TUESDAY, Jan. 14, 2014 (HealthDay News) -- Frequent colds are a
normal part of young children's lives, but sometimes a stuffy nose
becomes a more severe lung infection. Now, a new study clarifies
some of the factors that put certain kids at greater risk.
The study, published online Jan. 13 in the journal
Pediatrics, focused on babies and preschoolers infected with
human rhinoviruses -- a large group of viruses that cause many
cases of the common cold.
Traditionally, rhinoviruses were thought to only cause cold
symptoms. But recent research has suggested that the viruses may
occasionally cause more severe lung infections, like pneumonia and
bronchitis, in certain children.
In the new study, that seemed to be the case. Brazilian
researchers looked at test results for 434 babies and preschoolers
who were taken to the doctor for respiratory symptoms.
A small number of children -- 31 -- were infected with only a
rhinovirus, yet had "moderate" to "severe" symptoms, such as
wheezing, difficulty breathing and heavy coughing.
But nearly all of those babies and children also had underlying
risk factors for more serious respiratory infections -- including
premature birth, heart disease and asthma.
It's known that those conditions make young children more
vulnerable to lung infections, according to Dr. David Nichols, head
of pediatric pulmonology at National Jewish Health in Denver.
So the new findings underscore the importance of trying to
shield those kids from cold viruses, said Nichols, who was not
involved in the study.
"Parents of those children usually are vigilant," he noted, but
other people in their lives might not realize they should stay away
when they have mild cold symptoms.
Jonny Yokosawa, the senior researcher on the study, agreed.
Keeping vulnerable babies and young children away from other kids
with colds is important, according to Yokosawa, who is based at the
Federal University of Uberlandia in Brazil.
He also said medical centers need to be particularly rigorous
about protecting those vulnerable children from rhinoviruses.
The findings are based on records from 434 babies and children
up to 5 years old who had a range of symptoms, from a stuffy nose
to a hacking cough to wheezing. Their parents took them to clinics
where doctors took nasal swabs and had them tested for viruses.
Overall, 42 percent of the children were infected with a
rhinovirus, often along with other viruses. The most common
"co-infection" was respiratory syncytial virus (RSV).
RSV causes colds, but can also trigger inflammation in the small
airways of the lungs (in a condition called bronchiolitis) or lead
to pneumonia. RSV is the most common cause of pneumonia and
bronchiolitis in infants, according to the U.S. Centers for Disease
Control and Prevention.
And in this study, RSV was the major cause of those more-severe
infections; about 60 percent of children carrying RSV -- whether
alone or along with rhinoviruses -- had more serious symptoms.
According to Nichols, the good news is that for most children,
rhinovirus infection is likely to cause only mild symptoms. RSV, on
the other hand, "continues to be a common cause of moderate/severe
respiratory illness in young children," he said.
According to the CDC, almost all children contract an RSV
infection by their second birthday. Anywhere from 25 percent to 40
percent of kids develop bronchiolitis or pneumonia the first time
they're exposed to the virus.
Most kids recover from an RSV infection in a week or two, the
CDC says, but a small percentage of children who develop more
severe symptoms need to be hospitalized.
The American Academy of Pediatrics has more on
kids and colds.