Covid changes circulation of other viruses, and hospitals face out-of-season outbreaks

The Covid pandemic has altered the frequency and circulation of other common respiratory viruses in children and adults, such as those that cause colds and the flu.

The period of seclusion in the last three years changed the seasonality of these pathogens, which in general was well established, in the autumn and winter periods. As a result, hospitals face off-season outbreaks of respiratory illnesses.

“Covid has greatly disrupted seasonality [dos outros vírus] and even with the seasons, it’s out of the usual pattern. It is difficult now to predict the protagonism, that is, which virus will be dominant in each season”, explains the pediatrician and director of immunizations of the Brazilian Society of Pediatrics, Renato Kfouri.

Kfouri recalls that the period when schools were closed ended up delaying this first contact of babies with respiratory viruses in general, not just the coronavirus.

Although, on the one hand, it was positive because there was a period without the occurrence of respiratory problems, on the other hand, the delay in building immunity made children more susceptible to these different agents.

“More important than the dominant virus is when that child has the first infection, and this we saw that changed a lot in the pandemic”, he says.

This is the case of João Lucca, who, at almost three months old, was treated at Sabará Children’s Hospital with a respiratory condition in early December. He was diagnosed with bronchiolitis caused by respiratory syncytial virus (RSV), which he caught from his older brother, 2-year-old Pedro Henrique.

“I went to look for the symptoms and then I found out that it could be bronchiolitis. The worst phase was on the fifth day, which is when the doctors call the peak of the disease, but now he is recovering and will be discharged soon”, said the mother. by João Lucca, Joelma dos Santos, 40.

In addition to the change in seasonality, the off-season cold also contributes to this, but it is still difficult to predict when the scenario will return to normal. “At the end of December 2021 we had an influenza epidemic [causador da gripe], then the syncytial virus, then the flu again in September. It begins to have a more well-known seasonality, but it is still very early”, says Kfouri.

In Sabará, cases of RSV exploded in the months of October and November, a period that is considered off-season. From November 27th to December 3rd, a third of the exams performed had a positive diagnosis for RSV.

“Every year we experience absolutely dramatic situations in the period of seasonality of respiratory viruses, with a lack of beds, demand surpassing supply, and because they are seasonal, structures are not maintained for a long time. And without this predictability, it became even more messy”, says Daniella Bonfim, technical director of the hospital.

It is common for young children to catch viruses that are common in childhood from other older children, such as adenovirus, rhinovirus and RSV itself, which, although they have relatively mild clinical manifestations in older children, like the flu, can cause complications in babies.

This was the case of seven-month-old Gabriela, who was admitted to the Intensive Care Unit (ICU) of Sabará at the end of November with bronchiolitis. Caused by a co-infection of adenovirus and RSV, Gabriela and her older brother Pedro, three years old, who also had flu-like symptoms, were infected along with other children at the school.

“It started with him, with symptoms in his eyes and ears. It was difficult because we had to come to the hospital with two small children, with different conditions, since she had difficulty breathing and it was more of an otitis in him”, reports the father and project analyst, Lucas Pegorari Espósito, 33.

Despite seeming worrying, the infectologist and medical manager of Sabará, Francisco de Oliveira Júnior, recalls that contracting infections at this age is common. “This relationship between children’s schools and the appearance of respiratory viruses has always been well known, the difference is that with Covid isolation, and also with the use of masks, we managed to delay this process”, he explains.

However, Junior warns of the possible discharge of cases of respiratory syndromes after the end of year festivities, as occurred in previous years. “It is very likely that we will see a recrudescence”, he recalls.

Therefore, protective measures must continue even after the emergency period of the pandemic. “It is very important to reinforce hygiene and protection measures at this time, to prevent that small child or baby from having contact with someone with respiratory syndrome at the slightest sign of the flu”, says Bonfim.

virus monitoring

In Brazil, epidemiological surveillance monitors circulating viruses, and is exercised in three instances: municipal, through municipal surveillance services, state, with epidemiological surveillance centers (CVE), which coordinate services in municipalities, and nationally, under the supervision of the Health Surveillance Secretariat of the Ministry of Health.

Often, the services that report and identify respiratory viruses are the same for other pathogens such as Zika and dengue. The notification of flu syndromes is made by e-SUS Notifica, and of Srag (severe acute respiratory syndrome) by Sivep-Flu, both from the Ministry of Health.

The sentinel centers make the notification of flu syndromes, while the registration of Srag is compulsory since 2009 (with the H1N1 epidemic). Sentinel hospitals are infectious disease surveillance centers that collect a defined percentage of samples for virus type analysis. The objective is to provide data on the frequency of pathogens in circulation, thus being able to identify outbreaks and changes in seasonality.

With a strong performance in the pandemic, Júnior hopes that these existing services will not be discontinued after the Covid health emergency period. “These surveillance services already existed, but they were reinforced with the pandemic, when hospitals and the population itself became more interested in identifying, knowing what the virus was, and this brought more accurate notification”, he says.

According to the Municipal Secretary of Health of São Paulo, all hospitals in the private or public network have a professional responsible for making notifications of flu syndromes or Srag. The capital also has seven sentinel units that collect five samples per day, the main one for viruses in children being Hospital Municipal Infantil Menino de Jesus.

Also according to the folder, the ministerial ordinances ensure the financing of laboratories for the sequencing of viruses, with the Instituto Adolfo Lutz and Butantan units recognized in São Paulo.

The Secretary of State for Health, sought during the administration of Rodrigo Garcia (PSDB), confirmed the identification at times of the year outside the typical seasons, the circulation of other viruses, such as influenza A H3N2 at the end of December 2021 and beginning of January 2022 , and reiterated that the coronavirus continues to circulate, along with other respiratory viruses that affect children, adults and the elderly.

According to the folder, there was a reinforcement of surveillance structures during the pandemic, with new techniques for laboratory and genomic analysis, and that it regularly publishes epidemiological bulletins.

The Ministry of Health, sought at the end of Jair Bolsonaro’s (PL) management, said it continues with active surveillance, even with the end of Espin (Public Health Emergency of National Importance). The folder reported that surveillance services were strengthened with the pandemic, jumping from 114 sentinel units in 2019 to 342 in 2022 (200% increase), and that the monitoring of Sars-CoV-2 was integrated with that of other respiratory viruses of public health importance.

Finally, the ministry said that the pandemic also accelerated the expansion of the National Genetic Sequencing Network (RNSG) due to the need for genomic surveillance of circulating Sars-CoV-2 lineages in Brazil. “Since then, the Ministry of Health has started to publish weekly Covid-19 epidemiological bulletins, which provide information on SRAG caused by other viruses”, he added.