Genomic Epidemiology and Antimicrobial Susceptibility of Human Brucellosis - Shenzhen City, Guangdong Province, China, 2005-2024.

WHAT IS ALREADY KNOWN ABOUT THIS TOPIC?: Brucellosis is a zoonotic disease historically concentrated in pastoral regions of China; however, an increasing number of cases have been reported in large urban centers in recent years.

WHAT IS ADDED BY THIS REPORT?: Analysis of 191 human-derived Brucella isolates collected in Shenzhen between 2005 and 2024 showed that Brucella melitensis predominated and that Shenzhen isolates were interspersed with strains from multiple provinces, suggesting repeated introductions from other regions. Most cases occurred in working-age adults, and both imported cases and Shenzhen-resident cases without documented external exposure were identified.

WHAT ARE THE IMPLICATIONS FOR PUBLIC HEALTH PRACTICE?: These findings suggest that brucellosis control in highly urbanized settings should prioritize surveillance for imported infections, improved traceability and regulation of animal-derived food products, targeted protection of high-risk occupational groups, and continued genomic and antimicrobial susceptibility surveillance.