Biological Control Agents in Agriculture: Evaluating Their Potential as Vectors of Human Pathogens

Abstract

Biological control agents (BCAs) are increasingly employed in sustainable agriculture as environmentally friendly alternatives to synthetic pesticides for the management of insect pests and plant diseases. Predatory insects, parasitoids, entomopathogenic fungi, bacteria, nematodes, and insect-specific viruses contribute significantly to integrated pest management by reducing pesticide use, preserving biodiversity, and enhancing ecosystem resilience. Despite their well-established agricultural benefits, concerns have emerged regarding their potential role as reservoirs or mechanical carriers of human pathogens due to their interactions with soil, irrigation water, organic amendments, crops, and contaminated environments. This review examines the diversity of biological control agents, their mechanisms of pest suppression, and the environmental pathways through which they may encounter microorganisms of public health importance. Particular emphasis is placed on differentiating biological transmission from incidental mechanical carriage and evaluating current evidence regarding pathogen persistence and dissemination. The review further discusses modern pathogen detection techniques, biosafety assessment frameworks, regulatory guidelines, and quality assurance practices governing the production and application of biological control agents. Current evidence indicates that approved biological control agents generally pose a very low risk to human health when produced and applied under appropriate regulatory standards. Future research integrating genomics, metagenomics, microbiome analysis, and One Health approaches will strengthen biosafety evaluation while supporting the continued expansion of sustainable biological pest management in modern agriculture.