POSITIVE LYME-DISEASE SEROLOGY IN PATIENTS WITH CLINICAL AND LABORATORY EVIDENCE OF HUMAN GRANULOCYTIC EHRLICHIOSIS

In 10 consecutive patients with an acute febrile illness, human granul ocytic ehrlichiosis was confirmed with specific polymerase chain react ion studies, serologic conversion, or both. Although no patients had t he clinical features most suggestive of early Lyme disease (eg, erythe ma migrans or cranial nerve palsy), tests for antibody to Borrelia bur gdoferi produced a reaction in most patients. In 6 of 7 patients (86%) with evaluable results, enzyme-linked immunosorbent assay yielded pos itive or equivocal findings, and an immunoblot technique yielded posit ive findings in 60% to 90% of patients, depending on the criteria used for interpretation. Inasmuch as approximately 25% of nymphal Ixodes s capularis ticks in Westchester County, New York, are infected with B b urgdoferi, the probability that at least of these patients were coinfe cted with B burgdorferi and human granulocytic ehrlichiosis by the sam e tick bite is estimated to be .00003. These observations suggest that serodiagnosis is insufficient to establish the presence of coinfectio n with B burgdorferi.