologists recommend measures that could slow the rate of progression. There are no prospective clinical trials to support these recommendations, but they are based on scientific understanding of the mechanisms underlying the disease pathology. There are three strategies doctors recommend for potential harm reduction: reducing retinal exposure to damaging ultraviolet light,  avoiding excess Vitamin A with the hope of lowering lipofuscin accumulation and maintaining good general health and diet.Ultra-violet light has more energy and is a more damaging wavelength spectra than visible light. In an effort to mitigate this, some ophthalmologists may recommend that the patient wears a broad-brimmed hat or sunglasses when they are outdoors. Sometimes, doctors also instruct their patients to wear yellow-tinted glasses (which filter out blue light) when indoors and in artificial light or in front of a digital screen. Certain foods, especially carrots, are rich in vitamin A, but the amount from food is not harmful. Foods with a high vitamin A content are often yellow or orange in color, such as squash, pumpkin, and sweet potato, but some, such as liver, are not. There are supplements on the market with more than a daily allowance of vitamin A that should be avoided, but each individual should discuss this with their doctor. Smoking, overweight or obesity, and poor diet quality may also contribute to more rapid degeneration.