There are lots of strains of Bart, too many to make sure u don't have one just because the test was negative...
Best way to make sure is to run a microscopy. In US you could try Fry Labs
frylabs.com/services-list/bartonella-spp/The most common are Quintana and Henselae, but it depends on how lucky u are. I am from Europe and this is how i got diagnosed:
- i've done a microscopy - they saw spirochetes + bartonella-like organisms
- next step, i asked for IFM IgG tests for Quintana and Hanselae - i got negative for Hanselae and positive for Quintana
- next i asked for WB for Borrelia sensu lato (RN-AT) http://www.biognost.be/nl/anti-borrelia-euroline-rn-at-521.aspx - positive.
Conclusion: Borrelia with co-infection Bart. Later i ran more complex tests in Germany, on co-infections and identified several others.