The global incidence of dengue has increased considerably over the last two decades, posing a significant challenge to public health. Between 2000 and 2019, the World Health Organization (WHO) documented that the number of reported cases worldwide had increased tenfold, from 500,000 to 5.2 million.
Native to tropical and subtropical regions, dengue is primarily transmitted by the Aedes aegypti and Aedes albopictus mosquitoes. For decades it was considered an endemic disease of Asia, Latin America and the Caribbean. However, several factors have contributed to its global expansion in recent years.
Climate change, uncontrolled urbanization with poor sanitary conditions, poverty, overcrowding, water storage, deforestation and migration are interacting and evolving, creating a complex scenario of risk of dengue and other mosquito-borne diseases. Another factor in the growth of the disease is the increase in international travel from dengue endemic countries, which increases the risk of imported cases and inevitably also the risk of local outbreaks.
According to the latest data recorded by the WHO, the disease is endemic in more than 100 countries in the regions of Africa, the Americas, Southeast Asia, the Eastern Mediterranean and the Western Pacific.
The Americas, South-East Asia and Western Pacific Regions are the most affected, with around 70% of the global burden of the disease concentrated in Asia. Meanwhile, in Europe dengue is not endemic, there have only been sporadic outbreaks in Spain, Italy and France, and these cases are mainly related to tourism.
The climate plays a fundamental role:
The mosquito was controlled in the 40's/50's, but in the '70s it began to grow in America, and not only the mosquito, but other diseases such as dengue, chikungunya, Zika and yellow fever. Climate change, the consequences of the El Niño phenomenon that increases temperatures, precipitation and humidity, caused the eggs of this mosquito to accelerate their evolution time and, therefore, we have more adults that bite. That is why this disease has grown exponentially in many countries around the world.
Symptoms of the disease:
Many people do not have any symptoms, and when symptoms occur they may be confused with other illnesses, such as the flu. They usually begin 4 to 10 days after being bitten by an infected mosquito. Dengue causes a high fever of 104 degrees Fahrenheit/40 degrees Celsius and any of the following signs:
- Headache
- Muscle, bone or joint pain
- Nausea/Vomiting
- Pain behind the eyes
- Inflamed glands
- Rash
Most people recover in about a week. In some cases, symptoms worsen and can be fatal. This is called severe dengue, dengue hemorrhagic fever, or dengue shock syndrome. It occurs when blood vessels become damaged and leak, and when the number of clot-forming cells (platelets) in the bloodstream decreases. This can lead to shock, internal bleeding, organ failure, and even death.
Prevention and Control:
Dengue prevention and control depend on integrated strategies that include epidemiological surveillance, vector control and public education. Some of the key measures are:
- The elimination of mosquito breeding sites, such as containers of stagnant water, and the use of insecticides and larvicides are essential to reduce the population of mosquito vectors.
- Using insect repellents, mosquito nets, and protective clothing can help prevent mosquito bites.
- Timely reporting of suspected and confirmed cases is crucial to containing the spread of the virus.
- Research and development of dengue vaccines has advanced in recent years. The Dengvaxia vaccine has been approved in several countries, although its use is restricted to certain populations due to safety and efficacy considerations.
Dengue has transcended its regional limits to become a global public health concern. The spread of this disease reflects global interconnectedness and emerging challenges in infectious disease control. International cooperation and strengthening prevention and control strategies are essential to confront dengue and mitigate its impact on global health.
