My understanding is that a titer test is only done if a test is positive, since it's a measure of concentration.
B. henselae is Bartonella, a co-infection of Lyme (a bacteria that causes other illnesses). Many of these tests depend on the presence of antibodies for a positive result; if your body doesn't produce antibodies (which many don't), you will get a false negative.
E. chaffeenis is Ehrlichiosis, another co-infection of Lyme.
Your son's labs would be considered normal: see: http://labs.unchealthcare.org/labstestinfo/e_tests/erlichia_ab_igm.htm
I can help you with the rest if you need help figuring it all out, but I'm really tired at the moment! Follow up with me tomorrow if you don't get the answers you need - the other thing you could do is call the laboratory for a more detailed/layperson explanation.
Post Edited (madrivergirl30) : 9/17/2010 12:55:10 PM (GMT-6)