Dengue Virus: Commonest mosquito-borne viral infection in humans
Published at : 19 Oct 2020
Dengue Virus, Aedes aegypti, Break bone fever, mosquito-borne viral infection, dengue fever, dengue hemorrhagic fever, dengue shock syndrome, capillary leak syndrome ,Dengvaxia,CYD-TDV
Dengue is the commonest mosquito-borne viral infection in humans. Every year, over 100 million people get infected with dengue and around ten-thousand people die from it. It used to be localized to Asia, South America, and Africa. But increased global mobility due to tourism and migrations is slowly making dengue a global disease.
Dengue is an RNA virus in the family, Flavivirus. It has four different antigenic varieties. Infection with one type provides lifelong immunity to that type, but only short term immunity to other types. If you get a subsequent infection with a different type, it increases the risk of developing severe complications of dengue.
Dengue is transmitted mainly by the mosquito Aedes aegypti, which breeds in standing water containers such as tires, barrels, and discarded bottles. The mosquito becomes infective about two weeks after feeding on an infected person and remains infective for life.
Symptoms appear about 5-6 days after the mosquito bite. Dengue can present in many ways.
1. Some patients are asymptomatic or develop only a mild fever.
2. In Classic Dengue Fever, the patient gets fever for about three days. The fever then subsides and returns again in a couple of days. This biphasic pattern of fever is called saddleback fever.
a. Fever is associated with fatigue, skin rashes, retro-orbital pain and backache. It’s also called break-bone fever because of severe joint and muscle pains.
3. Dengue hemorrhagic fever is a severe form of dengue. It’s believed to be the result of two or more sequential infections with different antigenic types.
a. It starts as a mild upper respiratory tract infection.
b. Then all of a sudden Plasma of the blood leaks into the pleural space and peritoneal cavity. This phenomenon is known as capillary leak syndrome. These patients also have low platelet levels and may develop bleeding into the skin or gastrointestinal tract and go into dengue shock syndrome.
NS1 antigen testing or virus isolation can be done in the early stages of fever, to support the clinical diagnosis. Antibodies specific to dengue can be identified after the initial phase of the disease.
There is no effective cure for dengue. But supportive care is essential to prevent death from complications.
One dengue vaccine has been licensed so far, but there are a few issues about its safety. Destroying the breeding sites of mosquitos and applying mosquito repellents are the best ways to prevent dengue.
Dengue VirusAedes aegyptiBreak bone fever