Epidemiology of Brucellosis in Humans and Livestock: A Systematic Review and Meta-Analysis (2000–2025) from Pakistan

Abstract

This is a systematic review and meta-analysis based on the synthesis of epidemiological evidence on brucellosis within the Pakistani population in the period 2000 to 2025. Based on 87 included studies, the national prevalence of brucellosis was 8.7% (95% CI: 6.910.4) by pooling studies, and livestock had a higher prevalence of brucellosis seroprevalence (9.4%) than in humans (6.2%). It showed that there is a lot of heterogeneity in terms of regions with Punjab (10.8%) and Sindh (8.9%) being major hotspots because of intensive farming of livestock. The major reservoirs of animals were small ruminants and especially goats (12.3%). The human occupational risk was greatest among veterinarians and abattoir workers (9.1%), and farmers (7.6%). Key routes of transmission were eating unpasteurized dairy products and direct contact with infected animals and their tissues. Although the decrease in prevalence was rather modest after 2010, the disease remains a major endemic issue. It is mainly perpetuated by its lack of a national policy on its eradication, scattered control measures, inconsistent diagnostic protocols and poor surveillance. High statistical heterogeneity (I² = 93.4%) highlights the inconsistency in the methods of study. The evidence elucidates the urgent necessity of integrated One Health approach, including standardized diagnostics, animal-human surveillance, mass livestock vaccination and focused public health education that will help decrease the high socioeconomic cost of this overlooked zoonosis in Pakistan.