Winter increases concern for respiratory viruses

Cases of SRAG (severe acute respiratory syndrome) recorded in the first 24 (from December 29, 2024 to June 14, 2025) this year were 30% higher than those notified in the same period last year. This increases the warning to winter, which officially began on Friday (20.Jun.2025), as many respiratory viruses circulate more during this period, increasing the amount of infections and severe cases.

“In winter people get more indoors, in the offices, they walk public transportation with closed windows. This increases people’s proximity, and most respiratory infections are transmitted by droplets. When we cough, speak, sneeze, these droplets may fall near the eye, nose and mouth of other people and contaminate them. to perceive”says infectologist and teacher at, Silvia Fonseca.

Two factors that also contribute to this picture are the irritation of respiratory pathways because of cold and dry weather, which are thus more vulnerable to infections, and a feature of influenza virus causing it more transmissible and more replicable in the human organism at low temperatures.

Data from (Oswaldo Cruz Foundation) have been showing the increase in influenza infections. Considering all more than 103,000 severe cases of respiratory syndrome already accounted for this year by the newsletter, almost 53,000 had a positive laboratory result for some viruses.

Of these, about 27% were caused by some kind of influenza A or B. But from mid -May to mid -June, the incidence of influenza rose to more than 40%.

Among the mortality data, influenza stands out in both analyzes. Half of the nearly 3,000 deaths caused by Srag after an infection by some virus, occurred after a flu infection. This proportion rises to 74.6% when only those with positive diagnosis for respiratory viruses recorded in the last 4 weeks are considered.

For infectologist Silvia Fonseca, the perception that flu is a light disease still compromises the main form of prevention of these deaths. “Influenza virus can rapidly evolve into respiratory failure, pulmonary infections and prolonged hospitalizations, especially in the elderly and patients with chronic diseases. Annual vaccination is the most effective way to reduce this risk.”says the teacher.

Vaccination

According to the panel of vaccination, until Friday (20.jun), less than 40% of the target audience had been vaccinated against influenza this year. The campaign began most of the country in April, precisely to immunize the most vulnerable people before the period of higher circulation of the disease. The immunizer protects against subtypes at H1N1 and H3N2 and B and has great effectiveness against severe cases and deaths.

Another deadly infection that can be prevented with a vaccine is that of COVID-19. Although the incidence between viruses caused by viruses has fallen, it was still 30.9% in the 24 weeks epidemiological this year. And in the last 4 weeks, while positive tests for Covid-19 were only 1.6% of all serious cases caused by viruses, the proportion between deaths was 4.2%, which proves the lethality of coronavirus, especially in the elderly.

Among children, concern remains with VSR (respiratory sintendatory virus), the main cause of bronchiolitis, an inflammation that affects the thinner structures of the lungs and can cause death, especially among under 2 years.

There is VSR vaccine for elderly and pregnant women-which transmit antibodies to the newborn-but only in private clinics. The Ministry of Health has already announced the incorporation of the vaccine for pregnant women in the SUS (Unified Health System) from the 2nd semester.

The period of largest circulation of the VSR begins in the fall and already gives signs of fall, according to the Infogipe Bulletin, but the cases are still numerous. Considering the entire year of 2025, it was the most prevalent pathogen, diagnosed in 45.3% of serious cases caused by viruses. VSR was also responsible for 13% of positive diagnostic deaths recorded in the last 4 weeks.

Nursing professor at Estácio Andréia Neves de Sant’Anna Faculty says that the norms of respiratory label are still valid and help to reduce the spread of viruses:

• Avoid clusters and closed environments;
• Wash hands with soap and water or use gel alcohol;
• Use disposable scarf for nasal hygiene;
• cover the nose and mouth when sneezing or coughing;
• Avoid playing eyes, nose and mouth;
• Do not share objects of personal use, such as cutlery, dishes, glasses or bottles;
• keep the environments well ventilated; and
• Avoid close contact with people with flu symptoms.

In addition, the expert points out that rest, balanced diet, and plenty of hydration, can help the body recover more easily.

With information from.