Distribution, seroprevalence and risk factors for bovine brucellosis in Brazil: Official data, systematic review and meta-analysis

•Pooled seroprevalence of bovine brucellosis in Brazil was 2% (95% CI: 1%, 3%).•Total sample size (number of animals evaluated) ranged from 109 to 686086.•Purchase of animals for breeding was the most frequent risk factor.•It is suggested broad surveys with updated seroprevalence data and risk factors. Bovine brucellosis is an endemic disease in Brazil, and evidence-based assessments of the available literature on its seroprevalence and risk factors are limited. The aim of this study was to systematically review and summarize studies related to seroprevalence and risk factors of bovine brucellosis in the entire Brazil, in addition to comparing published data with the most recent official reports. Articles available in scientific databases and published between October 2006 and October 2021 were evaluated. Forty-five publications were included in the meta-analysis on the seroprevalence of brucellosis and 29 publications in the review on risk factors. The largest number of publications was found for the State of Mato Grosso do Sul (n=4), and the highest and lowest seroprevalences were observed in Acre (11%; 95% CI: 8.0–14.0%) and in the Federal District (0.4%; 95% CI: 0.2–0.7%). The main risk factors were the purchase of animals for breeding, vaccination, the number of heifers (female ≥2 years), the presence of calving paddocks and the occurrence of abortions. The need for new official studies has been suggested to determine the true prevalence of bovine brucellosis in Brazil, supported by the National Program for the Control and Eradication of Animal Brucellosis and Tuberculosis. La brucelosis bovina es una enfermedad endémica en Brasil y existen pocos datos sobre su seroprevalencia y factores de riesgo basados en la evidencia. Los objetivos de este estudio fueron revisar y resumir sistemáticamente los resultados sobre seroprevalencia y factores de riesgo de la brucelosis bovina en todo Brasil reportados en la bibliografía, además de comparar los datos publicados con los de los informes oficiales más recientes. Se evaluaron los artículos disponibles en las bases de datos científicas publicados entre octubre de 2006 y octubre de 2021. Se incluyeron 45 publicaciones en el metaanálisis sobre la seroprevalencia de brucelosis y 29 publicaciones en la revisión de los factores de riesgo. El mayor número de publicaciones informan datos para el estado de Mato Grosso do Sul (n=4) y las seroprevalencias más altas y más bajas se observaron en Acre (11%; IC 95%: 8,0-14,