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%;) was observed as a mild, self- limited complaint associated Pp. 06 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.