Meta-analysis of the prevalence of norovirus and hepatitis a virus in berries

Abstract

Norovirus (NoV) and hepatitis A virus (HAV) stand as the predominant agents associated with viral foodborneinfections. Outbreaks have been documented to be caused by various types of food items, including fresh and/orfrozen berries. Comprehensive data concerning crucial viral pathogens in berries remain limited and are notcurrently available in aggregate form. Consequently, the present study aimed to compile the existing informationregarding the prevalence of NoV and HAV in this matrix. Records of foodborne viruses were systematicallyextracted from database repositories up to December 2022, adhering to PRISMA standards and were subjected toa multilevel random effect meta-analysis model to determine the mean occurrence rate of NoV and HAV. A highheterogeneity across studies was observed (I2 = 82 %), reflecting variations in the prevalence of sampling lo-cations, years, berry types, and sample conditions, among other potential contributing factors. The prevalence ofNoV and HAV in berries was calculated at 2.12 % (95 % CI 1.74–2.59 %), and no statistically differences wereobserved among the viral types or genogroup categories. However, it is important to clarify that this estimateshould be taken with caution given the high heterogeneity. There was no discernible correlation between viralprevalence and any particular berry type. However, there was a temporal correlation observed with the year ofsampling, revealing a significantly decreasing trend throughout the study period. A significant influence of thesample condition (fresh or frozen) was observed in relation to the prevalence of NoV GII and HAV. Overall higherviral prevalences were identified in berries originating from African countries as compared to those sourced fromother continents. It was also noted that the prevalence of NoV GI was significantly higher in samples collecteddirectly from farms compared to those obtained from retailers. The outcomes of this comprehensive meta-analysis propose that while viral contamination of berries is diminishing in more recent times, the prevalenceremains substantial in certain African countries, having a significant risk for foodborne infections. It is imperativeto implement intervention strategies in these regions to enhance product safety.