Global disparities in intestinal helminth infection dynamics among food handlers from 1990 to 2022: A call for targeted interventions

Intestinal helminths infect over 1.5 billion people globally, with food handlers serving as critical vectors in their transmission. This study aimed to quantify the transmission dynamics of intestinal helminths among food handlers by estimating the Force of Infection (FoI) and Infection Clearance Rate (ICR), providing evidence for targeted public health interventions. We employed a Susceptible-Infected-Susceptible (SIS) compartmental model, formalized by ordinary differential equations (ODEs), to estimate FoI and ICR. Crucially, these parameters were inferred from cross-sectional prevalence data rather than longitudinal individual follow-up. Models were calibrated using data from a global meta-analysis comprising 220,705 food handlers across 29 countries. We assessed variations in transmission dynamics across regions, parasite species, demographics, sample sources, environments, and diagnostic methods. Parameter optimization was performed using a differential evolution algorithm to ensure robustness. Global FoI and ICR estimates were 0.0050 and 0.0087, respectively. Since the clearance rate exceeds the force of infection, the model indicates a net decline in the prevalence of infection. Declining trends predominated across most strata, including all three regions, most demographic subgroups, and 3 of 10 parasite species. However, India and Kenya showed expanding burdens. Regionally, Asia and South America had higher transmission parameters than Africa. Nationally, Iran exhibited the highest FoI and ICR (declining trend), while Kenya showed the lowest point estimates. Trichostrongylus spp. showed the highest species-level parameters; E. vermicularis the lowest. Elevated values were observed in males, the 26-30 age group, high-HDI countries (with declining trend due to effective surveillance), illiterate individuals, and shops/restaurants. This study provides the first global estimates of FoI and ICR for intestinal helminths among food handlers, revealing significant regional, species-related, and demographic differences. These findings highlight the need for targeted public health interventions including mass drug administration (MDA), hygiene education, improved diagnostics, and stricter regulatory measures-in strata with elevated transmission pressure.