Human animal contact, land use change and zoonotic disease risk: a protocol for systematic review.

Background: Zoonotic diseases pose a significant risk to human health globally. The interrelationship between humans, animals, and the environment plays a key role in the transmission of zoonotic infections. Human-animal contact (HAC) is particularly important in this relationship, where it serves as the pivotal interaction for pathogen spillover to occur from an animal reservoir to a human. In the context of disease emergence linked to land-use change, increased HAC as a result of land changes (e.g., deforestation, agricultural expansion, habitat degradation) is frequently cited as a key mechanism. We propose to conduct a systematic literature review to map and assess the quality of current evidence linking changes in HAC to zoonotic disease emergence as a result of land-use change.

Method: We developed a search protocol to be conducted in eight (8) databases: Medline, Embase, Global Health, Web of Science, Scopus, AGRIS, Africa-Wide Info, and Global Index Medicus. The review will follow standard systematic review methods and will be reported according to the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) guidelines. The search will consist of building a search strategy, database search, and a snowballing search of references from retrieved relevant articles. The search strategy will be developed for Medline (through PubMed) and EMBASE databases. The search strategy will then be applied to all eight (8) databases. Retrieved articles will be exported to EndNote 20 where duplicates will be removed and exported to Rayyan®, to screen papers using their title and abstract. Screening will be conducted by two independent reviewers and data extraction will be performed using a data extraction form. Articles retrieved will be assessed using study quality appraisal tools (OHAT-Office for Health Assessment and Technology Risk of Bias Rating Tool for Human and Animal Studies, CCS-Case Control Studies, OCCSS-Observational Cohort and Cross-Sectional Studies, and CIS-Controlled interventional studies). Data will be analysed using descriptive statistics and a meta-analysis where data permits.

Discussion: The review will provide an important systematic literature aggregate of existing evidence on the role and evidence quality linking HAC to the emergence of zoonoses via land-use change. The outcome of the proposed review will produce a high-level evidence document that could inform intervention points and further research priorities.

Registration: The review will be registered with PROSPERO.