A Comparative Trial of a Single Dose of Azithromycin versus Doxycycline for the Treatment of Mild Scrub Typhus

Background. Scrub typhus is one of the most important endemic infections in the Asia-Pacific region. Although tetracyclines or chloramphenicol are the recommended drugs of choice for the treatment of scrub typhus, reports of doxycycline-resistant strains have prompted a search for alternative treatments. Methods. We conducted a prospective, open-label, randomized trial from September 2002 through November 2003 to compare azithromycin with doxycycline for the treatment of mild scrub typhus. The time to defervescence was assessed to compare the efficacy of the 2 treatment regimens. Results. A total of 93 patients were randomly assigned to receive either a single 500-mg dose of azithromycin or a 1-week course of daily oral 200-mg dose of doxycycline. Cure was achieved in 47 (100%) of 47 patients in the azithromycin-treated group and in 43 (93.5%) of 46 patients in the doxycycline-treated group (P = .117). The median time to defervescence was 21 h for the azithromycin-treated group and 29 h for the doxycycline-treated group (P = .097). There were no serious adverse events during the study. No relapses occurred in either group during a 1-month follow-up period. Conclusion. The single 500-mg dose of azithromycin was as effective as the 1-week course of daily 200-mg doses of doxycycline for the treatment of mild scrub typhus acquired in South Korea.