Dengue fever has developed into one of the leading global health concerns, specifically for the areas of the world that are identified as tropical and subtropical. With the increase in urbanization that is occurring in those areas of the world, the perfect breeding conditions are established for the propulsion of the Aedes aegypti mosquito. This mosquito is described as the main vector of dengue worldwide. Among the Aedes aegypti mosquitoes, some are proportionally highly adapted and widely distributed in both rural and urban areas. It breeds in man-made containers, whereas larvae prefer temporary standing water in a sunny location and can be found in anything that holds water.
The dengue virus comes in four different serotypes: DENV-1, DENV-2, DENV-3, and DENV-4. That literally means that a single person could actually experience up to four infections of dengue in their lifetime, with each one being from one of the different serotypes. The first infection is usually asymptomatic or only causes classic dengue fever, and this could easily be controlled with supportive care. But once a different serotype infects a person, the risk of experiencing some severe complications is actually high. It is through the help of a process called antibody-dependent enhancement (ADE) that the antibodies resulting from the previous infection actually allow the new serotype to enter the cells, thereby causing a heavier immune response.
Symptoms of dengue appear 4-10 days after the mosquito bite and can range from mild to severe. Initial signs of the disease manifest as the abrupt development of high fever, the presence of severe headaches, pain behind the eyes, and joint and muscle pain; thus, dengue earned its nickname, the "breakbone fever." A characteristic rash tends to appear. In mild cases, there may be slight bleeding from the nose or gums. Most patients recover within one week, but a few patients proceed to severe dengue: a potentially deadly evolution of the disease that involves plasma leakage, leading to fluid accumulation; severe bleeding; organ damage; and, if not treated correctly using modern Western medical methods, death in some cases.
The cases of dengue are increasing at an alarmingly high rate worldwide. Contributing factors for the increase in numbers are the associated climatic factors, which expand the geographical spread of Aedes mosquitoes; increased traveling and trade; and inadequate control measures applied against mosquitoes. Since no antiviral medication has been specifically developed for dengue, management aims at providing good supportive care by way of hydration, analgesia, and close monitoring for complications.
Since the disease is transmitted by mosquitoes, dengue control is highly dependent on the control of mosquitoes and avoiding their bites. This could be through various means, including the traditional methods of chemical and biological controls such as indoor and outdoor residual spraying and larviciding. Others include clearing bushes and drainages, use of repellent, protective clothing, and fixed window and door screens. A public health campaign should clearly take precedence in the dissemination of these preventative measures.
In short, dengue fever is a re-emerging threat with first priority on the global agenda. Knowledge of the causes and signs of this disease is the first step in the combat against dengue, but action to avoid and detect it early are needed to lessen its impacts.
