Coronavirus Symptoms in Children and Infants Are Usually Mild—But Severe Complications Sometimes Occur
Previous research suggested that infants and children rarely experience severe coronavirus symptoms. But experts found that kids (especially those with underlying conditions) may be at greater risk than previously thought. Here's what parents need to know.
The novel coronavirus, SARS-CoV-2, (and the disease it causes, COVID-19) has the entire world on edge, but perhaps nobody is as concerned as parents. It can seem impossible to shield children from illnesses when germs are unpredictable and omnipresent. And while experts initially reported that COVID-19 mostly spares children and infants, recent research suggests they aren't entirely off the hook. Here's what parents need to know about the coronavirus and children, plus tips for preventing the respiratory illness.
What are Coronavirus Symptoms in Children?
It's true that COVID-19 doesn't appear to affect children as severely. The Centers for Disease Control and Prevention (CDC) analyzed 149,760 confirmed cases between February 12 and April 2, 2020, and it reported that only 1.7 percent of patients were younger than 18 years old. Available research suggests that most children with COVID-19 have mild symptoms like fever, runny nose, cough, and gastrointestinal issues such as vomiting and diarrhea. Some children experience no symptoms whatsoever.
A World Health Organization (WHO) - China Joint Mission report on the coronavirus, published in mid-February 2020, found that only 2.5 percent of children diagnosed with COVID-19 had “severe” symptoms, and 0.2 percent were considered "critical." The recorded complications include acute respiratory distress syndrome and septic shock, according to the CDC.
However, a recent study published on May 11 in JAMA Pediatrics focused on the "early experience of COVID-19 in pediatric intensive care units (PICUs)" by collecting research from 46 PICUs in North America. It found that 48 American children were admitted to 14 PICUs between March 14 and April 3. A majority (83 percent) had underlying medical conditions, 38 percent needed ventilators, and 4.2 percent died.
Adding to the bad news, a new illness dubbed pediatric multisystem inflammatory syndrome has sickened around 93 children and killed at least three in New York City. The mysterious illness resembles Kawasaki disease, and it appears to be linked to COVID-19. Symptoms include fever, rash, abdominal pain, vomiting, and diarrhea, according to Demetre C. Daskalakis, M.D., MPH, deputy commissioner of the New York City Health Department's Division of Disease Control, in a letter to colleagues. And while more information is needed, experts think it may be an immune system overreaction to COVID-19 exposure.
How Are Babies and Infants Being Affected?
Since babies don't have fully formed immune systems, it would make sense that they'd be severely affected by the virus. According to the 2020 AAP study of those affected in China, while kids of all ages are susceptible, young children might be more vulnerable. The proportion of severe and critical cases was 10.6 percent for infants under 1 and 7.3 percent for kids ages 1 to 5, compared to 3 percent for 15- to 18-year-olds. Like older children, however, babies display mild symptoms in most cases, but might also be asymptomatic.
In China, for example, only nine infants had confirmed coronavirus cases between December 8 and February 6, according to a February 14 report published in JAMA. The infants were between 1 month and 11 months old, but none required intensive care. No severe complications were reported either.
But while this is great news, it might lead to another problem: Babies might unknowingly spread coronavirus to their parents or caregivers. Take this case in Singapore published in the journal Clinical Infectious Diseases, which involves a 6-month-old baby. After a mother and nanny were hospitalized with pneumonia—and the father came down with a fever and sore throat—hospital staff found the baby had high levels of the coronavirus in his "throat, blood, and stool," according to the Los Angeles Times. The baby was asymptomatic, which caused the coronavirus to spread easily to caregivers. He didn't develop any symptoms during a subsequent hospital stay (with the exception of a very short-lived fever).
These "silent cases" could help spread the coronavirus even further, which is particularly worrisome for grandparents and caregivers with compromised immune systems.
Why is the Coronavirus Generally Mild for Children?
Since the coronavirus is a novel disease, experts still don’t know many things about it—including why children usually have lower transmission rates and milder symptoms. “We don’t definitively know the reason,” says K.C. Rondello, M.D., MPH, CEM, clinical associate professor at the College of Nursing and Public Health at Adelphi University. “Everyone from virologists to epidemiologists to infectious disease doctors are completely stymied as to why we’re seeing this phenomenon.”
Here are a few theories, however, within the medical community:
Kids Have a Better Immune Response
One theory is that children have better immune responses than adults, which helps them fight off the coronavirus. “Children’s immune systems are not fully functional until later in their development. As a result, they have a considerably stronger and more robust immune response to pathogens than adults,” explains Dr. Rondello.
What’s more, “The death rate for COVID-19 is higher among individuals with certain pre-existing conditions, such as cardiovascular disease, diabetes, and cancer. This may help explain why many children seem to be at lower risk, since they are less likely to have these types of preexisting conditions,” says Aimee Ferraro, Ph.D., faculty member for Walden University’s Master of Public Health (MPH) program.
Many experts tentatively support the hypothesis, but there’s also a hitch: The coronavirus seems to spare most infants even though their immune systems aren’t fully formed yet.
Experts Might Not Be Identifying All Coronavirus Cases
Robert Frenck, M.D., medical director of the Division of Infectious Diseases at Cincinnati Children’s Hospital, says that a reporting bias might be to blame. When the coronavirus first emerged, doctors in America and China were only testing people with severe symptoms. But they’ve since found that milder, cold-like symptoms may also occur.
“It’s possible that the coronavirus causes a spectrum of illnesses, and that medical organizations are only identifying the more serious ones,” summarizes Dr. Frenck. Children might not be getting diagnosed if they’re only experiencing mild symptoms—which means the coronavirus may be affecting more children (and people in general) than reported.
Kids Could Have "Immunological Cross-Protection"
According to Dr. Rondello, a number of different viruses could give you the common cold—including milder forms of coronavirus. “Children get colds a lot, so they’re already being exposed to more benign, less intense coronaviruses. They could have potentially built immunity to them,” he says. Dr. Rondello calls this “immunological cross-protection.”
Smoking is a Potential Risk Factor
An earlier theory suggested that smoking might be a risk factor for COVID-19, since smokers tend to have greater SARS-COV receptors. “And since children do not smoke, they would be less susceptible to lower respiratory tract infections like COVID-19,” says Dr. Ferraro. This hypothesis has fallen out of favor, though, since experts found that the coronavirus transmission was comparable in counties with both high levels and low levels of smoking.
How to Prevent Coronavirus in Children
Like the cold and flu, the coronavirus is a respiratory illness that spreads through contaminated droplets. These droplets enter the body through the eyes, nose, and mouth, says Miryam Wahrman, PhD, biology professor and director of the microbiology research lab at William Paterson University in Wayne, New Jersey, and author of The Hand Book: Surviving in a Germ-Filled World.
The absolute best coronavirus prevention method, says Dr. Wahrman, is washing your hands with soap and water for at least 20 seconds. Alcohol-based hand sanitizer can also work in a pinch. Washing your hands is especially important before eating or touching your face. Parents should also disinfect common surfaces like doorknobs and countertops often.