Early Appearance of RSV Cases, Combined with Influenza and COVID-19, Raises Concern about Possibility of a Tripledemic During This Flu Season
Experts advise clinical laboratories to prepare now for a marked increase in demand for RSV, COVID-19, and influenza testing
Are the COVID-19 lockdowns responsible for the increase in cases of respiratory syncytial virus (RSV)? Some physicians believe that may be the case and it has hospitals, clinical laboratories, and pathology groups scrambling to prepare for a possible “tripledemic,” according to UC Davis Health.
The addition of RSV as we move into what is predicted to be a bad influenza (flu) season has prompted the Centers for Disease Control and Prevention (CDC) to issue a Health Alert Network (HAN) advisory which states, “Co-circulation of respiratory syncytial virus (RSV), influenza viruses, SARS-CoV-2, and others could place stress on healthcare systems this fall and winter.” This is especially true of clinical laboratories that still struggle to keep pace with demand for COVID-19 testing.
“COVID cases are expected to rise during the winter. This will be occurring at the same time we expect to see influenza rates increase while we are already seeing an early start to RSV season,” said Dean Blumberg, MD (above), chief of pediatric infectious diseases at UC Davis Children’s Hospital. “With all three viruses on the rise, we are worried about an increase in the rates of viral infection that may lead to an increase in hospitalizations.” Clinical laboratories should prepare for a marked increase in demand for RSV testing, as well as COVID-19 and influenza. (Photo copyright: UC Davis Health.)
Masking, Lockdowns, and Social Distancing Could be Responsible
Every winter in the United States, outbreaks of the flu and RSV occur. However, this year the RSV outbreak appears to be more serious. The CDC warns that “surveillance has shown an increase in RSV detections and RSV-associated emergency department visits and hospitalizations in multiple US regions, with some regions nearing seasonal peak levels.”
The current spread of RSV infections taking place in the US varies from prior outbreaks in notable ways:
- Incidents are happening in the fall, whereas RSV outbreaks usually peak starting in late December.
- Older children as well as infants are being hospitalized.
- Current cases appear to be more severe.
- Episodes are rising at a time when pediatric hospitalizations are already higher than usual due to other illnesses like COVID-19, influenza, and biennial enteroviruses.
Some experts believe that masking and social distancing due to the COVID-19 pandemic resulted in a respite of RSV infections in 2020. However, cases intensified in 2021, most likely a result of fewer young children being exposed to RSV during the previous year.
Most children typically have had at least one RSV infection before the age of two and the illness becomes less troublesome as children get older.
“The theory is that everyone’s now back together and this is a rebound phenomenon,” Jeffrey Kline, MD, Associate Chair of Research, Wayne State University School of Medicine in Detroit, told MarketWatch. “If we think about the relative increase—ninefold increase—that’s not nothing, especially in the pediatric [emergency departments]. Holy mackerel.”
Most RSV Infected Children Require Hospitalization
Kline is in charge of a surveillance network that aggregates information regarding incidents of viral infections from 70 US hospitals. The data shows that more children are being hospitalized with COVID-19 than with RSV, but that 5% of children are testing positive for both illnesses. About 60% of children in that group require hospitalization.
According to the CDC, individuals with RSV will typically begin to experience symptoms within four to six days after getting infected. Symptoms of RSV, which tend to appear in stages, include:
- Runny nose
- Decrease in appetite
“RSV causes a mild cold illness in most people. But it can be very dangerous for very young children and older adults. And young infants are usually the most at risk of hospitalizations in what physicians would call their first RSV season,” said Andrea Garcia, JD, Vice President, Medicine and Public Health, American Medical Association (AMA), in a November 2 AMA update on the current flu season.
“In a pre-pandemic year,” she added, “we would see 1% to 2% of babies younger than six months with an RSV infection maybe needing to be hospitalized. And virtually all children have gotten an RSV infection by the time they’re two-years-old.”
Infants are at a much higher risk of experiencing severe disease due to RSV because their immune systems are not fully developed, and those under six months old are unable to breathe through their mouths if they are congested.
“Age by itself is a risk factor for more severe disease, meaning that the younger babies are usually the ones that are sick-sick,” Asuncion Mejias, MD, PhD, a principal investigator with the Center for Vaccines and Immunity at the Abigail Wexner Research Institute, Nationwide Children’s Hospital, in Columbus, Ohio, told MarketWatch. “We are also seeing older kids, probably because they were not exposed to RSV the previous season.”
Mejias is studying whether prior exposure to COVID-19 alters how a baby’s immune system reacts to RSV, and if it may lead to more severe illness in those babies.
“That is something to work on and understand,” she said.
Comorbidities and Compromised Immune Systems also a Factor
Older adults and adults with weakened immune systems are predisposed to RSV infections, but there are things people can do to mitigate their chances of becoming ill from RSV.
“[RSV] is spread through contact with droplets from the nose and throat of infected people when they cough or sneeze. It can also be spread through respiratory secretions on surfaces,” said Garcia in the AMA update. “So, it’s a really good idea to clean and disinfect surfaces, especially in areas where young children are constantly touching things. Handwashing is always important. And if you are sick, please stay home.”
She added, “Premature infants, children with certain medical conditions, are also eligible to take a monthly monoclonal antibody treatment during RSV season, and that can help them stay out of the hospital.”
Most RSV infections typically go away on their own within a week or two. But such infections can lead to more severe illnesses, such as bronchiolitis and pneumonia. The more serious cases may require hospitalization with additional oxygen, IV fluids, and even intubation with mechanical ventilation. In most cases, hospitalization only lasts a few days, according to the CDC.
Be Prepared for a Tripledemic
“Health officials are concerned that this could be a sign of what’s to come,” stated Garcia in the AMA update. “A difficult winter, with multiple respiratory viruses circulating.”
For clinical laboratory managers, the early arrival of RSV cases at the front end of this influenza season provides an opportunity to position their labs to better meet the demand for RSV testing. They should also advise their client physicians that there may be a surge of respiratory illnesses during this flu season.