What are the Risk Factors of Dengue Fever?

Dengue Fever: Modifiable & Non-Modifiable Risk Factors

The threat of dengue looms as soon as summer approaches. It is a serious concern worldwide, causing flu-like symptoms and death in severe cases. 

But there is no need to fear; properly understanding its causes and symptoms, along with taking preventive measures, can help protect against this deadly disease. In addition to this, certain risk factors contribute to its spread across different regions. 

What is Dengue Fever?

Dengue or break-bone fever is an acute viral infection that spreads from a type of mosquito called Aedes aegypti to people. A higher number of cases are observed in subtropical and tropical regions. 

The majority of people affected by dengue will be asymptomatic, but commonly, the symptoms include high fever, headache, nausea, and rash. In severe cases, it can lead to internal haemorrhage and become fatal. 

What are the Risk Factors of Dengue Fever?

Risk factors of dengue include:

Living in Tropical Areas

Aedes aegypti is commonly found in tropical and sub-tropical areas like Africa, Latin America, and Southeast Asia. Hence, residing in these regions can increase the risk of exposure to mosquitoes and viruses.  

History of Previous Infection

The risk of developing severe dengue symptoms is higher in patients with a history of previous infection. This occurs due to antibody-dependent enhancement (ADE), where antibodies can worsen the new infection with a different dengue virus serotype.  

Age

Age is one of the critical risk factors for severe dengue fever for several reasons:

1. Children under 10 and adults above 60 are more susceptible to dengue due to weaker or less developed immune systems. 
2. Elderly individuals who have experienced previous dengue infections face a higher risk of secondary infection. 
3. With the advancement of age, different age-related physiological changes can contribute to the risk of infection in adults.   
   Comorbidities

Chronic conditions like diabetes, liver disease, hypertension, and kidney disease can increase the risk of dengue infection. These complications weaken your immune system, increasing the risk of both primary and secondary infections. 

Pregnancy

During pregnancy, the immune system usually weakens due to several hormonal and physiological changes. This is why dengue fever during pregnancy is a significant risk factor. These risks include low birth weight, premature birth, and even stillbirth.  

Environmental Factors

Different environmental factors like stagnant water in flowerpots, tyres, ditches, and warm, humid weather favour the breeding of the dengue mosquito. Moderate temperature ranging around 30-30℃ is optimal for dengue transmission. Unplanned urbanisation increases the stagnation of wastewater, leading to an increased risk of dengue infection. 

Pleural Effusion

Pleural effusion is the accumulation of fluid in the pleural space, the area between the lungs and the chest wall. It is a risk factor for severe dengue fever, as it is associated with plasma leakage and capillary leak syndrome. These are some of the major hallmarks of Dengue Haemorrhagic Fever (DHF).    

Hepatomegaly

Dengue primarily affects the liver, leading to swelling along with other complications. Conditions like hepatomegaly (enlarged liver) can increase the severity of dengue fever and other potential complications.

What are the Symptoms of Dengue Fever?

Patients having mild or no symptoms usually get better in 1-2 weeks. Rarely, dengue can become severe and lead to death. 
Symptoms usually start occurring within 4-10 days and last for 2-7 days. These include:

●  High Fever (temperature rising above 40℃ or 104℉).
●  Pain behind the eyes.
●  Severe headache
●  Nausea
●  Swollen Glands
●  Vomiting 
●  Skin Rashes

How to Diagnose Dengue?

Common diagnostic tests for Dengue fever include:

●  ELISA (Enzyme-Linked Immunosorbent Assay)

It is done to detect the amount of antibodies present in the patient’s serum. In the case of dengue, it also determines the predominance of the dengue virus in the blood. 

●  NS1 Antigen Test

This diagnostic test detects NS1, a dengue virus protein that is present in high quantities after the first 7 days of the onset of infection.   

●  RT-PCR

It detects the genetic material (RNA) of the dengue virus in the patient's blood. This helps in early detection of the infection after several days of the onset. 

Early detection and the use of preventive measures are the two pillars to prevent the spread of dengue in communities. Acetaminophen (paracetamol) is administered to reduce pain and other fever-like symptoms.