Navigating the Informal Food Economy: A Critical Narrative Review of Health Literacy, Hygienic Practices and Foodborne Disease Prevention

Abstract

Informal food economies provide affordable meals, income and everyday food access for large urban and peri-urban populations, yet they also concentrate food-safety risks in settings where water, sanitation, storage, waste services and regulatory support are often unreliable. This critical narrative review examines how health literacy, hygienic practice and structural conditions interact to shape the prevention of foodborne disease in street-food and related informal-market settings. Literature published from 1 January 2000 to 26 June 2026 was sought through PubMed, Europe PMC, AGRIS, OpenAIRE, OpenAlex, DOAJ, Semantic Scholar and the WHO Global Index Medicus, supplemented by citation searching and authoritative institutional sources. Evidence from cross-sectional surveys, direct observation, microbiological research, intervention studies, qualitative work, systematic reviews and food-system governance research was appraised for methodological strength, behavioural validity, external applicability and consistency. The literature consistently shows that food-safety knowledge is neither absent nor sufficient: vendors may recognise basic hygiene principles while being unable to enact them when potable water, handwashing facilities, protected storage, waste removal, time, space or financial margins are constrained. Knowledge-attitude-practice surveys therefore provide an incomplete proxy for food-safety capability, especially when practice is self-reported. Direct observation and intervention research more clearly demonstrate a capability-opportunity gap. Training reliably improves knowledge, but evidence for sustained behavioural, microbiological and disease outcomes is weaker and more heterogeneous. The strongest recent vendor-specific trial evidence indicates that participatory training coupled with enabling tools can improve observed practice, while qualitative findings show persistent infrastructure, regulatory and economic barriers. Consumer risk perception and purchasing incentives are also underdeveloped components of prevention. An integrated capability-opportunity-literacy interpretation is proposed in which effective prevention requires usable knowledge, practical skills, enabling infrastructure, incentives, supportive governance and feedback. Future research should prioritise objective behavioural and microbiological endpoints, longer follow-up, causal designs, economic and livelihood effects, and co-designed interventions that treat vendors as partners rather than passive regulatory targets.