Susceptible Persons Research Articles

Transport Characteristics and Transmission Risk of Virus-Containing Droplets from Coughing in Outdoor Windy Environment.

Particle dispersions have been widely studied inside rooms, but few databases have examined the transmission risk of respiratory droplets outdoors. This study investigated the wind effect on the dispersion of coughed droplets and the influence of social distancing on the infection risk in different susceptible persons using computational fluid dynamics simulations. Infection risk was evaluated based on direct depositions and exposure fractions. The results indicated that a reverse and upward flow formed in front of an infected man, and it enhanced as the wind strengthened, which transported more medium particles higher and increased the deposition on both infected and susceptible persons. Small particles moved above the neck, and they rarely deposited on the body. Medium particles larger than 60 μm were more likely to deposit and could reach the head of a healthy person under stronger winds. The exposure fraction achieved peak values when numerous particles passed the breathing zone. Although longer social distancing could alleviate the particle deposition on the face and delay the most dangerous time, its effect on infection risk was ambiguous. The infection risk was larger for a shorter susceptible person because more particles were deposited on the face, and the exposure fraction contributed by particles above the neck was larger.

Penetration and aerosolization of cough droplet spray through face masks: A unique pathway of transmission of infection

The advent of the COVID-19 pandemic has necessitated the use of face masks, making them an integral part of the daily routine. Face masks occlude the infectious droplets during any respiratory event contributing to source control. In the current study, spray impingement experiments were conducted on porous surfaces like masks having a different porosity, pore size, and thickness. The spray mimics actual cough or a mild sneeze with respect to the droplet size distribution (20–500 μm) and velocity scale (0–14 m/s), which makes the experimental findings physiologically realistic. The penetration dynamics through the mask showed that droplets of all sizes beyond a critical velocity penetrate through the mask fabric and atomize into daughter droplets in the aerosolization range, leading to harmful effects due to the extended airborne lifetime of aerosols. By incorporating spray characteristics along with surface tension and viscous dissipation of the fluid passing through the mask, multi-step penetration criteria have been formulated. The daughter droplet size and velocity distribution after atomizing through multi-layered masks and its effects have been discussed. Moreover, the virus-emulating particle-laden surrogate respiratory droplets are used in impingement experiments to study the filtration and entrapment of virus-like nanoparticles in the mask. Furthermore, the efficacy of the mask from the perspective of a susceptible person has been investigated.

Robust and Intuitive Model for COVID-19 Epidemic in Slovenia

The main goal of epidemic modelling is to support the epidemic management through forecasts and analyses of past developments. With this in mind a robust and intuitive SEIR (Susceptible, Exposed, Infectious, Recovered) type model has been developed, applied and verified during the multiple waves of the COVID-19 epidemics in Slovenia since March 2020. The model parameters were based on the general characteristics of the COVID-19 disease reported globally for the entire planet and refined with the aggregate data available mostly on a daily basis in Slovenia, as for example the number of confirmed cases, hospitalized patients, hospitalized patients in intensive care units and deceased. The Slovenian aggregate data was also used to estimate the degree of immunisation due to past infections and vaccination, which reduces the number of susceptible persons for the disease.
 Examples of the model application are presented to illustrate its robustness and intuitiveness in both the forecasts and analyses of past developments. The analyses of past developments provided specific estimates of modelling parameters for Slovenia and quantified the effects of pharmaceutical and non-pharmaceutical interventions and various events on the development of the epidemics as measured through the reproduction number R. This empirically obtained information was then applied in the forecasts. Accurate forecasts are a great support for decision makers and for hospitals to plan appropriate actions in advance. The inherent uncertainties in the model and data were quantified through intuitive sensitivity analyses represented as different scenarios. The observed accuracy of the forecasts was impressively good also in demanding conditions, when various complex processes influencing the spread of the disease were going on in parallel. This demonstrates the robustness and relevance of the proposed model.

Impact of the SARS-CoV-2 pandemic on vaccine-preventable disease campaigns

BackgroundThe COVID-19 pandemic has contributed to the widespread disruption of immunization services, including the postponement of mass vaccination campaigns.MethodsIn May 2020, the World Health Organization and partners started monitoring COVID-19-related disruptions to mass vaccination campaigns against cholera, measles, meningitis A, polio, tetanus-diphtheria, typhoid, and yellow fever through the Immunization Repository Campaign Delay Tracker. The authors reviewed the number and target population of reported preventive and outbreak response vaccination campaigns scheduled, postponed, canceled, and reinstated at 4 time points: May 2020, December 2020, May 2021, and December 2021.FindingsMass vaccination campaigns across all vaccines were disrupted heavily by COVID-19. In May 2020, 105 of 183 (57%) campaigns were postponed or canceled in 57 countries because of COVID-19, with an estimated 796 million postponed or missed vaccine doses. Campaign resumption was observed beginning in July 2020. In December 2021, 77 of 472 (16%) campaigns in 54 countries, mainly in the African Region, were still postponed or canceled because of COVID-19, with about 382 million postponed or missed vaccine doses.InterpretationThere is likely a high risk of vaccine-preventable disease outbreaks across all regions because of an increased number of susceptible persons resulting from the large-scale mass vaccination campaign postponement caused by COVID-19.

New Rapid, Simple, and Cheap Methods to Determine Tyramine in Fermented Beverages and Culture Medium

Fermented beverages are frequently contaminated with biogenic amines, produced by lactic acid bacteria that exhibit decarboxylase activity. Wine spoilage can occur when increased tyramine concentrations creates a product harmful to consumers. Determination of tyramine is important because it elevates blood pressure, which might cause a migraine attack in susceptible persons. We developed two rapid, inexpensive, and simple methods, a colorimetric technique and a thin-layer chromatography technique, to determine tyramine concentrations in culture medium and wine without complicated extraction procedures. The new colorimetric method showed high correlation between absorbance and tyramine concentrations from 1.0 to 100 mg/L in Moeller culture broth and red wine (r² = 0.9995 and 0.9988, respectively). Thin-layer chromatography (nTLC) with a new visualization reagent also demonstrated a high correlation among tyramine concentrations between 5.0 and 100 mg/L and absorbance, with an r² of 0.988. Both new methods showed a high correlation with high-performance liquid chromatography (colorimetric method, r² = 0.9995; nTLC, r² = 0.9982) and exhibited good tyramine recovery (>83%). The detection limit of the two new methods was comparable with existing analytical methods. The new assays are simple, inexpensive, and do not require any laborious pre-treatment of the samples. Both methods are suitable for routine analysis to quickly and safely monitor tyramine in a research or wine quality control laboratory. The methods were validated in various matrices: in culture media frequently used in microbiology laboratories, in common Argentine wine varietals, such as Cabernet Sauvignon and Torrontés, and in other fermented beverages, such as sparkling wine, cider, and craft beer.

An overview on the incorporation of novel ingredients on nutritional, textural, and organoleptic properties of gluten-free cereal products

Background: Celiac disease is an autoimmune disorder launched by gluten ingestion in genetically susceptible persons. This component leads to an inflammation of the small intestine which causes malabsorption of some important nutrients including calcium, iron, folic acid, and liposoluble vitamins. A gluten-free diet, that is strictly followed by affected patients throughout their whole lives, constitutes the unique effective treatment for celiac disease. Aims: Several gluten-free cereals, pseudo-cereals, legumes, starches (rice, corn, sorghum, millets, buckwheat, quinoa, teff, chestnuts, chia, potato starch, peas, etc.), and various gluten substitutes (xanthan and gum guar) were utilized to maintain the physical and sensory properties of gluten-free cereal products. This review examined recent advances in the formulation of gluten-free cereal-based products using innovative gluten-free flours. Conclusions: Consequently, this review presents and summarizes recent findings in the improvement of the technological, nutritional, and sensory properties of gluten-free cereal products. However, the preparation of cereal-based gluten-free products still remains a difficult process. Therefore, the diet must be not only exempt from gluten but also healthy to avoid nutrient, vitamins, and minerals deficiencies. Thus, a great deal of this review focuses on studying novel and healthy gluten-free ingredients which should fulfill all quality requirements for bakery and pastry products as well as satisfy the needs of celiac consumers. Keywords: gluten-free products, alternative flours, celiac disease.

Psoriasis between Autoimmunity and Oxidative Stress: Changes Induced by Different Therapeutic Approaches.

Psoriasis is defined as chronic, immune-mediated disease. Regardless of the development of new therapeutic approaches, the precise etiology of psoriasis remains unknown and speculative. The aim of this review was to systematize the results of previous research on the role of oxidative stress and aberrant immune response in the pathogenesis of psoriasis, as well as the impact of certain therapeutic modalities on the oxidative status in patients with psoriasis. Complex immune pathways of both the innate and adaptive immune systems appear to be major pathomechanisms in the development of psoriasis. Oxidative stress represents another important contributor to the pathophysiology of disease, and the redox imbalance in psoriasis has been reported in skin cells and, systemically, in plasma and blood cells, and more recently, also in saliva. Current immune model of psoriasis begins with activation of immune system in susceptible person by some environmental factor and loss of immune tolerance to psoriasis autoantigens. Increased production of IL-17 appears to be the most prominent role in psoriasis pathogenesis, while IL-23 is recognized as master regulator in psoriasis having a specific role in cross bridging the production of IL-17 by innate and acquired immunity. Other proinflammatory cytokines, including IFN-γ, TNF-α, IL-1β, IL-6, IL-22, IL-26, IL-29, or IL-36, have also been reported to play important roles in the development of psoriasis. Oxidative stress can promote inflammation through several signaling pathways. The most noticeable and most powerful antioxidative effects exert various biologics compared to more convenient therapeutic modalities, such as methotrexate or phototherapy. The complex interaction of redox, immune, and inflammatory signaling pathways should be focused on further researches tackling the pathophysiology of psoriasis, while antioxidative supplementation could be the solution in some refractory cases of the disease.

Effect of lockdown and vaccination on the course of the COVID-19 pandemic in Germany.

Incidence(t), derived from observational data published by the Robert Koch Institute, Berlin, Germany, is a commonly used parameter to illustrate the course of the COVID-19 pandemic in Germany. The parameter tα(t), equivalent to the doubling-time of the virus described by our research group, has also been useful in this regard. To identify and compare parameters suitable for monitoring the course of the pandemic and to evaluate the extent to which these reflect qualitatively and quantitatively the effects of interventional measures introduced to control the pandemic. Parameters potentially useful for monitoring the course of the pandemic were obtained empirically or derived using the Bateman SIZ model and observational data for the daily increase in the number of new infections. The doubling-time in the number of infections, tα(t) was obtained by curve-fitting observational data for the previous 14-day interval and a fixed value for tbeta (half-life for rate of recovery = 6.24 days). The effects of the interventional measures on the course of the pandemic as reflected in the modulation of the identified parameters were evaluated. A total of 5 different parameters (Incidence(t), R9(t), tα_stable(S), Incidencecalc(t+14), tα(t)) of potential value in monitoring the course of the pandemic were identified. Lockdown measures altered Incidence(t), and these effects could be quantitated from alterations in the reproduction factor, R9(t), a parameter with prognostic value reflecting the consequences of non-intervention. The parameter tα_stable(S) is a function of the proportion of susceptible persons and therefore reflects the effects of vaccination. Although vaccination was in progress, together with lockdown and restrictions associated with the Recovered-Vaccinated-tested rule, R9(t) remained above 1.0 apparently due to the emergence of the more virulent Mδ variant (4th wave of the pandemic in Germany). i) The newly identified parameters provide qualitative and quantitative information on the course of the COVID-19 pandemic in Germany. ii) R9(t) is a suitable parameter for assessing the effects of interventional measures and may have prognostic value. iii) The parameter tα_stable(S), a function of the proportion of susceptible persons, reflects the effects of vaccination. iv) Incidencecalc(t+14) provides prognostic information on the projected course of the pandemic with the assumption that the factors driving the pandemic do not change and is recommended as a suitable parameter for making decisions in real-time, with minimum delay, whether lockdown measures should be implemented.

Universal Hepatitis B Antibody Screening and Vaccination in Pregnancy: A Cost-Effectiveness Analysis.

To evaluate the cost effectiveness of universal screening for hepatitis B immunity and vaccination among pregnant women in the United States. We designed a decision-analytic model to evaluate the outcomes, costs, and cost effectiveness associated with universal hepatitis B virus (HBV) immunity screening in pregnancy with vaccination of susceptible individuals compared with no screening. A theoretical cohort of 3.6 million women, the approximate number of annual live births in the United States, was used. Outcomes included cases of HBV, hepatocellular carcinoma, decompensated cirrhosis, liver transplant and death, in addition to cost and quality-adjusted life-years (QALYs). Model inputs were derived from the literature, and the willingness-to-pay threshold was $50,000 per QALY. Univariate sensitivity analyses and Monte Carlo simulation models were performed to evaluate the robustness of the results. In a theoretical cohort of 3.6 million women, universal HBV immunity screening and vaccination resulted in 1,702 fewer cases of HBV, seven fewer cases of decompensated cirrhosis, four fewer liver transplants, and 11 fewer deaths over the life expectancy of a woman after pregnancy. Universal screening and vaccination were found to be cost effective, with an incremental cost-effectiveness ratio of $1,890 per QALY. Sensitivity analyses demonstrated the model was robust even when the prevalence of HBV immunity was high and the annual risk of HBV acquisition low. Among pregnant women in the United States, universal HBV immunity screening and vaccination of susceptible persons is cost effective compared with not routinely screening and vaccinating.

The impact of perceived air pollution on labour supply: Evidence from China

Air pollution and ageing populations are two of the most important issues facing in the development of all countries around the world, and the resulting debate between air pollution and labour supply has become increasingly intense. This paper uses data from the 2017 China Migrants Dynamic Survey (CMDS data), exploring the impact of perceived air pollution on labour supply of the migrants based on the perspective of the heterogeneity of different groups' sensitivity to air pollution. After overcoming the reverse causality between perceived air pollution and labour supply using an instrumental variables approach, we find that there is a significant negative effect of perceived air pollution on labour supply. At the same time, this negative effect shows some heterogeneity in terms of the presence of susceptible persons in the family, workers' income levels and household registration. Therefore, in the current economic and social development, in addition to improving measured air quality, it is also necessary to focus on improving the perceived air quality of citizens, as well as improving the working environment of the vulnerable groups in the labour market and protecting their basic labour rights and interests, which is of positive significance for the continuation of the demographic dividend and providing impetus for high-quality and sustainable economic development.

A zonal model for assessing the infection risk distribution of COVID-19 in indoor environments

Nowadays, the search for new solutions to the pandemic situation caused by the spread of SARS-CoV-2 is one of the most important issues worldwide. The difficulties encountered in finding an effective cure for the infection and the ongoing vaccination campaign place a priority on minimising the transmission of this disease. This paper deals exclusively with the airborne route of transmission for COVID-19, proposing a model for the evaluation of infection risk. It starts from the well-known Wells-Riley model and its successive modifications and tries to couple it with a zonal model which analyses the air movement in an indoor environment. The objective of this model is evaluating whether the infection risk depends considerably on the position of the infected subject and the susceptible person in the room and how different ventilation concepts affect these aspects. The model was applied to an office room with a mixing ventilation system. The results obtained concern the sub-division of the considered volume in four cells, each one perfectly mixed. The evaluation of infection risk in different positions was carried out and an analysis on the parameters affecting this value was performed.

A Study on Pulmonary Tuberculosis and Risk Factors in New and Re-Treated Presumptive Patients at Wad Madani Tuberculosis Center, Sudan (2018-2019): A Cross-Sectional Study

Introduction: The increase in cases of drug-resistant pulmonary tuberculosis, especially in endemic areas, is mainly associated with re-treatment, although resistant tubercle bacilli can be easily transmitted between all susceptible persons. Objective: The study aimed to describe pulmonary tuberculosis, risk factors and MDR in new and re-treated suspected patients attending Wad Madani Tuberculosis Center that provides service in central Sudan. Methods: Cross-sectional laboratory based study among 300 presumptive pulmonary tuberculosis patients during 2018 and 2019 was conducted. Cases were divided into new and re-treated. Mycobacterium tuberculosis DNA and rpoB gene of multi-drug resistance (MDR) were detected in sputum samples by GeneXpert assay as manufacturer instructions. Results: Out of 300 suspected participants, 34% (103/300) were diagnosed as pulmonary tuberculosis using GeneXpert method. The frequency of males, the age group from 21 to 40 and rural housing were the most with percentage reach 68% (70/103), 51% (53/103) and 58.3% (60/103) respectively. All observed symptoms were significantly associated with pulmonary tuberculosis. New cases represented 59.2% (61/103) while re-treated was 40.8% (39/103). The overall frequency of MDR patients was 9.7% (10/103) of which 50% (5/103) had relapse situation. Conclusion: It appeared that the cases of MDR pulmonary tuberculosis are on the increase compared to previous findings, recommended measures must be taken to control the spread of tuberculosis and the causes of re-treatment and relapse must be studied.

Sensitization to common aeroallergens in the atopic population of Malatya Province, Turkey: A retrospective analysis using skin prick test

Aim: Asthma and allergic rhinitis (AR) are chronic disorders that occur frequently and affect the quality of life. It is important to identify aeroallergens in a certain region to diagnose and treat asthma and AR in susceptible persons. We aimed to determine the distribution of aeroallergen sensitization rates using the skin prick test (SPT) in adult patients with AR and/or asthma in Malatya Province, Turkey. Materials and Methods: Between May 2018 and December 2021, we retrospectively reviewed the data of patients with AR and/or asthma and sensitivity to at least one aeroallergen on the SPT. Results: Of the 419 patients enrolled in our study, 334 (79.7%) had only AR, 68 (16.2%) had both AR and asthma, and 17 (4.1%) had only asthma. A total of 259 (61.8%) patients were women, and the mean age was 30.52 ± 10.06 years. Sensitization to grass mix was most common (71.8%), and its rate was higher among patients with only AR and those with AR and asthma (75.1% vs. 64.7%, p = 0.001) than in patients with only asthma. However, the sensitization rate to Dermatophagoides pteronyssinus was higher in patients with only asthma (47.1%, p < 0.001) than in the other groups. Conclusions: We found that grass mix was the most common sensitizing aeroallergen in accordance with the geographic and climatic characteristics of Malatya Province. This information may help with diagnosis, management, and prevention of AR and asthma.

Theoretical Analysis of the SIRVVD Model for Insights Into the Target Rate of COVID-19/SARS-CoV-2 Vaccination in Japan

The effectiveness of the first and second dose vaccinations are different for COVID-19; therefore, a susceptible-infected-recovered-vaccination1-vaccination2-death (SIRVVD) model that can represent the states of the first and second vaccination doses has been proposed. By the previous study, we can carry out simulating the spread of infectious disease considering the effects of the first and second doses of the vaccination based on the SIRVVD model. However, theoretical analysis of the SIRVVD Model is insufficient. Therefore, we obtained an analytical expression of the infectious number, by treating the numbers of susceptible persons and vaccinated persons as parameters. We used the solution to determine the target rate of the vaccination for decreasing the infection numbers of the COVID-19 Delta variant (B.1.617) in Japan. Further, we investigated the target vaccination rates for cases with strong or weak variants by comparison with the COVID-19 Delta variant (B.1.617). This study contributes to the mathematical development of the SIRVVD model and provides insight into the target rate of the vaccination to decrease the number of infections.

Airborne infection probability in relation of room air distribution: an experimental investigation

The objective of this study was to investigate the importance of room air distribution in airborne cross-infection. Tracer gas measurements were performed in a field lab arranged as an office with two breathing thermal manikins. The room was ventilated with a mixing air distribution operating at a constant supply airflow rate of 60 L/s (4 ACH) under different air discharge scenarios: 2-way, 3-way and 4-way. Room air temperature was kept at 22.0±0.2°C. Respiratory-generated airborne pathogens were simulated by N2O dosed into the exhaled air of the manikin acting like an infected person. The N2O concentration was measured in the inhaled air of the second manikin (simulating susceptible person), exhaust and occupied zone. Measured values were used to calculate infection probability by modified Wells-Riley method. The infection probability in the occupied zone depended on the air discharge scenario. The highest infection probability of 2.9-3.9% was obtained in the inhaled air of the exposed manikin in all experimental cases. The results reveal that room air distribution is of major importance for airborne cross-infection. Therefore, during ventilation design and operation, air distribution should be carefully considered in practice. Infection probability calculated using original Wells-Riley method was underestimated compared to values obtained through measurements.

Chapter 6 - Obstructive sleep apnea

Obstructive sleep apnea (OSA) is a disease that results from loss of upper airway muscle tone leading to upper airway collapse during sleep in anatomically susceptible persons, leading to recurrent periods of hypoventilation, hypoxia, and arousals from sleep. Significant clinical consequences of the disorder cover a wide spectrum and include daytime hypersomnolence, neurocognitive dysfunction, cardiovascular disease, metabolic dysfunction, respiratory failure, and pulmonary hypertension. With escalating rates of obesity a major risk factor for OSA, the public health burden from OSA and its sequalae are expected to increase, as well. In this chapter, we review the mechanisms responsible for the development of OSA and associated neurocognitive and cardiometabolic comorbidities. Emphasis is placed on the neural control of the striated muscles that control the pharyngeal passages, especially regulation of hypoglossal motoneuron activity throughout the sleep/wake cycle, the neurocognitive complications of OSA, and the therapeutic options available to treat OSA including recent pharmacotherapeutic developments.

An autologous colonic organoid-derived monolayer model to study immune: bacterial interactions in Crohn's disease patients.

ObjectivesCrohn's disease (CD) initiation and pathogenesis are believed to involve an environmental trigger in a genetically susceptible person that results in an immune response against commensal gut bacteria, leading to a compromised intestinal epithelial barrier and a cycle of inflammation. However, it has been difficult to study the contribution of all factors together in a physiologically relevant model and in a heterogenous patient population.MethodsWe developed an autologous colonic monolayer model that incorporated the immune response from the same donor and a commensal bacteria, Faecalibacterium prausnitzii. Two‐dimensional monolayers were grown from three‐dimensional organoids generated from intestinal biopsies, and the epithelial integrity of the epithelium was measured using transepithelial electrical resistance. We determined the effect of immune cells alone, bacteria alone and the co‐culture of immune cells and bacteria on integrity.ResultsMonolayers derived from CD donors had impaired epithelial integrity compared to those from non‐inflammatory bowel disease (IBD) donors. This integrity was further impaired by culture with bacteria, but not immune cells, despite a higher frequency of inflammatory phenotype peripheral T cells in CD donors. Variability in epithelial integrity was higher in CD donors than in non‐IBD donors.ConclusionWe have developed a new autologous model to study the complexity of CD, which allows for the comparison of the barrier properties of the colonic epithelium and the ability to study how autologous immune cells directly affect the colonic barrier and whether this is modified by luminal bacteria. This new model allows for the study of individual patients and could inform treatment decisions.

Infiltrating cardiomyopathy presenting with recurrent ventricular tachycardia

Abstract Infiltrative cardiomyopathy (ICM) refers to a heterogeneous group of myocardial disorders mainly cardiac amyloidosis, sarcoidosis, and hemochromatosis with characteristic deposition of abnormal substances within cellular and intercellular spaces, which leads to the development of ventricular diastolic dysfunction, systolic dysfunction, or both. Sarcoidosis is a multisystem, granulomatous disease of unknown etiology. Accumulating evidence suggests that it is caused by an immunological response to an unidentified antigenic trigger in genetically susceptible persons. Cardiac sarcoidosis is a manifestation of sarcoidosis that is challenging to diagnose due to its clinical silence. The consequences of cardiac sarcoidosis include conduction defects, arrhythmias, cardiomyopathy, congestive heart failure, and sudden cardiac death (SCD). This case describes a 45-year-old female with a history of recurrent ventricular tachycardia in a patient previously diagnosed as dilated nonischemic cardiomyopathy. Who was later diagnosed as ICM, most probably cardiac sarcoidosis with the help of cardiac magnetic resonance imaging (MRI). Initial testing for infiltrating cardiomyopathy should include echocardiography, cardiac MRI, and fluorodeoxyglucose–positron emission tomography study. Treatment focuses on optimizing heart failure therapy and placement of a biventricular implantable cardioverter-defibrillator for primary prevention of SCD.

The Genomic Physics of COVID-19 Pathogenesis and Spread.

Coronavirus disease (COVID-19) spreads mainly through close contact of infected persons, but the molecular mechanisms underlying its pathogenesis and transmission remain unknown. Here, we propose a statistical physics model to coalesce all molecular entities into a cohesive network in which the roadmap of how each entity mediates the disease can be characterized. We argue that the process of how a transmitter transforms the virus into a recipient constitutes a triad unit that propagates COVID-19 along reticulate paths. Intrinsically, person-to-person transmissibility may be mediated by how genes interact transversely across transmitter, recipient, and viral genomes. We integrate quantitative genetic theory into hypergraph theory to code the main effects of the three genomes as nodes, pairwise cross-genome epistasis as edges, and high-order cross-genome epistasis as hyperedges in a series of mobile hypergraphs. Charting a genome-wide atlas of horizontally epistatic hypergraphs can facilitate the systematic characterization of the community genetic mechanisms underlying COVID-19 spread. This atlas can typically help design effective containment and mitigation strategies and screen and triage those more susceptible persons and those asymptomatic carriers who are incubation virus transmitters.

Mathematical modelling of the epidemiology of COVID-19 infection in Ghana

In this paper, Covid-19 patients with self-immunity is incorporated in the Susceptible-Exposed-Infected-Quarantined-Recovered (SEIQR) model is applied to describe the epidemiology of Covid-19 infection in Ghana. Based on data on the epidemiology of the Covid-19 infection in Ghana, we observed that, on an average, three persons contract the Covid-19 infection from an infected person daily based using the basic reproductive number (Ro) derived from the SEIQR model. In addition, the threshold condition for the long term stability of the Covid-19 infection in Ghana is derived from this model. Based on the Dulac criterion, it was observed that for a long period of time the epidemiology of Covid-19 in Ghana will be under control. Again, we observed that both the transmission rate natural death rate of a person in the various classes mostly influence the spread of Covid-19 infection followed by the exposed rate from exposure class to the infected class, then the rate at which an infected person is quarantined and finally, the rate at an exposed person is quarantined. On the other hand, the rate at which an exposed person recovers from his/her have least influence on the spread of Covid-19 infection in the country. Nevertheless, the rates of birth, transmission of Covid-19 infection to a susceptible person, exposure to Covid-19 infection and Covid-19 patient who is quarantined by the facilities provided by the Ghana Health Service (GHS) are in direct relationship with Ro. However, the rates at which a quarantiner dies from a Covid-19 infection, an infected person dies from a Covid-19 infection, natural death from each class and the recoveries from an infected class, exposed class and quarantined class are in relationship with Ro.