Cockroaches as Salmonella vectors: a systematic review and meta-analysis of public health and environmental impacts.

Cockroaches are significant mechanical vectors for bacterial pathogens, posing considerable public health risks in human-inhabited environments, such as hospitals, homes, and food-handling establishments. This systematic review and meta-analysis aimed to determine the global prevalence of Salmonella contamination in cockroaches. A comprehensive search of PubMed, Scopus, Web of Science and Google Scholar were conducted to identify relevant papers published between January 2000 and December 2025. The searching process identified 31 eligible studies comprising 8,021 samples from 12 countries. The overall pooled prevalence of Salmonella was 15.2% (95% CI: 8.3-23.6%), with substantial heterogeneity across studies (I2 = 98%). Higher prevalence was observed in lower-middle-income countries (18.0%), in regions with tropical or humid subtropical climates, and in the species Blattella germanica (10.5%). Non-typhoidal Salmonella was more frequently detected (10.9%) than typhoidal strains (3.9%). Internal body parts of cockroaches showed higher contamination levels, emphasizing their role as active reservoirs. These findings underscore the importance of cockroaches as persistent reservoirs of Salmonella and highlight the need for improved sanitation, targeted pest management, and climate-responsive public health strategies in high-risk settings.