Changes in the epidemiological characteristics of human brucellosis in Shaanxi Province from 2008 to 2020

Abstract

In the present study, surveys of case numbers, constituent ratios, conventional biotyping, and multilocus sequence typing (MLST) were applied to characterize the incidence rate and epidemiological characteristics of human brucellosis in Shaanxi Province, China. A total of 12,215 human brucellosis cases were reported during 2008–2020, for an annual average incidence rate of 2.48/100,000. The most significant change was that the county numbers of reported cases increased from 36 in 2008 to 84 in 2020, with a geographic expansion trend from northern Shaanxi to Guanzhong, and southern Shaanxi regions; the incidence rate declined in previous epidemic northern Shaanxi regions while increasing each year in Guanzhong and southern Shaanxi regions such as Hancheng and Xianyang. The increased incidence was closely related to the development of large-scale small ruminants (goats and sheep) farms in Guanzhong and some southern Shaanxi regions. Another significant feature was that student cases (n = 261) were ranked second among all occupations, accounting for 2.14% of the total number of cases, with the majority due to drinking unsterilized goat milk. Three Brucella species were detected (B. melitensis (bv. 1, 2, 3 and variant), B. abortus bv. 3/6, and B. suis bv. 1) and were mainly distributed in the northern Shaanxi and Guanzhong regions. Three known STs (ST8, ST2, and ST14) were identified based on MLST analysis. The characteristics that had not changed were that B. melitensis strains belonging to the ST8 population were the dominant species and were observed in all nine regions during the examined periods. Strengthened human and animal brucellosis surveillance and restriction of the transfer of infected sheep (goats) as well as students avoiding drinking raw milk are suggested as optimal control strategies.

National epidemiology of culture-confirmed brucellosis in Israel, 2004–2022

“…B. melitensis biotype 1 was the dominant serotype responsible for 69.1% of the cases, followed by B. melitensis biotype 2 (26.0%) and B. melitensis biotype 3 (4.3%). In the Middle East, Eurasia, China, and France, B. melitensis biotype 3 is predominant among human isolates, while B. melitensis biotype 2 is rarely reported [32][33][34][35]. B. melitensis biotype 1 was reported as the predominant human biotype in Latin America and Spain and the predominant veterinary biotype in South Africa [36][37][38].…”

Seroprevalence of human brucellosis among the tribal and non-tribal population residing in an eastern state of India: Findings from the state-wide serosurvey

“…Several climatic variables such as rainfall, temperature, relative humidity, and sunshine duration influence seasonal fluctuations in the transmission of human brucellosis ( Yang et al, 2020 ). Hence, to formulate targeted control measures against human brucellosis, it is necessary to analyze the epidemic situation, demographic features, seasonal data, incidence rate in that region, geographical distribution, and genetic profiles of Brucella isolated in this province ( An et al, 2021 ).…”

Childhood Brucellosis: A Single-Center Experience from the Central Mediterranean Region of Turkey

“…The rate of pediatric brucellosis cases in the Shaanxi province of China has been reported as 4.3% of all cases. 9 Although brucellosis in children is seen in both sexes, in studies conducted in Turkey, East India, and Saudi Arabia, male predominance has been reported at the rate of 51.7 to 69.6% in pediatric brucellosis cases. 10 11 12 13 The mean age of Saudi children was 7.7 years, and the mean age range was reported to be between 5 and 11 years in a childhood brucellosis case series published in Turkey.…”