Assessment of Potential Risks Associated with the Dissemination of Genetically Modified Metarhizium Fungus for Vector Control through Expert Elicitation

Abstract

Background: Vector-borne diseases such as malaria, dengue, and chikungunya remain a major global public health challenge, with current control strategies increasingly limited by insecticide resistance and changing vector behavior. Consequently, innovative approaches such as genetically modified entomopathogenic fungi have emerged as promising alternatives, though their environmental safety and long-term impacts require careful evaluation. Aims: This study aimed to assess the potential risks associated with the environmental release of genetically modified Metarhizium pingshaense (Mp-Hybrid) for malaria vector control, using a structured and systems-based risk assessment approach. Study Design: A cross-sectional study based on structured expert elicitation was conducted to evaluate risk-related factors associated with Mp-Hybrid deployment. Place and Duration of Study: The study was conducted in Burkina Faso between march 2023 and January 2024, involving experts from national research and academic institutions. Methodology: A total of 30 risk-related factors, including biological hazards, transmission modifiers, operational risks, and socio-economic factors, were identified through literature review and expert consultation. Nineteen experts assessed the probability of occurrence and the magnitude of consequences for each factor using a scoring scale from 0 to 10. Scores were normalised and combined using a risk function (R = P × C). Variability among responses was used as an indicator of uncertainty. Comparative analyses were conducted to assess differences between experts with and without specific knowledge of Metarhizium. Results: The overall risk associated with the release of Mp-Hybrid was estimated to be low (mean risk score: 0.118). Most factors were characterised by low probability estimates, although some were associated with moderate potential consequences, particularly those related to ecological interactions and system-level factors. The probability of successful infection of malaria vectors was high, suggesting strong potential effectiveness of the intervention. Differences between expert groups were observed mainly in consequence assessments, with non-specialists assigning higher severity scores. Conclusion: The findings suggest that genetically modified Metarhizium pingshaense may represent a promising complementary tool for malaria vector control with a relatively low perceived risk profile. However, uncertainties remain, particularly regarding long-term ecological and epidemiological effects. A cautious and phased implementation, supported by robust monitoring, regulatory oversight, and community engagement, is recommended. Further empirical studies are needed to validate these findings and support evidence-based decision-making.