Introduction
It is a mosquito-borne viral disease occurring in tropical and subtropical areas. Dengue is an endemic disease, which means that it occurs regularly, in tropical regions of the world.
The risk of contracting dengue infection has increased dramatically due to increases in long-distance travel, population growth and urbanization, lack of sanitation, ineffective mosquito control, and increases in the surveillance and reporting of dengue cases.
How does dengue spread?
The dengue virus is transmitted to humans via the bite of an infected mosquito.
When a mosquito bites a person who has dengue virus in his or her blood, the mosquito becomes infected with the dengue virus. An infected mosquito can later transmit that virus to healthy people by biting them. Dengue cannot be spread directly from one person to another, and mosquitoes are necessary for transmission of the dengue virus.
Aedes Mosquito
The dengue virus is carried and spread by mosquitoes belonging to the genus Aedes, which includes a number of mosquito species. Of these species, the primary vector of the dengue virus is the species Aedes aegypti. They bite during the day time.
The Aedes mosquito becomes infective only when it feeds on viremic patients (one day prior before to the end of febrile period)
How is dengue transmitted to humans?
Typically, four days after being bit by an infected Aedes aegypti mosquito, a person will develop viremia, a condition in which there is a high level of the dengue virus in the blood. Viremia lasts for approximately five days, but can last as long as twelve days. On the first day of viremia, the person generally shows no symptoms of dengue. Five days after being bit by the infected mosquito, the person develops symptoms of dengue fever, which can last for a week or longer.
Symptoms of Dengue Fever
Headache
Eye Pain
High fever
Rashes
Muscle pain
Joint pain
Vomiting
Bone pain
Symptoms of severe dengue/ warning signs
Belly pain, tenderness
Persistent vomiting
Bleeding from nose or gums
Vomiting blood or blood in stools
Feeling tired, restless or irritable
Drowsiness
Difficulty in breathing
If any warning signs are seen the patient should be immediately taken to the Emergency Department of the nearby Hospital.
Investigations
Dengue NS1 Antigen Rapid Test.
Dengue IgM/IgG Antibody Rapid Test.
Blood hemogram especially WBC and Platelet count to rule out risk of bleeding.
Also other routine blood investigations
Management of dengue fever
It is a self limiting illness with no specific antiviral treatment currently available.
Bed rest: Rest as much as possible .
Control high fever: Sponging of the patient’s skin with cool water if the fever remains high. Give paracetamol every 6 hours if needed for high fever.
Hydration: Take plenty of fluids and look out for any signs of dehydration.
When the fever is going away, look for any danger signs. Report to a clinic or emergency department if any signs of severe dengue appear.
Prevention of Dengue
Use of mosquito repellent: These include mosquito wipes, repellent bands or mosquito patches.
Wear protective clothing: Less exposed skin, lower the chances of being bitten. Cover windows with mosquito nets during monsoon season.
Refrain from breeding grounds: Mosquitoes inhabit areas like stagnant water pools created in and around the house. Therefore one has to ensure that no part of the house has an unnecessary collection of dirt or filth. Having a clean and tidy home is extremely important to prevent dengue mosquitoes from infecting you.
Be knowledgeable about dengue fever: It is important for families to be informed about dengue, it’s effects and precautions they need to take.
During the mosquito breeding season in India, which is usually during monsoon, make sure to take precautions to avoid being infected by the mosquito.
Dr. Noel Menezes M.D
Associate Professor
Department of Biochemistry
Goa Medical College