The fear of covid is not over yet and people have started falling prey to dengue. It starts with rain and lasts till the severe cold starts. Dengue is a mosquito-borne viral infection. It is found in tropical and subtropical climates around the world.
India is a country with a tropical climate and it is affected by this disease almost every year.
It is mainly a disease caused by the bite of a particular species of mosquito. Dengue symptoms appear in humans between the 4th to 14th days after being bitten by a dengue mosquito. This is called the incubation period.
A Brief History of Dengue and severe Dengue-
The first apparent incidence of dengue in India was recorded in the year 1946. After that, for the next few years, no dengue fever was observed in India. In the year 1963-1964, some cases were reported on the east coast of India. It started to spread northwards and reached Delhi in 1967 and Kanpur in 1968. Gradually it spread to almost all the regions of India.
Before 1970, only a few countries were facing this problem, but after that, more than 100 countries around the world are severely affected by this disease. Countries in the Asian continent are representing about 70% of the global prevalence of this disease.
About Dengue Virus – DENV
Dengue virus is transmitted through the bite of an infected female mosquito, the Aedes mosquito.
Such mosquitoes usually bite during the day. And their peak biting period is early in the morning and before sunset in the evening.
The virus responsible for dengue disease is termed as dengue virus (DENV). There are four variants or serotypes of this virus. It is therefore can infect people with dengue disease more than one time. All four variants of Dengue viruses (DV) are referred to as DV-1, DV-2, DV-3 and DV-4.
The Aedes mosquitoes are the primary vector of the dengue virus. Mainly such mosquitoes thrive in urban habitats and breed mostly in freshwater contained in man-made containers. It is believed that the peak biting times of Dengue mosquitoes are generally early in the morning and in the evening before sunset.
It is said that recovery from infection provides lifelong immunity against dengue. But the fact is that the immunity develops only against the particular serotype of the virus through which the person was affected. Subsequent infections by other serotypes may happen and can increase the risk of developing severe dengue.
While many DENV (Dengue virus) infections produce only mild illness and cause an acute flu-like illness. Occasionally in the case of severe dengue, it may develop into a potentially fatal complication.
Symptoms of Dengue and severe dengue-
The most common symptom of this disease is high fever, body pain, severe headache, muscle and joint pains, nausea, vomiting, swollen glands, rashes on body parts etc.
Some other related complications and symptoms are severe bleeding, organ impairment and/or plasma leakage.
Severe dengue has a higher risk of death if left untreated or carelessly managed appropriately.
There is no specific treatment for dengue/severe dengue. Early detection of disease and access to proper medical care lowers the severity of the disease.
How it is transmitted:
Transmission of the Dengue virus is possible through mosquito vectors. The different modes of transmission may be-
1. Mosquito-to-human transmission
Infected female Aedes aegypti mosquitoes carry the virus of dengue. When it bites a human being, it transmits the dengue virus.
2. Human-to-mosquito transmission
Mosquitoes can become infected from people who are actively suffering from DENV. This can be someone who has symptomatic dengue infection, or asymptomatic having no signs of illness.
3. Pregnant mother to her baby
It can also be transmitted from a pregnant mother to her baby.
How it can be diagnosed:
The most common method to diagnose dengue is to go for a pathological blood test.
There are commercially-produced rapid diagnostic test kits available which take very little time to determine the result. It is available with most of the pathologies & testing centres.
Prevention and Cure:
Prevention and cure of the Dengue virus depend on effective vector control measures, sustained community involvement, Effective environmental management, implementing & maximizing the use of predatory fish that feed on mosquito larvae, preventing mosquito breeding etc.
Following measures can be taken-
- Regular cleaning of mosquitoes breeding sources
- Remove/cover/empty unused or artificial man-made habitats that can hold water
- Cleaning of domestic water storage containers regularly
- Using insecticides to water storage outdoor containers/ pots or wetland areas
- Special protection from mosquito bites inside the house, workplace, School, parks etc
- Use mosquito net, lattice doors & windows, repellents and other possible safety measures
- Avoid skin exposure to mosquitoes by wearing proper clothes.
- Educate the community to keep their surroundings clean.
- Regular fogging in residential and commercial premises to kill the mosquitoes.
- The regular spray of DTC and other effective insecticides
- Release of mosquitofish in ponds and lakes. It is a biological method to control mosquitoes. One mosquitofish can eat up to 150 larvae in only eight hours.
- Active mosquito and virus surveillance
Common myths about Dengue:
Dengue is a mild infection and this is not a deadly viral fever:
Dengue infection could be mild or severe. It can get severe within no time if not treated timely and even lead to mortality also. Some variants of the dengue virus are dangerous.
The patient with dengue cannot get another infection:
Dengue patients can be get affected by other infections also. A dengue patient can be covid positive at the same time. It is possible for an individual to contract two different viral strains at the same time.
Only small children or older people are exposed to dengue
It is a misconception that children and elderly people only can get affected by dengue. Any age group person can be infected by dengue. A person having weakened immune defence can develop severe symptoms.
Any mosquito bite can cause dengue
It is a myth that all mosquitoes are carriers of the dengue virus. Dengue infection can only be spread via the bite of the female Aedes mosquito only. It is said that dengue mosquito bites only in morning and evening time but not scientifically established fact. We must take precautions round the clock.
Dengue is contagious
Dengue is not spread from person to person. It is not a contagious disease. It is borne by the Aedes mosquito bites only.
A person who has had dengue once cannot get it again.
It is not 100% true because the dengue virus has four variants. It means you may develop immunity against one variant but are exposed to the remaining variants. You are still susceptible to the other variants of dengue.
Low platelets mean you are suffering from dengue
The shortfall in the number of platelets is a sign of dengue but there are many other reasons for platelets loss. Dengue is not the only cause. One should go for proper treatment & investigations to confirm the diagnosis.