The study, which appears in the March 15 issue of Clinical Infectious Disease, confirmed the suspected close link between the two most common diseases of young children, viral colds and ear infections. It also identified the viruses associated with higher rates of ear infections.
"Understanding how viruses and ear infections are linked will definitely help us find new ways to prevent ear infections," said Dr. Tasnee Chronmaitree, a paediatric infectious disease specialist who is the study's principal investigator. "To break the link you must first understand it."
Ear infections are the driving force behind antibiotic resistance, a troubling medical issue, as physicians often administer antibiotics for the painful, persistent ailment.
Chonmaitree has studied otitis media (ear infection) for more than two decades. She said parents could best protect their children by avoiding exposure to sick children and to have their children vaccinated against influenza. She suggested that children in day care might face reduced exposure to viruses if they are enrolled in smaller day care facilities with fewer children.
Funded by the National Institutes of Health, Chonmaitree and colleagues followed 294 children ages 6 months to 3 years for up to one year each. Researchers documented about 1,300 cold episodes and a 61 percent rate of ear infection complication including asymptomatic fluid in the middle ear, which can cause hearing problems. Researchers also identified the types of cold viruses - adenovirus, respiratory syncytial virus and coronavirus - that most often resulted in ear infection.
"Because we now know that the common cold is the precursor to an ear infection, it is important for parents to make extra efforts to prevent their children from catching colds," Chonmaitree said. "It's important to avoid exposure to sick children or adults, to avoid day care attendance, if possible, and if that's not an option, to choose a smaller group day care."
Chonmaitree also recommended the use of influenza vaccine, the only vaccine available to prevent respiratory viral infection, which is now available for children older than 6 months. The antiviral drug has also been shown to prevent ear infections associated with influenza, she said.
Chonmaitree and colleagues will continue to study the role of viruses in ear infection aiming to find a way to prevent the disease. Continued funding from the NIH will allow them to study children born with genetic variations who are prone to having ear infections and at the interactions between genes and the environment.