E BELOW B. quintana Ab, IgM < 1:16 --INTERPRETIVE INFORMATION: Bartonella quintana Ab, Ism -- Less than 1:16 Negative-No significant level of Bartonella quintana IgM antibody -- detected. -- 1:16 or greater Positive-Presence of IgM antibody -- to Bartonella quintana detected, -- suggestive of current or