Asymptomatic cases of dengue worry experts – 02/14/2024 – Balance and Health

Asymptomatic cases of dengue — those in which people are bitten by mosquitoes Aedes aegypti, but do not present symptoms— experts worry. Estimates indicate that they represent 30% to 50% of those infected, on average, according to infectologists interviewed by the report.

“The problem with asymptomatic people is that they do not seek out the health system and serve to spread the disease, transmitting it to the mosquito that becomes infected and transmits it to other people. The asymptomatic person will not be notified, will not be known by the health system nor will they be treated. to this end”, explains Antonio Carlos Bandeira, member of the Arbovirus Committee of the SBI (Brazilian Society of Infectious Diseases).

“Asymptomatic people are a risk in terms of public health, because they facilitate the continued expansion of dengue cases”, highlights Bandeira.

He also warns of the possibility of some people — especially children and adolescents — developing only one symptom, such as fever.

“Adolescents and children may only show part of the symptoms. This can also happen with adults. These people can have a specific fever. So, the health system has to be very attentive even to symptoms that do not cover the entire characteristic of a person. classic case of dengue. People who only start to have a fever, but are living in areas with a lot of dengue transmission, would have to be investigated,” he says.

For Paulo Abrão, vice-president of the São Paulo Society of Infectious Diseases, it is important to be aware of the number of asymptomatic dengue cases and explain to the population that it is necessary to take extra care in prevention.

“If there are 500 thousand reported cases, they are symptomatic people, who went to the doctor, presented themselves, got a diagnosis and were notified. If we consider that 50% of cases are asymptomatic, this means that we have another 500 thousand people patients who don’t know they are sick. The more cases, the more asymptomatic, the more the mosquito has a place to bite and pick up the virus from the blood and transmit it to another person”, explains Abrão.

How do I know if I already had dengue and was asymptomatic?

According to Antonio Bandeira, the serological test for dengue detects antibodies to the disease.

“From the 10th, 12th day of the initial dengue fever, the person already produces IgG antibodies and they are permanent, for the rest of their life. These antibodies are not used to diagnose the acute disease, which was occurring at that time. They They are a marker that the person had dengue at some point in the past”, explains Bandeira.

Dengue has four serotypes. When an individual is infected by one of them they acquire immunity against that virus, but are still susceptible to the others.

In case of reinfection, the disease can present itself in a severe form, according to infectologist Ralcyon Teixeira, from Emilio Ribas Hospital.

Vaccination has the possibility of eliminating the risk of the second episode of dengue being worse.

“A focus for the future is to try to increase the number of people covered by the vaccine, from a public health point of view and when there is better stock in the private network. The dengue vaccine can act better on those who have already had the first episode of the disease avoiding the severe form if it occurs the second time”, says Teixeira.

In the current scenario, it is important to protect yourself. Use repellent approved by Anvisa (National Health Surveillance agency). Doctor Antonio Bandeira recommends using an icaridin-based product, as it is safer. Opt for pants and blouses with long sleeves. And whoever can, get the vaccine.

“We have public homework to do. One is the urbanization of the most critical areas, favelas, communities. And the complete urbanization of the country, in terms of sewage. We know that mosquitoes lay their eggs in dirty and clean water”, he says Flag.

“If Brazil were Switzerland, even with these high temperatures, we wouldn’t have the number of cases we have today. It’s not just the mosquito, it’s not just the heat. There are practically mosquitoes in the country’s 5,000 municipalities. And now, with Due to the warming phenomenon, many of the cities in the Southeast and South regions, especially in the western part, are now full of mosquitoes, because they spread in this heat corridor”, concludes Bandeira.

In Paulo Abrão’s opinion, if each group of neighbors formed a task force to eliminate breeding sites and report neglected vacant lots to the city hall, the situation would be better in terms of the number of cases. The doctor also advises the use of repellents approved by Anvisa and appropriate according to age group, the placement of screens on windows and mosquito nets.

“And having this notion of silent transmission is important because it increases awareness and alerts regarding prevention measures”, says doctor Paulo Abrão.