Arthritis Home > The Role of Bacteria and Genetics in Reactive Arthritis: Is It Contagious?
Bacteria and Genetics -- What's the Relationship?Reactive arthritis research scientists do not know exactly why some people exposed to these bacteria develop reactive arthritis and others do not, but they have identified a genetic factor, human leukocyte antigen (HLA) B27, that increases a person's chance of developing it.
Approximately 80 percent of people with reactive arthritis test positive for HLA-B27. However, inheriting the HLA-B27 gene does not necessarily mean you will get reactive arthritis. Eight percent of healthy people have this gene, and only about one-fifth of them will develop reactive arthritis if they contract the triggering infections.