Dengue - Infectious Diseases

What is Dengue?

Dengue is a mosquito-borne viral infection caused by the dengue virus (DENV), which belongs to the Flaviviridae family. There are four distinct serotypes of the virus, known as DENV-1, DENV-2, DENV-3, and DENV-4. Infection with one serotype provides lifelong immunity to that serotype but not to the others, making repeated infections possible.

How is Dengue Transmitted?

The primary vectors for dengue transmission are Aedes mosquitoes, particularly Aedes aegypti and Aedes albopictus. These mosquitoes thrive in tropical and subtropical environments and are known to bite during the daytime, with peaks in early morning and late afternoon.

What are the Symptoms of Dengue?

Dengue infection can range from asymptomatic to severe. Common symptoms include high fever, severe headache, pain behind the eyes, joint and muscle pain, rash, and mild bleeding (such as nose or gum bleeding). Severe dengue, also known as dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS), can cause severe bleeding, organ impairment, and plasma leakage, which can be fatal.

How is Dengue Diagnosed?

Diagnosis of dengue is primarily based on clinical symptoms and confirmed through laboratory tests. Common diagnostic methods include serological tests to detect antibodies against the dengue virus, and molecular techniques like reverse transcription-polymerase chain reaction (RT-PCR) to identify viral RNA.

What Treatments are Available for Dengue?

There is no specific antiviral treatment for dengue. Management primarily involves supportive care to alleviate symptoms. This includes maintaining adequate fluid intake to prevent dehydration, using analgesics like acetaminophen for pain relief, and avoiding non-steroidal anti-inflammatory drugs (NSAIDs) like aspirin, which can increase the risk of bleeding. In severe cases, hospitalization may be required for intravenous fluids and close monitoring.

How Can Dengue Be Prevented?

Prevention focuses on reducing mosquito breeding sites and minimizing mosquito bites. Key measures include using insect repellent, wearing long-sleeved clothing, using mosquito nets, and eliminating stagnant water where mosquitoes can breed. Additionally, the Dengvaxia vaccine has been approved in some countries for use in individuals who have previously been infected with dengue.

What is the Global Impact of Dengue?

Dengue is a major public health concern worldwide, with an estimated 390 million infections occurring annually. The disease is endemic in over 100 countries, particularly in Southeast Asia, the Pacific Islands, the Americas, Africa, and the Eastern Mediterranean. The spread of dengue is influenced by factors such as urbanization, international travel, and climate change.

What Are the Challenges in Controlling Dengue?

Controlling dengue poses several challenges, including the lack of a specific treatment, limited effectiveness of vector control measures, and the difficulty in maintaining long-term preventive strategies. Additionally, the presence of multiple serotypes complicates vaccine development and increases the risk of severe disease upon secondary infections.