Potential Transmission Routes Research Articles

Distribution of Clostridioides difficile ribotypes and sequence types across humans, animals and food in thirteen European countries

Clostridioides difficile is a One Health pathogen found in humans, animals, and environment, with food representing a potential transmission route. One Health studies are often limited to single country or selected reservoirs and ribotypes. This study provides a varied and accessible collection of C. difficile isolates and sequencing data derived from human, animal, and food sources across thirteen European countries. A total of 441 strains (human hospital and community associated cases n = 280, animal n = 96, food n = 65) were analysed by ribotyping, toxinotyping and whole genome sequencing (WGS). We detected 83 sequence types (STs), with ST11 (n = 80 isolates) and ST1 (n = 54 isolates) being the most represented. Several STs included strains originating from all source combinations. Further genomic analysis confirmed close genetic relatedness in some of the STs. Additionally, genomic analysis identified ten strains from cryptic clades (C-I to C-III) and four of them were mono-toxigenic possessing only a variant form of tcdA gene. Amongst 106 ribotypes, ten were shared between all three sources and 68 were source specific. Some ribotypes were only found at intersection of human and food source (RT023, RT027), or between human and animal source (RT009, RT045, RT046). C. difficile ribotypes and STs in Europe were diverse. In this collection some ribotypes showed potential association with food or animal transmission routes. C. difficile strains from divergent clades CI-III, currently emerging in human population, were rare and mostly food associated.

Microbial community dynamics in blood, faeces and oral secretions of neotropical bats in Casanare, Colombia

Bats are known reservoirs for a wide range of pathogenic microorganisms, including viruses, bacteria, fungi, helminths, and protozoa, which can be transmitted and infect other zoonotic organisms. Various studies have utilised next-generation sequencing (NGS) to describe the pathogens associated with bats. Although most have characterised microbial communities in specific body fluids, few have analysed the composition and diversity of these microbial communities across different body fluids at the individual level. In this study, we employed two next-generation sequencing techniques: amplicon-based sequencing of the V4 hypervariable region of the 16S- and 18S-rRNA genes and viral metagenomics, to describe the prokaryotic, eukaryotic, and viral communities present in blood, faeces, and oral swab samples collected from two genera of bats (Carollia and Phyllostomus) in the department of Casanare, eastern Colombia. A total of 60 samples corresponding to the three bodily fluids were processed and analysed. The results indicated that the microbial communities across the body fluids were mainly composed of bacteria, fungi, protozoa, and various DNA and RNA viruses, showing a variability of microbial genera and species. The abundances, diversity metrics, and correlations of these microorganisms displayed patterns associated with bat genus and body fluids, suggesting that the ecological characteristics of these microbial communities may be influenced by the ecological and physiological traits of the bats. Additionally, we found similar community compositions of bacteria, some fungal genera, and viruses in the three body fluids, indicating a possible circulation of these microbes within the same bat. This could be due to microbial movement from the gut microbiota to other physiological systems or transmission via blood-feeding vectors. Furthermore, our results revealed the presence of various microbes of public health concern, including Bartonella spp., Mannheimia haemolytica, Rhodotorula spp., Piroplasmida spp., Toxoplasma gondii, Alphacoronavirus spp., and Bat circovirus. The abundance of these pathogenic microbial species across the three bodily fluids suggests potential transmission routes from bats to other organisms, which may contribute to the emergence of zoonotic disease outbreaks. These findings highlight the variability of microorganisms present within the same bat and the different pathogen-host interactions that may regulate the presence and transmission of these zoonotic microbes. Further research is required to elucidate the genomic features, ecological interactions, and biological activities of these microbial communities in bats.

Amphimeriasis in Ecuador-Prevalence, Knowledge, and Socio-Cultural Practices Among Indigenous Chachi and Montubios Populations: A Mixed-Methods Cross-Sectional Study.

Amphimerus, a liver fluke, is the causative agent of amphimeriasis, a foodborne disease acquired thought the consumption of infected raw or undercooked river fish-a practice embedded in traditional culinary customs. Amphimeriasis represents a significant public health issue and has been endemic in Ecuador since 2011, particularly among the Chachi Amerindians and Montubios populations residing in tropical ecoregions. By employing a mixed-methods research design, we conducted a community-based, cross-sectional study. A survey comprising of 63 questions on KAP was administrated in person to community members, health personnel, and academic staff in the two populations. Additionally, 67 semi-structured interviews were performed. Microscopy was achieved on 273 human and 80 dog fecal samples to detect Amphimerus eggs. A total of 86 questionnaires (54 Chachi) and 67 interviews (44 Chachi), out of 300 residents, were completed. Among the respondents, 31.4% were aware of Amphimerus, locally referred to as "liver worm". Although 79.1% reported not consuming raw fish, most admitted eating raw fish with lime juice and salt, a preparation known as "curtido", and 59.3% reported consuming smoked fish. Here, 86.1% of participants considered "liver worm" a serious disease, and 55.8% recognized raw or marinated fish as a potential transmission route. The Chachi showed a preference for smoked fish, whereas the Montubios favoured "curtido". The prevalence of Amphimerus infection was 23% in humans and 16.2% in dogs. Differences in KAP were observed between infected and non-infected individuals. Local health and academic personnel demonstrated insufficient knowledge about amphimeriasis. Some religious individuals refrained from participating, stating that they were "with God". Despite the high prevalence of Amphimerus infection in both humans and dogs, knowledge about the parasite, the disease, and its transmission routes remains limited. Health education initiatives should be designed to modify the population's KAP. It is crucial for national and local health authorities, as well as religious leaders, to be informed and actively involved in the prevention and control of amphimeriasis.

Antibiotic resistance genes are transferred from manure-contaminated water bodies to the gut microbiota of animals through the food chain

Fecal-contaminated water may enter the food chain and become an important route for the transmission of antibiotic resistance genes (ARGs) to the human microbiome. However, little is known about the spread of ARGs from fecal contamination in water bodies along the aquatic food chain. In this study, laboratory-raised Daphnia magna and Aristichthys nobilis were used to investigate the effects of the addition of manure on target ARGs in water and their intestinal contents to determine the potential transmission route of ARGs in the aquatic food chain system. The abundance of target ARGs in water as well as D. magna and A. nobilis intestinal contents significantly increased when fecal contamination was present. ARGs bioaccumulated along the food chain, with four ARGs (tetM-01, tetX, qnrS, and sul2) detected regularly. Mn and Cr were key environmental factors that promoted the transfer of ARGs along the food chain. Fecal addition significantly changed the structure of microbial communities in water, D. magna gut, and A. nobilis gut. The ARG spectrum was significantly correlated with the composition and structure of the bacterial community. Proteobacteria, Bacteroidetes, and Firmicutes were identified as the main host bacteria and were likely to act as carriers of ARGs to promote the spread of antibiotic resistance in the food chain. The composition and structure of bacterial communities, along with mobile genetic elements, were two key drivers of ARG transfer. These findings provide new insights into the distribution and spread of ARGs along the freshwater food chain.

Seroprevalence of Rickettsia Spp. and Orientia tsutsugamushi in Indigenous Populations from the Sierra Nevada de Santa Marta, Colombia.

Background: Rickettsia spp. are vector-borne zoonotic pathogens that cause febrile illness in humans. Rickettsioses is not included in the Colombian national surveillance system and is subsequently expected to be underreported. This cross-sectional study aimed to determine the seroprevalence of Rickettsia spp. and the closely related Orientia tsutsugamushi in two indigenous populations residing in the Sierra Nevada de Santa Marta, Colombia. Materials and Methods: Serum samples (n = 539) were collected from the Wiwa and Koguis people between 2021 and 2022. Serum samples were screened for spotted fever group (SFG) and typhus group (TG) Rickettsia spp. using the Fuller laboratories Rickettsia IgG IFA kit and for O. tsutsugamushi with the Scrub Typhus Detect™ IgG ELISA. Results: We observed an overall seroprevalence of 26.2% (95% confidence interval [CI] 22.5-30.1] for Rickettsia spp. of the SFG, 5.4% (95% CI 3.6-7.6) for Rickettsia spp. of the TG and 4.3% (95% CI 2.7-6.3) for O. tsutsugamushi. Common risk factors for zoonotic disease infections were assessed for 147 of the Wiwa participants. Increased odds of seropositivity for SFG Rickettsia spp. were observed for Wiwa participants who cared for livestock, including assisting with the birth of cattle (odds ratio [OR] = 8.85; 95% CI 1.54-50.90; p = 0.015) and goats (OR = 7.60; 95% CI 1.70-33.90; p = 0.008). Conclusions: These results highlight a notable exposure to Rickettsia spp., especially the SFG, in rural Colombia. Together with recent reports of high mortality for Rocky Mountain Spotted Fever in nearby regions of South America, more detailed investigations focusing on improving knowledge and awareness as well as "One Health" and "causes-of-fever" studies are needed. The characterization of Rickettsia spp. infections in humans, livestock, and tick vectors with their potential transmission routes could make a high impact on these easily treatable diseases.

Genome-scale analysis of Mycobacterium avium complex isolates from Portugal reveals extensive genetic diversity

Opportunist infections caused by nontuberculous mycobacteria (NTM) have emerged as a significant public health problem. Among these, species of the Mycobacterium avium complex (MAC) are the main responsible for the increase in the number of human disease cases. In order to address the current needs in the detection and surveillance of MAC disease cases, we evaluated different species classification methodologies (BLASTn-based marker-gene approach, Kraken v2, rMLST and MLST databases) and their congruence with a core-SNP phylogenetic approach, based on whole genome sequencing (WGS) data. For this purpose, we used a collection of 142 MAC isolates from Portuguese patients diagnosed between 2014 and 2022. The marker-gene approach (based on the rpoB, hsp65 and groEL genes), showed the best results, allowing the identification of the 142 MAC isolates to the species/subspecies level (M. avium subsp. hominissuis, M. intracellulare, M. intracellulare subsp. chimaera, M. intracellulare subsp. yongonense, M. marseillence and M. colombiense). Additionally, we performed drug susceptibility testing that confirmed clarithromycin efficacy as a first-line treatment for MAC disease, as 93 % of the Portuguese isolates were susceptible. Using a core-SNP approach we also performed an in-depth phylogenetic analysis within each identified species group, and despite the high genetic diversity within the MAC species, we were able to clearly distinguish all the species/subspecies and identify genetic clusters with epidemiological potential.We highlight not only the need for the standardization of an appropriate genotyping approach for species identification and management of MAC disease, but also a more robust large-scale WGS data analysis, in a One Health perspective, in order to identify potential routes of transmission.

Spatiotemporal Data Modelling for Epidemiological Research in Hospitals.

Nosocomial infections are a great source of concern for healthcare organizations. The spatial layout of hospitals and the movements of patients play significant roles in the spread of outbreaks. However, the existing models are ad-hoc for a specific hospital and research topic. This work shows the design of a data model to study the spread of infections among hospital patients. Its spatial dimension describes the hospital layout with several levels of detail, and the temporal dimension describes everything that happens to the patients in the form of events, which can relate to the spatial dimension. The model is meant to be sufficiently general to fit any hospital layout and to be used for different epidemiological research topics. We proved the model's suitability by defining six queries based on patients' movements and contacts that could assist in several epidemiological research tasks, such as discovering potential transmission routes. The model was implemented as an RDF* knowledge graph, and the queries were in SPARQL*. Finally, we designed two experiments in which two outbreaks of Clostridium difficile were analyzed using several queries (four in the first experiment and two in the second) on a knowledge graph (105,000 nodes, 185,000 edges) with synthetic data.

Sequence Types and Antimicrobial Resistance Profiles of Salmonella Typhimurium in the Food Chain in Singapore.

Salmonella remains a significant foodborne pathogen globally with S. Typhimurium presenting as a frequently occurring serovar. This study aimed to characterize 67 S. Typhimurium isolates from humans, food, farms, and slaughterhouses collected in Singapore from 2016 to 2017. Using whole-genome sequencing analysis, the isolates were found to belong to either ST19 (n = 33) or ST36 (n = 34). ST36 predominated in human intestinal and chicken isolates, while human extra-intestinal and non-chicken food isolates belonged to ST19. Plasmids were predicted in 88.1% (n = 59) of the isolates with the most common incompatibility group profiles being IncFIB(S), IncFII(S) and IncQ1. IncFIB(S) (adjusted p-value < 0.05) and IncFII(S) (adjusted p-value < 0.05) were significantly more prevalent in ST19 isolates, while Col156 (adjusted p-value < 0.05) was more significantly found in ST36 isolates. ST36 isolates exhibited higher resistance to multiple antibiotic classes such as penicillins, phenicols, folate pathway inhibitors, aminoglycosides, β-lactam/β-lactamase inhibitor combinations, tetracyclines, and fluoroquinolones. Phylogenetics analysis suggested potential shared routes of transmission among human, chicken, farm and slaughterhouse environments. Taken together, this study offers a cross-sectional epidemiological insight into the genomic epidemiology and antimicrobial landscape of S. Typhimurium isolates in Singapore, informing strategies for future public health and food safety surveillance.

Detection of novel orthoparamyxoviruses, orthonairoviruses and an orthohepevirus in European white-toothed shrews.

While the viromes and immune systems of bats and rodents have been extensively studied, comprehensive data are lacking for insectivores (order Eulipotyphla) despite their wide geographic distribution. Anthropogenic land use and outdoor recreational activities, as well as changes in the range of shrews, may lead to an expansion of the human-shrew interface with the risk of spillover infections, as reported for Borna disease virus 1. We investigated the virome of 45 individuals of 4 white-toothed shrew species present in Europe, using metagenomic RNA sequencing of tissue and intestine pools. Moderate to high abundances of sequences related to the families Paramyxoviridae, Nairoviridae, Hepeviridae and Bornaviridae were detected. Whole genomes were determined for novel orthoparamyxoviruses (n=3), orthonairoviruses (n=2) and an orthohepevirus. The novel paramyxovirus, tentatively named Hasua virus, was phylogenetically related to the zoonotic Langya virus and Mòjiāng virus. The novel orthonairoviruses, along with the potentially zoonotic Erve virus, fall within the shrew-borne Thiafora virus genogroup. The highest viral RNA loads of orthoparamyxoviruses were detected in the kidneys, in well-perfused organs for orthonairoviruses and in the liver and intestine for orthohepevirus, indicating potential transmission routes. Notably, several shrews were found to be coinfected with viruses from different families. Our study highlights the virus diversity present in shrews, not only in biodiversity-rich regions but also in areas influenced by human activity. This study warrants further research to characterize and assess the clinical implications and risk of these viruses and the importance of shrews as reservoirs in European ecosystems.

Comprehensive Metatranscriptomic Analysis of Plant Viruses in Imported Frozen Cherries and Blueberries.

The possibility of new viruses emerging in various regions worldwide has increased due to a combination of factors, including climate change and the expansion of international trading. Plant viruses spread through various transmission routes, encompassing well-known avenues such as pollen, seeds, and insects. However, research on potential transmission routes beyond these known mechanisms has remained limited. To address this gap, this study employed metatranscriptomic analysis to ascertain the presence of plant viruses in imported frozen fruits, specifically cherries and blueberries. This analysis aimed to identify pathways through which plant viruses may be introduced into countries. Virome analysis revealed the presence of six species of plant viruses in frozen cherries and blueberries: cherry virus A (CVA), prunus necrotic ringspot virus (PNRSV), prune dwarf virus (PDV), prunus virus F (PrVF), blueberry shock virus (BlShV), and blueberry latent virus (BlLV). Identifying these potential transmission routes is crucial for effectively managing and preventing the spread of plant viruses and crop protection. This study highlights the importance of robust quality control measures and monitoring systems for frozen fruits, emphasizing the need for proactive measures to mitigate the risk associated with the potential spread of plant viruses.

Optimal control analysis for the Nipah infection with constant and time-varying vaccination and treatment under real data application

In the last two decades, Nipah virus (NiV) has emerged as a significant paramyxovirus transmitted by bats, causing severe respiratory illness and encephalitis in humans. NiV has been included in the World Health Organization’s Blueprint list of priority pathogens due its potential for human-to-human transmission and zoonotic characteristics. In this paper, a mathematical model is formulated to analyze the dynamics and optimal control of NiV. In formulation of the model we consider two modes of transmission: human-to-human and food-borne. Further, the impact of contact with an infected corpse as a potential route for virus transmission is also consider in the model. The analysis identifies the model with constant controls has three equilibrium states: the NiV-free equilibrium, the infected flying foxes-free equilibrium, and the NiV-endemic equilibrium state. Furthermore, a theoretical analysis is conducted to presents the stability of the model equilibria. The model fitting to the reported cases in Bangladesh from 2001 to 2015, and the estimation of parameters are performed using the standard least squares technique. Sensitivity analysis of the model-embedded parameters is provided to set the optimal time-dependent controls for the disease eradication. The necessary optimality conditions are derived using Pontryagin’s maximum principle. Finally, numerical simulation is performed to determine the most effective strategy for disease eradication and to confirm the theoretical results.

North American crayfish harbour diverse members of the Nudiviridae

Three novel crayfish-infecting nudiviruses from crayfish in North America represent the first genomic confirmation of nudiviruses in crayfish: Faxonius propinquus nudivirus (FpNV), Faxonius rusticus nudivirus (FrNV), and Faxonius virilis nudivirus (FvNV). Histopathology and electron microscopy revealed nuclear infections, including nuclear hypertrophy in hepatopancreatic epithelial cells and the presence of membrane-bound bacilliform virions. Metagenomic sequencing resulted in complete circular genome assembly, and phylogenetic analyses (based on nudivirus core genes) placed these viruses within the unofficial Epsilonnudivirus genus. One of the nudiviruses was detected in the antennal gland of its host, and another is correlated with invasive crayfish decline in one infected lake ecosystem - suggesting a potential route for viral transmission through water, and possible population level impact. This study highlights the importance of genomic and ecological data in elucidating the diversity and evolutionary relationships of the Nudiviridae, while expanding their known diversity and range of host species.

Use of Whole Genome Sequencing for Investigation of Potential Hospital-Acquired Vancomycin Resistant Enterococcus

Background: Whole genome sequencing (WGS) is a relatively new method for analyzing outbreaks and modes of transmission, particularly for multidrug resistant bacteria. This study sought to investigate clusters of patients with genetically related Vancomycin-Resistant Enterococcus spp. (VRE) bacteremia for shared hospital environmental exposures. Methods: All VRE blood culture isolates from patients from July 1, 2021 to June 30, 2022 underwent Illumina WGS. Core single nucleotide polymorphisms (SNPs) were identified, and multi-locus sequence typing (MLST) was performed across the VRE isolates. Clusters were defined as isolates with 15 or fewer core genome SNPs and were investigated for potential transmission routes. For each cluster, patients were evaluated in the 12 weeks before and after the first VRE isolate for shared hospital environmental exposures (hospital unit, patient rooms, procedural rooms, and radiology suites). Hospital units were comprised of patient rooms located geographically together on the same floor of the hospital. Results: A total of 82 VRE isolates underwent WGS. Thirty-eight (46%) clustered genetically with at least one other isolate. Clusters included 2 to 15 patients per group and represented 10 distinct MLST subgroups (Figure 1). Nine hundred and thirty-nine hospital environmental exposures were identified across the 38 patients. For each cluster, there was a total of 341 (36.3%) shared exposures. Shared environmental exposures occurred in radiology suites (35, 38.5%), patient rooms (32, 35.6%) and procedural rooms (23, 25.6%). Of the patients who shared the same hospital unit, 10 (31.3%) had the same patient room with 7 (70%) of them being in the emergency department (ED). Overall, the ED represented 7 (21.9%) of the shared hospital units. Each cluster had at least one shared hospital environmental exposure found. Conclusions: Use of WGS can help investigate outbreak clusters of resistant organisms such as VRE. In this study, nearly half of all VRE blood isolates were able to be segregated into clusters with at least one other isolate. Although VRE colonization of hospital rooms is well described, patient rooms represented the smallest proportion of shared hospital environmental exposures. This study thus suggests other environmental transmission routes such as radiology suites and procedural rooms warrant closer investigation.

Exploring viral contamination in urban groundwater and runoff

The reliance of the global population on urban aquifers is steadily increasing, and urban aquifers are susceptible to pathogenic contamination through sources such as sewer leakage or urban runoff. However, there is insufficient monitoring of groundwater quality in urban areas. In this study, quantitative polymerase chain reaction (qPCR) was employed to evaluate the presence of human fecal viral indicators and viral pathogens in urban wastewater (n = 13) and groundwater (n = 12) samples from four locations in Barcelona with different degrees of urbanization, as well as in runoff samples (n = 2). Additionally, a target enrichment sequencing (TES) approach was utilized to explore the viral diversity within groundwater and runoff samples, offering insights into viral contamination and potential virus transmission routes in urban areas.Human adenovirus (HAdV) was identified in all wastewater samples, 67 % (8/12) of groundwater samples, and one runoff sample by qPCR indicating human viral fecal contamination. The viral pathogen Norovirus genogroup GI (NoV GI) was detected in wastewater and two winter groundwater samples from highly and medium urbanized areas. NoV genogroup GII (NoV GII), Enterovirus (EV) and SARS-CoV-2 were exclusively detected in wastewater. Human and other vertebrate viruses were detected in groundwater and runoff samples using TES. This study gives insights about the virome present in urban water sources, emphasizing the need for thorough monitoring and deeper understanding to address emerging public health concerns.

Environmental monitoring of a freezing tunnel and its close surroundings in the potato processing industry: Insights into Listeria monocytogenes contamination, cleaning and disinfection efficacy, and transmission risks

Produce is a known vehicle for Listeria monocytogenes, with the number of produce-related outbreaks increasing. Consumers occasionally misuse frozen vegetables as ready-to-eat instead of ready-to-cook, raising the possibility of L. monocytogenes contamination. Environmental monitoring studies focusing on the freezing step in frozen produce are relatively scarce, yet essential, as this step could cause post-contamination. In this study, conducted between February 2021 and December 2021, a total of 607 samples were collected and analyzed for the presence of L. monocytogenes and surrounding microflora (sulfite-reducing Clostridia, Escherichia coli, coliforms, Pseudomonas spp., lactic acid bacteria, thermophiles, and anaerobic spores). These samples were taken after heat treatment, within and around a freezing tunnel in a frozen potato processing facility. Overall, 33.7% (n = 486) of the fixed infrastructure (food contact surfaces, non-food contact surfaces, and surroundings) and 48.8% (n = 121) of the mobile elements (e.g., staff, cleaning utensils, and transport trolleys) tested positive for L. monocytogenes. The cleaning and disinfection (C&D) could reduce L. monocytogenes to undetectable levels, but its execution proved inconsistent. C&D reduced the positive samples by 26.2% (n = 122) inside the freezing tunnel and by 30.9% (n = 184) outside the freezing tunnel. The main areas of concern proved to be the conveyor belt area for post-contamination risk and the staff as a transmission vehicle with cell counts up to 4.8 log CFU normalized over a surface of 50 cm2. During production, L. monocytogenes positive samples increased in the production environment outside the freezing tunnel going from 27.7% (n = 65) to 46.7% (n = 76) on the fixed elements and from 31.8% (n = 22) to 75.0% (n = 24) on mobile elements. Areas prone to L. monocytogenes contamination contained higher cell counts of coliforms, sulfite-reducing Clostridia, and lactic acid bacteria. Monitoring the presence of L. monocytogenes assists in enhancing the overall hygiene within the processing plant by discovering hard-to-reach places susceptible to contamination, potential transmission routes, and the verification of the C&D procedure. It demonstrates how environmental monitoring can contribute to the overall hygiene of the frozen produce industry.

Seroprevalence study in humans and molecular detection in Rhipicephalus sanguineus ticks of severe fever with thrombocytopenia syndrome virus in Thailand

Severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging tick-borne virus with a mortality rate of up to 30%. First identified in China in 2009, it was later reported in other Asian countries, including Thailand in 2020. SFTSV has been detected in several tick species, including Rhipicephalus sanguineus, known for infesting dogs. We conducted a seroprevalence study of SFTSV in Bangkok and Nong Khai, Thailand, by analyzing 1162 human samples collected between 2019 and 2023. The testing method relied on IgG detection using ELISA and confirmed though a virus seroneutralization test. The results indicated that out of the participants, 12 (1.1%) tested positive for anti-SFTSV IgG antibodies; however, none exhibited positive results in the seroneutralization assay. Additionally, molecular detection of SFTSV, Crimean-Congo hemorrhagic fever (CCHF), Coxiella spp., Bartonella spp., and Rickettsia spp. was performed on 433 Rh. sanguineus ticks collected from 49 dogs in 2023 in Chachoengsao Province, Thailand. No evidence of these pathogens was found in ticks. These findings highlight the importance of exploring viral cross-reactivity. Furthermore, it is important to conduct additional studies to isolate SFTSV from animals and ticks in order to identify the potential transmission routes contributing to human and animal infections in Thailand.

Phenotypic and genomic analysis of bacteria from war wounds in Dnipro, Ukraine.

To better understand the source and potential transmission routes of antibiotic-resistant bacteria infecting injured service members in Ukraine. Phenotypic and genomic characterizations were performed on 11 Gram-negative pathogens cultured from war wounds at an intermediate evacuation hospital in Dnipro. The analysis revealed both susceptible and extensively drug-resistant strains present in cultures, including high-risk global clones carrying carbapenemases. Globally distributed carbapenemase-producing lineages are being acquired early in the medical evacuation process.

Infectious hepatitis E virus is associated with the mature sperm head.

Hepatitis E virus (HEV) is the leading cause of acute viral hepatitis worldwide. HEV associated pregnancy mortality has been reported as up to 30% in humans. Recent findings suggest HEV may elicit effects directly in the reproductive system with HEV protein found in the testis, viral RNA in semen, and viral replication occurring in placental cell types. Using a natural host model for HEV infection, pigs, we demonstrate infectious HEV within the mature spermatozoa and altered sperm viability from HEV infected pigs. HEV isolated from sperm remained infectious suggesting a potential transmission route via sexual partners. Our findings suggest that HEV should be explored as a possible sexually transmittable disease. Our findings propose that infection routes outside of oral and intravenous infection need to be considered for their potential to contribute to higher mortality in HEV infections when pregnancy is involved and in HEV disease in general.

On the efficacy of facial masks to suppress the spreading of pathogen-carrying saliva particles during human respiratory events: Insights gained via high-fidelity numerical modeling.

Respiratory fluid dynamics is integral to comprehending the transmission of infectious diseases and the effectiveness of interventions such as face masks and social distancing. In this research, we present our recent studies that investigate respiratory particle transport via high-fidelity large eddy simulation coupled with the Lagrangian particle tracking method. Based on our numerical simulation results for human respiratory events with and without face masks, we demonstrate that facial masks could significantly suppress particle spreading. The studied respiratory events include coughing and normal breathing through mouth and nose. Using the Lagrangian particle tracking simulation results, we elucidated the transport pathways of saliva particles during inhalation and exhalation of breathing cycles, contributing to our understanding of respiratory physiology and potential disease transmission routes. Our findings underscore the importance of respiratory fluid dynamics research in informing public health strategies to reduce the spread of respiratory infections. Combining advanced mathematical modeling techniques with experimental data will help future research on airborne disease transmission dynamics and the effectiveness of preventive measures such as face masks.

Molecular epidemiology of a Parainfluenza Type 3 virus outbreak: Informing infection control measures on adult hematology wards

ObjectivesParainfluenza virus type 3 (PIV3) outbreaks among hematology patients are associated with high morbidity and mortality. Prompt implementation of infection prevention (IP) measures has proven to be the most efficacious approach for controlling PIV3 outbreaks within this patient population. The most suitable IP measures can vary depending on the mode of virus transmission, which remains unidentified in most outbreaks. We describe the molecular epidemiology of an outbreak of PIV3 among hematology patients and the development of a new method that allows for the differentiation of outbreak and community strains, from which a closed outbreak could be inferred. MethodsPatients were screened for respiratory viruses using multiplex-PCR. PIV3 positive samples with a cycle threshold (Ct)-value of <31 underwent a retrospective characterization via an in-house developed sequence analysis of the hemagglutinin-neuraminidase (HN) gene. ResultsBetween July and September 2022, 31 hematology patients were identified with PIV3. Although infection control measures were implemented, the outbreak persisted for nine weeks. Sequencing the HN gene of 27 PIV3 strains from 27 patients revealed that all outbreak strains formed a distinct cluster separate from the control strains, suggestive of a nosocomial transmission route. ConclusionsSequencing the HN gene of PIV3 strains in an outbreak setting enables outbreak strains to be distinguished from community strains. Early molecular characterization of PIV3 strains during an outbreak can serve as a tool in determining potential transmission routes. This, in turn, enables rapid implementation of targeted infection prevention measures, with the goal of minimizing the outbreak's duration and reducing associated morbidity and mortality.