Infected Population Research Articles

Cost-effectiveness of treating all hepatitis B-positive individuals in the United States.

Chronic hepatitis B virus (HBV) infection is a leading cause of liver disease and related mortality globally. However, most of the infected individuals in the United States remain undiagnosed and untreated. There is a need to understand more completely the economic and disease burden impact of removing treatment restrictions and increasing diagnosis and treatment. The PRoGReSs model, a dynamic HBV model that tracks the infected population by year, disease stage, and gender, was used to quantify the disease and economic burden of chronic HBV infection in the United States from 2020 to 2050 based on four scenarios: a status quo (base) scenario and three treat-all scenarios, in which screening, diagnosis, and treatment were maximized at different annual treatment price levels of $5382, $2000 and $750. Compared to the base scenario, the treat-all scenarios would avert 71,100 acute and 11,100 chronic incident cases of HBV, and 169,000 liver-related deaths from 2020 to 2050. At an annual treatment cost of $2000, treating all HBV infections would be highly cost-effective, and at $750 would be cost saving and would achieve a positive return on investment before 2050. Maximizing the diagnosed and treated HBV population in the United States would avert a significant number of cases of advanced liver disease and related mortality. Such interventions can also be cost-effective compared to the status quo strategy, and cost saving at a treatment price threshold of $750 annually, above the current lowest annual treatment cost of $362.

Isolation and characterization of three bacteriophages infecting Erwinia amylovora and their potential as biological control agent

BackgroundFire Blight, incited by Erwinia amylovora, is one of the most damaging pear and apple diseases in the world. Fire blight was introduced to Egypt in the 1960 and threatens the Egypt’s costs for pear industry. Currently, Phage therapy is considered to be secured biological method for controlling plant bacterial diseases. This investigation aimed to isolate and identify molecularly for bacteria causing fire bright disease. As well as isolation and identification bacteriophages via spot and plaque assay techniques from pear fire blight lesions and soil. On the other hand, bacteriophages were identified based on plaque morphology, virion morphology, physical characters, profile of DNA restriction and protein.ResultsPathogenicity test revealed that healthy seedlings and pear fruits were responsive to fire blight E. amylovora. Considering the relatively wide host range and greatest protein and genetic variability, using restriction enzyme pattern, the three diversity phage isolates named, EAP1, EAP2 and EAP3 showed a lack of diversity out of five were fatherly characterized. The phages confirmed the close relation of EAP1, EAP2 to Siphoviridae (hexagonal head and long flexible non-contractile tail) and EAP3 to Myoviridae (icosahedral head and contractile tail). The phages retained higher lytic competence of 90.4; 92.68 and 95.25% for EAP1, EAP2 and EAP3, respectively. The phages were stable at strong alkaline (pH 10) 2% salt solution conditions and UV spectra. While EAP3 phage revealed the hexagonal head and very short tail that belongs to Myoviridae family. Bacteriophages were characterized by digestion of the phage DNA with three restriction endonucleases and were placed into three groups based on the patterns. Bacteriophages were 9 used for reducing bacterial infection populations and severity on pear. In a bioassay, the biocontrol of E. amylovora was evaluated using disks of immature pear fruit. On the pear disk surface, bacterial exudate was considerably suppressed by all phage isolates. According to measurements of the bacterial population still present on the disk surface, phage therapy could reduce it by up to 97%. Bacteriophages reduced pear fire blight disease severity on pear fruit trails.ConclusionThe results indicated that bacteriophage isolates may demonstrate variable reactivity against E. amylovora. Bacteriophages reduced pear fire blight disease severity on pear fruit trials. The results indicated that bacteriophage isolates may demonstrate variable reactivity against E. amylovora.

An extended SEIRDV compartmental model: case studies of the spread of COVID-19 and vaccination in Tunisia and South Africa.

In the wake of the unprecedented health crisis triggered by the global COVID-19 pandemic, countries are still grappling with the pandemic's immediate health and socioeconomic consequences. This paper presents an extended SEIRD model with vaccination to study the evolution of COVID-19 in South Africa and Tunisia since the commencement of the vaccination campaign in each country, respectively. Epidemiologists often quantify a risk reduction following the implementation of non-pharmaceutical containment measures and vaccines when attempting to stem the spread of pandemics. However, an important question they often ask is the effectiveness of the non-pharmaceutical containment measures (social distancing and lockdowns) and the efficacy of such measures, including vaccines. Africa's COVID-19 vaccine roll-out stands at 16% as of April 2022; however, the continent lags behind many developing countries even though it harbours about 16% of the world population. While proliferating literature quantifies the efficacy and effectiveness of COVID-19 vaccines, very little has been done using the SEIRDV model in African countries. This study compares the model-predicted results with the available data to estimate the dynamics of the infected population, using data from 20-03-2021 to 30-12-2021. A simulation of the SEIRDV model is performed and fitted to the data. Simulating the model involves solving a system of Ordinary Differential Equations numerically by taking the initial values for the key model parameters as inputs. After simulating the SEIRDV model, the model parameters are compared with real-world COVID-19 and vaccination data in order to estimate the values of the different parameters that best fit the observed data. The results of the study showed an inverted U-shaped trend for the infection rate after vaccination, indicating that increasing the vaccination rates reduces the transmission rates. Therefore African countries must continue to scale up the vaccination campaigns, and the world needs to endeavour to ensure an equitable vaccination roll-out to developing countries.

Mathematical Model of Malaria Transmission with Anti-Malarial Herbal Therapy as Control

Conventional anti–malarial drugs (chloroquine, Artesunate, Quinine, Amodiaquine etc) are used by most malaria-endemic countries as first-line treatment for uncomplicated malaria. However, resistance by plasmodium parasite against these conventional anti–malarial drugs has necessitated the need for herbal medicine as alternative. So in this study, we formulate a mathematical model of malaria transmission in two interacting population of human (host) and mosquito (vector) incorporating anti-malarial herbal therapy as first line treatment for uncomplicated malaria infection. The region where the model is epidemiological feasible and mathematically well–posed is established and the basic reproduction number R_0 is derived using next generation matrix approach. The numerical experiment carried out to access the impact of the control measure on malaria transmission revealed a reduction in the number of complicated infectious human population. Hence this research work suggests a massive campaign on use of anti-malarial herbal therapy as first- line treatment for malaria infection cases.

Contact-number-driven virus evolution: A multi-level modeling framework for the evolution of acute or persistent RNA virus infection.

Viruses evolve in infected host populations, and host population dynamics affect viral evolution. RNA viruses with a short duration of infection and a high peak viral load, such as SARS-CoV-2, are maintained in human populations. By contrast, RNA viruses characterized by a long infection duration and a low peak viral load (e.g., borna disease virus) can be maintained in nonhuman populations, and the process of the evolution of persistent viruses has rarely been explored. Here, using a multi-level modeling approach including both individual-level virus infection dynamics and population-scale transmission, we consider virus evolution based on the host environment, specifically, the effect of the contact history of infected hosts. We found that, with a highly dense contact history, viruses with a high virus production rate but low accuracy are likely to be optimal, resulting in a short infectious period with a high peak viral load. In contrast, with a low-density contact history, viral evolution is toward low virus production but high accuracy, resulting in long infection durations with low peak viral load. Our study sheds light on the origin of persistent viruses and why acute viral infections but not persistent virus infection tends to prevail in human society.

Sleep disturbance and anxiety symptoms among asymptomatic COVID-19 carriers in Shanghai, China: the mediating role of entrapment and defeat

BackgroundThe COVID-19 pandemic increases the risk of psychological problems, especially for the infected population. Sleep disturbance and feelings of defeat and entrapment are well-documented risk factors of anxiety symptoms. Exploring the psychological mechanism of the development of anxiety symptoms is essential for effective prevention. This study aimed to examine the mediating effects of entrapment and defeat in the association between sleep disturbance and anxiety symptoms among asymptomatic COVID-19 carriers in Shanghai, China.MethodsA cross-sectional study was conducted from March to April, 2022. Participants were 1,283 asymptomatic COVID-19 carriers enrolled from the Ruijin Jiahe Fangcang Shelter Hospital, Shanghai (59.6% male; mean age = 39.6 years). Questionnaire measures of sleep disturbance, entrapment, defeat, anxiety symptoms, and background characteristics were obtained. A mediation model was constructed to test the mediating effects of entrapment and defeat in the association between sleep disturbance and anxiety symptoms.ResultsThe prevalence rates of sleep disturbance and anxiety symptoms were 34.3% and 18.8%. Sleep disturbance was positively associated with anxiety symptoms (OR [95%CI] = 5.013 [3.721–6.753]). The relationship between sleep disturbance and anxiety symptoms (total effect: Std. Estimate = 0.509) was partially mediated by entrapment (indirect effect: Std. Estimate = 0.129) and defeat (indirect effect: Std. Estimate = 0.126). The mediating effect of entrapment and defeat accounted for 50.3% of the association between sleep disturbance and anxiety symptoms.ConclusionSleep disturbance and anxiety symptoms were prevalent among asymptomatic COVID-19 carriers. Entrapment and defeat mediate the association between sleep disturbance and anxiety symptoms. More attention is needed to monitoring sleep conditions and feelings of defeat and entrapment to reduce the risk of anxiety.

Retraction Note: A fuzzy rough hybrid decision making technique for identifying the infected population of COVID-19.

[This retracts the article DOI: 10.1007/s00500-020-05451-0.].

Dynamics analysis of a spatiotemporal SI model

In this article, we investigate a susceptible-infected (SI) model with the saturated treatment, the non-monotonic incidence rate, the logistic growth, and the homogeneous Neumann boundary conditions. The global existence and the uniform boundedness of the parabolic system are performed. After that, we investigate the global stability of the disease free equilibrium (DFE) and the endemic equilibrium (EE), respectively. In the end, we give a priori estimates, some propositions of the nonconstant steady states to the elliptic system. Meanwhile, we find that the diffusion rates of the susceptible and the infected population can affect the nonexistence of the nonconstant steady states. An interesting finding is DFE and basic reproduction number do not exist when the intrinsic growth rate of the susceptible class less than the rate of susceptible individuals being vaccinated.

20-Month monitoring of SARS-CoV-2 in wastewater of Curitiba, in Southern Brazil.

The COVID-19 pandemic resulted in the collapse of healthcare systems and led to the development and application of several approaches of wastewater-based epidemiology to monitor infected populations. The main objective of this study was to carry out a SARS-CoV-2 wastewater based surveillance in Curitiba, Southern Brazil Sewage samples were collected weekly for 20months at the entrance of five treatment plants representing the entire city and quantified by qPCR using the N1 marker. The viral loads were correlated with epidemiological data. The correlation by sampling points showed that the relationship between the viral loads and the number of reported cases was best described by a cross-correlation function, indicating a lag between 7 and 14days amidst the variables, whereas the data for the entire city presented a higher correlation (0.84) with the number of positive tests at lag 0 (sampling day). The results also suggest that the Omicron VOC resulted in higher titers than the Delta VOC. Overall, our results showed that the approach used was robust as an early warning system, even with the use of different epidemiological indicators or changes in the virus variants in circulation. Therefore, it can contribute to public decision-makers and health interventions, especially in vulnerable and low-income regions with limited clinical testing capacity. Looking toward the future, this approach will contribute to a new look at environmental sanitation and should even induce an increase in sewage coverage rates in emerging countries.

A mathematical model to study the spread of COVID-19 and its control in India

Abstract In this article, a nonlinear mathematical model is proposed and analyzed to study the spread of coronavirus disease (COVID-19) and its control. Due to sudden emergence of a peculiar kind of infection, no vaccines were available, and therefore, the nonpharmaceutical interventions such as lockdown, isolation, and hospitalization were imposed to stop spreading of the infectious disease. The proposed model consists of six dependent variables, namely, susceptible population, infective population, isolated susceptible population who are aware of the undesirable consequences of the COVID-19, quarantined population of known infectives (symptomatic), recovered class, and the coronavirus population. The model exhibits two equilibria namely, the COVID-19-free equilibrium and the COVID-19-endemic equilibrium. It is observed that if basic reproduction number R 0 < 1 {R}_{0}\lt 1 , then the COVID-19-free equilibrium is locally asymptotically stable. However, the endemic equilibrium is locally as well as nonlinearly asymptotically stable under certain conditions if R 0 > 1 {R}_{0}\gt 1 . Model analysis shows that if safety measures are adopted by way of isolation of susceptibles and quarantine of infectives, the spread of COVID-19 disease can be kept under control.

Hepatitis C virus (HCV) infection in Malaysia: findings from a nationwide cross-sectional study

Hepatitis C virus (HCV) infection in Malaysia: findings from a nationwide cross-sectional study

Efficacy and safety of PD-1/PD-L1 inhibitors combined with anti-angiogenic therapy for the unresectable hepatocellular carcinoma and the benefit for hepatitis B virus etiology subgroup: a systematic review and meta-analysis of randomized controlled trials

BackgroundHepatocellular carcinoma (HCC) is the third leading cause of cancer-related death, worldwide. The predominant causative factor for HCC is hepatitis B virus (HBV) infection. We conducted a meta-analysis to estimate the efficacy and safety of PD-1/PD-L1 inhibitors combined with anti-angiogenic therapy for the first-line treatment of the unresectable HCC and to evaluate the benefits of different geographic regions and etiology stratifications.MethodsRandomized clinical trials published up to 12th November 2022 were searched by online databases. Moreover, effects of hazard ratio (HR) for overall survival (OS) and progression-free survival (PFS) were extracted from included studies. Pooled odds ratio (OR) and 95% CI for objective response rate (ORR), disease control rate (DCR), and treatment-related adverse events (TRAEs) were calculated.ResultsA total of 3057 patients from five phase III randomized clinical trials were collected and reviewed for this meta-analysis. The pooled HR of OS (HR = 0.71; 95% CI: 0.60–0.85) and PFS (HR = 0.64; 95% CI: 0.53–0.77) demonstrated significantly better benefit in PD-1/PD-L1 inhibitors combination group than targeted monotherapy to treat unresectable HCC. In addition, combination therapy showed better ORR and DCR, with ORs of 3.29 (95% CI: 1.92–5.62) and 1.88 (95% CI: 1.35–2.61), respectively. The subgroup analysis indicated that PD-1/PD-L1 inhibitors combination therapy was significantly superior to anti-angiogenic monotherapy for HBV-related HCC in terms of OS (HR = 0.64; 95% CI: 0.55–0.74) and PFS (HR = 0.53; 95% CI:0.47–0.59), while there was no significant difference in patients with HCV (OS, HR = 0.81, p = 0.1) or non-viral (OS, HR = 0.91, p = 0.37; PFS, HR = 0.77, p = 0.05).ConclusionsMeta-analysis revealed for the first-time that PD-1/PD-L1 inhibitors combination therapy for unresectable HCC was associated with better clinical outcomes than anti-angiogenic monotherapy, especially for HBV infection and Asian population.

Prevalence of R5 and X4-Tropic strains in HIV-1 Infected bangladeshi population

PurposeHIV uses CD4 as main receptor to infect a cell. Also, it uses coreceptor (CCR5 or CXCR4) as a surrogate marker. In Bangladesh, nearly 50% of the identified strains are subtype C. In this study, we have examined viral genotypic co-receptor tropism in Bangladesh People Living with HIV (PLHIV). MethodsWe identified a co-receptor on V3 sequences of the HIV env gene. The online Geno2pheno tools was used. The threshold limit of a 10% false-positive rate was used. Samples from HIV-infected individuals aged 5–50 years were taken from which we obtained a good quality of 55 sequences. The viral tropism frequency in different circulating Bangladeshi HIV subtypes was analyzed using SPSS. ResultsAbove two third of the samples, (61.8%; 34 of 55) were HIV-1 subtype C. We identified 83.6% (46 of 55) of the samples were R5tropic, 16.4% (9 of 55) as X4 tropic, HIV-1 strains. The R5 tropic strains among key population infected with different HIV-1 subtype in the Bangladeshi population is common. ConclusionsThis finding can help with suitable drug selection in reverse-transcriptase (RT) or protease (PR) drug-resistance strains.

Plasmodium vivax infection changes the peripheral immunoregulatory network: CD4 T follicular cells and B cells.

Regulatory and effector cell responses to Plasmodium vivax, the most common human malaria parasite outside Africa, remain understudied in naturally infected populations. Here we describe peripheral CD4+ T and B cell populations during and shortly after an uncomplicated P. vivax infection in 38 continuously exposed adult Amazonians. Consistent with previous observations, we found an increased frequency in CD4+ CD45RA- CD25+ FoxP3+ T regulatory cells that express the inhibitory molecule CTLA-4 during the acute infection, with a sustained expansion of CD21- CD27- atypical memory cells within the CD19+ B-cell compartment. Both Th1- and Th2-type subsets of CXCR5+ ICOShi PD-1+ circulating T follicular helper (cTfh) cells, which are thought to contribute to antibody production, were induced during P. vivax infection, with a positive correlation between overall cTfh cell frequency and IgG antibody titers to the P. vivax blood-stage antigen MSP119 . We identified significant changes in cell populations that had not been described in human malaria, such as an increased frequency of CTLA-4+ T follicular regulatory cells that antagonize Tfh cells, and a decreased frequency of circulating CD24hi CD27+ B regulatory cells in response to acute infection. In conclusion, we disclose a complex immunoregulatory network that is critical to understand how naturally acquired immunity develops in P. vivax malaria. This article is protected by copyright. All rights reserved.

Development and feasibility testing of an integrated PTSD and adherence intervention cognitive processing therapy-life steps (CPT-L) to improve HIV outcomes: Trial protocol

Despite high rates of Post-Traumatic Stress Disorder (PTSD) in persons living with HIV (PLWH) and poor HIV-related health outcomes associated with PTSD, an effective evidence-based treatment for PTSD symptoms in PLWH does not exist. Negative reinforcement conceptual models posit that avoidant behavior (hallmark symptom of PTSD) demonstrated by PLWH with co-occurring PTSD can contribute to poor antiretroviral therapy (ART) adherence. However, research evaluating the impact of evidence-based treatment for PTSD among HIV infected populations on HIV outcomes is scarce. The Cognitive Processing Therapy (CPT) protocol is an evidence-based PTSD treatment that may address internalized stigma with targeted modifications and improve ART adherence and subsequent viral suppression through reduction of avoidant coping. This study will be the first pilot open-label randomized control trial (RCT) to test feasibility of an integrated evidence-based PTSD treatment (CPT) with an adherence intervention (Lifesteps) delivered in a Ryan White clinic to improve PTSD symptoms, adherence to ART, and retention in HIV care. Primary aims are to (1) conduct theater testing of the CPT and Lifesteps research protocol and evaluate acceptability (n = 12) and (2) deliver a modified CPT protocol (CPT-Lifesteps, or CPT-L) in 60 PLWH/PTSD exploring impact of CPT-L on PTSD symptoms and HIV outcomes compared to a Lifesteps + Standard of Care condition. This innovative research extends PTSD treatment approaches as a paradigm to reduce barriers to ART adherence. Findings of this innovative study are significant because they support the Undetectable = Untransmittable (UU) campaign and can help prevent the transmission of HIV infection through increased viral suppression.

Susceptible-Infected-Susceptible Dynamics with Mitigation in Connection of Infected Population

The susceptible-infected-susceptible epidemic model is analyzed through a degree-based mean-field approach. In this work, a mitigation factor is introduced in the probability of finding an infected individual following an edge. This modification simulates situations where the infected population reduces its participation in the dynamics of disease propagation, as may happen with the seclusion or hospitalization of infected individuals. A detailed investigation of this new model and its comparison to the original one (without the mitigation factor) was performed on the Barabási-Albert network, where some important results were analytically accessible.

Structural and functional analysis of the cerato-platanin-like protein Cpl1 suggests diverging functions in smut fungi.

Plant-pathogenic fungi are causative agents of the majority of plant diseases and can lead to severe crop loss in infected populations. Fungal colonization is achieved by combining different strategies, such as avoiding and counteracting the plant immune system and manipulating the host metabolome. Of major importance are virulence factors secreted by fungi, which fulfil diverse functions to support the infection process. Most of these proteins are highly specialized, with structural and biochemical information often absent. Here, we present the atomic structures of the cerato-platanin-like protein Cpl1 from Ustilago maydis and its homologue Uvi2 from Ustilago hordei. Both proteins adopt a double-Ψβ-barrel architecture reminiscent of cerato-platanin proteins, a class so far not described in smut fungi. Our structure-function analysis shows that Cpl1 binds to soluble chitin fragments via two extended grooves at the dimer interface of the two monomer molecules. This carbohydrate-binding mode has not been observed previously and expands the repertoire of chitin-binding proteins. Cpl1 localizes to the cell wall of U. maydis and might synergize with cell wall-degrading and decorating proteins during maize infection. The architecture of Cpl1 harbouring four surface-exposed loop regions supports the idea that it might play a role in the spatial coordination of these proteins. While deletion of cpl1 has only mild effects on the virulence of U. maydis, a recent study showed that deletion of uvi2 strongly impairs U. hordei virulence. Our structural comparison between Cpl1 and Uvi2 reveals sequence variations in the loop regions that might explain a diverging function.

Diagnosis and Treatment of Fungal Infections in Lung Transplant Recipients.

Fungal infections are a significant source of morbidity in the lung transplant population via direct allograft damage and predisposing patients to the development of chronic lung allograft dysfunction. Prompt diagnosis and treatment are imperative to limit allograft damage. This review article discusses incidence, risk factors, and symptoms with a specific focus on diagnostic and treatment strategies in the lung transplant population for fungal infections caused by Aspergillus, Candida, Coccidioides, Histoplasma, Blastomyces, Scedosporium/Lomentospora, Fusarium, and Pneumocystis jirovecii. Evidence for the use of newer triazole and inhaled antifungals to treat isolated pulmonary fungal infections in lung transplant recipients is also discussed.

Time delay induces a back to back Hopf bifurcation on oncolytic virotherapy.

This study analyzes a basic mathematical model for the dynamic interactions among tumor cells, infected tumor cells and viruses population, focusing on the viral lytic cycle for oncolytic virotherapy. I study the time delay effect of viral infection on tumor cell populations by identifying bifurcation thresholds in both the burst rate and time delay of viral infection in oncolytic virus therapy. Time delay plays an important role in changing the structure of tumor cell populations in a dynamical system. The multi-bifurcation thresholds of the time delay are observed and also dependent on the bursting rate. This study demonstrates a strong relationship between viral burst rates and time delays in population dynamics. The results of this study show that time delay affects oscillation generation and results in back-to-back Hopf bifurcation. This study provides insight into understanding the relationship between the two control parameters, in which tumor cell populations pattern from equilibrium steady-state solutions to periodic solutions and from periodic solutions to equilibrium-state solutions.

Myotonic dystrophy type 1 in the COVID-19 era

IntroductionMyotonic dystrophy type 1 (DM1) is the most prevalent muscular dystrophy in adults. People with DM1 might represent a high-risk population for respiratory infections, including COVID-19. Our aim was to evaluate the characteristics of COVID-19 infection and vaccination rate in DM1 patients.MethodsThis cross-sectional cohort study included 89 patients from the Serbian registry for myotonic dystrophies. Mean age at testing was 48.4 ± 10.4 years with 41 (46.1%) male patients. Mean duration of the disease was 24.0 ± 10.3 years.ResultsCOVID-19 infection was reported by 36 (40.4%) DM1 patients. Around 14% of patients had a more severe form of COVID-19 requiring hospitalization. The severity of COVID-19 was in accordance with the duration of DM1. A severe form of COVID-19 was reported in 20.8% of patients who were not vaccinated against SARS-CoV-2 and in none of the vaccinated ones. The majority of 89 tested patients (66.3%) were vaccinated against SARS-CoV-2. About half of them (54.2%) received three doses and 35.6% two doses of vaccine. Mild adverse events after vaccination were recorded in 20.3% of patients.ConclusionsThe percentage of DM1 patients who suffered from COVID-19 was like in general population, but with more severe forms in DM1, especially in patients with longer DM1 duration. The study indicated an overall favorable safety profile of COVID-19 vaccines among individuals with DM1 and its ability to protect them from severe COVID-19.