Volume 78, Issue 6
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645


We retrospectively analyzed 92 cases of severe rickettsial infections in patients (median age = 49 years, 57% male, 37.0% with scrub typhus) in Hong Kong. Immunofluorescence assay was used for diagnostic confirmation. Identification of ≥ 1 diagnostic sign (exposure history, rash, or eschar) was possible in 94.6% of the cases. Multivariate analysis suggested that pulmonary infiltrates (odds ratio [OR] = 25.2, 95% confidence interval [CI] = 3.9–160.9, = 0.001) and leukocytosis (OR = 1.3, 95% CI = 1.0–1.5 per unit increase, = 0.033) were independent predictors of admission to an intensive care unit (14.1%). Delayed administration of doxycycline was independently associated with major organ dysfunction (23.9%; oxygen desaturation, renal failure, severe jaundice, encephalopathy, cardiac failure) (OR = 1.2, 95% CI = 1.0–1.5 per day delay, = 0.046; adjusted for age and rickettsia biogroup) and prolonged hospitalization > 10 days (25%) (OR = 1.4, 95% CI = 1.1–1.9 per day delay, = 0.014). Treatment with fluoroquinolone/clarithromycin did not correlate with clinical outcomes ( > 0.05). Early empirical doxycycline therapy should be considered if clinico-epidemiologic signs of rickettsial infections are present.


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  • Received : 01 Nov 2007
  • Accepted : 15 Feb 2008

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