Quantitative Detection of Hepatitis A, Rotavirus and Genogroup I Norovirus by RT‐qPCR in Fresh Produce from Packinghouse Facilities

Abstract

Food‐borne outbreaks caused by virus have been associated with the consumption of fresh produce. However, it is difficult to track the source of contamination due to the lack of sensitive methods of detection. In this study, we evaluated the presence of norovirus (NoV), rotavirus (RV) and hepatitis A virus (HAV) in fresh produce from the northwestern part of Mexico by reverse transcription quantitative PCR (RT‐qPCR). Fresh produce was sampled from field and packinghouse facilities during different stages of the packing process. Surfaces of equipment, as well as water used for disinfection were also sampled. A total of 46 samples were analyzed for the quantification of virus: HAV was found in 28.2% of the samples, NoV in 32.6% and RV in 13.0%. Eleven samples were positive with at least two different viruses. These results show a high prevalence of these viruses in fresh produce and highlight the need to establish further virological surveys for this kind of products. Practical Applications Viruses are considered important causal agents of food‐borne diseases. Many outbreaks implicate the consumption of fresh produce, mainly because fresh vegetables are usually consumed raw or with minimum processing. In spite of this, in many undeveloped countries, analyses for microbial quality imply testing for bacterial but not for viruses' contamination. For that reason, it is necessary to generate information on the risk of virus transmission in fresh produce. In that way, producers can be warned of the risk of virus contamination, and they could implement good manufacturing practices to improve sanitary conditions in fresh produce processing plants for consumer protection to diminish food‐borne outbreaks. We evaluated the prevalence of enteric viruses in fresh produce, water and surfaces of equipment by reverse transcriptase quantitative PCR, a sensitive method not commonly used for sanitary monitoring of food products.

Processing Strategies to Inactivate Hepatitis A Virus in Food Products: A Critical Review

“…For example, a hepatitis A outbreak because of consumption of contaminated green onions affected at least 601 individuals and resulted in 3 deaths (Wheeler and others ). HAV has also been detected in market lettuce (Monge and Arias ; Hernandez and others ; Pebody and others ), in 1.32% of salad vegetable samples collected from European countries (Kokkinos and others ), and 28.2% of the Mexican samples (Felix‐Valenzuela and others ). Moreover, in recent years, an increasing number of HAV outbreaks has been associated with foods of foreign origin in industrialized countries (Table ).…”

“…Contamination levels ranged from 1.1 × 10² to 4.1 × 10⁶ RNA copies/g digestive tissue (Manso and Romalde ). Felix‐Valenzuela and others () reported HAV concentrations ranging from 2.8 × 10 2 to 2.4 × 10 3 genomic copies per gram of Mexican parsley, green onions, and coriander. These concentrations were by far greater than the infective dose for HAV, estimated to be around 10 and 100 viral particles (Yezli and Otter ).…”

Application of viability PCR to discriminate the infectivity of hepatitis A virus in food samples

“…In salad vegetables from European countries 1.32, 3.42, 2 and 2.95% of samples were positive for HAV, HEV, NoV GI and NoV GII, respectively (Kokkinos et al, 2012). In samples from Mexico, HAV was found in 28.2% of samples, NoV in 32.6% and rotavirus in 13.0% (Felix-Valenzuela et al, 2012). Moreover, NoV genomes have frequently been detected in salad vegetables (28.2, 33.3 and 50% of samples from Canada, Belgium and France, respectively); however, sequence confirmation was not successful for the majority of the samples tested.…”

A quantitative exposure model simulating human norovirus transmission during preparation of deli sandwiches

“…However, the presented model does not go into detail regarding the origin of the HuNoV load on the lettuce. The HuNoV contamination level and frequency of HuNoV presence on the lettuce were based on multiple studies (Kokkinos et al, 2012;Felix-Valenzuela et al, 2012;Baert et al, 2011;Mattison et al, 2010;Cheong et al, 2009;Allwood et al, 2004). These input parameters were named Initial _contam_level_lettuce and Initial_contam_chance_ lettuce, respectively (Table 1).…”

“…Results indicate that this source could be a relative important source if no ill food handlers are present and/or if good hygienic practices are respected. Despite recent efforts however, data describing the HuNoV prevalence on lettuce remain limited (Kokkinos et al, 2012;Felix-Valenzuela et al, 2012;Mattison et al, 2010). Further research may therefore be needed to assure a better risk estimation of this contamination source.…”