The Carrier Rates of Pseudomonas Aeruginosa in Family Members of Children With Cystic Fibrosis

People with CF (cystic fibrosis) often have lung infections which occur repeatedly or worsen over time. The lung infections are most often caused by bacteria. Pseudomonas aeruginosa (Pa) is the bacterium that causes one of the most consequential lung infections in people with CF. Many young children do not have Pa in their lungs but will become infected as they get older. The investigators want to learn more about how Pa is passed from person to person, especially to someone with CF. The respiratory secretions of someone colonized with Pa can transmit or pass on the bacterium. The bacterium can be passed through direct contact by two individuals kissing or touching hands. Another way to pass Pa is by indirect contact such as touching an object like an eating utensil or drinking glass that has been used by someone with Pa.

There are many unanswered questions about Pa lung infections in people with CF. For example, it is not known why some people with CF develop Pa lung infections earlier than others. Nor is it known why it is difficult to eradicate Pa in some children and why some children's condition to deteriorate quicker than other after becoming infected with Pa.

Biological parents of children with CF are carriers of one CF causing gene mutation. It is also possible that they are carriers of additional, but milder, CF-related gene mutations. It is possible that the carrier status of the parents of CF children place them at risk of acquiring and carrying Pa in their lungs.

Biological parents of children who have CF will be asked to participate. This study plans to assess the frequency of Pa in biological parents and to correlate the clinical and microbiological status of CF children with PA carrier rates of their parents.

Parents will be asked to complete questionnaires at one routine, clinic visit, have nasal and throat cultures collected during their child's routine scheduled visit and again 3-4 months later (at another routine visit). The investigators are also asking permission to review the medical records of their child with CF.

Inclusion criteria

• Biological parents of children with CF will be invited to participate and included if their children meet the following criteria:

• children's age is more than 5 years and less than 20 years of age.

Exclusion criteria

• Biological parents of children younger than 5 years of age or older than 20 years of age.
• Step parents.