Flu epidemic slows down in Rio de Janeiro after almost 1 month of discharge

After almost a month of high, the flu epidemic showed signs of a decline in the last week in Rio de Janeiro. Attendances decreased both in the state and in the municipal network, despite continuing to be much higher than normal, according to data from the Health Departments.

The daily average of adults and children with flu-like illness dropped 23% in emergency care units (UPAs) in the state, compared to the first and second week of December. The number dropped from 5,112 to 4,094 — in mid-November it was 167.

In the municipal network, the reduction was 16% in urgent and emergency units between the weeks before and after, going from 2,071 to 1,727 per day. All those who had clinical indication had the Covid test, with less than 1% of positive results.

Rio has been experiencing an explosion of H3N2 influenza infections since the end of November, with a variant that escapes the vaccine applied in early 2021. The virus has spread to several states, such as São Paulo, Espírito Santo, Bahia and Rondônia. The country’s numbers, however, are still uncertain because of the instability in the SUS notification system.

“Today the epidemic is already nationwide. It has broken out everywhere. You don’t even need to do an math. The cases in December already indicate this, despite the fact that there are departments denying it. It is necessary to guide the population”, says epidemiologist Paulo Lotufo, head professor at the Faculty of Medicine at USP.

The Rio de Janeiro database, which only includes severe cases of the disease, indicates that, even with the data blackout, notifications soared. There were 15 in October, 183 in November and 254 in December, considering the date of onset of symptoms.

The vast majority of cases, however, is not accounted for, as it involves mild symptoms, according to secretariats and doctors. This is because the main responsible for transmission is the H3N2 virus, which is quite contagious, but less dangerous, and patients are predominantly young and adults.

The state secretariat states that “the number of deaths from influenza registered so far does not deviate from the endemic pattern”. Five deaths were caused by the virus this year, against 1 in 2020 and 2 in 2019. The more lethal H1N1, on the other hand, caused 63 deaths in 2019, 1 in 2020 and 2 in 2021.

“The number of cases is impressive. Last Friday, we saw more than a thousand people in Volta Redonda. It’s a lot,” says health doctor Carlos Vasconcellos, undersecretary of the city in the south of Rio de Janeiro and one of the directors of the doctors union (Sinmed/ RJ).

Vasconcellos says he has not yet felt the drop in attendance at the end. “I don’t feel like it’s falling that much, but as it’s a quick service, that is, the person is medicated and gets a certificate, it doesn’t stress the network so much. The pressure is more at the entrance, in the emergency line”, he says.

To deal with this pressure, so-called “griparians”​ were set up, separate spaces to receive the sick.

There is still no clear explanation for the outbreak of this unseasonable epidemic in midsummer. Everything indicates that the H3N2 virus was “imported” from the northern hemisphere, which entered the cold season, and may have found a vulnerable population without immunity against this pathogen.

In addition to low immunization, experts point out the relaxation of restrictive measures and the fact that the coronavirus has practically reigned alone in the last two years, which changed with the advance of vaccination against Covid and caused other viruses to reappear.

“This year, people have not mobilized much to get the flu vaccine, which does not provide high protection, but it does provide some degree of protection. We also saw a movement to reopen and abolish masks in September in Rio, which harmed,” says epidemiologist Diego Xavier, from Fiocruz.

Sanitarist Carlos Vasconcellos also mentions the milder climate in Rio de Janeiro this year.

For Lotufo, from USP, it is still too early to know the reasons for the rapid increase in cases, but he says that some characteristics of influenza may play in our favor going forward.

“We know much more about the flu than we did about Covid. Flu transmission occurs mainly during symptoms, which are strong, so the person stays at home feeling depressed. There is also a remedy, Tamiflu or Oseltamivir”, he says.

“In 2019, H1N1 came to Brazil at the end of June, SP extended vacations in August and we managed to hold it. Now, the schools are out, which is very positive. On the other hand, people are traveling more,” he says.

The guidelines for those who have symptoms are to wear a mask at all times, including at home, and notify family members or people with whom you have had contact, in addition to seeking health facilities only if necessary, to avoid further transmission. Taking a Covid test is also important to confirm or rule out the disease.