CLINICAL AND LABORATORY SPECTRUM OF CULTURE-PROVEN HUMAN GRANULOCYTICEHRLICHIOSIS - COMPARISON WITH CULTURE-NEGATIVE CASES

We describe the clinical and laboratory manifestations of human granul ocytic ehrlichiosis (HGE) in eight patients for whom cultures were pos itive for the HGE agent and compare them with 15 patients for whom cul tures were negative but who fulfilled a modified New York State survei llance definition for HGE. Polymerase chain reaction analysis was posi tive in 8 (100%) of 8 culture-positive cases vs. 3 (20%) of 15 culture -negative cases (P < .001), morulae were detected in 7 (100%) of 7 cul ture-positive cases in which tests were performed vs. 0 of 15 culture- negative cases (P < .001), and a fourfold change in antibody titer was demonstrated in 6 (75%) of 8 culture-positive cases vs. 9 (69%) of 13 culture-negative cases (P = not significant). Patients for whom cultu res were positive had higher mean oral temperatures +/-SD at presentat ion than did patients for whom cultures were negative (38.6 degrees C +/- 0.7 degrees C vs. 37.2 degrees C +/- 0.8 degrees C, respectively; P = .002). Other symptoms and signs were not significantly different b etween the two groups. Multivariate analysis revealed that the lymphoc yte count at presentation was significantly lower in culture-positive cases than in culture-negative cases. Clinical response to treatment w as similar in the two groups. Culture confirmation of NGE is the gold standard for defining the sensitivity and specificity of other diagnos tic tests presently being developed.