Window of Treatment Initiation for Human Brucellosis, Implications for Treatment Efficacy, and Prevention of Chronic Infection: Figure 1.

To the Editor—Brucellosis is a common zoonotic infectious disease, with >500 000 new cases reported annually worldwide [1, 2]. Brucellosis is caused by the intracellular bacterial pathogen Brucella. Because of Brucella's unique interaction with the human immune system, brucellosis is prone to become a chronic infection, which is difficult to cure. Timely diagnosis and treatment are considered to be the most efficient strategies to prevent chronic infections [3]. Although several treatment regimens have been recommended [4], treatment failure and relapse occur at high frequency [5], resulting in increased medical cost and patient suffering [1]. Whether the treatment delay results in treatment failure and relapse remains unknown, and the optimal treatment initiation time will be valuable for efficient treatment and prevention of chronic infection. To analyze the treatment delay, we first examined the distribution of time to treatment among 160 826 cases of brucellosis reported in the national surveillance system of China from January 2005 to July 2010. Average time from onset of symptoms to treatment was 36.97 days (95% confidence interval, 36.43–37.51 days). Treatment began >2 months after symptoms in 15.05% cases and >3 months in 8.00% cases. Delayed treatment time is related to several factors including awareness of the disease, endemic resident, income, career, and education.