Dengue cases rise: Are dengue DENV-2 strain reinfection cases really severe? Here's what we know

Amidst the COVID pandemic, another viral infection that's ringing off alarm bells is dengue. Dengue cases are spiralling out of control all across the country, and led to a lot of mayhem over an infection which was considered seasonal and milder in context. With the active cases overtaking COVID cases in some states, the seasonal infection is also reported to have caused a lot more reinfections, and posed risky outcomes for those who have contracted dengue before, making the infection spread on through mosquito bites all the more concerning. But can infections be really that severe? How worried should be we at this point?

Also read: Foods to eat and avoid for faster dengue recovery

A case of reinfection refers to a possibility of catching a disease caused by an infectious pathogen more than once, of the same serotype. In simpler terms, it refers to the causality wherein an individual happens to contract the same infection more than once in a given period.

While we have come to hear of the reinfection cases in the context of COVID, wherein the cases and the symptoms are said to be 'lighter', with dengue, reinfection cases are not only possible, it's also something which poses a certain level of added threat. Since the dengue virus has four serotypes, which can circulate and cause infection, it is suggested that an individual can contract dengue upto four times in a lifetime, or get reinfected by dengue four times over.

The current strain in circulation, spread on by the bite of the female aedes aegypti mosquito is the DENV-2 strain, or D2 which is the second serotype. While some of the serotypes, including D1 are said to only lead to a milder form of the illness, the other forms can be more consequential for the health and cause different symptoms as well. Thus, it can mean that a person who has contracted one strain of the dengue virus before, and recovered from it, can still get the other three strains and infections through his or her lifetime. Within each serotype, there can also be different substrains present, which carry different properties that can possibly escape immune detection or prevent the body from mounting an effective defensive response.

The D2 strain of dengue is also said to be more prevalent this year, which arguably raises the stakes for the infections to take a turn for the worse.

Now, while it has been suggested that the D2 strain is the primary strain in circulation, it's also the reason why reinfection cases are certainly more troublesome. While it's incredibly risky for someone who has contracted dengue before to be vulnerable to this strain, it is believed that strains like D2 have been particularly associated with severe symptoms and intensity of symptoms, which can also lead to death if not managed in time. Some medical authorities have also cited the DENV-2's apparent capability to facilitate viral entry, and cause the infamous dengue-shock syndrome or the dengue-hemorrhagic fever, which are all symptoms associated with severe dengue.

With the D2 strain, for people who have already had dengue before, there are also chances of immune complications. If an individual is infected with DENV-2 some time after a DENV-1 infection, there is a risk that the immune system ends up overreacting instead of destroying the DENV-2 serotype, making the illness more potentially serious.

While a battle against any infection mounts some protective antibodies, the immunity is only lasting against a particular serotype. The lack of cross-immunity makes people susceptible to catching the other strains in question. Since we also do not currently have vaccines against dengue, natural immunity can also wane over time, and lead to potential threats.

More so, a case of reinfection could prove murkier for those who present certain risk factors for severe illness. Those who are above the age of 60, have serious comorbidities (including diabetes, high blood pressure and vascular complications, or two or more comorbidities), currently pregnant, or have immunity-suppressing conditions can face a more severe threshold of infection, and have a higher than usual risk of hospitalizations and mortality. Experts have also suggested that the D2 serotype of dengue can also be highly infectious for kids.

Dengue can be an infection which can present symptoms like a high fever, body pain, breakbone pain, headaches, scabs and rashes. When the infection takes a turn for the severe, it can compromise vital organ functioning and manifest into severe symptoms which can be hard to manage, and require medical help. Some of the symptoms, which can be particularly expected with the DENV-2 strain include:

-High fever for more than a week (more than 103-104 degrees at times)

-Abdominal pain

-Rashes and redness

-Nausea and vomiting

-Platelet loss

-Signs of dengue hemorrhagic fever

-Swelling in the body

Any pressing symptoms should be attended to at once, and treated. If the infection isn't managed well, it could also lead to the fatal dengue-shock syndrome, or DSS. To know more about the signs which point out infection severity, read here.

As stated above, reinfections can be riskier for those who have battled an infection from previous serotypes, or over an age, or have concerning comorbidities. However, the best ways to prevent a dengue infection through and through remain on enforcing protective norms, when the season swells. Apart from building good immunity and following proper lifestyle modifications, ensure that you:

-Clean and disinfect standing water sources and avoid water stagnation.

-Replace water in pots, stands, bird feeders every day.

-Try and wear full sleeved clothes to avoid exposing yourself to mosquitoes

-Make use of mosquito repellants

-Use essential oils, repellants, sprays and nets to avoid mosquitoes at home