Dengue fever is a mosquito-borne viral infection that poses a significant public health risk in tropical and subtropical climates around the world. With its incidence rising dramatically in recent years, understanding this disease is crucial. This complete guide answers all your questions about dengue, from its causes and symptoms to treatment and prevention.
1. What is Dengue Fever? What Causes It?
Dengue fever is an illness caused by the dengue virus (DENV). It is not spread from person to person like a cold or the flu. Instead, the virus is transmitted to humans through the bite of an infected mosquito.
- Primary Vector: The female Aedes aegypti mosquito is the main species that spreads the virus. The Aedes albopictus mosquito can also act as a vector.
- The Virus: There are four distinct, but closely related, serotypes of the virus: DENV-1, DENV-2, DENV-3, and DENV-4. Recovery from one serotype provides lifelong immunity against that specific one, but a subsequent infection by a different serotype increases the risk of developing severe dengue.
2. How is Dengue Transmitted? Is it Communicable?
Yes, dengue is a communicable disease (it can be transmitted), but it is not contagious from person to person.
The transmission cycle works like this:
- A mosquito bites a person infected with the dengue virus.
- The mosquito becomes infected with the virus.
- After an incubation period of about a week, the infected mosquito can now transmit the virus to other people it bites for the rest of its life.
- The virus is not spread through coughing, sneezing, touching, or sharing food and drinks.
3. What Are the Symptoms of Dengue Fever?
Symptoms usually begin 4-10 days after the mosquito bite and last for 2-7 days. Many people, especially children, may experience no symptoms, but when they appear, they can include:
- High sudden fever (104°F or 40°C)
- Severe headache
- Pain behind the eyes
- Severe muscle, bone, and joint pain (often called “breakbone fever”)
- Nausea and vomiting
- Swollen glands
- Skin rash (may appear a few days after the fever starts)
- Fatigue and weakness
4. What are the Warning Signs of Severe Dengue?
Severe dengue (formerly known as dengue hemorrhagic fever or dengue shock syndrome) is a life-threatening complication. Warning signs usually appear as the initial fever is subsiding (around days 3-7 of the illness). This is a medical emergency, and immediate hospitalization is required.
Watch for these severe symptoms:
- Severe abdominal pain
- Persistent vomiting (often with blood)
- Bleeding from the gums or nose
- Blood in vomit, urine, or stool
- Rapid breathing
- Fatigue and restlessness
- Cold or clammy skin
- A sudden drop in blood pressure (shock)
5. How is Dengue Diagnosed? How Long do Test Results Take?
If you suspect dengue, a doctor will evaluate your symptoms, travel history, and order a blood test to confirm the diagnosis. The timing of results depends on the test:
- NS1 Antigen Test: Detects the presence of the virus itself. It is most effective in the first 3-5 days of illness. Results: Often within a few hours to 24 hours.
- PCR Test: A molecular test that detects the genetic material of the virus. Very accurate in the early stages. Results: Typically 1-3 days.
- IgM/IgG Antibody Test: Detects antibodies your immune system produces to fight the infection. IgM antibodies appear first, while IgG antibodies appear later and remain for life. This test is more useful after day 5 of illness. Results: Usually within 24-48 hours.
6. What is the Treatment for Dengue Fever? Is There an Antibiotic?
There is no specific antibiotic or antiviral medicine to cure dengue. Since it is a viral infection, antibiotics are completely ineffective. Treatment is supportive and focuses on relieving symptoms and preventing complications.
Management includes:
- Rest: Get plenty of bed rest.
- Hydration: Drink ample fluids—water, oral rehydration solution (ORS), or coconut water—to prevent dehydration from fever and vomiting.
- Pain and Fever Relief: Use acetaminophen (paracetamol).
- AVOID: NSAIDs like aspirin, ibuprofen, and naproxen sodium, as they increase the risk of bleeding.
For severe dengue, hospitalization is necessary for:
- Intravenous (IV) fluid and electrolyte replacement
- Continuous monitoring of blood pressure and blood counts
- Blood transfusion (if there is significant bleeding)
7. How Can Dengue Be Prevented?
Prevention is the best strategy, as there is no definitive cure. Prevention focuses on avoiding mosquito bites and controlling mosquito populations.
- Prevent Mosquito Bites:
- Use EPA-registered insect repellents containing DEET, picaridin, or oil of lemon eucalyptus.
- Wear long-sleeved shirts and long pants, especially during the day.
- Use mosquito nets while sleeping if needed.
- Ensure windows and door screens are secure.
- Control Mosquito Breeding:
- The Aedes mosquito breeds in clean, stagnant water.
- Weekly, empty, scrub, and cover any containers that hold water: flower pots, plant saucers, discarded tires, buckets, water coolers, and pet water bowls.
- Support community efforts for fogging and cleaning public spaces.
- Vaccine: A vaccine (Qdenga) is available in some countries, but its use depends on age, previous dengue infection status, and local health authority guidelines. It is not a standalone solution and must be combined with other prevention measures.
8. When is Dengue Season?
Dengue season coincides with the warm, rainy months that provide ideal breeding conditions for mosquitoes. The timing varies by region:
- In India (e.g., Delhi): The season typically runs from July to November, peaking in September and October after the monsoon rains.
- Southeast Asia and Northern Australia: Often during the wet season.
- Tropical Latin America and the Caribbean: Risk exists year-round, often increasing during rainy periods.
9. Frequently Asked Questions (FAQ)
Q: What does the dengue mosquito look like? (डेंगू का मच्छर कैसा होता है?)
A: The Aedes aegypti mosquito is dark with distinctive white markings and bands on its legs and body. It is sometimes called the “tiger mosquito.”
Q: Can you get dengue twice?
A: Yes. There are four dengue virus serotypes. Infection with one provides lifelong immunity only to that specific serotype. A second infection with a different serotype increases the risk of severe dengue.
Q: What should I eat if I have dengue?
A: Focus on a healthy, balanced diet that is easy to digest:
- Hydrating fluids: ORS, water, coconut water, fresh fruit juices.
- Protein-rich foods: Papaya leaf extract (believed to help increase platelet count), lentils, chicken soup.
- Fruits and vegetables: Citrus fruits, leafy greens.
- Avoid oily, spicy, and processed foods.
Conclusion: Vigilance and Prevention are Key
Dengue fever is a serious illness, but most cases can be managed successfully with timely medical care, proper hydration, and rest. Understanding the warning signs of severe dengue is critical for seeking immediate help. Since the mosquito that spreads dengue bites primarily during the day, constant vigilance—through repellents, clothing, and eliminating breeding sites—is the most effective weapon we have against this disease.
Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for diagnosis and treatment tailored to your specific condition.
