On Thursday, August 30, the Georgia Lyme Disease Association ran this article on their blog about Lyme Disease in the Southeast. It is a very good article about how the CDC never followed its own rules to declare southern counties as endemic for Lyme after two laboratory confirmed cases or a confirmed infected tick. As a result Lyme Disease cases are reportable only with a rash AND strict CDC positive testing. In official endemic counties in the Northeast, a case is reportable with only a rash. Since most people with a rash won't test positive yet, that automatically excludes most early cases in the South.
Also, genetic variety of Borrelia in the South results in fewer CDC positives. They say they need their own testing interpretation because of the wide genetic variations. More Lyme patients there are likely to test false negative.
http://galymediseaseassoc.blogspot.com/