The prevalence of camel brucellosis and associated risk factors: A global meta-epidemiological study

Abstract

Camel brucellosis is a widespread and critical zoonotic infection caused by <i>Brucella abortus</i> and <i>Brucella meli-tensis</i> that negatively impact dairy and meat products.The current meta-analysis covers studies published over a course of 40 years, between 1 January 1980 and 1 April 2021, aiming to investigate the global prevalence of Brucella spp. in camels and related risk factors in different camel-keeping areas. Chi-squared test (I2 index) was applied to evaluate the heterogeneity of studies. A random-effect model (REM) estimated the pooled prevalence among subgroups. The literature search on camel brucellosis was performed among the available databases, including CABI, PubMed, Embase, Web of Science, Cochrane, Scielo, Scopus, and Science Direct. A total of 56 publications, comprising 205 data reports, were evaluated. Our results showed that the overall prevalence of camel brucellosis in the world was 9.23%. The lowest and highest prevalence rates of <i>Brucella</i> spp. infections among camels were reported in Oman (0.34%, 95%CI: 0.18–0.55) and Sudan (37.41%, 95%CI: 25.27–50.31), respectively. According to different risk factors, subgroup analysis showed that the location, sex, herd size, age, and mixed rearing with other animals could be considered the main risk factors impacting the occurrence of brucellosis in camels.The reported <i>Brucella</i> spp. in dromedary camel was <i>Brucella melitensis</i> (Biovar 1, 2, and 3), <i>Brucella</i> abor-tus (Biovar 3, 5, and 6), and <i>Brucella</i> suis. Our study represented remarkable differences between the prevalence of <i>Brucella</i> spp. in male (6.83% in 41 studies) and female (9.64% among 62 studies) camels. However, the present meta-epidemiological study would help improve control and surveillance approaches to prevent the spread of camel brucellosis among herds.