Diagnosis of Human Ehrlichiosis with the Indirect Fluorescent Antibody Test: Kinetics and Specificity

• Published in: The Journal of infectious diseases 1990-07, Vol.162 (1), p.91-95
• Main Authors: Dawson, Jacqueline E., Fishbein, Daniel B., Eng, Thomas R., Redus, Martha A., Greene, Neilie R.
• Format: Article
• Language: English
• Subjects: Antibodies; Antibodies, Bacterial - analysis; Antibodies, Bacterial - biosynthesis; Bacteriological methods and techniques used in bacteriology; Bacteriology; Biological and medical sciences; Coxiella burnetii; Diseases; Ehrlichia - immunology; Ehrlichiosis; Epidemiology; Fever; Fluorescent Antibody Technique; Fundamental and applied biological sciences. Psychology; Humans; Infections; Kinetics; Major Articles; Microbiology; Predictive Value of Tests; Rickettsia; Rickettsia rickettsii; Rickettsiaceae - immunology; Rickettsiaceae Infections - diagnosis; Rocky Mountain spotted fever; Typhus
• ISSN: 0022-1899; 1537-6613
• DOI: 10.1093/infdis/162.1.91

Human ehrlichiosis, an acute febrile illness caused by Ehrlichia canis or a closely related rickettsial organism, was first identified in 1986. From 1986 through 1988, sera from 85 patients demonstrated a fourfold rise or fall in antibody titer to E. canis. Seven (22%) of 32 patients initially tested during the first week after onset of illness, 17 (68%) of 25 tested during the second week, and all 18 tested during the third week had titers that exceeded the minimum positive titer of ⩾80. Of the 85 confirmed ehrlichiosis patients, 31 (36.5%) also had indirect fluorescent antibody titers considered diagnostic of infection with Rickettsia rickettsii, Rickettsia typhi, or Coxiella burnetii, but in most these diagnoses were not supported by epidemiologic, clinical, or serologic evidence. These results emphasize that patients suspected of having a tick-borne infection should be tested for antibodies to E. canis as well as for those to other rickettsiae.