Dengue reinfection: Can you catch dengue twice? Here's what you should know

The rise in the number of dengue infection cases has become an emerging national health concern. With people falling ill daily and some even succumbing to the illness, health officials continue to urge people to take all preventive measures. But apart from the fact that there are no safe and effective vaccines against the virus, what makes it worse is that a person even after being infected with dengue can contract the viral disease again, multiple times. That said, let us understand why it happens and what we can do to stay safe.

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Dengue is highly unpredictable. Anyone can contract it and while some people only develop mild to moderate symptoms, there are people who experience severe complications, including dengue hemorrhagic fever.

Dengue is transmitted by the bite of an Aedes mosquito infected with any one of the four dengue viruses. Given that the infection spreads primarily via mosquito bites, it can be very difficult to distinguish between a normal mosquito bite and dengue mosquito bite.

Additionally, with the current DENV-2 or D2 strain in circulation, the severity of the disease and cases of reinfection have only increased. While it belongs to the second serotype of dengue, D1 is the first distinct serotype, said to be milder and manageable.

It takes about 4-10 days for the dengue virus to affect the body. However, as per experts, symptoms may arise at any given point of time after that.

A mild dengue infection may cause fever, severe headache, muscle or joint pain, nausea, swollen glands and rashes. However, as and when the infection takes a severe turn, it can lead to respiratory distress, blood leaking and pooling under the surface of the skin, abdominal pain, an extreme drop in the blood platelet levels and loss of consciousness.

Read also: Dengue hemorrhagic fever: All you need to know about this rare complication

A reinfection is when a person catches an illness twice or multiple times. It is the probability of contracting a disease caused by an infectious virus more than once. This terminology was widely used while we were battling severe cases of COVID-19 and added to many of our already existing worries.

In terms of dengue, it is believed that a person can get the infection multiple times, irrespective of how young, the kind of medical conditions, lifestyle habits, he or she is used to. Considering dengue belongs to the Flaviviridae family, constituting of four distinct serotypes of the virus called DENV-1, DENV-2, DENV-3 and DENV-4, it is suggested that an individual can contract dengue upto four times in a lifetime, or get reinfected by dengue four times over.

Unlike COVID-19, which is believed to have low reinfection rates, the dengue virus is not the same. Since the dengue virus has four serotypes, if a person contracts one type of a dengue strain, recovers from it, then he or she develops immunity only against one distinct serotype. That means that the person continues to remain vulnerable to the other three strains and may get infected during his or her lifetime at any given time.

Experts say that each serotype contains different substrains, which carry different compounds that can dodge immune detection or prevent the body from showcasing strong immune responses.

This year, the D2 strain of dengue is also said to be more prevalent , which has increased the number of cases, even in those who have previously contracted the disease.

Dengue fever can take a severe toll on a person's body. It can lead to tremendous fatigue, cause high body temperature and impair limb movements, due to its effect on the joints and muscles. However, it has been suggested that a reinfection can be all the more severe and deadly.

Currently, the D2 strain in circulation is the reason behind why reinfection cases are increasing and becoming more severe than ever. It has been suggested that people who have previously been infected with dengue are likely to be more prone to the D2 strain. To top it off, the symptoms can be more severe, leading to complications. As of now, the DENV-2 strain is said to cause the infamous dengue-shock syndrome or the dengue-hemorrhagic fever, which are all symptoms associated with severe dengue.

In addition, experts say that people affected by the strain or those who are reinfected may develop immune complications. Given that a person contracts the D2 strain right after the D1 strain, it is believed that the immune system, rather than triggering immune responses, stops reacting. This further complicates matters and leads to severe complications.

At such a time, when reinfection cases are rising and the D2 strain is more rampant than ever, preventive measures are your silver bullet.

Currently there aren't any safe and effective vaccines available for dengue. Although there is a dengue vaccine called Dengvaxia (CYD-TDV), which is the first vaccine against dengue, licensed in 2015 and available in some countries for people aged 9 to 45 years, the WHO recommends that the vaccine be given only to people with confirmed previous dengue virus infection.

That said, precaution is better than anything else when it comes to dengue. Apart from practicing good hygiene, one must remember to clean and disinfect standing water sources and avoid water stagnation. Wear full length clothes and apply mosquito repellants when needed.