Actual Infection Research Articles

P-215. Screening to Prophylax against Clostridioides difficile Infection: A Trial of Primary Prophylaxis in C. difficile Carriers

Abstract Background Clostridioides difficile infection (CDI) is one of the five urgent threats identified by the Centers for Diseases Control and Prevention (CDC). In addition to actual infection, C. difficile can colonize patients, particularly those with other gastrointestinal pathologies and with frequent healthcare exposure. Several studies have shown the potential benefit of secondary prophylaxis to prevent recurrence of CDI in patients with a recent prior infection. The Screening to Prophylax against CDI study (StoP CDI) was a double blinded randomized placebo-controlled trial of vancomycin primary prophylaxis for CDI in patients on high-risk antibiotics who were asymptomatic carriers of C. difficile. The study also aimed to determine the carriage rate of C. difficile in the hospitalized population and whether carriage of C. difficile was a risk factor for CDI. Methods All adult inpatients in three Detroit-area hospitals were screened for new antibiotic starts and then for inclusion and exclusion criteria. Patients who qualified were consented to be screened by PCR for the presence of toxigenic C. difficile, and if positive were approached to participate in the trial of prophylaxis. Carriage rates in all screened patients were determined as were rates of CDI in the groups receiving vancomycin prophylaxis or placebo, those who were carriers but declined to participate in the randomized portion of the study, and those who were not carriers. Results 1294 patients consented to be screened and 728 provided a stool sample, of whom 81 (11.1%) were found to be carriers of toxigenic C. difficile. Twenty-seven patients agreed to be randomized, 13 were randomized to vancomycin prophylaxis and 14 to placebo. None of the randomized patients developed CDI; however, 2 of 48 evaluable carriers who were not randomized developed CDI, corresponding to a rate of CDI in non-prophylaxed carriers of 4.2%. Of 640 evaluable non-carriers, 4 were diagnosed with CDI giving a rate of 0.63%. Conclusion Over 10% of adult hospitalized patients are carriers of C. difficile. The risk of developing CDI among carriers was 6.7x higher than in non-carriers. Vancomycin prophylaxis in carriers may reduce the risk for CDI but the number of patients was too small to fully test this hypothesis. Disclosures Christopher F. Carpenter, MD, AstraZeneca: Grant/Research Support|Cidara Therapeutics: Advisor/Consultant|Dompe Farmaceutici: Grant/Research Support|F2G LTD: Advisor/Consultant|Rebiotix: Advisor/Consultant Matthew Sims, MD, PhD, Adaptive Phage Therapeutics: Principal Investigator Clinical Trial|Applied Biocode: Advisor/Consultant|Applied Biocode: Principal Investigator Clinical Trial|Astra Zeneca: Sub-investigator Clinical Trial|Biotest AG: Principal Investigator Clinical Trial|ContraFect: Principal Investigator Clinical Trial|Dompe: Sub-investigator Clinical Trial|Janssen: Principal Investigator Clinical Trial|Leonard-Meron Biosciences: Principal Investigator Clinical Trial|Novozyme: Principal Investigator Clinical Trial|OpGen: Advisor/Consultant|OpGen: Principal Investigator Clinical Trial|Pfizer: Principal Investigator Clinical Trial|Prenosis: Advisor/Consultant|Prenosis: Principal Investigator Clinical Trial|QIAGEN: Principal Investigator Clinical Trial|Seres: Advisor/Consultant|Seres: Principal Investigator Clinical Trial|Venatorx: Advisor/Consultant

Vascular Access Device Infections: Current Management Practices and the Role of Multidisciplinary Teams at a Large Hospital in Northern Italy.

Introduction: Vascular access device (VAD)-associated infections, including catheter-related (CRBSI) and catheter-associated bloodstream infections (CABSI), present significant challenges in patient care. While multidisciplinary VAD teams (VATs) are equipped with protocols for managing these infections, adherence to these guidelines in real-life practice is inconsistent. This study aims to evaluate the alignment between actual VAD infection management practices and VAT-recommended protocols. Methods: We conducted a retrospective, single-center study at Luigi Sacco Hospital (May 2021-October 2023) involving non-ICU adult patients with diagnosed CRBSI or CABSI. VAT experts independently reviewed infection management choices, which were divided into eight specific procedural options. These options included variations in VAD removal, timing of repositioning, and combinations of antimicrobial lock therapy and systemic therapy. Concordance between real-life practices and VAT recommendations was evaluated using Cohen's kappa coefficient. Results: Of 2419 VAD placements, 146 (6%) developed infections (84 CABSI, 62 CRBSI). Clinicians removed VADs in 66.4% of cases compared to 62.3% per VAT recommendations, with moderate overall agreement (Cohen's kappa = 0.58). Analysis of the eight management categories revealed moderate to low alignment (unweighted kappa = 0.44, weighted kappa = 0.30) between real-life practices and VAT guidance, with slightly improved concordance in CRBSI cases. Conclusions: Our findings underscore a discrepancy between real-life VAD infection management and VAT-recommended protocols, suggesting a need for clearer, more accessible guidelines and increased multidisciplinary collaboration. Enhanced VAT consultation and simplified protocol dissemination may improve consistency in infection management and ultimately lead to better patient outcomes.

Prevalence of HPV infection in the general population of young and adult males in Italy.

The most prevalent sexually transmitted disease in the world has the human papillomavirus (HPV) as its etiological agent. To evaluate the prevalence of previous and actual HPV infection and the clinical manifestations in unselected males. A total of 718 males participating to a surveillance program were asked to complete a study visit at our unit, including semen collection, balanopreputial sulcus swab, and blood collection for total anti-HPV immunoglobulin G (IgG). When HPV-DNA was detected, we performed HPV fluorescence in situ hybridization, oral and anal swab, and penoscopy. Because previous studies demonstrated a very high risk for HPV infection in subjects with history of HPV-induced lesions, with a partner with diagnosed HPV infection or reporting couple infertility or sexual promiscuity and an increase of the risk in males having sex with males, in subjects with unprotected sexual intercourses or in heavy smokers, patients were therefore stratified according to the presence of these known risk factors (RFs). Actual HPV infection was detected in 401/718 subjects (55.85%). Oral HPV-DNA was reported in 80 subjects and anal HPV infection in 52 subjects. Anti-HPV IgG antibodies have been detected in 288 subjects. The overall prevalence of HPV exposition, considering actual and/or previous infection was 77.99%. Among infected men, high-risk HPV genotypes were detected in 66.08%. A total of 514 subjects were considered as the RF population, while 150 were classified in the non-RF population. There was a significantly higher prevalence of condylomatosis (odds ratio [OR] 4.07) and of seminal infection (OR 6.22) in the RF group. These data represent an alert for the healthcare system to perform informative and screening campaigns for HPV infection in males and to promote HPV vaccination both in young people and for adult males with RF for HPV infections.

Prevalence of SARS-CoV-2 antibodies at the University hospital Heidelberg and correlation with SARS-CoV-2 incidence

BackgroundSince the onset of the SARS-CoV-2 pandemic in late 2019, many studies suggest that actual infection rates may far exceed reported cases. Therefore, this study provides a comprehensive overview of anti-SARS-CoV-2 antibody measurements and their significance in epidemiological surveillance, especially regarding the true extent of SARS-CoV-2 infections, allowing more detailed insights into the dynamics of the pandemic. MethodsAntibodies were measured using the Elecsys® Anti-SARS-CoV-2 assay for the nucleocapsid (N) protein and the SARS-CoV-2 IgG (sCOVG) assay for the spike (S) protein. A total of 25197 specimens from University Hospital Heidelberg were analyzed between May 2020 and December 2023, with 16957 samples measured for both antibodies, 2756 for anti-N only, and 5484 for anti-S only.For the epidemiological tracing of the SARS-CoV-2 incidence we analyzed changes in the anti-N positivity rate and anti-S positivity rate within our tertiary hospital setting across consecutive quarters. ResultsAnti-N measurements allowed for a retrospective analysis of SARS-CoV-2 epidemiological developments, revealing significant changes (p <0.05) in the anti-N positivity rate following incidence peaks (increase) and low incidence periods (decrease) with only three non-significant transitions.On the other hand, the anti-S positivity rate showed only four significant transitions between consecutive quarters. ConclusionThe anti-N positivity rate is an effective and straightforward retrospective serological tool for tracking epidemiological trends, while the anti-S rate is influenced by vaccination and epidemiology as well, making it inept for the tracing of epidemiological changes. Although the recent development in SARS-CoV-2 epidemiology with increasing intervals between infection waves already provide an enhanced statistical robustness, we recommend the determination of the anti-N positivity rate in larger study populations.

State of infection prevention knowledge among healthcare professionals in Japan: a questionnaire survey analysis using text mining

Healthcare-associated infections (HAIs) are an important issue that needs to be addressed continuously in healthcare institutions Healthcare professionals (HCPs) are expected to strengthen educational programmes on infection prevention. Although the incidence of HAIs in Japan has been decreasing, the actual state of knowledge on infection prevention among HCPs remains unclear. To clarify the actual infection prevention knowledge of HCPs in Japan. The study participants were 1158 HCPs working in healthcare institutions with frequent contact with patients (283 doctors, 591 nurses, 115 physical therapists, 97 radiologists and 72 medical technologists). HCPs described the infection prevention behaviours they adhered to consciously via an online self-administered questionnaire. Data were analysed by text mining. Categories were extracted from the responses to reveal HCPs' infection prevention knowledge. More than half of the participants (64.9%) were aged >40 years, and 48.1% had >20 years of clinical experience. The majority of the participants were nurses (51.0%), 43.9% had a bachelor's degree, and 56.6% were female. Seven categories regarding infection prevention knowledge were extracted: 'performing hand hygiene and gargling', 'wearing personal protective equipment', 'strengthening one's immunity', 'protecting oneself and patients from infection', 'distinguishing clean and unclean zones', 'actions to prevent transmission to others in daily life activities' and 'maintaining distance from others'. These results suggest that most HCPs working in healthcare settings in Japan prioritize and adhere to standard precautionary measures, and the low incidence of HAIs may be influenced by perceptions of the knowledge of 'handwashing and gargling' among HCPs.

Differential associations between SARS-CoV-2 infection, perceived burden of the pandemic and mental health in the German population-based cohort for digital health research

Understanding the potential adverse effects of the COVID-19-pandemic on mental health remains a challenge for public health. Differentiation between potential consequences of actual infection with SARS-CoV-2 and the subjective burden of the pandemic due to measures and restrictions to daily life still remains elusive. Therefore, we investigated the differential association between infection with SARS-Cov-2 and subjective burden of the pandemic in a study cohort of 7601 participants from the German population-based cohort for digital health research (DigiHero), who were recruited between March 4th and April 25th 2022. Data was collected using the online survey tool LimeSurvey® between March and October 2022 in consecutive surveys, which included questionnaires on infection status and symptoms following COVID-19 as well as retrospective assessment of the subjective burden of the pandemic. We observed an association of a past SARS-CoV-2 infection on deteriorated mental health related symptoms, whereas no association or interaction with burden of the pandemic occurred. The association was driven by participants with persistent symptoms 12 weeks after infection. On a symptom specific level, neuropsychiatric symptoms such as exhaustion and fatigue, concentration deficits and problems with memory function were the primary drivers of the association with small effect sizes between 0.048 and 0.062 ηp2.

Caenorhabditis elegans SynMuv B gene activity is down-regulated during a viral infection to enhance RNA interference.

Small RNA pathways regulate eukaryotic antiviral defense. Many of the Caenorhabditis elegans mutations that were identified based on their enhanced RNAi, the synMuv B genes, also emerged from unrelated genetic screens for increased growth factor signaling. The dozen synMuv B genes encode homologues of the mammalian dREAM complex found in nearly all animals and plants, which includes the lin-35/retinoblastoma oncogene. We show that a set of highly induced mRNAs in synMuv B mutants is congruent with mRNAs induced by Orsay RNA virus infection of C. elegans. In wild type animals, a combination of a synMuv A mutation and a synMuv B mutation are required for the Muv phenotype of increased growth factor signaling. But we show that Orsay virus infection of a single synMuv A mutant can induce a Muv phenotype, unlike the uninfected single synMuv A mutant. This suggests that decreased synMuv B activity, which activates the antiviral RNAi pathway, is a defense response to viral infection. Small RNA deep sequencing analysis of various dREAM complex mutants uncovers distinct siRNA profiles indicative of such an siRNA response. We conclude that the synMuv B mutants maintain an antiviral readiness state even in the absence of actual infection. The enhanced RNAi and conservation of the dREAM complex mutants suggests new therapeutic avenues to boost antiviral defenses.

Restricted health service utilization and subsequent positive self-care behavior during the early COVID-19 pandemic in China.

The reallocation of health resources, epidemic prevention and control measures during the COVID-19 pandemic triggered widespread restricted health service utilization, some residents and patients tried positive self-care behavior to maintain their health, yet the efficacy of this intervention remains unclear. Based on the reasoned action approach (RAA) theory, this study aimed to investigate the correlation between self-care behavior and restricted health service utilization among adults in China, trying to discover the vulnerable groups and external and intrinsic factors that affect self-care behavior among Chinese adults. Data on demographics, socioeconomic, health status, and self-care behavior were collected in "The Early China COVID-19 Survey," a cross-sectional anonymous online survey of the general population in China. Self-care behavior was measured by four indicators: weight control (WC), physical activity (PA), prevention behavior (PB), and online medical consultation (OMC). The multiple linear models and binary logistic regression were used to examine whether restricted health service utilization (RHSU) is associated with self-care behaviors; also, adjusted multivariate logistic regression was used to analyze subgroup heterogeneity. In total, 8,428 adult participants completed the survey, the mean OMC score was 1.51 (SD 1.34), the mean PB score was 18.17 (SD 3.44), and the proportion of participants who engaged in WC and PA was 42.30 and 62.57%, respectively. According to the multiple regression model, the RHSU was significantly positively correlated with all four indicators of self-care (WC: OR = 1.34, p < 0.001, PA: OR = 1.34, p < 0.05, MC: OR = 1.30, p < 0.001, PB: coef = 0.16, p < 0.05). We also observed some significant differences in the intensity of this relationship by subgroup analysis, precisely, OMC (high vs. moderate vs. low infection-risk level: OR = 1.48; 1.41; 1.19, p < 0.1), PA (male vs. female: OR = 1.27;1.06; p < 0.05, high vs. Moderate and low infection-risk level: OR = 1.51; 1.17; 1.02, p < 0.05), PB (Chronic disease groups vs. no: coef = 0.46; 0.1, p < 0.05). Restricted health service utilization predicts more positive self-care behavior, and the intensity of partial correlation was significantly different in the subgroups of sex, actual infection risk level of the living area, and chronic diseases. These findings highlight the urgent demand for self-care behavior among Chinese adults during the pandemic and provide new insights for developing self-care and reducing the burden on the healthcare system in the long term.

Theoretical and numerical study of case reporting rate with application to epidemiology

A clear understanding of actual infection rate is imperative for control and prevention of diseases. In particular, it helps in formulating effective vaccination strategies and in assessing the level of herd immunity required to contain the virus. In this paper, we conduct theoretical and numerical study of a novel optimization procedure aimed at stable estimation of incidence reporting rate and time-dependent effective reproduction number from real data on new incidence cases, daily new deaths, and vaccination percentages. The iteratively regularized optimization algorithm can be applied to a broad class of data fitting problems constrained by various biological models, where one has to account for under-reporting of cases. To that end, general nonlinear observation operators in real Hilbert spaces are considered in the proposed convergence analysis. To illustrate theoretical findings, numerical simulations with SVIsIvRD compartmental model and real data for Delta variant of COVID-19 pandemic in different states of the US are conducted.

Seroepidemiology of pertussis in Huzhou: A population-based, cross-sectional study.

The resurgence of pertussis has occurred around the world. However, the epidemiological profiles of pertussis cannot be well understood by current diseases surveillance. This study was designed to understand the seroepidemiological characteristics of pertussis infection in the general population of Huzhou City, evaluate the prevalence infection of pertussis in the population, and offer insights to inform adjustments in pertussis prevention and control strategies. From September to October 2023, a cross-sectional serosurvey was conducted in Huzhou City, involving 1015 permanent residents. Serum samples were collected from the study subjects, and pertussis toxin IgG antibodies (Anti-PT-IgG) were quantitatively measured using enzyme-linked immunosorbent assay (ELISA). The analysis included the geometric mean concentration (GMC) of Anti-PT-IgG, rates of GMC≥40IU/mL, ≥100IU/mL, and <5IU/mL. Stratified comparisons were made based on age, vaccination history, and human categories. Among the 1015 surveyed individuals, the geometric mean concentration (GMC) of Anti-PT-IgG was 10.52 (95% CI: 9.96-11.11) IU/mL, with a recent infection rate of 1.58%, a serum positivity rate of 11.43%, and a proportion with <5IU/mL of 40.49%. Among 357 children with clear vaccination history, susceptibility decreased with an increasing number of vaccine doses (Z = -6.793, P < 0.001). The concentration of Anti-PT-IgG exhibited a significant post-vaccination decline over time (Z = -5.143, P < 0.001). In women of childbearing age, the GMC of Anti-PT-IgG was 7.71 (95% CI: 6.90-8.62) IU/mL, with no significant difference in susceptibility among different age groups (χ2 = 0.545, P = 0.909). The annual pertussis infection rate in individuals aged ≥3 years was 9321 (95%CI: 3336-16039) per 100,000, with peak infection rates in the 20-29, 40-49, and 5-9 age groups at 34363 (95%CI: 6327-66918) per 100,000, 22307.72 (95%CI: 1380-47442) per 100,000, and 18020(95%CI: 1093-37266) per 100,000, respectively. In 2023, the actual pertussis infection rate in the population of Huzhou City was relatively high. Vaccine-induced antibodies exhibit a rapid decay, and the estimated serum infection rate increases rapidly from post-school age, peaking in the 20-29 age group. It is recommended to enhance pertussis monitoring in adolescents and adults and refine vaccine immunization strategies.

A meta-analysis on the risk of infection associated with intravenous iron therapy in cancer-associated anaemia: a double-edged sword?

The increased use of i.v. iron in the treatment of cancer-associated anemia raises concerns about its risk of infectious complications. High levels of circulating iron could increase the risk of infection by compromising natural defence mechanisms and promoting pathogen growth. Since the risk of infection is particularly high in the oncological population, we have examined whether the use of i.v. iron increases the risk of infectious complications among cancer patients. Among 18 randomized trials in our systematic review, only 8 reported infectious complications, with no significant difference linked to the type of i.v. iron preparation. Two trials showed a statistically significant increase in infectious complications, one trial found a lower risk, while the remaining 5 reported no significant difference. Our meta-analysis revealed a numerical increase in infectious complications in the i.v. iron group, but the lack of statistical significance and significant heterogeneity among the trials limit definitive conclusions on the actual infection risk. Our findings suggest some increased risk in infectious complications after the administration of i.v. iron for cancer associated anaemia. However, i.v. iron therapy appears generally safe and effective in cancer-associated anaemia.

Molecular diagnosis of Taenia saginata from two patients in Palestine: two case reports

BackgroundTaeniasis, is a worldwide foodborne zoonotic disease caused by two principal species; Taenia saginata and Taenia solium. The tapeworm infects the intestine causing taeniasis in humans. Taeniasis is a very rare parasitic infection in Palestine with very few annual cases of unknown species. The infection rate and the disease status are not clear due to the lack of reports about the actual number of patients.Case presentationTwo Palestinian patients; one male of 22 years old from Hebron and the other is female of 33 years old from Ramallah were referred to Palestinian Health Services in the West Bank, Palestine, complained of weight loss, abdominal pain and presence of motile segments of creamy color in the their stool. Microscopic analysis of the stool samples from infected cases revealed Taenia eggs and proglottids, confirmed taeniasis infection. The parasite species was identified as T. saginata by polymerase chain reaction (PCR) amplification and sequencing of the cytochrome oxidase -1 (COX-1) gene.ConclusionTaeniasis is an unusual parasitic infection in Palestine, there is a growing concern that the actual numbers of infected individuals are much higher and the occurrence of human taeniasis is principally due to people’s eating habits in consumption of raw or undercooked beef meat. This report highlighted for the first time the existence of taeniasis infection in the country; which necessitates the need to conduct further research and surveillance to reveal the actual infection rate and the available Taenia species.

Changes and predictors of mental health of Chinese university students after the COVID-19 pandemic: A two-year study

BackgroundPsychological repurcussions of COVID-19 pandemic has received wide attention, but there's limited attention paid to psychological recovery afterwards. This study focuses on the changes and predictive factors of mental health of Chinese university students post-pandemic. MethodsThis study included 1175 Chinese undergraduate students sampled in May 2022 and May–June 2023, right before and after peaks of infections following the end of lockdown policy in China. The participants completed a survey of demographic variables, and three questionnaires: 12-item General Health Questionnaire, Positive Psychological Capital Questionnaire, and Prosocial Tendencies Measure. ResultsThe participants sampled in 2023 have significant lower GHQ scores and higher PPQ scores than those sampled in 2022, while there is no significant difference in PTM scores between them. The proportion of participants with GHQ-12 scores exceeding 12 in 2023 showed slightly decrease compared to that in 2022. The infection of significant others, the sense of hope, and PPQ self-efficiency, hope and optimism subscale scores were significantly associated with GHQ-12 scores in 2023, but actual infection or quarantine experience were not. ConclusionsThe mental health and psychological capital of the university students have been significantly improved within a year. It is worthy to pay attention to the infection of significant others, the sense of hope, and psychological capital in a pandemic to improve the mental health of university students. LimitationsCompared to a cross-sectional study, longitudinal research is the better choice for a two-year comparison.

Lessons from the coronavirus pandemic: a review of how the disease spreads in indoor spaces

Abstract In the post-coronavirus era, it is important to understand how infections spread in the indoor environment. The modes of transmission that are of interest to this research are droplet-borne and airborne transmission. In these transmission cases, there is a dependency on air to transport pathogens. The buoyancy of pathogens depends on the mass of the particles or droplets, volume of the indoor space and air velocity. Understanding this is key to reaching a sound methodology for control. The case studies consist of two main groups: the first group is research based published prior to the onset of the pandemic, and the second group is based on studies of actual infection cases subsequent to the onset of the pandemic. When examining the cases, it is apparent that the three main factors that are constantly recurrent are population density, airflow rate and air recirculation. In a lot of cases, air stagnation and lack of air change are conclusive causative factors of infection transmission, while in a couple of cases, it was shown that infective agents can travel more than 3 m, another factor to be taken into consideration. When there is a total lack of airflow and air change, population density becomes the main causative factor. This research presents a set of guidelines for the ventilation of spaces in different types of indoor environment through exploring the role of the built environment in the transmission of infection and how building design can effect change on public health.

Identification of influential vertices in complex networks: A hitting time‐based approach

AbstractUnravelling the dynamics of network vertices is pivotal, and traditional centrality measures have limitations in adapting to structural changes, directed and weighted networks, and temporal analyses. This paper introduces a ground breaking approach ‐ hitting time‐based centrality. Utilizing network matrix notations and a random walk model on a connected network , we establish a Markov chain to quantify the hitting time, hitting distance, and hitting centrality, providing a nuanced measure prioritizing central vertices. Through extensive experiments using Kendall's tau coefficient, the paper evaluates the method's correlation with actual influence in the Susceptible‐Infectious (SI) model, showcasing superior performance across diverse network sizes and structures. The hitting centrality method exhibits sensitivity to connectivity dynamics, effective incorporation of temporal dynamics, and robust handling of weighted and directed networks. Positive Kendall's tau coefficients underline the method's proficiency in prioritizing influential vertices by correlating hitting centrality values with actual infection ability. The demonstrated robustness to structural changes enhances its utility for dynamic network analysis. In conclusion, our hitting time‐based centrality approach emerges as a promising method, mitigating the shortcomings of traditional measures. By integrating information propagation speed, accommodating network dynamics, and enabling time‐dependent analyses, it offers a comprehensive tool for evaluating vertex importance and influence in complex networks.

Spontaneous Perinephric Abscess with Atypical Mycobacteria: An Entity to Ponder

Abstract Although chronic pulmonary disease due to atypical mycobacteria also known as non-tuberculous mycobacterial (NTM) infections are recognised with increasing frequency, very few cases of primary urinary involvement with this organism have been reported. It is important to distinguish between simple colonisation by these organisms and actual infection caused by them. Differentiation between NTM infection and urinary tuberculosis is also important in determining the therapeutic regimen. We present the report of a case of perinephric abscess produced by NTM in a healthy male individual.

Spatial prediction of the probability of liver fluke infection in water resource within sub-basin using an optimized geographically-weighted regression model.

Infection with liver flukes (Opisthorchis viverrini) is partly attributed to their ability to thrive in sub-basin habitats, causing the intermediate host to remain within the watershed system throughout the year. It is crucial to conduct spatial monitoring of fluke infection at a small basin analysis scale as it helps in studying the spatial factors influencing these infections. The number of infected individuals was obtained from local authorities, converted into a percentage, and visually represented as raster data through a heat map. This approach generates continuous data with dependent variables. The independent set comprises nine variables, including both vector and raster data, that establish a connection between the location of an infected person and their village. Design spatial units optimized for geo-weighted modeling by utilizing a clustering and overlay approach, thereby facilitating the optimal prediction of alternative models for infection. The Model-3 demonstrated the strongest correlation between the variables X5 (stream) and X7 (ndmi), which are associated with the percentage of infected individuals. The statistical analysis showed t-statistics values of -2.045 and 0.784, with corresponding p-values of 0.016 and 0.085. The RMSE was determined to be 2.571%, and the AUC was 0.659, providing support for these findings. Several alternative models were tested, and a generalized mathematical model was developed to incorporate the independent variables. This new model improved the accuracy of the GWR model by 5.75% and increased the R 2 value from 0.754 to 0.800. Additionally, spatial autocorrelation confirmed the difference in predictions between the modeled and actual infection values. This study demonstrates that when using GWR to create spatial models at the sub-basin level, it is possible to identify variables that are associated with liver fluke infection.

THE IMPACT OF THE COVID-19 PANDEMIC ON INFORMAL CAREGIVERS OF PERSONS WITH DEMENTIA IN THE POST-VACCINATION ERA

Abstract The COVID-19 pandemic disproportionately impacted individuals living with dementia and their family care-partners. Prior to the pandemic, many family care-partners had insufficient support to manage stressors and experienced resultant negative physical and mental consequences. Systematic reviews of studies from the early pandemic suggest that circumstances dramatically worsened for family care-partners’, though it is unclear whether and how they were impacted by ongoing fluctuations in COVID-19 risk for infection and safety guidelines following the availability of vaccines. Using qualitative design informed by a stress-and-coping theoretical framework, our objective was to characterize the ongoing impact of the pandemic on family care-partners of persons living with dementia. We used purposive sampling to recruit participants from a larger survey study of dementia caregiving during the COVID-19 pandemic. Study participants (n=18) completed a 1-hour virtual interview with that was transcribed, de-identified, and analyzed using thematic analysis. We identified 4 overarching themes characterizing family caregivers’ stressors that included: 1) changes in care, routines, and support; 2) actual or feared COVID-19 infection; 3) changes in the functioning and health of care-partners and care-recipients; 4) experiences with care facilities care transitions. We also identified 4 overarching themes characterizing care-partners’ coping strategies, including: 1) care-partner resourcefulness; 2) participation in meaningful, enjoyable, and restorative activities; 3) personal outlook and attitudes to reduce distress; and 4) connection with specific formal and informal supports. Our findings underscore the continued challenges that family care-partners experience and highlight important skills, supports, and resources to mitigate negative health outcomes and other long-term consequences.

Mathematical analysis of global dynamics and optimal control of treatment for an age-structured HBV infection model

Evidences show that cell-to-cell infection occurs in HBV infection and is a very efficient way which may lead to more than half of the viral infection. Hence we formulate an HBV infection model with cell-to-cell infection, meanwhile, we incorporate the infection age of infected cells. For dynamic behaviors, we firstly establish the well-posedness and asymptotic smoothness of the model; then show the global threshold dynamical behaviors, which are determined by the reproduction number; and finally perform numerical simulations not only to verify the theoretical results but also to explore effects of cell-to-cell infection on viral load and infection concentration. Our finding is that ignoring the cell-to-cell infection will underestimate the actual HBV infection status. For optimal control of treatment for HBV, we introduce two time-varying control measures and investigate the corresponding optimal control problem. We derive the characteristic expression of the optimal control and discuss effects of control costs and integrated control. The results show that high control cost will not result in better control effectiveness, while integrated optimal control can reach the best control objectives compared with the two single ones. Moreover, infection age can greatly influence HBV infection at the initial stage.

Defining microbial community functions in chronic human infection with metatranscriptomics.

The microbial diversity in polymicrobial infections (PMIs) allows for community members to establish interactions with one another, which can result in enhanced disease outcomes such as increased antibiotic tolerance and chronicity. Chronic PMIs result in large burdens on health systems, as they affect a significant proportion of the population and are expensive and difficult to treat. However, investigations into physiology of microbial communities in actual human infection sites are lacking. Here, we highlight that the predominant functions in chronic PMIs differ, and anaerobes, often described as bystanders, may be significant in the progression of chronic infections. Determining the community structure and functions in PMIs is a critical step toward understanding the molecular mechanisms that increase the virulence potential of the microbial community in these environments.