Dengue Fever Types: DENV 1, 2, 3, 4 and their Symptoms

Dengue fever is a viral, mosquito-borne disease that has become one of the most common viral infections in India, predominantly during and after the monsoon season. The infection is transmitted by the bite of an infected Aedes aegypti mosquito, which serves as the primary vector for the dengue virus. Scientifically, dengue fever is not attributed to a single virus; instead, it is associated with four distinct dengue virus types: DENV-1, DENV-2, DENV-3, and DENV-4. These 4 strains of the dengue virus belong to the Flavivirus family and are closely related to each other but antigenically distinct in terms of severity. Which means that an infection with one serotype, for instance DENV-1, confers lifelong immunity solely against DENV-1 and not against the other serotypes. Additionally, it is important to note that the designation of DENV 1 through DENV 4 does not indicate any order of severity or prevalence among these serotypes.

To elaborate further on the distinct characteristics of dengue subtypes, each dengue fever type exhibits unique epidemiological characteristics and can lead to varying clinical outcomes. For instance, DENV-1 dengue is often associated with classical dengue symptoms, while DENV-2 has been linked to more severe presentations that must be diagnosed in a timely manner. Similarly, DENV-3 and DENV-4 infections may differ in severity and recovery time. Hence, understanding the different types of dengue fever is essential for preventive care and effective health management through reliable testing facilities, such as Max Lab.

What is Dengue Fever?

The root cause of dengue fever is the bite of an infected female Aedes aegypti mosquito that transmits the dengue virus from one host to another. When an infected mosquito bites a healthy individual, the virus enters the bloodstream and multiplies, ultimately leading to infection. Dengue fever is caused by the dengue virus (DENV), a member of the Flavivirus genus that includes four distinct dengue virus types: DENV-1, DENV-2, DENV-3, and DENV-4. The different types of dengue virus are closely related but antigenically distinct, meaning an individual infected with one serotype gains immunity only to that specific serotype for a lifetime and remains vulnerable to others.

After an incubation period of about 4 to 10 days, when the virus has spread in the host, some common symptoms, such as sudden high fever, headache, pain behind the eyes, joint and muscle pain, nausea, and a skin rash, begin to appear. In most cases, dengue fever presents as a self-limiting febrile illness; however, in certain hosts, it can rapidly progress to severe illness, characterised by plasma leakage, bleeding tendencies and a rapid fall in platelet count, requiring close medical intervention.

Understanding disease progression is crucial because a secondary infection with a different serotype may increase the risk of complications through an exaggerated immune response, a phenomenon known as antibody-dependent enhancement (ADE). Hence, timely diagnosis, typically through the Dengue NS1 Antigen test or IgG antibody test, available at Max Lab, is essential for early detection and effective management of the disease.

Dengue Virus Serotypes: An Overview

As mentioned earlier, the dengue virus exists in four antigenically distinct serotypes, namely, DENV-1, DENV-2, DENV-3 and DENV-4; each serotype represents a unique strain of the virus with slight variations in surface proteins and its genetic composition. Though these differences are minor, they influence how the host's body responds to infection. Importantly, infection with one serotype provides lifelong immunity against that specific dengue virus type, but not against the remaining other serotypes. This means that an individual can be infected with dengue up to four times in their lifetime, each time by a different serotype.

All 4 types of dengue strains are capable of causing illness ranging from mild dengue fever to severe complications, such as dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS). However, it is important to note that clinical presentation and disease severity can vary across serotypes. 

The following section provides a closer look at each type of dengue strain, their characteristics, symptom patterns and clinical implications.

What is DENV-1?

DENV-1 is the classic strain of the dengue virus and is considered one of the most widespread and historically recognised strains. It is commonly responsible for initial outbreaks in dengue-endemic areas and primarily causes classical dengue fever rather than the more severe forms of the disease. Although the virus-induced infection is mild, it is clinically important because it shapes immune responses that may affect future infections with other dengue virus serotypes. Once the virus enters the bloodstream, it triggers an immune response that leads to inflammation and the onset of symptoms within four to ten days.

Common Symptoms of DENV-1

• Sudden onset of persistent fever; often high
• Severe headache and pain behind the eyes
• Muscle and joint pain (often described as “breakbone pain”)
• Mild bleeding is observed from the gums or the nose
• Consistent feeling of vomiting, nausea and fatigue
• Skin rashes also appear after two to five days of the onset of the fever

Although the symptoms of dengue DENV-1 often subside within a week with proper care, like hydration and adequate rest, it is recommended to seek medical supervision for the right course of action.

How is DENV-1 Diagnosed and Managed?

With accurate and early diagnosis, individuals can get relief from the infection. Some of the tests often recommended by medical experts include:

• Dengue NS1 Antigen Test

The test detects early infection (within the first five days of fever).

• Dengue IgM and IgG Antibody Tests

The test confirms current or past infections.

One can book the above-mentioned tests online at Max Lab, which comes with a guarantee of prompt detection and effective clinical management.

What is DENV-2?

Unlike DENV-1, dengue type 2, commonly known as DENV-2, is often regarded as one of the most virulent strains. The dengue type has been associated with more severe outbreaks and a higher likelihood of complications, such as dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). In several renowned studies, infections caused by DENV-2 have been shown to have a greater potential to cause vascular leakage and bleeding tendencies, particularly in individuals who have had a prior infection with another dengue virus strain.

Common Symptoms of DENV-2

• Persistent high fever lasting 2 to 7 days
• Severe headache and retro-orbital pain
• Persistent feeling of vomiting, nausea and loss of appetite
• Severe muscle weakness and body pains
• Abdominal pain and tenderness
• Spontaneous bleeding, typically from the nose, gums or under the skin
• Restlessness or irritability in severe cases

As the fever subsides after 7 days, individuals may experience warning signs, such as a feeling of cold, fatigue and difficulty breathing, which often signal progression towards DHF or DSS.

How is DENV-2 Diagnosed and Managed?

For early and accurate detection, diagnostic evaluation must include:

• Dengue NS1 Antigen Test
• Dengue IgM and IgG Antibody Test
• Complete Blood Count (CBC)

What is DENV-3?

DENV-3, or the third type of dengue virus, has gained attention in recent years due to its reemergence in several parts of India and Southeast Asia, leading to recurrent outbreaks. The strain of the dengue virus is known for causing infections that can vary in severity, ranging from mild fever to high fever or more serious cases involving DHF. The reappearance of dengue type 3 after years of low circulation often contributes to large-scale outbreaks, as population immunity against this subtype of the virus tends to be lower.

Common Symptoms of DENV-3

• High, persistent fever accompanied by chills
• Severe body ache, joint pain and back pain
• Intense headache and pain behind the eyes
• Skin rash appearing a few days after fever onset
• Mild bleeding from the gums or nose
• Nausea, vomiting and fatigue
• In some severe cases, abdominal pain accompanied by fluid accumulation

Individuals infected with DENV-3 may experience prolonged weakness and a feeling of nausea and fatigue even after the fever subsides.

How is DENV-3 Diagnosed and Managed?

Accurate laboratory diagnosis by reputed facilities, such as Max Lab, helps determine the presence and progression of DENV-3 dengue infection. Commonly advised tests include:

• Dengue NS1 Antigen Test
• Dengue IgM and IgG Test 
• Complete Blood Count and Platelet Count

What is DENV-4?

DENV-4, or the fourth type of strain of the dengue virus, is the least frequently reported among the four strains. Although it accounts for a smaller percentage of global dengue infections, its presence is clinically significant. Outbreaks involving dengue type 4 often occur in regions where other serotypes have already circulated, contributing to complex immune responses and mixed infections. Although DENV-4 dengue is a smaller contributor to infections globally, the infections causes by DENV-4 are not necessarily milder. In rare cases, it has been linked to severe dengue, particularly in individuals with prior exposure to another strain.

Common Symptoms of DENV-4

• Sudden high fever
• Severe headache and retro-orbital pain
• Muscle and joint pain
• Mild bleeding from the gums or easy bruising
• Persistent feeling of nausea, vomiting and loss of appetite
• Rash or flushing of the skin
• In severe or secondary cases, abdominal pain, fluid accumulation or low platelet count

The symptoms of DENV-4 usually begin 4 to 10 days after exposure and may last about a week, with fatigue lasting for an extended period.

How is DENV-4 Diagnosed and Managed?

Like all 4 strains of the dengue virus, timely and accurate testing remains the cornerstone of effective treatment plans. Diagnostic evaluation must include:

• Dengue NS1 Antigen Test
• Dengue IgM and IgG Tests
• CBC Test and Platelet Monitoring

To sum up, understanding the nuances of the 4 types of dengue virus is important for accurate diagnosis, effective treatment and disease prevention. Since the symptoms of dengue DENV-1, 2, 3 and 4 often overlap, early and reliable testing becomes essential. Max Lab offers comprehensive dengue diagnostic tests, including NS1 Antigen and IgM/IgG antibody testing, to enable timely detection and informed medical management, helping individuals recover safely and efficiently.