Dengue fever, a viral infection transmitted by mosquitoes, has become an escalating global health concern since the 1940s. The surge in cases can be attributed to various factors, including increased long-distance travel, rapid population growth, urbanization, inadequate sanitation, ineffective mosquito control measures, and improved surveillance and reporting systems. Dengue is now prevalent in tropical regions, with Southeast Asia, the Pacific Islands, and the Middle East being particularly affected. Approximately 40% of the world’s population lives in areas with a risk of contracting dengue. The disease is endemic in over one hundred countries across Africa, the Americas, Asia, the Caribbean, and the Pacific.
The pronunciation of “dengue” is “DEN-gee.”
What is Dengue Fever?
Dengue fever, also known as “break-bone fever,” is a painful viral infection transmitted by Aedes mosquitoes to humans in tropical and subtropical regions. Symptoms include high fever, body aches, and in severe cases, shock and hemorrhagic fever. With almost half the global population at risk, dengue is a leading cause of illness, demanding urgent medical attention.
How is Dengue caused?
Dengue fever is transmitted to humans through the bite of an infected mosquito, specifically certain species of Aedes mosquitoes. These mosquitoes act as vectors, vehicles that carry and transmit the dengue virus to its host organism, which in this case, is humans. The virus enters the bloodstream when an infected mosquito bites a person with dengue virus in their blood, leading to infection.
Dengue fever is caused by one of four closely related dengue viruses, which are part of the Flaviviridae family. These viruses are named DENV-1, DENV-2, DENV-3, and DENV-4 (Dengue virus serotypes 1 to 4). All four serotypes can cause dengue fever in humans and are transmitted by infected Aedes mosquitoes, primarily Aedes aegypti and Aedes albopictus. When a mosquito carrying one of these dengue viruses bites a person, the virus is transmitted into their bloodstream, leading to the development of dengue fever. The virus can damage blood components, leading to blood vessel leakage and internal bleeding, resulting in severe dengue with life-threatening symptoms.
Dengue is spread solely through mosquito bites and cannot be transmitted directly from person to person. Aedes mosquitoes, responsible for transmitting dengue, also carry other viruses like Zika and chikungunya. Pregnant individuals with dengue can pass the virus to their babies during pregnancy or childbirth, making it the only way the disease can be transmitted from person to person. Otherwise, the presence of mosquitoes is necessary for the transmission of the dengue virus.
Symptoms of Dengue Fever
- Usually mild or asymptomatic, with recovery in 1-2 weeks for most people.
- Symptoms appear 4-10 days after infection and last 2-7 days.
Common symptoms: high fever (40°C/104°F), severe headache, pain behind the eyes, muscle and joint pains, nausea, vomiting, swollen glands, and rash.
Severe symptoms may follow: severe abdominal pain, persistent vomiting, bleeding gums or nose, fatigue, restlessness, blood in vomit or stool, thirst, pale and cold skin, weakness.
Warning signs of severe dengue: severe stomach pain, persistent vomiting, bleeding from gums or nose, blood in urine, stools, or vomit, bleeding under the skin, difficult or rapid breathing, fatigue, irritability, restlessness.
- Infants, pregnant women, and those with a previous dengue infection are at higher risk of severe dengue.
- Dengue fever can be mistaken for other illnesses, like the flu.
- Severe dengue is a medical emergency, requiring immediate care.
Diagnosing Dengue Fever
To diagnose dengue infection, doctors conduct a range of blood and imaging tests. If you experience symptoms after being in proximity to individuals with dengue, it’s crucial to inform your doctor for proper evaluation. Common tests include:
- Complete Blood Count (CBC): Assesses platelet count and evidence of anemia associated with severe dengue.
- Dengue Serology Test (Dengue IgG & IgM): Detects post-exposure antibodies produced by the immune system, effective after 4 days.
- Dengue Virus Antigen Detection (NS1): Confirms early dengue infection within 1-2 days of exposure.
For severe cases, additional tests may include:
- Liver Function Tests (LFT): Identifies liver-related abnormalities due to dengue virus impact.
- Renal Function Test (RFT): Examines kidney-related issues caused by dengue infection.
- ECG: Evaluates heart electrical disturbances due to dengue-related electrolyte imbalances.
- Ultrasound Abdomen (USG): Investigates abdominal conditions like fluid buildup linked to dengue.
- Chest X-ray: Identifies pleural and pericardial effusions associated with dengue.
- D-dimer Test: Assesses blood clot dissolution, elevated in severe dengue cases.
- 2D Echocardiography (2D Echo): Checks for heart muscle damage due to severe dengue.
- Fibrinogen Test: Measures blood clotting ability, relevant in excessive bleeding seen in complicated dengue hemorrhagic fever.
- Fibrin Degradation Products (FDP) Test: Assesses clot-dissolving activity and fibrinolysis in dengue hemorrhagic fever.
Preventing and Controlling Dengue
Dengue is a viral disease transmitted by mosquitoes that are active during the day. Protecting yourself from mosquito bites is crucial to lower the risk of contracting dengue. Here are some preventive measures:
- Wear clothes that cover as much of your body as possible.
- Use mosquito nets while sleeping during the day, and consider using nets sprayed with insect repellent for added protection.
- Install window screens to keep mosquitoes out of your living spaces.
- Apply mosquito repellents containing DEET, Picaridin, or IR3535.
- Consider using mosquito coils and vaporizers indoors to repel mosquitoes.
If you do get infected with dengue, it’s important to take the following steps:
- Rest and stay hydrated by drinking plenty of liquids.
- Use acetaminophen (paracetamol) for pain relief, but avoid non-steroidal anti-inflammatory drugs like ibuprofen and aspirin.
- Be vigilant for severe symptoms and promptly contact your doctor if you notice any concerning signs.
Currently, the only approved vaccine for dengue is Dengvaxia, which is effective for individuals with evidence of past dengue infection. However, several other dengue vaccine candidates are undergoing evaluation. Preventing dengue involves not only protecting yourself but also minimizing mosquito breeding grounds. Remove sources of standing water, such as old tires, cans, and flower pots, which are common breeding sites for mosquitoes.
Treatment of Dengue Fever
Dengue fever treatment primarily revolves around symptom management and providing supportive care, as there is currently no targeted antiviral therapy for the dengue virus itself. Here are key elements of dengue fever treatment:
- Rest and hydrate: Proper rest and adequate fluids are vital for managing dengue fever. Drinking water, oral rehydration solutions, and electrolyte-rich beverages prevent dehydration from fever and sweating.
- Reduce fever: Use acetaminophen (paracetamol) for fever relief. Avoid non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen, as they may increase bleeding risks in dengue-infected individuals.
- Avoid aspirin: Steer clear of aspirin, especially for children and young adults, as it can cause the severe Reye’s syndrome affecting the liver and brain.
- Monitor symptoms: Keep a close watch on the patient’s condition, especially if the fever persists for more than three days or severe symptoms like continuous vomiting, bleeding, or signs of shock occur.
- Hospitalization: Severe dengue fever cases may need hospitalization for intravenous fluids and supportive care, especially in severe dengue (hemorrhagic fever or dengue shock syndrome).
- Transfusion: Platelet transfusion may be necessary for severe cases with significant bleeding and declining platelet levels to prevent complications.
- Manage pain: Use appropriate pain medications to relieve distressing symptoms like severe headaches, muscle, and joint pain.
It is important to remember that there is no specific antiviral medication for treating dengue fever. Hence, the focus of treatment lies in alleviating symptoms and preventing complications. If you suspect you or someone else has dengue fever, seek immediate medical attention, especially if symptoms worsen or become severe.
Conclusion
In conclusion, dengue fever is a concerning global health issue transmitted by mosquitoes. Its prevalence is increasing, affecting tropical regions significantly. Preventive measures like using repellents, nets, and eliminating breeding sites are crucial. While the Dengvaxia vaccine is available for those with past dengue infection, there’s no specific antiviral treatment. Managing symptoms, staying hydrated, and adequate rest are vital for dengue fever treatment. Seeking prompt medical attention for severe symptoms is essential for better outcomes. Dengue remains a serious health threat, necessitating continuous efforts in prevention, early detection, and supportive care to combat its impact on affected individuals and communities.
References
- World Health Organization (WHO). (2020). Dengue and severe dengue.
- Centers for Disease Control and Prevention (CDC). (2021). Dengue.
- Gubler, D. J. (2010). Dengue, Urbanization and Globalization: The Unholy Trinity of the 21st Century. Tropical Medicine and Health, 38(Suppl 4), S3–S11. doi:10.2149/tmh.2009-18
- Wilder-Smith, A., Ooi, E.-E., Horstick, O., & Wills, B. (2019). Dengue. The Lancet, 393(10169), 350–363. doi:10.1016/s0140-6736(18)32560-1
- Simmons, C. P., Farrar, J. J., Nguyen, V. V. C., & Wills, B. (2012). Dengue. New England Journal of Medicine, 366(15), 1423–1432. doi:10.1056/nejmra1110265
