Azithromycin activities against Orientia tsutsugamushi strains isolated in cases of scrub typhus in Northern Thailand.

Azithromycin was given to mice and humans infected with strains of Orientia tsutsugamushi from northern Thailand, where drug-resistant scrub typhus occurs. Azithromycin and doxycycline yielded comparable mouse survival rates (73 and 79%, respectively; P > 0.5). Symptoms, signs, and fever in two pregnant women abated rapidly with azithromycin. Prospective human trials are needed.