Risk factors associated with life-threatening rickettsial infections.
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 > or = 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, P = 0.001) and leukocytosis (OR = 1.3, 95% CI = 1.0-1.5 per unit increase, P = 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, P = 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, P = 0.014). Treatment with fluoroquinolone/clarithromycin did not correlate with clinical outcomes (P > 0.05). Early empirical doxycycline therapy should be considered if clinico-epidemiologic signs of rickettsial infections are present.
Lee
Nelson
N
Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, People's Republic of China. leelsn@cuhk.edu.hk
Ip
Margaret
M
Wong
Bonnie
B
Lui
Grace
G
Tsang
Owen Tak Yin
OT
Lai
Jak Yiu
JY
Choi
Kin Wing
KW
Lam
Rebecca
R
Ng
Tak Keung
TK
Ho
Jenny
J
Chan
Yin Yan
YY
Cockram
Clive S
CS
Lai
Sik To
ST
D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D017291:Clarithromycin / Q000627:therapeutic use; D004318:Doxycycline / Q000627:therapeutic use; D005260:Female; D024841:Fluoroquinolones / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012282:Rickettsia Infections / Q000175:diagnosis* / Q000188:drug therapy / Q000503:physiopathology; D012307:Risk Factors
D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D017291:Clarithromycin; D004318:Doxycycline