What is Dengue?

Introduction:

The dengue virus (serotypes 1, 2, 3, and 4) are enveloped, single-stranded RNA viruses that are members of the Flaviviridae family and are transmitted by vectors.1,2 Dengue is a serious public health issue that affects people all over the world.

What is Dengue? 

The mosquito Aedes aegypti, which bites during the day, is transformed to human habitats, and prefers human blood meals, is the primary agent of human-to-human transmission. In over 100 nations, the risk of dengue infection is greater than 1 billion people.

Dengue, a systemic febrile illness lasting three to seven days and characterized by the virus in the blood, fever, rash, headache, and muscle and joint pain, can be caused by any of the four dengue virus serotypes. Dengue can manifest as dengue hemorrhagic fever (DHF), a  condition characterized by hemorrhagic manifestations, capillary leakage, and, in severe cases leads to hypovolemic shock.

How Dengue Spreads?

The bites of infected Aedes species mosquitoes (Ae.) transmit dengue viruses to humans. Ae.aegypti or albopictus). The same kinds of mosquitoes transmit Zika viruses.

It is impossible to pass dengue from one person to another. However, a person with dengue fever can transmit the disease to other mosquitoes. During the period when the virus circulates and reproduces in the blood system, humans are known to spread the infection from one country or region to another.

How can I prevent dengue at home?

7 Easy and Effective Dengue Preventative Measures

•  Reduce Mosquito Habitat.
•  Stay in houses with good security.
•  Use insect repellents.
•  Put on Protective Gear.
•  Sleep in an insect net.
•  Water should not remain stagnant anywhere.
•  Keep your home bright and airy.

Symptoms and Diagnosis

Symptoms:

Dengue:

Dengue can cause mild illness or no symptoms at all, but it can also cause flu-like symptoms like:

• Severe headache 
• Pain behind the eyes 
• High temperature of 40°C (104°F)
• Vomiting, 
• Swollen glands 
• Rash
• Muscle, joint, or bone pains are so severe that dengue fever is sometimes referred to as "break-bone fever."

Severe Dengue:

The number of platelet cells that are responsible for forming clots.

—falls when blood vessels become damaged and leaky, resulting in severe dengue. So, severe dengue can result in death, organ failure, shock, internal bleeding, bleeding gums or nose, and organ failure. The following are signs of severe dengue:

• Severe abdominal pain that doesn't go away
• Frequent vomiting
• Rapid breathing
• Bleeding gums or nose
• Fatigue
• Restlessness
• Liver enlargement
• Blood in vomit or stool

Diagnosis:

There are several ways to diagnose dengue infection, which need a blood sample. The gold standard is the reverse transcriptase-polymerase chain reaction (RT–PCR), which detects the virus. It can be used immediately following infection. 

Additionally, there are rapid diagnostic tests that look for the virus's NS1 protein. Whether an infection is recent (within the last three months) or previous, serological methods can be used to confirm it.

Serological methods:

Anti-dengue antibodies can be detected using serological techniques like enzyme-linked immunosorbent assays (ELISA) to confirm the presence of a current or previous infection. IgM antibodies can be found less than a week after infection and for about three months after that.

A recent DENV infection is indicated by the presence of IgM. IgG antibodies remain in the body for years and take longer to develop. A previous infection is indicated by the presence of IgG.

 Treatment:

Dengue fever has no specific treatment.

Patients should rest, drink plenty of water, and see a doctor.

Patients may be sent home, referred for in-hospital management, or need immediate treatment and referral, depending on the clinical manifestations and other factors.

Supportive care:

The fever, muscle aches, and pains can be controlled with supportive care like fever reducers and painkillers

• Acetaminophen and paracetamol are the most effective treatments for these symptoms.
• Avoid taking NSAIDs (non-steroidal anti-inflammatory drugs) like aspirin and ibuprofen.

Blood thinners may make worse the prognosis in a disease with a risk of bleeding.

For severe dengue, clinical consideration by doctors and attendants experienced with the impacts and movement of the sickness can save lives - diminishing death rates to under 1% in the larger parts of the countries.

Vaccination against dengue:

The First dengue vaccine, Dengvaxia® (CYD-TDV) created by Sanofi Pasteur was authorized in December 2015 and has now been endorsed by administrative experts in ~20 countries. The outcomes of further analysis to determine serostatus at the time of vaccination were made public in November 2017.

When compared to unvaccinated participants, the analysis revealed that the subset of trial participants who were inferred to be seronegative at the time of the first vaccination had a higher risk of more severe dengue and hospitalizations from dengue.

As a result, people aged 9 to 45 who live in endemic areas and have had at least one episode of dengue virus infection in the past,

should get the CYD-TDV vaccine. The evaluation of some more dengue vaccine candidates is ongoing.

Risk factors

A person is more likely to get severe dengue if they have been infected with DENV in the past.

Multiple social and environmental factors are associated with dengue transmission during urbanization, particularly unplanned urbanization: populace thickness, human versatility, admittance to a dependable water source, water capacity practice, and so forth.

The population's knowledge, attitude, and practice about dengue, as well as the implementation of routine sustainable vector control activities in the community, also affect the community's risk of dengue.

As a result, disease risks may shift with climate change in tropical and subtropical regions,

and vectors may adjust to the new climate and environment.

Prevention and control:

During the first week of illness, if you know you have dengue, you should protect getting bitten again by mosquitoes.

Because the virus may be circulating in the blood, you run the risk of passing it on to new, uninfected mosquitoes, which in turn could infect other people.

A  serious dengue risk factor is human habitation's proximity to breeding sites for mosquito vectors. Combat mosquitoes are currently the primary strategy for preventing the transmission of the dengue virus. This is made possible by

Prevention of mosquitoes from breeding:

•  Managing and altering the environment to prevent mosquitoes from entering egg-laying habitats;
• Properly disposing of solid waste and removing artificial habitats created by humans that can hold water;
• Weekly covering, emptying, and cleaning of water storage containers for use at home;
• Putting the right insecticides in outdoor water storage containers;

 Personal protection from mosquito bites

• Utilizing personal home security measures like vaporizers, repellents, coils, and window screens.  These precautions must be taken the whole day, both inside and outside the home (for example: at work or school) because mosquitoes bite most during the day.
• It is recommended to wear clothing that reduces skin contact with mosquitoes.

  Active surveillance for viruses and mosquitoes:

• To determine whether control measures are working, it's important to keep an eye on the diversity and plenty of vectors.
• Use active screening of mosquitoes to check the prevalence of the virus in the mosquito population.
• Clinical and environmental surveillance can be combined with vector surveillance.

I have written a detailed article about Malaria, Click Here If you want to learn about

• Its causes and Risk Factors
• Signs and Symptoms
• Diagnosis
• Treatment
• Complications 
• Prevention