Traveler's diarrhea in Thailand: randomized, double-blind trial comparing single-dose and 3-day azithromycin-based regimens with a 3-day levofloxacin regimen.
BACKGROUND
Traveler's diarrhea in Thailand is frequently caused by Campylobacter jejuni. Rates of fluoroquinolone (FQ) resistance in Campylobacter organisms have exceeded 85% in recent years, and reduced fluoroquinolone efficacy has been observed.


METHODS
Azithromycin regimens were evaluated in a randomized, double-blind trial of azithromycin, given as a single 1-g dose or a 3-day regimen (500 mg daily), versus a 3-day regimen of levofloxacin (500 mg daily) in military field clinics in Thailand. Outcomes included clinical end points (time to the last unformed stool [TLUS] and cure rates) and microbiological end points (pathogen eradication).


RESULTS
A total of 156 patients with acute diarrhea were enrolled in the trial. Campylobacter organisms predominated (in 64% of patients), with levofloxacin resistance noted in 50% of Campylobacter organisms and with no azithromycin resistance noted. The cure rate at 72 h after treatment initiation was highest (96%) with single-dose azithromycin, compared with the cure rates of 85% noted with 3-day azithromycin and 71% noted with levofloxacin (P=.002). Single-dose azithromycin was also associated with the shortest median TLUS (35 h; P=.03, by log-rank test). Levofloxacin's efficacy was inferior to azithromycin's efficacy, except in patients with no pathogen identified during the first 24 h of treatment or in patients with levofloxacin-susceptible Campylobacter isolates, in whom it appeared to be equal to azithromycin. The rate of microbiological eradication was significantly better with azithromycin-based regimens (96%-100%), compared with levofloxacin (38%) (P=.001); however, this finding was poorly correlated with clinical outcome. A higher rate of posttreatment nausea in the 30 min after receipt of the first dose (14% vs. <6%; P=.06) was observed as a mild, self-limited complaint associated with single-dose azithromycin.


CONCLUSIONS
Single-dose azithromycin is recommended for empirical therapy of traveler's diarrhea acquired in Thailand and is a reasonable first-line option for empirical management in general.
Tribble
David R
DR
Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD 20910, USA. tribbled@nmrc.navy.mil
Sanders
John W
JW
Pang
Lorrin W
LW
Mason
Carl
C
Pitarangsi
Chittima
C
Baqar
Shahida
S
Armstrong
Adam
A
Hshieh
Paul
P
Fox
Anne
A
Maley
Elisabeth A
EA
Lebron
Carlos
C
Faix
Dennis J
DJ
Lawler
James V
JV
Nayak
Gautam
G
Lewis
Michael
M
Bodhidatta
Ladaporn
L
Scott
Daniel A
DA
D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D017963:Azithromycin / Q000008:administration & dosage / Q000627:therapeutic use*; D002169:Campylobacter Infections / Q000188:drug therapy*; D016123:Campylobacter jejuni / Q000187:drug effects* / Q000302:isolation & purification; D017714:Community-Acquired Infections / Q000188:drug therapy; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D024881:Drug Resistance, Bacterial / Q000187:drug effects*; D004403:Dysentery / Q000188:drug therapy* / Q000382:microbiology / Q000821:virology; D004927:Escherichia coli Infections / Q000188:drug therapy; D005260:Female; D006801:Humans; D064704:Levofloxacin; D008297:Male; D008889:Military Personnel; D015242:Ofloxacin / Q000008:administration & dosage / Q000627:therapeutic use*; D012480:Salmonella Infections / Q000188:drug therapy; D013785:Thailand
D000900:Anti-Bacterial Agents; D064704:Levofloxacin; D017963:Azithromycin; D015242:Ofloxacin