Leptospira and leptospirosis in China.

PURPOSE OF REVIEW: In this review, we introduce the epidemiological features, clinical types, laboratory diagnosis, and routine surveillance of leptospirosis in China.

RECENT FINDINGS: Leptospirosis has been prevalent sporadically in China in recent years, but its incidence has decreased, probably due to the lower leptospire-carrying rate in pigs. Leptospira interrogans serogroup Icterohaemorrhagiae serovar Lai is the most common pathogen in Chinese leptospirosis patients and Apodemus agrarius is its major animal host. At least 75% of Chinese leptospirosis patients suffer from the mild influenza-like type of leptospirosis that is caused by any serovars of L. interrogans. However, leptospirosis patients with the pulmonary diffuse hemorrhagic type have a high mortality (40-60%). L. interrogans serovar Lai is the causative agent in 75% of the pulmonary diffuse hemorrhagic leptospirosis patients. Several outer membrane protein antigens exist in all the L. interrogans serovars prevailing in China and predominant T- and B-cell combined epitopes in the outer membrane protein antigens have been identified that can be used for developing novel universal leptospirosis vaccines.

SUMMARY: Leptospirosis cases in the Chinese population have gradually decreased in recent years, but it is still an important zoonotic infectious disease. The development of universal vaccines is critical for the prevention and control of leptospirosis.