Sticky fingers, runny noses: Little kids are sweet, but they can also pass on dangerous germs to loving grandparents, new research confirms.
The study found that contact with pre-school and kindergarten-aged kids may be the leading transmission route for bacteria that can cause dangerous pneumonias in folks over 60.
The same Streptococcus pneumoniae that can trigger ear infections and sinus trouble in tots can cause dangerous respiratory illness in the elderly, said researchers led by Dr. Anne Wyllie, from the Yale School of Public Health.
Kids were far better vectors than adults of passing the bug along to the elderly.
"Our study found no clear evidence of adult-to-adult transmission," Wyllie said, "even though there were households in which an individual was positive for pneumococcus across numerous sampling moments, and instances where both adults in the household carried pneumococcus around the same time."
"Instead, we found that transmission was highest among older adults who had frequent contact with young children," she said.
Her team will report the findings later this month at the European Congress of Clinical Microbiology and Infectious Diseases, in Barcelona.
According to the U.S. Centers for Disease Control and Prevention, pneumococci bacteria account for 150,000 hospitalizations in the United States every year (many among the elderly), and these germs are also the leading cause of pneumonia in children.
Pneumococci are passed by inhaling respiratory droplets, and people without symptoms can still transmit infections.
The CDC estimates that anywhere from 20% to 60% of school-age kids may carry the bacterium, whether they display symptoms or not.
In the new study, Wyllie's team tracked pneumococci transmission within 93 households in New Haven, Conn. The study involved married couples age 60 and older without younger people living in the home.
Using saliva samples and questionnaires, rates of illness were tracked over two fall-winter periods, in 2020-2021 and 2021-2022.
Overall, about 15% of people in the study did test positive for pneumococci infection at some point during the study.
However, the odds of testing positive was six times higher among older folk who had regular (daily or every few days) contact with children versus those that didn't, Wyllie and team found.
Younger kids (under the age of 10) were more of a risk for passing on infection to adults compared to older children. Preschoolers (ages 2 to 5) posed the greatest threat, the study found.
The risk for older folks of contracting the pneumonia bacterium rose the more often they engaged with little ones.
Of course, there's one way for grandma and grandad to cut their odds for bacterial pneumonia: Vaccination.
Wylie's team noted that soon after kids routinely began getting the pneumococcal conjugate vaccine (PCV), pneumonia illnesses among children fell by over 90%. Vaccines can protect older folks, as well.
"The main benefit of adult pneumococcal vaccination is to directly protect older adults who are exposed to children who may still carry and transmit some vaccine-type pneumococcal strains despite successful national childhood vaccination programs," Wyllie said in a meeting news release.
Because these findings are to be presented at a medical meeting, they should be considered preliminary until published in a peer-reviewed journal.
More information
Find out more about bacterial pneumonia at Johns Hopkins Medicine.
SOURCE: European Congress of Clinical Microbiology and Infectious Diseases, news release, April 3, 2024
