From infestation to infection: a systematic review of arthropod-mediated microbial transmission in hospitals

Abstract Objectives: To evaluate the evidence for arthropod-associated transmission of pathogens in healthcare facilities and synthesize available literature to support infection prevention practice and policy. Methods: We conducted a systematic review following PRISMA guidelines. PubMed, Ovid MEDLINE, Embase, and CENTRAL were searched using terms related to insects/arthropods, microbial transmission, and healthcare-associated infection, supplemented by grey literature and citation tracking. No date, language, or study-type restrictions were applied. After deduplication and screening in Covidence, 73 studies met inclusion criteria. Eligible studies described microbial isolation or transmission involving arthropods within healthcare environments. Data were extracted by multiple reviewers using a standardized manual and verified by a senior author. Analyses were descriptive and focused on identifying evidence of patient transmission and microbial carriage among arthropods. Results: Included studies spanned all world regions, most commonly from Asia and South America. Cockroaches, flies, and ants were the primary arthropods examined, with samples collected from both clinical and non-clinical hospital areas. Six studies investigated direct patient transmission, and three provided genetic or circumstantial evidence linking arthropods to patient infections, including Klebsiella pneumoniae , multidrug-resistant Enterobacter cloacae , and dengue virus. The majority of studies identified arthropods carrying clinically significant bacteria (eg, Staphylococcus aureus , Enterococcus faecalis , Acinetobacter baumannii , Pseudomonas aeruginosa ), fungi ( Aspergillus, Candida ), and viruses. Conclusions: Arthropods in healthcare environments commonly harbor clinically relevant and antimicrobial-resistant microbes, and limited but compelling evidence supports their potential role in patient transmission. Strengthened pest management and environmental hygiene are essential components of infection prevention.