Human norovirus contamination challenge in fresh produce: a global prevalence and meta-analytic assessment

Among fresh produce (FP)-associated foodborne infections, human noroviruses (HNoV) are the leading causative agent. The present study aimed to assess the prevalence of HNoV in FP.

FP-associated HNoV records mined from 5 repositories until 25/05/2022 according to PRISMA standards were appraised, fitted to a generalized linear mixed-effects model and subgroup analysed by sample type, genogroup, and geographical location. Further, heterogeneity was assessed in the model coupled with a leave-one-out-cross-validation. The overall prevalence of HNoV in FP was 9.3% (95% confidence interval [CI] 3.7-21.7. HNoV prevalence was higher in fruits (9.8%[3.7-23.5]) than vegetables (9.4%[3.1-25.3]). Regarding geographical distribution, FP-associated HNoV prevalence varied from Africa (25.8%, 5.7-66.7), Asia (23.2%[4.6-65.0]), Europe (5.6%[0.7-33.9]), North America (12.4%[1.8-52.7]) to South America (7.5%[0.0-100.0]). HNoV GI overall prevalence in FP was 5.3% (2.5-11.1) and varied by sample type (fruits: 4.9%[1.7-13.2]; vegetables: 5.8%[1.6-18.8]). While the occurrence of GII in FP was 1.7% (0.7-3.9) and varied by sample type (fruits: 2.5%[1.0-6.5]; vegetables: 0.9%[0.2-4.9]), GIGII (detection of both GI and GII) was 0.3% (0.1-1.0) with 0.4% (0.1-2.2) and 0.2% (0.0-1.5) in fruits and vegetables, respectively. In all cases, the test for sample/regional prevalence differences were not significantly different with the exception of GII regional prevalence differences (p = 0.03).

This study suggests that FP represents a critical vehicle for HNoV dissemination, a global and a high risk for public health.