Search Results (127)

Determining the transmission routes of pathogens in indoor environments is challenging, with most studies limited to specific case analyses and pilot experiments. When pathogens are instantaneously released by a patient in an indoor environment, the peak infection risk may not occur immediately but may instead appear at a specific moment during the pathogen’s spread. We developed a concise model to describe the temporal crest of infection risk. The model incorporates the transmission and degradation characteristics of aerosols and surface particles to predict infection risks via air and surface routes. Only four real-world outbreaks met the criteria for validating this phenomenon. Based on the available data, norovirus is likely to transmit primarily via surface touch (i.e., the fomite route). In contrast, crests of infection risk were not observed in outbreaks of respiratory diseases (e.g., SARS-CoV-2), suggesting a minimal probability of surface transmission in such cases. The new model can serve as a preliminary indicator for identifying different indoor pathogen transmission routes (e.g., food, air, or fomite). Further analyses of pathogens’ transmission routes require additional evidence. Full article

Objectives: Burkholderia cepacia complex (Bcc), a Gram-negative organism, is a well-recognized cause of hospital outbreaks, often linked to a contaminated shared source, such as multidose medications. In this study, we report an outbreak of Bcc infections in a tertiary care hospital, associated with the intrinsic contamination of a prepared solution used in interventional radiology (IR) procedures. Additionally, we provide a detailed explanation of the interventions implemented to control and interrupt the outbreak. Methods: Records from the infection control committee from 1 January 2023 to 31 October 2024 were screened to identify cases with Bcc growth in cultured blood, urine, or respiratory samples. Clinical and laboratory data were collected in March 2025. Bacterial identification was performed using conventional methods and MALDI-TOF (Bruker Daltonics, Bremen, Germany). Controls were matched to cases by ward, date of initial growth, and duration of hospitalization. Demographic and clinical data of these patients were systematically collected and analyzed. Microbiological cultures were obtained from environmental objects of concern and certain medications. Results: A total of 82 Burkholderia species were identified. We enrolled 77 cases and 77 matched controls. The source of contamination was identified in ready-to-use intravenous medications (remifentanil and magnesium preparations) in the IR department. These preparations were compounded in advance by the team and were used repeatedly. Although the outbreak originated from contaminated IV medications used in IR, secondary transmission likely affected 28 non-IR patients via fomites, shared environments, and possible lapses in isolation precautions. The mortality rate among the cases was 16.9%. Infection with Bcc was associated with prolonged intensive care unit stays (p = 0.018) and an extended overall hospitalization duration (p < 0.001); however, it was not associated with increased mortality. The enforcement of contact precautions and comprehensive environmental decontamination successfully reduced the incidence of the Bcc outbreak. No pathogens were detected in cultures obtained after the disinfection. Conclusions: The hospital transmission of Bcc is likely driven by cross-contamination, invasive medical procedures, and the administration of contaminated medications. Implementing stringent infection control measures such as staff retraining, updated policies on medication use, enhanced environmental decontamination, and strict adherence to isolation precautions has proven effective in curbing the spread of virulent and transmissible Bcc. Full article

Enteroviruses of the Picornaviridae family are transmitted primarily by the fecal–oral route. Transmission may occur following hand contact with contaminated fomites and subsequent ingestion of virus conveyed to the mouth by the contaminated hand. The persistence of these viruses on fomites likely plays a role in this transmission scenario. Six echoviruses (1, 2, 3, 5, 6, and 7) that cause frequently reported clinical cases in the United States were studied, along with poliovirus type 1 vaccine strain LSc-2ab. The infectivity half-lives of the enteroviruses deposited on vinyl tile coupons in a 10% fecal solution ranged from 1.7 to 12.6 h. The echovirus serotypes most commonly associated with reported infections persisted longer on the vinyl tiles than the less commonly reported types. This increased persistence on surfaces may favor the transmission of these echoviruses through the fecal–oral route. These results inform the future selection of appropriate model enteroviruses for challenging newly formulated and eco-friendly disinfectants or other strategies in infection prevention and control for enteroviruses. Full article

Microplastic particles (MPs) are an emerging global pollutant of increasing concern due to their widespread occurrence, persistence, and multifaceted impact on aquatic ecosystems. This study provides a comprehensive review of peer-reviewed literature from 2011 to 2025, analysing the presence, distribution, and microbiological associations of MPs in surface waters across five continents. The findings confirm that MPs are present in both marine and freshwater systems, with concentrations varying by region, hydrology, and proximity to anthropogenic sources. Polyethylene and polypropylene were identified as the most common polymers, often enriched in river mouths, estuaries, and aquaculture zones. A key focus of this review is the plastisphere—microbial biofilms colonizing MPs—which includes both environmental and pathogenic bacteria such as Vibrio, Pseudomonas, and Acinetobacter. Notably, MPs serve as vectors for the spread of antibiotic resistance genes (ARGs), including sul1, tetA and ermF, and β-lactamase genes like blaCTX-M. This highlights their role in enhancing horizontal gene transfer and microbial dissemination. The results emphasize the need for standardized monitoring protocols and further interdisciplinary research. In light of the One Health approach, understanding the microbial dimension of MP pollution is essential for managing risks to environmental and public health. Full article

Background: Reusable tourniquets are commonly used to aid venipuncture and blood collection. However, inadequate disinfection may lead to bacterial contamination and increase the risk of healthcare-associated infections (HAIs). Tourniquets can function as fomites, facilitating the spread of pathogenic bacteria. This study assessed microbial contamination of reusable tourniquets in the emergency department and operating theatre, focusing on clinically relevant HAI-associated pathogens. Methods: Tourniquets from four hospital departments (emergency: adult observation and resuscitation; surgical theatres: pediatric and adult general surgery) were sampled at three time points (n = 12). DNA was extracted and analyzed via 16S rRNA sequencing using NGS technology to identify microbial contamination and taxonomic composition. Results: Sequencing revealed 131 bacterial species across the 12 tourniquets, including clinically important pathogens. Among the top ten HAI-associated groups, Klebsiella spp. were detected in 5/12 samples, Enterococcus spp. in 9/12, Staphylococcus aureus in 1/12, Pseudomonas aeruginosa in 9/12, and Acinetobacter spp. in 10/12. No Escherichia coli, Clostridium difficile, coagulase-negative staphylococci, Proteus spp., or Enterobacter spp. were found. Emergency department tourniquets showed higher bacterial loads; operating theatres had greater species diversity. Conclusions: Reusable tourniquets harbor significant bacterial contamination. Considering disinfection challenges and the lack of guidelines, single-use tourniquets should be considered to reduce HAI risk. Full article

The transmission of infectious diseases via the use of public restrooms has been previously documented. The goal of this study was to compare bacterial contamination in public vs. household restrooms and, using quantitative microbial risk assessment (QMRA), to assess the probability of infection from fomite contact with selected high-touch sites within the restrooms. Fomite surfaces in four public and four household restrooms were sampled over a period of two months. The public restrooms were in an office building occupied by 80 individuals and were considered moderate usage. The toilet seat, toilet flush handle, countertops, and floor were sampled for heterotrophic, coliform, and Escherichia coli bacteria. The highest numbers of heterotrophic bacteria and coliforms were detected on the countertops, followed by the floor. The greatest numbers of E. coli were recovered from the countertops in the household restroom, but the greatest numbers in the public restroom were recovered from the toilet flush handle. Numbers of heterotrophic bacteria and coliforms were 10 to 100 times greater in household restrooms than in public restrooms. The QMRA suggested that the greatest risk of acquiring a norovirus infection involved the touching of the countertops in household restrooms and the toilet flush handles in public restrooms. Full article

Trichomonas tenax is an anaerobic flagellate usually found in the oral cavity of humans and domestic animals. It is very likely to be transmitted through kissing, sharing saliva, contaminated utensils, and water. However, research on its transmission dynamics is scarce. Hence, there is a need to identify potential knowledge gaps in T. tenax transmission for future research and emphasize the importance of the One Health approach in controlling the spread of this flagellar protozoan. Trichomonas tenax has been found in humans, dogs, cats, horses, and birds at various body sites, including the lungs and the urogenital tract, in addition to the oral cavity. Its transmission is influenced by environmental factors such as temperature and socioeconomic factors such as age, income, smoking, and public awareness, along with poor oral hygiene and systemic diseases. Direct host-to-host transmission also plays an important role; however, transmission through fomites or contaminated water still needs to be scientifically proven to gain a better understanding of these mechanisms. More studies on this flagellate are warranted, especially using animal models and epidemiological studies, to better understand its transmission dynamics. Prioritizing research in these areas could result in a more comprehensive understanding of T. tenax transmission dynamics and the factors that influence it, ultimately aiding in the development of effective control and prevention strategies. It is also recommended to encourage collaboration between medical and veterinary professionals in addressing this zoonotic protozoan, recognizing that it aligns with the One Health approach. Full article

The dynamic relationship between microplastics (MPs) in the air and on the Earth’s surface involves both natural and anthropogenic forces. MPs are transported from the ocean to the air by bubble scavenging and sea spray formation and are released from land sources by air movements and human activities. Up to 8.6 megatons of MPs per year have been estimated to be in air above the oceans. They are distributed by wind, water and fomites and returned to the Earth’s surface via rainfall and passive deposition, but can escape to the stratosphere, where they may exist for months. Anthropogenic sprays, such as paints, agrochemicals, personal care and cosmetic products, and domestic and industrial procedures (e.g., air conditioning, vacuuming and washing, waste disposal, manufacture of plastic-containing objects) add directly to the airborne MP load, which is higher in internal than external air. Atmospheric MPs are less researched than those on land and in water, but, in spite of the major problem of a lack of standard methods for determining MP levels, the clothing industry is commonly considered the main contributor to the external air pool, while furnishing fabrics, artificial ventilation devices and the presence and movement of human beings are the main source of indoor MPs. The majority of airborne plastic particles are fibers and fragments; air currents enable them to reach remote environments, potentially traveling thousands of kilometers through the air, before being deposited in various forms of precipitation (rain, snow or “dust”). The increasing preoccupation of the populace and greater attention being paid to industrial ecology may help to reduce the concentration and spread of MPs and nanoparticles (plastic particles of less than 100 nm) from domestic and industrial activities in the future. Full article

Autochthonous Chagas disease remains a health risk for humans in Latin American countries but is rarely found among residents of the United States (US), despite the presence of competent insect vectors and small mammal reservoirs of Trypanosoma cruzi in the lower two-thirds of the US. This report discusses the differences in the rates of autochthonous Chagas disease in Latin America and the US. The key to the differences may lie in the mode (or means) of transmission of parasites to humans. In both Latin America and the US, the so-called vectorial transmission of Chagas disease to humans is the mode of acquisition accepted by most authorities. This mode involves the improbable combination of an infected kissing bug defecating near the mouth or eyes or the site of the bite, followed by the bite victim rubbing infected feces into the wound site or mucous membranes. Outbreaks of Chagas disease due to fecal–oral contamination, known as oral Chagas, have been recorded in Latin America for decades, and at present, oral Chagas is the predominant mode of infection recognized in Brazil. It is perhaps time to consider fecal–oral transmission in its many manifestations as a risk factor for Chagas disease in the US rather than reflexively invoking vectorial transmission. Fecal–oral transmission includes contamination of food and drink by triatomine feces and infection via contaminated fomites and surfaces at home and at worksites, as well as transmission from infected small mammals and other routes discussed in this report. Full article

Restrooms are associated with the transmission of bacterial and viral illnesses. Disinfecting contaminated surfaces is associated with reducing transmission risk. The goal of this study was to determine how cleaning/disinfecting frequency affects restroom pathogen contamination. The Phase 1 intervention included cleaning toilet surfaces (the toilet bowl, water, and rim) using 9.5% w/w hydrochloric acid. The Phase 2 intervention used fomite-specific products to clean/disinfect additional restroom surfaces, including the vanity countertop, sink faucet handle, toilet seat, flush handle, floor, and doorknob. A designated household member was responsible for cleaning/disinfecting surfaces at the beginning of each interval. Fomite sample collection was randomized, and samples were tested for heterotrophic, coliform, and Escherichia coli bacteria after specified intervals: 1, 2, 3, or 7 days. The greatest numbers of bacteria and largest reductions occurred on fomites after three days. A statistically significant difference was found for heterotrophic bacteria (p = 0.009), coliforms (p = 0.10), and E. coli (p = 0.13) with cleaning/disinfecting every three days. A quantitative microbial risk assessment (QMRA) estimated a >98% reduction in risk of infection by norovirus with an every-3-day cleaning/disinfection routine on the most heavily contaminated sites. Results indicate an optimal cleaning frequency of twice weekly for minimizing exposure to pathogens. Full article

In 2011–2013, we isolated and characterized small ruminant lentiviruses (SRLVs) from two flocks, one of goats and the other of sheep, that had never been in direct contact. Phylogenetic analysis of these viruses indicated a common origin, which led us to hypothesize indirect transmission of these viruses between the two flocks. Since, to our knowledge, there are no published data on the tenacity of these viruses, we started this work. In the first part, we monitored the loss of infectivity of two prototypic SRLV strains, MVV 1514 and CAEV-CO, over time, in liquid suspension. As expected, the suspensions stored at 4 °C better preserved the infectivity of the viruses. Additionally, viruses resuspended in milk, the medium mirroring the in vivo situation, proved more tenacious than those maintained in a cell culture medium. These viruses, subjected to harsh treatments such as drying and resuspending, partially maintained their replication capacity. After an immediate loss of nearly 1 log₁₀ TCID₅₀ immediately after desiccation, the viruses maintained their replication capacity for at least three weeks when desiccated in milk. These results suggest that fomites, clothing, or pastures contaminated with secretions or milk from infected animals might mediate the infection of animals independently of direct contact. Full article

The increasing need for effective antiviral strategies has led to the development of innovative surface coatings to combat the transmission of viruses via fomites. The aim of this review is to critically assess the efficacy of antiviral coatings in mitigating virus transmission, particularly those activated by visible light. The alarm created by the COVID-19 pandemic, including the initial uncertainty about the mechanisms of its spread, attracted attention to fomites as a possible source of virus transmission. However, later research has shown that surface-dependent infection mechanisms need to be carefully evaluated experimentally. By briefly analyzing virus–surface interactions and their implications, this review highlights the importance of shifting to innovative solutions. In particular, visible-light-activated antiviral coatings that use reactive oxygen species such as singlet oxygen to disrupt viral components have emerged as promising options. These coatings can allow for obtaining safe, continuous, and long-term active biocidal surfaces suitable for various applications, including healthcare environments and public spaces. This review indicates that while the significance of fomite transmission is context-dependent, advances in material science provide actionable pathways for designing multifunctional, visible-light-activated antiviral coatings. These innovations align with the lessons learned from the COVID-19 pandemic and pave the way for sustainable, broad-spectrum antiviral solutions capable of addressing future public health challenges. Full article

The effectiveness of copper-based composites, specifically cupric ion (Cu²⁺)-modified phyllosilicate minerals, was evaluated in reducing the concentration of infectious agents in the environment while minimizing metal ion release. The phyllosilicate minerals, vermiculite, exfoliated and unexfoliated, and sepiolite, all modified with Cu²⁺, were compared with copper oxide for their antiviral activity against non-enveloped porcine parvovirus (PPV) and enveloped human coronavirus 229E (HCoV). Sepiolite effectively removed PPV and HCoV from the solution, regardless of Cu²⁺ presence, while vermiculite showed substantial viral clearance only when Cu²⁺ was present. The kinetics of viral clearance was fast, with complete clearance within one hour in many cases. To better understand the mechanism of virus clearance, EDTA was added at different times during the clearance study for PPV. EDTA prevented virus clearance in all vermiculite samples, whereas sepiolite containing copper still demonstrated substantial virus clearance. The addition of BSA before the virus binding was able to block binding in all cases. It was determined that binding is the key mechanism, and PPV can be eluted from the minerals with EDTA and still be infectious. This study provides the potent antiviral mechanisms of Cu²⁺-modified phyllosilicate minerals, offering insights for designing paints and plastics for high-touch surfaces to reduce viral transmission and enhance public health significantly. Full article

Trypanosoma vivax infection is an emerging condition that causes damage and mortality among cattle and is transmitted by mechanical vectors or contaminated fomites. This disease has been spreading in southern Brazil, causing anemia, weight loss, diarrhea, abortion, and infertility; however, its behavior and host–parasite relationships are not yet fully understood. To clarify this issue, animals that presented clinical signs were subjected to an immunochromatographic screening test. An indirect immunofluorescence test was then performed on samples collected before treatment (the gold standard test), which showed that in the herd of 20 cows, we had 14 seropositive for T. vivax. Blood samples were collected before and after treatment to study the effects of the disease and treatment, with the cows divided into two groups: infected and uninfected. Cows were evaluated for hematologic, biochemical, and antioxidant responses, comparing them with uninfected and infected animals, as well as pre- and post-treatment (isometamidium chloride—1 mg/kg body weight [BW]). There was no difference (p > 0.05) between groups in milk production and feed intake; however, ten days after treatment, there was an increase of 1.72 kg of milk in cows diagnosed as infected with T. vivax. Seropositive cows had lower erythrocyte counts, hemoglobin concentrations, hematocrit, platelet counts, and lymphocyte and granulocyte counts. In seropositive cows, the higher total protein concentration is due to increased globulins, which the protein profile by electrophoresis showed to be related to higher levels of immunoglobulins (IgA and other heavy-chain immunoglobulins), ceruloplasmin, haptoglobin, ferritin, C-reactive protein; associated with lower transferrin levels. The activity of the enzymes aspartate aminotransferase, gamma-glutamyl transferase, cholinesterases, and creatine kinase were compared in seronegative and seropositive cows for T. vivax. Lower serum calcium levels were observed in seropositive cows. Cows diagnosed with trypanosomosis presented high levels of reactive oxygen species, lipid peroxidation, protein oxidation, nitrite/nitrate activity, superoxide dismutase, and glutathione peroxidase. The enzymes catalase and glutathione S-transferase presented lower activity in the blood of seropositive cows compared to the control on the day of diagnosis, which was no longer observed ten days after treatment. The animals exhibited hypogalactia, anemia, thrombocytopenia, leukopenia, and acute phase response accompanied by liver and muscle tissue damage and oxidative stress, demonstrating the effect of T. vivax infection in naturally infected Jersey cows. Full article

Resuspended particles from human activities can contribute to pathogen exposure via airborne fomite contamination in built environments. Studies investigating the dissemination of resuspended viruses are limited. The goal of this study was to explore viral dissemination after aerosolized resuspension via human activities on indoor flooring. Nylon carpet or wood flooring was seeded with virus (MS2) or virus laden dust then evaluated after activities, i.e., walking and vacuuming. Statistically significant differences were found in dispersal of virus laden dust after vacuuming carpet (p-value = 5.8 × 10⁻⁶) and wood (p-value = 0.003, distance > 12 in/30 cm). Significant differences were also found between floor materials and virus laden dust dispersal vacuuming (p = 2.09 × 10⁻⁵) and walking (p = 2.68 × 10⁻²). A quantitative microbial risk assessment (QMRA) scenario using Norovirus and a single fomite touch followed by a single hand-to-mouth touch indicated a statistically significant difference associated with virus laden dust particles and vacuuming carpet(p < 0.001). Infection risks were 1 to 5 log₁₀ greater for dust exposure. The greatest risk reductions from fomites were seen across vacuuming carpet no-dust scenarios for surfaces <30 cm from flooring. More research is needed to determine the role resuspension plays in exposure and transmission of potentially infectious agents. Full article