Human enteric pathogenic viruses can enter the environment through discharge of waste materials from infected persons, and be transmitted back to susceptible persons to continue the cycle of disease. Contamination of food with viruses may also promote disease outbreaks. A number of studies have investigated the survival characteristics of several enteric viruses in various environments and foodstuffs, to help explain the transmissibility of these pathogens. This review deals with published work on enteric virus survival on fomites, and in waters, soil, and foods; the results of these studies have illustrated the robust survival of viruses in these environments. Much information is lacking, however, especially for foodstuffs and soils, and no detailed information is available concerning the survival of noroviruses, the most significant foodborne type.

Numerous viruses of human or animal origin can spread in the environment and infect people via water and food, mostly through ingestion and occasionally through skin contact. These viruses are released into the environment by various routes including water run-offs and aerosols. Furthermore, zoonotic viruses may infect humans exposed to contaminated surface waters. Foodstuffs of animal origin can be contaminated, and their consumption may cause human infection if the viruses are not inactivated during food processing. Molecular epidemiology and surveillance of environmental samples are necessary to elucidate the public health hazards associated with exposure to environmental viruses. Whereas monitoring of viral nucleic acids by PCR methods is relatively straightforward and well documented, detection of infectious virus particles is technically more demanding and not always possible (e.g. human norovirus or hepatitis E virus). The human pathogenic viruses that are most relevant in this context are nonenveloped and belong to the families of the Caliciviridae, Adenoviridae, Hepeviridae, Picornaviridae and Reoviridae. Sampling methods and strategies, first-choice detection methods and evaluation criteria are reviewed.

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Numerous outbreaks have been attributed to the consumption of raw or minimally processed leafy green vegetables contaminated with enteric viral pathogens. The aim of the present study was an integrated virological monitoring of the salad vegetables supply chain in Europe, from production, processing and point-of-sale. Samples were collected and analysed in Greece, Serbia and Poland, from 'general' and 'ad hoc' sampling points, which were perceived as critical points for virus contamination. General sampling points were identified through the analysis of background information questionnaires based on HACCP audit principles, and they were sampled during each sampling occasion where as-ad hoc sampling points were identified during food safety fact-finding visits and samples were only collected during the fact-finding visits. Human (hAdV) and porcine (pAdV) adenovirus, hepatitis A (HAV) and E (HEV) virus, norovirus GI and GII (NoV) and bovine polyomavirus (bPyV) were detected by means of real-time (RT-) PCR-based protocols. General samples were positive for hAdV, pAdV, HAV, HEV, NoV GI, NoV GII and bPyV at 20.09 % (134/667), 5.53 % (13/235), 1.32 % (4/304), 3.42 % (5/146), 2 % (6/299), 2.95 % (8/271) and 0.82 % (2/245), respectively. Ad hoc samples were positive for hAdV, pAdV, bPyV and NoV GI at 9 % (3/33), 9 % (2/22), 4.54 % (1/22) and 7.14 % (1/14), respectively. These results demonstrate the existence of viral contamination routes from human and animal sources to the salad vegetable supply chain and more specifically indicate the potential for public health risks due to the virus contamination of leafy green vegetables at primary production.

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The aim of the study was to identify the Cryptosporidium parvum subtypes circulating in Polish cattle and their distribution in relation to the age and health status of tested animals. In total, 779 fecal samples were obtained from young cattle originating from 237 farms. C. parvum strains were identified at the 18 small-subunit ribosomal RNA (SSU rRNA), COWP, and LIB13 loci and were subsequently analyzed by sequencing at the 60-kDa glycoprotein (GP60) locus for subtype determination. The presence of 71 C. parvum strains belonging to IIa, IId, or IIl subtype families was shown. The strains from the IIa allele family prevailed with IIaA17G1R1, IIaA17G2R1, and IIaA15G2R1 subtypes occurring frequently. Two novel subtypes IIaA10G1R1 and IIlA19R3 were detected for the first time in a bovine host. The highest C. parvum prevalence (22.5 %, confidence interval (CI) = 2.5 %) was observed among the youngest animals up to 2 weeks of age, followed by the prevalence among those aged 2 to 4 weeks (6.6 %, CI = 2.6 %) and then among older cattle (4.9 %, CI = 2.1). The occurrence of diarrhea in animals was associated with the presence of the IIaA16G1R1b subtype, while infections caused by IIaA15G2R1 strains were more likely to be asymptomatic. The geographical distribution of subtypes revealed that strains from the IIa subtype family were detected all over the country frequently compared to the IId and IIl subtypes, the sporadic appearances of which confirmed their endemic occurrence. Subtype analysis revealed the presence of zoonotic strains indicating cattle as a reservoir for human cryptosporidiosis.

The aim of this study was molecular identification of Cryptosporidium species and assessment of their prevalence in different breeds of sheep and goat reared in Poland. In addition, the relationship between animal age, breed type, and the frequency of Cryptosporidium infections was determined. Fecal samples from 234 lambs and 105 goat kids aged up to 9 weeks, representing 24 breeds and their cross-breeds were collected from 71 small ruminant farms across Poland. The identification of Cryptosporidium species was performed at the 18 SSU ribosomal RNA (rRNA) and COWP loci followed by subtyping of C. parvum and C. hominis strains at GP60 gene locus. The presence of Cryptosporidium DNA at the 18 SSU rRNA locus was detected in 45/234 (19.2%) lamb feces samples and in 39/105 (37.1%) taken from goats. The following Cryptosporidium species: C. xiaoi, C. bovis, C. ubiquitum, C. parvum, and C. hominis were detected in small ruminants. Infections caused by C. xiaoi were predominant without favoring any tested animal species. Subsequent GP60 subtyping revealed the presence of C. parvum IIaA17G1R1 subtype in sheep and IIdA23G1 subtype in goats. IIdA23G1 subtype was detected in a goat host for the first time. There were no significant differences found in frequency of infections between the age groups (<3 and 3–9 weeks) of lambs (P = 0.14, α > 0.05) or goat kids (P = 0.06, α > 0.05). In addition, there was no correlation observed between the frequency in occurrence of particular parasite species and breed type in relation to native sheep breeds (F = 0.11; P = 0.990 > 0.05). In the case of goats, more breed-related differences in parasite occurrence were found. The results of this study improve our knowledge on the breed-related occurrence of Cryptosporidium infections in the population of small ruminants reared in Poland.

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