Risk Factors for African Swine Fever Transmission in Southeast Asia: A Systematic Review and Meta-Analysis

1. Purpose and Rationale African Swine Fever (ASF) has emerged as the most significant threat to the swine industry in Southeast Asia since its introduction to the region in 2019. The disease has led to massive economic losses, threatened food security, and endangered native wild suid populations, such as the bearded pig (Sus barbatus). While numerous primary studies have investigated individual outbreaks, the results are often fragmented due to variations in production systems (commercial vs. smallholder), differing levels of biosecurity, and the inherent reporting bias found in the region. In Malaysia and neighboring nations, the "secretive" nature of the informal pig sector often leads to under-reporting, making it difficult to pinpoint the most dangerous transmission drivers. The purpose of this research is to perform a systematic review and meta-analysis to quantitatively synthesize the risk factors associated with ASF transmission in SEA. By pooling data from various studies, this project aims to provide a statistically significant "Map of Risk" that transcends individual study limitations. 2. Research Objectives a. To identify and categorize the primary anthropogenic and environmental risk factors for ASF in SEA. b. To calculate the Pooled Odds Ratios (OR) for these risk factors to determine which behaviors or conditions are most likely to result in an outbreak. c. To evaluate the impact of study quality and reporting bias on the current understanding of ASF epidemiology in the region. 3. Methodology Overview This study will follow the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) framework. We will search four major databases (Scopus, Web of Science, PubMed and CABI) for peer-reviewed literature published between 2018 and 2026. To capture "hidden" data common in the Malaysian context, a robust search of grey literature (DVS Malaysia reports, FAO situational updates) will also be conducted. Data will be analyzed using a random-effects model in R to account for expected heterogeneity across different Southeast Asian countries. 4. Expected Outcomes a. A Quantitative Hierarchy of Risk: The project will produce a definitive list of transmission drivers ranked by their statistical significance. b. Identification of Knowledge Gaps: It will highlight which areas of the SEA pig industry are most "data-poor," providing a roadmap for future field research (specifically for my subsequent PhD chapters). c. Evidence-Based Policy Recommendations: The outcomes will provide the Department of Veterinary Services (DVS) and regional stakeholders with evidence to prioritize biosecurity interventions where they are most effective.