scholarly journals Basic reproduction numbers of three strains of mouse hepatitis viruses in mice

2022 ◽  
Author(s):  
Masataka Nakayama ◽  
Shigeru Kyuwa
Keyword(s):  
Hepatitis Viruses ◽  
Reproduction Numbers

scholarly journals Basic reproduction numbers of three strains of mouse hepatitis viruses in mice

2021 ◽  
Author(s):  
Masataka Nakayama ◽  
Shigeru Kyuwa
Keyword(s):  
Gastrointestinal Tract ◽  
Immunosorbent Assay ◽  
Hepatitis Virus ◽  
Mouse Hepatitis Virus ◽  
Laboratory Animals ◽  
Enzyme Linked Immunosorbent Assay ◽  
Laboratory Mice ◽  
Hepatitis Viruses ◽  
Viral Growth ◽  
Reproduction Numbers

Mouse hepatitis virus (MHV) is a murine coronavirus and one of the most important pathogens in laboratory mice. Although various strains of MHV have been isolated, they are generally excreted in the feces and transmitted oronasally via aerosols and contaminated bedding. In this study, we attempted to determine the basic reproduction numbers of three strains of MHV to improve our understanding of MHV infections in mice. Five-week-old female C57BL/6J mice were inoculated intranasally with either the Y, NuU, or JHM variant strain of MHV and housed with two naive mice. After 4 weeks, the presence or absence of anti-MHV antibody in the mice was determined by the enzyme-linked immunosorbent assay. We also examined the distribution of MHV in the organs of Y, NuU, or JHM variant-infected mice. Our data suggest that the transmissibility of MHV is correlated with viral growth in the gastrointestinal tract of infected mice. To the best of our knowledge, this is the first report to address the basic reproduction numbers among pathogens in laboratory animals.

The prevalence of infection with hepatitis viruses in patients with lichen planus

Infectio ro ◽  
2017 ◽  
Vol 1 (49) ◽  
Author(s):  
Mădălina Irina Mitran ◽  
Ilinca Nicolae ◽  
Mircea Tampa ◽  
Cristina Iulia Mitran ◽  
Mircea Ioan Popa ◽  
...  
Keyword(s):  
Lichen Planus ◽  
Hepatitis Viruses

COVID-19: Time-Dependent Effective Reproduction Number and Sub-notification Effect Estimation Modeling (Preprint)

2020 ◽  
Author(s):  
Eduardo Atem De Carvalho ◽  
Rogerio Atem De Carvalho
Keyword(s):  
New York ◽  
Reproduction Number ◽  
Moving Average ◽  
Real Data ◽  
Time Dependent ◽  
Initial Value ◽  
Health Authorities ◽  
Reproduction Numbers ◽  
Effect Estimation ◽  
The Impact

BACKGROUND Since the beginning of the COVID-19 pandemic, researchers and health authorities have sought to identify the different parameters that govern their infection and death cycles, in order to be able to make better decisions. In particular, a series of reproduction number estimation models have been presented, with different practical results. OBJECTIVE This article aims to present an effective and efficient model for estimating the Reproduction Number and to discuss the impacts of sub-notification on these calculations. METHODS The concept of Moving Average Method with Initial value (MAMI) is used, as well as a model for Rt, the Reproduction Number, is derived from experimental data. The models are applied to real data and their performance is presented. RESULTS Analyses on Rt and sub-notification effects for Germany, Italy, Sweden, United Kingdom, South Korea, and the State of New York are presented to show the performance of the methods here introduced. CONCLUSIONS We show that, with relatively simple mathematical tools, it is possible to obtain reliable values for time-dependent, incubation period-independent Reproduction Numbers (Rt). We also demonstrate that the impact of sub-notification is relatively low, after the initial phase of the epidemic cycle has passed.

scholarly journals Qualitative properties of mathematical model of English language education

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Atena Ghasemabadi ◽  
Nahid Soltanian
Keyword(s):  
Mathematical Model ◽  
Global Stability ◽  
Equilibrium Point ◽  
English Language ◽  
Language Education ◽  
Qualitative Properties ◽  
English Language Education ◽  
Compound Matrices ◽  
Reproduction Numbers ◽  
Coexistence Equilibrium

AbstractThis paper presents a mathematical model that examines the impacts of traditional and modern educational programs. We calculate two reproduction numbers. By using the Chavez and Song theorem, we show that backward bifurcation occurs. In addition, we investigate the existence and local and global stability of boundary equilibria and coexistence equilibrium point and the global stability of the coexistence equilibrium point using compound matrices.

scholarly journals SARS-CoV-2 vs. Hepatitis Virus Infection Risk in the Hemodialysis Population: What Should We Expect?

2021 ◽  
Vol 18 (11) ◽  
pp. 5748
Author(s):  
Luis D’Marco ◽  
María Jesús Puchades ◽  
Miguel Ángel Serra ◽  
Lorena Gandía ◽  
Sergio Romero-Alcaide ◽  
...  
Keyword(s):  
Hepatitis Virus ◽  
Contact Precaution ◽  
Hepatitis Viruses ◽  
International Consensus ◽  
Infection Treatment ◽  
High Incidence ◽  
Dramatic Rise ◽  
Infection Disease ◽  
Coronavirus Infection ◽  
Hepatitis Virus Infection

Since the dramatic rise of the coronavirus infection disease 2019 (COVID-19) pandemic, patients receiving dialysis have emerged as especially susceptible to this infection because of their impaired immunologic state, chronic inflammation and the high incidence of comorbidities. Although several strategies have thus been implemented to minimize the risk of transmission and acquisition in this population worldwide, the reported severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence varies across studies but is higher than in the general population. On the contrary, the screening for hepatitis viruses (HBV and HCV) has seen significant improvements in recent years, with vaccination in the case of HBV and effective viral infection treatment for HCV. In this sense, a universal SARS-CoV-2 screening and contact precaution appear to be effective in preventing further transmission. Finally, regarding the progress, an international consensus with updated protocols that prioritize between old and new indicators would seem a reasonable tool to address these unexpended changes for the nephrology community.

scholarly journals Special Issue “Structural Variations and Molecular Genetics of Hepatitis Virus and Related Viruses”

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1456
Author(s):  
Kei Fujiwara
Keyword(s):  
Molecular Genetics ◽  
Hepatitis Virus ◽  
Special Issue ◽  
Structural Variations ◽  
Hepatitis Viruses

In this special issue, we present collected updated data on the hepatitis viruses [...]

scholarly journals The Deterministic Evolution Of Illicit Drug Consumption Within a Given Population

2018 ◽  
Vol 62 ◽  
pp. 139-157 ◽  
Author(s):  
Yusra Bibi Ruhomally ◽  
Nabeelah Banon Jahmeerbaccus ◽  
Muhammad Zaid Dauhoo
Keyword(s):  
Drug Users ◽  
Illicit Drug ◽  
Drug Consumption ◽  
Dynamic Evolution ◽  
Evidence Based ◽  
Relative Importance ◽  
Epidemic Threshold ◽  
Drug Usage ◽  
Policy Makers ◽  
Reproduction Numbers

We study the NERA model that describes the dynamic evolution of illicit drug usage in a population. The model consists of nonusers (N) and three categories of drug users: the experimental (E) category, the recreational (R) category and the addict (A) category. Two epidemic threshold term known as the reproduction numbers, R0 and μ are defined and derived. Sensitivity analysis of R0 on the parameters are performed in order to determine their relative importance to illicit drug prevalence. The local and global stability of the equilibrium states are also analysed. We also prove that a transcritical bifurcation occurs at R0 = 1. It is shown that an effective campaign of prevention can help to fight against the prevalence of illicit drug consumption. We demonstrate persistence when R0 > 1 and conditions for the extinction of drug consumption are also established. Numerical simulations are performed to verify our model. Our results show that the NERA model can assist policy makers in targeting prevention for maximum effectiveness and can be used to adopt evidence-based policies to better monitor and quantify drug use trends.

scholarly journals Rapid review of available evidence on the serial interval and generation time of COVID-19

BMJ Open ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. e040263
Author(s):  
John Griffin ◽  
Miriam Casey ◽  
Áine Collins ◽  
Kevin Hunt ◽  
David McEvoy ◽  
...  
Keyword(s):  
Generation Time ◽  
Social Contact ◽  
Careful Consideration ◽  
Rapid Review ◽  
Eligibility Criteria ◽  
Reproduction Numbers ◽  
Serial Interval ◽  
Scientific Papers ◽  
The Mean ◽  
Parameter Values

The serial interval is the time between symptom onsets in an infector–infectee pair. The generation time, also known as the generation interval, is the time between infection events in an infector–infectee pair. The serial interval and the generation time are key parameters for assessing the dynamics of a disease. A number of scientific papers reported information pertaining to the serial interval and/or generation time for COVID-19. Objective Conduct a review of available evidence to advise on appropriate parameter values for serial interval and generation time in national COVID-19 transmission models for Ireland and on methodological issues relating to those parameters. Methods We conducted a rapid review of the literature covering the period 1 January 2020 and 21 August 2020, following predefined eligibility criteria. Forty scientific papers met our inclusion criteria and were included in the review. Results The mean of the serial interval ranged from 3.03 to 7.6 days, based on 38 estimates, and the median from 1.0 to 6.0 days (based on 15 estimates). Only three estimates were provided for the mean of the generation time. These ranged from 3.95 to 5.20 days. One estimate of 5.0 days was provided for the median of the generation time. Discussion Estimates of the serial interval and the generation time are very dependent on the specific factors that apply at the time that the data are collected, including the level of social contact. Consequently, the estimates may not be entirely relevant to other environments. Therefore, local estimates should be obtained as soon as possible. Careful consideration should be given to the methodology that is used. Real-time estimations of the serial interval/generation time, allowing for variations over time, may provide more accurate estimates of reproduction numbers than using conventionally fixed serial interval/generation time distributions.

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