How is Dengue Detected?

Diagnosing Dengue: How Doctors Confirm the Virus & When to Test 

Research estimates that nearly 400 million people get infected with dengue each year, but most (about 80%) have no symptoms. Dengue is a disease caused by the dengue virus (DENV), primarily transmitted by Aedes aegypti mosquitoes. It is prevalent in tropical and subtropical regions and can lead to serious health issues if not diagnosed early. 

Early detection of dengue is crucial for providing timely treatment and preventing the development of severe conditions, such as dengue hemorrhagic fever or dengue shock syndrome. 

Read ahead to understand the standard methods used to detect dengue and for more details. 

How to Detect Dengue? 

Listed below are some standard medical methods that can help determine dengue: 

Clinical Diagnosis 

Dengue is initially suspected based on the patient's clinical presentation and medical history. The following are common symptoms: 

• Sudden high fever 
• Severe headaches 
• Pain behind the eyes (retro-orbital pain) 
• Muscle and joint pain (“breakbone fever”) 
• Nausea or vomiting 
• Skin rashes 
• Extreme fatigue 
• Severe abdominal pain 
• Mucosal bleeding 

Doctors may clinically suspect dengue based on symptoms and exposure history, but laboratory confirmation is required. The clinical presentation may mimic that of other diseases, such as malaria, typhoid, or chikungunya; therefore, laboratory diagnosis is necessary. 

Early diagnosis improves clinical outcomes and supports public health surveillance, which can help authorities implement timely mosquito control measures. 

Laboratory Diagnosis 

Several tests are used to establish a dengue infection. The test utilized depends on the duration of the illness. A few of those tests include: 

1. NS1 Antigen Test

• Detects the dengue virus's non-structural protein 1 (NS1) in the blood. 
• Most effective during the first 1–5 days of fever. 
• Provides quick results and is widely used in clinics and hospitals. 
• Often available in both public and private health facilities, including insurance-backed services. 

2. RT-PCR Test

• Detects dengue viral RNA directly. 
• It can also identify the specific serotype of the virus, ranging from DENV-1 to DENV-4. 
• It is highly accurate but more expensive and is mainly performed in advanced laboratories. 
• Useful during the early stage (day 1 to day 5 of illness) 

3. IgM and IgG Antibody Tests

• Detect the body’s immune response to dengue infection. 
• IgM antibodies appear by day 4-5 and suggest a recent infection. 
• IgG antibodies appear later and indicate past or secondary infection. 
• These tests are essential for diagnosis in later stages of the illness, after day 6. 

Supportive Blood Tests 

Not diagnostic, but other blood tests assist in monitoring the severity of the disease: 

• CBC (Complete Blood Count): A low platelet count (<100,000/mm³) and a drop in white blood cells are common in dengue. 
• Hematocrit: A higher rate may signal plasma leakage, a warning sign of severe dengue. 
• Liver Function Tests (LFTs): This test can show raised liver enzymes. 

These supporting investigations are crucial for disease surveillance and for assessing the need for hospitalization, especially in children, older adults, and immunocompromised individuals. 

How to Prevent and Control Dengue? 

Dengue prevention and control are one of the best ways to fight this battle. The following are some effective prevention tips: 

• Prevent unclear water storage. 
• Use mosquito nets on windows and in bed to avoid mosquito bites. 
• Make use of proper disposal of dustbins. There should be separate bins for solid and liquid wastes.   
• Wear loose-fitting, long-sleeved shirts and pants. 
• Cover or clear domestic water storage regularly. 

Dengue fever treatment becomes easier once the doctors knows that dengue is in which stage. This is why spreading awareness regarding the prevention and control of dengue is the call of the hour. 

Reader Information: This article is intended for general informational and educational purposes only. Dengue symptoms, diagnostic methods, and treatment approaches may vary based on individual health conditions and disease severity. Readers are advised to seek timely medical evaluation and follow the guidance of licensed medical practitioners for accurate diagnosis and appropriate care.  

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