Epidemic status of brucellosis and MLVA genotyping characteristics of Brucella isolated from Hebei Province in 2016

Abstract

Objective \nTo analyze the brucellosis epidemic and genotyping characteristics of Brucella strains isolated from Hebei Province, and to provide scientific basis for brucellosis control and prevention. \n \n \nMethods \nDescriptive epidemiological analysis (including region, population, and time distribution characteristics) was performed using individual data of human brucellosis in Hebei Province from the National Notifiable Infectious Disease Reporting Information System of China Information System for Disease Control and Prevention in 2016, Brucella strains were isolated by phase culture bottles in Brucellosis Lab from Hebei Provincial Center for Disease Control and Prevention. Multiple-locus variable-number tandem-repeat analysis (MLVA) was used to identify the genotyping characteristics of the isolates. \n \n \nResults \nThere were 3 774 reported cases in 2016, and 11 cities in the province had reported the cases. The cases were found mainly in Zhangjiakou, Chengde and Tangshan. And 95.98% (167/174) of all counties were reported brucellosis cases. Vocational high risk population was farmers and herdsmen engaged in livestock and processing of animal products, accounting for 90.22% (3 405/3 774). Male had the highest incidence, accounting for 74.38% (2 807/3 774). The onset time was concentrated in January-August, accounting for 83.67% (3 161/3 774). Twenty-one strains of Brucella were isolated, twenty isolates were Brucella melitensis biovar 3, and one isolate was Brucella abortus biovar 3. Panel 1 (MLVA-8) identified three genotypes 42, 43, and 114, with genotype 42 representing 85.00% (17/20); Panel 1 + Panel 2A (MLVA-11) identified three genotypes 116, 122, 291, with genotype 116 representing 85.00% (17/20), which were identified as belonging to the East Mediterranean group. Panel 1 (MLVA-8) identified the genotype 36, Panel 1 + Panel 2A (MLVA-11) identified the genotype 72 of one Brucella abortus strain. It was identified as belonging to abortus C. \n \n \nConclusions \nThe brucellosis epidemic in Hebei is relatively severe, the pathogenic bacteria is mainly Brucella melitensis. The MLVA assay is a very practical and important molecular genotyping tool, it provides a basis for tracing the source of brucellosis infection. \n \n \nKey words: \nBrucellosis;\xa0Genotype;\xa0MLVA