Dengue Cases Rise: Symptoms, Diagnosis, Treatment And Vaccines — All You Need To Know

Here is everything you need to know about dengue identification, prevention, symptoms, vaccines, and treatment.

Dengue outbreak

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The number of dengue cases in the national capital increased by 10 during the past week (through July 30) bringing the total for this year to 169, the highest number since 2017, according to a civic body report. As monsoon season continues to lash Delhi and NCR, the cases of dengue are likely to rise.

According to World Health Organization (WHO), the incidence of dengue has grown dramatically around the world in recent decades, with a vast majority of cases underreported.

WHO estimates 39 crore dengue virus infections per year, of which 9.6 crore show symptoms. According to the National Vector Borne Disease Control Programme (NVBDCP), India registered over 1 lakh dengue cases in the year 2019. 

Here’s all you need to know about dengue identification, prevention, vaccines, and treatment.

What Is Dengue?

WHO defines Dengue as a mosquito-borne viral disease that has rapidly spread to all regions of the world in recent years. Dengue virus is transmitted by female mosquitoes mainly of the species Aedes aegypti and, to a lesser extent, Ae. albopictus. These mosquitoes are also vectors of chikungunya, yellow fever, and Zika viruses.

Dengue is widespread throughout the tropics, with local variations in risk influenced by climate parameters as well as social and environmental factors.

There are four different but closely related serotypes of the Flaviviridae family virus that causes Dengue and severe dengue (DENV), which is disease's primary cause. Immunity against that serotype is thought to last a lifetime following infection recovery.

The risk of acquiring severe dengue is increased by subsequent infections (secondary infection) by various serotypes.

There are four different serotypes of the dengue virus, each of which has its own specific epidemiological patterns. All four serotypes are hyperendemic in many countries, and they can co-circulate within a given area.

Both human health and the world and national economies are adversely affected by dengue. Infected travellers frequently bring DENV from one location to another; if susceptible vectors are found in these new regions, there is a possibility for local transmission to be established.

Dengue Symptoms: 

Dengue can manifest as a serious, flu-like illness that affects infants, young children, and adults but rarely results in death, even though the majority of cases are asymptomatic or exhibit mild symptoms. After an incubation period of 4–10 days following the bite from an infected mosquito, symptoms typically last for 2–7 days.

Dengue is divided into two main categories by the World Health Organization: mild dengue and severe dengue. The sub-classification of dengue with or without warning signals is intended to aid healthcare professionals in deciding which patients to admit to hospitals, assure close monitoring, and reduce the risk of contracting more severe dengue.

WHO website suggests that Dengue should be suspected when a high fever (40°C/104°F) is accompanied by 2 of the following symptoms during the febrile phase (2-7 days):

• Severe headache
• Pain behind the eyes
• Muscle and joint pains
• Nausea
• Vomiting
• Swollen glands
• Rash

Close monitoring is necessary for the following 24-48 hours if patients exhibit these symptoms during the critical phase in order to offer the necessary medical care, reduce complications, and reduce the chance of mortality. The convalescent phase should also involve continued close observation.

Diagnosis Of Dengue: 

Diagnosis of Dengue infection is done with a blood test. For patients with suspected dengue virus disease, (Nucleic acid amplification tests) NAATs are the primary technique for making a laboratory diagnosis. Serum samples obtained seven days or less after the onset of symptoms should be subjected to NAATs.

Treatment Of Dengue: 

There is no specific medication available for the treatment of dengue. Patients should relax, drink plenty of water, and consult a doctor. Patients can stay at home (if not serious), be sent for in-hospital management, or require emergency care and an urgent referral depending on the clinical symptoms and other factors.

Dengue Control By Bacteria: 

Wolbachia-infected mosquitoes have been effectively utilised by researchers from the World Mosquito Program to combat dengue in Indonesia. The researchers infected some mosquitoes with Wolbachia bacteria, released them into the city, and allowed them to breed with other local mosquitoes there until every mosquito in that region was infected with the infection (a strategy called population replacement).

At the end of 27 months, the researchers found that the incidence of dengue was 77% lower in areas where Wolbachia-infected mosquitoes had been released, as compared to the areas without such deployments. 

Dengue Vaccines: 

The Dengue vaccine CYD-TDV or Dengvaxia was approved by the US Food & Drug Administration in 2019. The use of the CYD-TDV vaccine is targeted at persons living in endemic areas, 9-45 years of age, who have had at least 1 episode of dengue virus infection in the past. Several additional dengue vaccine candidates are under evaluation.

It is too early to predict if there will be an outbreak of dengue in the national capital or not but the fact is certain that if necessary steps and initiatives are not taken by the government then a situation close to an outbreak may prevail, hence, it is the high time to advertise and create awareness regarding the preventive measures on an individual level to combat dengue.