Dengue Fever Overview and Symptoms

Dengue Fever Overview

• Dengue fever is a mosquito-borne viral illness caused by four related viruses.
• It's transmitted by the bite of an Aedes mosquito infected with a dengue virus.
• Transmission occurs when an infected mosquito bites a person, and the mosquito takes the virus and then transmits.
• Humans do not transmit dengue directly to each other.
• Globally, approximately 400 million people are infected annually with dengue, with 100 million developing mild to severe illness.
• Commonly found in tropical regions like Southeast Asia, the western Pacific, Latin America, and Africa. Cases in the U.S. are often related to travel.
• Risk of infection is increasing in parts of the southern U.S.

Symptoms

• Symptoms include high fever, headache, pain behind the eyes, joint/bone pain, muscle pain, nausea, vomiting, and skin rash.

Transmission Cycle

• Mosquito bites an infected person.
• The mosquito becomes infected.
• The infected mosquito bites others, infecting them.
• This cycle of infection continues within communities.

Diagnosis

• Diagnosis involves blood tests for dengue viruses.
• Methods include serological/antibody tests, MAC-ELISA tests, molecular tests (like NAATs and PCR), and complete blood count (CBC).
• Antibody tests detect proteins the body makes against the virus.
• MAC-ELISA detects proteins fighting dengue fever.
• Molecular tests identify genetic material of the virus.
• NAATs amplify the virus's DNA for detection.
• PCR is a type of NAAT.
• CBC counts blood cells; dengue can affect white blood cells and platelets.

Dengue Vaccine

• Dengue vaccines have been under development since the 1920s.
• Dengvaxia (licensed by Sanofi Pasteur) is the only FDA-approved vaccine.
• Qdenga, approved in the European Union, is another vaccine.
• Dengvaxia is recommended for people with previous dengue or living in high-risk areas. Given in three doses over six months, and for individuals aged 6–45 (or 9–60 in some countries).
• Qdenga is for those without prior dengue infection. Given in two doses over three months, and for individuals aged four and above.

Prevention and Control

• Mosquitoes are active during the day.
• Prevent bites using clothing, mosquito nets (especially if sleeping during the day and treated with repellent), window screens, and repellent creams (including DEET, Picaridin, or IR3535).
• Prevent breeding by removing standing water. Dispose of waste, cover and empty water containers weekly, and use appropriate insecticides.
• Treatment consists of rest, fluids, acetaminophen (paracetamol) for pain (avoid ibuprofen and aspirin), and monitoring for severe symptoms and contacting a healthcare professional promptly.

Conclusion

• Dengue is a significant health issue in tropical areas.
• Early recognition of symptoms is essential for better outcomes.
• Prevention via mosquito control and personal protection is key to reducing risk.