title: The serological response of patients infected with the agent of human granulocytic ehrlichiosis.
abstract: To characterize the serological response in humans to human granulocytic ehrlichiosis (HGE), we prospectively observed 152 patients for as long as 42 months. HGE was confirmed by detection of morulae in blood smears, polymerase chain reaction, blood culture, or a combination of these tests for 94 patients (62.3%), and 92 (97.8%) of the patients had specific serum antibodies thereafter. One hundred twenty-six (99.2%) of 127 patients tested at 1 month were seropositive (89 of 127 patients had seroconversion), and 150 (98.7%) of the 152 patients had become seropositive by 6 months. Eleven patients (7.3%) remained seropositive at 42 months. Neither antibiotic therapy initiated during the first week of illness nor preexisting immunosuppressive conditions abrogated a serological response. Indirect fluorescent antibody testing of acute-phase and convalescent-phase serum samples is a sensitive tool for laboratory confirmation of HGE.
authors.affiliation: Section of Infectious Diseases, St. Mary Duluth Clinic Health System, Duluth, MN 55805, USA. jbakken1@d.umn.edu
authors.forename: Johan S
authors.initials: JS
authors.lastname: Bakken
authors.forename: Irina
authors.initials: I
authors.lastname: Haller
authors.forename: Debbie
authors.initials: D
authors.lastname: Riddell
authors.forename: Jennifer J
authors.initials: JJ
authors.lastname: Walls
authors.forename: J Stephen
authors.initials: JS
authors.lastname: Dumler
mesh_terms: D000209:Acute-Phase Proteins; D000367:Age Factors; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D000917:Antibody Formation; D016873:Ehrlichiosis / Q000175:diagnosis / Q000188:drug therapy / Q000276:immunology*; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006098:Granulocytes / Q000276:immunology / Q000382:microbiology*; D006801:Humans; D007165:Immunosuppression Therapy; D007166:Immunosuppressive Agents / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D012698:Serologic Tests; D012737:Sex Factors
chemical_list: D000209:Acute-Phase Proteins; D000900:Anti-Bacterial Agents; D007166:Immunosuppressive Agents