Contribution of Limited Molecular Testing to Low Ehrlichiosis Diagnosis in High Incidence Area, North Carolina, USA

Indirect immunofluorescence antibody assays have been the primary method for laboratory diagnosis of ehrlichiosis. Detection of Ehrlichia spp. DNA by using PCR is now widely available through commercial laboratories. To prepare for Ehrlichia spp. PCR introduction, we assessed ehrlichiosis testing practices, quantified the proportion of samples eligible for PCR testing, and estimated the potential effect of implementing PCR at the University of North Carolina health system in North Carolina, USA, which is in an area with a high-incidence of ehrlichiosis. We found <1% of patient samples underwent PCR testing, even though rates of serodiagnostic algorithm completion (testing of acute and convalescent samples) were low (18.4%). Our findings show a need to educate providers on diagnostic and treatment guidelines for ehrlichiosis and raise awareness of the availability and advantage of PCR testing.