SPRINGFIELD — Community mitigation efforts enacted to curb the spread COVID-19 are believed to have reduced the transmission of other respiratory viruses, but those viruses may be making a comeback as safety measures are lifted.
The Centers for Disease Control and Prevention health alert network issued an advisory June 10 that inter-seasonal respiratory syncytial virus activity, most common in the U.S. in fall, winter and spring, is on the increase in parts of the South.
Dr. Christine A. McKiernan, director of Baystate Children’s Hospital’s pediatric intensive care unit, said the alert not only makes pediatricians aware of the increased spread of RSV that hospitalizes some 58,000 children annually in the country, but also helps put it on the radar of others such as daycare providers.
“It makes daycare providers and others aware that even as COVID rates are going down we may be seeing other respiratory viruses and we need to be prepared,” McKiernan said. “Are we going to be testing these kids? How is that going to be affecting quarantine protocols?”
McKiernan said the country has “very quickly gone from everyone masked and distant to everybody altogether without a mask” and that as a pediatrician she “does worry that we are going to see a surge in other respiratory viruses.” She sees safety measures such as masks “something to consider at this point” when on-site learning begins again in the new school year.
“I think about the implications of kids going back to school in the fall,” McKiernan said. “What does that mean for masking and some of the interventions we have done to decrease the risk of COVID-19 and should we be continuing those not just to decrease the risk for COVID, but to decrease the risk of all these respiratory viruses at least until we get kids vaccinated against COVID.”
Baystate Children’s pediatric intensive care unit saw its first case this year of RSV at the end of May, McKiernan said. Generally, all other such “viral infections have been much lower in the last 15 or 18 months because of all the precautions we have taken for COVID.”
RSV infections generally result in mild, cold-like symptoms, but can be severe in infants and older adults. The CDC is encouraging testing for RSV among patients presenting with acute respiratory illness who test negative for COVID-19. RSV results in approximately 2.1 million outpatient visits among children younger than five each year, but can infect children of any age.
“Normally in the winter, from November to March or so, we see five to 10 cases of RSV in the pediatric intensive care per week,” McKiernan said. “The floor sees more. January and February we could have 15 to 20 infants between our two units on any given day — not to mention what comes through the Emergency Department. This year we had zero including the ED. No swab was positive for RSV or influenza A or B this winter.”
She noted a recent report on RSV cases coming out of Australia, which is located in the Southern Hemisphere where summer is December to January. Researchers there analyzed data that shows a decline in cases of RSV in children the western part of the country when safety measures were in place against COVID-19 and an increase in cases “exceeding the median seasonal peak from 2012 to 2019” as those measures were lifted.
Reasons cited, including for a rise in the median age from 12.5 months to 18.4 months, were more young children with no previous exposure to RSV and a drop in immunity overall.
“As they unmasked coming into their summer, they saw a surge in respiratory viruses and because our respiratory viral pattern has really mirrored theirs six months later, I think we in pediatrics are preparing for that,” McKiernan said. “It is always better to be prepared and if it does not happen, we can feel good about it rather than act surprised when it happens.”
Besides its recent surge in RSV cases, Australia has also reported a gradual increase since January in influenza-like illness activity although this remains at historically low levels for the country.
The authorization of vaccines in December against the pandemic virus for those 16 years and older, and more recently expanded to include those 12 and older, has greatly reduced the spread of COVID-19 in those areas of the United States where immunization rates are high.
However, McKiernan feels that the resultant lifting of safety precautions and the potential for this to increase the circulation of other respiratory viruses poses a challenge, particularly for children too young to be vaccinated against COVID-19.
“Parents of a three-or-four-year-old who has some respiratory cold symptoms may not necessarily be rushing to their pediatrician, but parents do need to be aware that RSV is out there and contagious,” McKiernan said. “It is going to make things a little bit confusing this summer for people who are traveling or putting their kids back in programs that are daycare or summer care. It is going to complicate the situation a bit in differentiating RSV from COVID and thinking about keeping your children home when they have these symptoms and are not tested for RSV.”
McKiernan said the school year ahead “is going to be confusing” as well in terms of precautions to be taken particularly to protect for those too young to be vaccinated. She urged families to vaccinate their members six months and older against seasonal flu and to consider COVID vaccination now and when it is expanded to include those under 12.
“You could have an eight-year-old who has respiratory symptoms and comes to class and coughs,” McKiernan said. “Do you quarantine the whole class, do you test her for RSV. We know you can have RSV and COVID. This is not only about kids who are not yet immunized and therefore do not have that protection available to adults. It is about one more argument for kids to continue to wear masks when they go back to school and are in close quarters.”
The CDC advisory said that with the reduced circulation of seasonal RSV “older infants and toddlers might now be at increased risk of severe RSV-associated illness since they likely have not had typical levels of exposure to RSV during the past 15 months.”
Some states outside the South have been seeing an increase in detection of the virus this spring, but less than would be normal.
RSV is an RNA virus that spreads mainly through infected respiratory droplets when a person coughs or sneezes, and through direct contact with a contaminated surface. It is the most common cause of pneumonia as well as bronchiolitis, an inflammatory condition in the small airways in the lung, in children younger than one in the United States.
“A little bit of inflammation in an infant airway can start to make breathing difficult and to start to plug up airways,” McKiernan said. “In younger children and children with other medical conditions or children born prematurely or have bad asthma and children who have other medical conditions RSV can be quite severe.”
People infected with RSV are usually contagious for three to to eight days, but some can transmitted the virus for up to four weeks even after they no longer show symptoms. The CDC says children are often exposed to and infected with RSV outside the home, such as in school or child-care centers and then can then transmit the virus to other members of the family.
The virus can survive for several hours on hard surfaces such as tables and crib rails.
Each year in the United States, the CDC said RSV leads to on average approximately 58,000 hospitalizations with 100 to 500 deaths among children younger than five, and 177,000 hospitalizations with 14,000 deaths among adults aged 65 years or older.
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