Having more kids means everyone is sicker more often, science says. 

By Liz Steelman
Updated August 05, 2015
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Cough! Achoo! Ow! Does your family sound like a sick symphony with what seems to be a standing date of all the time? Well, according to a new study, it’s probably to be expected if there are a lot of you. Researchers at the University of Utah School of Medicine found that the number of weeks families spend sick during the year seems to increase with each child, but remains fairly constant—about 56 percent of the year—for those with two to four children.

The Better Identification of Germs-Longitudinal Viral Epidemiology, or BIG LoVE study, followed 26 households in a Utah community for one year. Researchers tested participants for nasal respiratory viruses weekly via nasal swab. The study, published in Clinical Infectious Diseases, found that childless adults had viruses for three to four weeks out of the year, while families with one child were infected for 18 weeks. Families with six children were infected for 45 weeks—that’s 87 percent of the year. But just because you have a virus doesn’t mean you’re actually sick: Only about half of those who tested positive for a viral infection showed typical symptoms like coughing and sneezing at any given time.

Families with children under five were more likely to be sick, too. The preschoolers had a virus 50 percent of the year and their parents were one-and-a-half times more likely to be sick than other adults who were childless or who had older children.

"A lot families go through wave after wave of illness. In fact, some of the kids we monitored had symptoms for 20 to 25 weeks in a row," study author Carrie Byington, M.D., professor of pediatrics and co-director of the Utah Center for Clinical and Translational Science, said in a statement. "This study helps us to understand what is normal in young children, and can help us determine when illness should be a cause for concern."