This study examines at the prevalence and spread of Hepatitis A Virus (HAV) and norovirus GI/GII in local and imported food products in Greece over a five-year period (2019–2024). A total of two hundred sixty-six food samples were evaluated using obligatory inspections and virus detection procedures, including 202 for Hepatitis A and 64 for Norovirus. High-risk categories analyzed were vegetables [138 (HAV), 17 (NoV)], fruits [16 (HAV), 7 (NoV)], soft fruits/berries [37 (HAV), 31 (NoV)], processed meals [4 (HAV), 4 (NoV)], and animal-based products [1 (HAV), 5 (NoV)]. Viral RNA was isolated using QIAamp Viral RNA Mini Kit and detected using established RT-qPCR procedures that met ISO requirements for high sensitivity and reproducibility. The results demonstrated HAV contamination mostly in vegetables (4.35% positive rate), with sporadic findings in other categories. Norovirus GI/GII was detected primarily in soft fruits/berries, with a category-specific positive rate of 6.45%. A temporal study revealed that HAV peaks in 2020, while Norovirus contaminations were detected in 2021 and 2024. The findings highlight the important need to incorporate viral testing into routine food safety procedures, especially for high-risk product categories. This study establishes a basic framework for public health initiatives that address gaps in foodborne virus surveillance in Greece. The study’s ramifications extend to global efforts to monitor and reduce foodborne virus contamination, pushing for higher regulatory requirements and targeted preventative actions.

The COVID-19 pandemic has underscored the importance of alternative epidemiological tools capable of providing real-time, population-level insights into infectious disease dynamics. Wastewater-based epidemiology (WBE) has emerged as a powerful, non-invasive method for tracking viral transmission within communities. While initially focused on SARS-CoV-2, WBE now offers the potential for multiplex surveillance of a broader range of respiratory pathogens. This study applied WBE to monitor the circulation of six major respiratory viruses such as Human adenovirus (HAdV), SARS-CoV-2, Influenza A and B, Respiratory Syncytial Virus (RSV) A/B, and Rhinoviruses, over a six-month period (ISO weeks 2022-40 to 2023-13) in the city of Patras, Greece. Weekly composite samples from a central wastewater treatment plant were analyzed via quantitative PCR, and viral genome concentrations were normalized per 100,000 inhabitants. The results revealed distinct circulation patterns: HAdV and SARS-CoV-2 were detected consistently throughout the period, while Influenza A peaked during the winter months, followed by Influenza B. RSV, however, appeared earlier in the season (first detectable from ISO week 2022-46) and overlapped with Influenza. Rhinoviruses displayed intermittent peaks, indicating multiple waves or persistent low-level transmission. Correlation analyses showed strong positive associations between influenza viruses, RSV, and SARS-CoV-2, suggesting synchronized seasonal trends. Hierarchical cluster analysis classified the viruses into three distinct groups: (1) an epidemic cluster including Influenza A/B, RSV, and Rhinoviruses; (2) a persistently present cluster represented by HAdV; and (3) a separate episodic cluster characterized by SARS-CoV-2. These groupings reflect differences in viral epidemiology and shedding behaviour. This study confirms the effectiveness of WBE in tracking the temporal dynamics of multiple respiratory viruses and provides evidence of its utility in supplementing traditional clinical surveillance systems. The consistent detection of underreported pathogens such as HAdV underscores the added value of environmental monitoring for public health preparedness and early warning applications. These findings advocate for the integration of WBE into routine respiratory virus surveillance frameworks.

Indoor particulate matter is a Group 1 carcinogen with no identified exposure threshold, and the portable air cleaners now widely deployed in European schools, hospitals and offices are almost always evaluated by a change in mean concentration measured before and after installation in the same room. We applied a probabilistic incremental lifetime cancer risk (ILCR) framework to size-resolved particulate matter in thirteen occupied micro-environments in five countries, monitored continuously at five-minute resolution within the TwinAIR pilot network, and then tested that evaluation design against the measurements it rests on. Risk was uniformly low: every site-by-fraction estimate fell below the 10⁻⁶ de minimis threshold by between one and three orders of magnitude, and the conclusion survived recomputation from the measured concentration distributions (11.2 to 353 times below the threshold across forty-two estimates) and the substitution of paediatric exposure parameters. The evaluation design did not survive. In the two rooms that received air cleaners, measured PM_2.5 rose by 7.8% and 21.0%, while a thermo-hygrometric regression explaining 1–6% of the variance—the concentration model underlying the probabilistic estimates—predicted reductions of 6.7% and 2.3%. Applying the same phase boundary to four sensors in three micro-environments that received no device produced changes from −74.3% to +37.2%, exceeding in magnitude and spanning in direction the contrast attributed to the intervention. The novelty of this work is therefore twofold: a harmonised probabilistic risk assessment of thirteen real occupied interiors on a single scale, and a demonstration, from the same network’s data, that within-room pre–post designs without concurrent controls cannot identify an air-cleaning effect.

Antimicrobial resistance (AMR) is a growing public health concern that requires surveillance approaches capable of capturing resistance circulation at the community level. Wastewater-based monitoring provides an opportunity to assess antibiotic-resistant bacteria and antimicrobial resistance genes (ARGs) beyond clinical settings. This study investigated selected bacterial indicators and ARGs in untreated urban wastewater from the municipal wastewater treatment plant of Patras, Greece. Influent wastewater samples were analysed for Escherichia coli, Pseudomonas aeruginosa and Enterococcus spp. using culture-based methods. Isolates were tested for antimicrobial susceptibility by disk diffusion and Etest, and results were interpreted according to EUCAST epidemiological cut-off values. Molecular detection of ARGs was performed by real-time PCR targeting intl1, sul1, qnrS1, blaTEM, blaVIM, vanA and ermB. A total of 16 E. coli, 13 P. aeruginosa and 17 Enterococcus spp. isolates were included in the phenotypic analysis. Among E. coli, non-wild-type profiles were detected in 14/16 isolates for meropenem and 15/16 isolates for ciprofloxacin, while only 1/16 isolates showed a non-wild-type profile for ampicillin. In contrast, all P. aeruginosa isolates were classified as wild type for meropenem but non-wild type for ciprofloxacin, while all Enterococcus spp. isolates were classified as wild type for vancomycin and ampicillin. Molecular screening showed that blaTEM was the most frequently detected gene in E. coli isolates, followed by lower detection frequencies of qnrS1, intl1 and sul1. In P. aeruginosa, intl1 and sul1 were detected in a subset of isolates, whereas blaVIM was not detected. None of the targeted ARGs were detected in Enterococcus spp. These findings highlight the potential of untreated urban wastewater as a complementary matrix for community-level AMR surveillance and support the combined use of phenotypic and molecular approaches to better characterize resistance patterns in environmental settings.

Antimicrobial resistance (AMR) is a major public health concern, and wastewater monitoring can complement clinical surveillance by capturing resistance signals at the population level. This exploratory study assessed selected antibiotic-resistant bacteria and antimicrobial resistance genes (ARGs) in untreated influent wastewater from the municipal wastewater treatment plant of Patras, Greece. Escherichia coli, Pseudomonas aeruginosa, and Enterococcus spp. were isolated using culture-based methods, tested for antimicrobial susceptibility by disk diffusion and Etest according to EUCAST epidemiological cut-off values, and screened by real-time PCR for intI1, sul1, qnrS1, blaTEM, blaVIM, vanA, and ermB. Among 16 E. coli isolates, non-wild-type (non-WT) profiles were detected on 14/16 for meropenem and 15/16 for ciprofloxacin, whereas only 1/16 was non-WT for ampicillin. All 13 P. aeruginosa isolates were wild type (WT) for meropenem but non-WT for ciprofloxacin, while all 17 Enterococcus spp. isolates were WT for vancomycin and ampicillin. Molecular screening showed that blaTEM was the most frequently detected gene in E. coli, while intI1 and sul1 were detected in subsets of P. aeruginosa isolates. No targeted ARGs were detected in Enterococcus spp. These findings provide preliminary, site-specific baseline information on selected AMR phenotypes and genetic determinants in wastewater-derived bacterial isolates from Patras.

Indoor-air research has largely examined infection, microbial ecology, immune effects and antimicrobial resistance separately, leaving the pathway from indoor biological sources to chronic respiratory outcomes insufficiently integrated. This narrative review synthesises evidence on indoor airborne pathogens and non-viable microbial components as health-relevant biological exposures beyond acute infection. Literature published between 2000 and February 2026 was reviewed from PubMed, Scopus and Web of Science, supplemented by guidance from WHO, ECDC, US EPA and ASHRAE. Viable microorganisms and non-viable components, including endotoxin, β-(1→3)-glucans, microbial DNA and extracellular vesicles, engage epithelial pattern-recognition pathways and promote inflammatory signalling. Findings included 6.5% higher TNF-α and 5% higher IL-8 per log-unit increase in fungal-spore exposure among sawmill workers; uncontrolled asthma in 45% of moisture- or mould-exposed versus 33% of non-exposed children; airborne resistance-gene and mobile-element loads of 0.55–479.44 copies/m³ in hospital departments; and a 32.8% reduction in viral diversity, but no significant reduction in high viral exposure, following classroom HEPA filtration. These findings support biological plausibility but reveal a fragmented evidence base dominated by observational studies, heterogeneous sampling and limited longitudinal exposure–response data. Indoor bioaerosols should be considered continuous exposures within the exposome, requiring research and regulation across microbiology, environmental engineering, medicine and public health.