Maximum Number Of Infectives Research Articles

Study of the Deep Processes of COVID-19 in Russia: Finding Ways to Identify Preventive Measures.

The novel coronavirus disease 2019 (COVID-19) pandemic has had a huge impact on all areas of human life. Since the risk of biological threats will persist in the future, it is very important to ensure mobilization readiness for a prompt response to the possible emergence of epidemics of infectious diseases. Therefore, from both a theoretical and practical standpoint, it is currently necessary to conduct a thorough examination of the COVID-19 epidemic. The goal of this research is to investigate the underlying processes that led to the COVID-19 pandemic in Russia and to identify ways to improve preventive measures and ensure mobilization readiness for a quick response to potential COVID-19-like pandemics. This research will analyze the daily dynamics of the number of infection cases and the number of new lethal cases of COVID-19. We analyzed the daily number of new cases of COVID-19 infection N(d), the daily number of new lethal cases L(d), their percentage ratio L(d)/N(d) 100% in Russia for 2 years of the pandemic (from the beginning of the pandemic to 23 March 2022), the rate of increase and decrease of these indicators (dN(d)/dd and dL(d)/dd), as well as their spectra created on the basis of wavelet analysis. Wavelet analysis of the deep structure of the N(d) and L(d) wavelet spectra made it possible to identify the presence of internal cycles, the study of which makes it possible to predict the presence of days with the maximum number of infections and new deaths in a pandemic similar to COVID-19 and outline ways and methods for improving preventive measures and measures to ensure mobilization readiness for a rapid response to the potential emergence of pandemics similar to COVID-19.

Healthcare in Indonesia

Indonesia is a large state of Southeast Asia, located on several thousand volcanic islands. In terms of population (277 million people), Indonesia ranks 4th in the world, after China, India and the United States. Most of the population (about 58%) lives on the island of Java, despite the fact that its area is only 7% of the total area of the state, which makes this island the most densely populated in the world. The population of Indonesia is very multinational; the bulk are Javanese, about 4% are Malays and the same number are Chinese. The average life expectancy is 71 years: 68 for men and 74 for women, while the average age of Indonesians is 29 years. The main medical problem of Indonesians is the high prevalence of infectious diseases - typhoid fever, hepatitis A, dengue fever, malaria. This is largely due to climatic conditions and poor water quality - only about 80% of the population has access to drinking water, and the main method of disinfection is sunlight irradiation. The coronavirus pandemic has claimed the lives of 144,000 Indonesians, bringing the country's fatality rate to 3.4%. The maximum number of infections occurred in the summer of 2021, when up to 44,000 new cases were registered in the country per day. Compared to European countries, Indonesia is under-vaccinated with only 44.3% of the population completing the full course of vaccination and being able to receive two doses. Despite the fact that one of the significant sources of filling the country's budget is tourism revenue, as of the beginning of 2022, the country remains closed to tourists.

Mathematical Modelling of Transmission Dynamics of COVID-19: A Case Study of Nepal

In this study, the SIR compartmental mathematical model has been proposed to predict the transmission dynamics of COVID-19 in Nepal. The model is analysed by deriving some important expressions such as the basic reproduction ratio and possible maximum number of infectives in the future. This study examines the applicability of the SIR model for the study of the COVID-19 pandemic and other similar infectious diseases. The prime objective of the study is to analyse and forecast the COVID-19 pandemic in Nepal for the upcoming time. The estimation of the parameters of the model is based upon data from January 20, 2020 to July 14, 2020. The model presented in the paper fitted to the time-series data well for the whole Nepal and its neighbouring countries such as India and China. The findings suggest that there is a potential for this model to contribute to better public health policy in combating COVID-19.

The Current Indian Epidemic of Dermatophytosis: A Study on Causative Agents and Sensitivity Patterns.

Background:In the recent years, the frequency, severity, clinical characteristics, treatment response, and relapse rate of dermatophytosis have dramatically changed in India. Given the surge in dermatophytosis, we had undertaken a study to isolate and identify the common species causing dermatophyte infection and to know the in vitro efficacy of the common antifungals against them.Materials and Methods:A total of 103 new cases that were not on any treatment for the past 3 months were included. Skin scrapings were collected for direct microscopic examination and for fungal culture in Sabouraud 4% dextrose agar (SDA) with chloramphenicol and cycloheximide slant tubes, and dermatophyte test media. Fungi were identified on the basis of their macroscopic and microscopic features with the help of lactophenol cotton blue staining and urease test. Also, the drug sensitivity of the dermatophytes was tested with the common antifungals.Results:Of the 55 cases (53.4%) that were positive for dermatophytes in the culture, 29 showed possible contamination. Trichophyton was the predominant organism (49 cases) with T. verrucosum being the commonest species (26 cases), followed by T. rubrum (15 patients), and T. mentagrophytes (8 cases). All species of Trichophyton were found to be most sensitive to itraconazole amongst systemic antifungals and luliconazole amongst topical antifungals.Conclusion:This study concluded that the causative agent for the dermatophytosis was changing in India and in our subset, T. verrucosum caused the maximum number of infections. Itraconazole and luliconazole had the highest sensitivity amongst systemic and topical antifungals, respectively. It also showed that terbinafine had comparatively less sensitivity to most organisms.

Коронавирус в регионах России: особенности и последствия распространения

Russia and the world are experiencing a pandemic that is unprecedented in modern history in terms of the number of cases and socio-economic consequences. The article discusses the features of the statistical accounting of morbidity and mortality and how much they could affect the available estimates. The authors believe that the fixed incidence of the population obeys the laws of the distribution of innovations and depends on the structure and interaction within regional communities. According to the above calculations, if current conditions remain, the maximum number of infections can exceed 160 thousand people, and the end of the epidemic should be expected no earlier than mid-June. We are now at a stage of exponential growth and diffusion across the country. In general, in Russia, the closure and bankruptcy of 50-60% of firms in 2020, according to the most pessimistic scenario, is fraught with a fall in GDP by 3-10% for the year.

Role of Bone Marrow Examination in the Evaluation of Infections: Clinico-Hematological Analysis in a Tertiary Care Centre.

Bone marrow examination (BME) is an important modality for investigation of case of pyrexia of unknown origin (PUO). However, its yield in the diagnosis of infections has not been extensively studied and its role has not been well established. The aim of the study was to investigate the usefulness of BME and to evaluate the etiological and clinico-hematological profile in cases of bone marrow infections. This was a retrospective study where bone marrow cases were retrieved and a review of bone marrow findings with an infectious etiology from July 2014 to June 2018 was done. Detailed history, clinical examination and hematological parameters at presentation were recorded. Clinico-hematological correlation using descriptive statistics was performed. The study included 55 cases, on analysis of which the maximum number of infections were those of leishmaniasis accounting for 35%, followed by HIV (29%) and tuberculosis (15%). Other etiological agents included fungal infections (histoplasmosis and aspergillosis), Enteric fever, Scrub typhus, parvovirus, falciparum malaria and filariasis. The most common clinical presentation was fever (80%) and the most common clinical finding was splenomegaly (66%). Bone marrow examination is an important diagnostic tool to delineate etiological diagnosis in infectious conditions, particularly those presenting with PUO. Moreover, it is particularly important if urgent diagnosis is required or if alternate diagnostic modalities have not revealed a reason for PUO.

Prevalence of Dermatophytic Infection and Detection of Dermatophytes by Microscopic and Culture Methods

Background: Dermatophytosis is considered as one of the major public health problems in the world and is the most commonly diagnosed skin disease in Bangladesh. The prevalence and characteristics of dermatophytic infections vary with climatic conditions, age, lifestyle and population migration patterns.Objective: To determine the prevalence of dermatophytic infection and sensitivity of different diagnostic procedures among the patients visiting dermatology outpatient department of Tairunnessa Memorial Medical College & Hospital, Gazipur, Bangladesh (TMMCH).Materials and Methods: This cross-sectional study was done during a period of 12 months from July 2015 to June 2016. Total 80 specimens were collected based on clinical presentations irrespective of age and sex. The diagnosis was confirmed by microscopic examination using 20% potassium hydroxide (KOH) and culture on Sabouraud’s dextrose agor medium.Results: Out of 80 samples, 31(38.75%) were found positive by culture and 21 (26.25%) were found positive by microscopic method which were also found positive by culture. This study found that most (51.62%) of the dermatophyteinfected cases were in the age group of 21−40 years followed by 41−60 years (29.03%) with male and female distribution 58.06% and 41.94% respectively The maximum number of infections was reported from groin followed by hands/legs and feet.Conclusion: The result of this study shows higher prevalence of dermatophytosis in both genders in this area. An accurate diagnosis can help in proper and effective treatment of dermatophytosis.J Enam Med Col 2018; 8(1): 11-15

A stochastic SIS epidemic model with heterogeneous contacts

A stochastic model for the spread of an SIS epidemic among a population consisting of N individuals, each having heterogeneous infectiousness and/or susceptibility, is considered and its behavior is analyzed under the practically relevant situation when N is small. The model is formulated as a finite time-homogeneous continuous-time Markov chain X. Based on an appropriate labeling of states, we first construct its infinitesimal rate matrix by using an iterative argument, and we then present an algorithmic procedure for computing steady-state measures, such as the number of infected individuals, the length of an outbreak, the maximum number of infectives, and the number of infections suffered by a marked individual during an outbreak. The time till the epidemic extinction is characterized as a phase-type random variable when there is no external source of infection, and its Laplace–Stieltjes transform and moments are derived in terms of a forward elimination backward substitution solution. The inverse iteration method is applied to the quasi-stationary distribution of X, which provides a good approximation of the process X at a certain time, conditional on non-extinction, after a suitable waiting time. The basic reproduction number R0 is defined here as a random variable, rather than an expected value.

New modelling approach concerning integrated disease control and cost-effectivity

Two new models for controlling diseases, incorporating the best features of different control measures, are proposed and analyzed. These models would draw from poultry, livestock and government expertise to quickly, cooperatively and cost-effectively stop disease outbreaks. The combination strategy of pulse vaccination and treatment (or isolation) is implemented in both models if the number of infectives reaches the risk level (RL). Firstly, for one time impulsive effect we compare three different control strategies for both models in terms of cost. The theoretical and numerical results show that there is an optimal vaccination and treatment proportion such that integrated pulse vaccination and treatment (or isolation) reaches its minimum in terms of cost. Moreover, this minimum cost of integrated strategy is less than any cost of single pulse vaccination or single treatment. Secondly, a more realistic case for the second model is investigated based on periodic impulsive control strategies. The existence and stability of periodic solution with the maximum value of the infectives no larger than RL is obtained. Further, the period T of the periodic solution is calculated, which can be used to estimate how long the infectious population will take to return back to its pre-control level (RL) once integrated control tactics cease. This implies that we can control the disease if we implement the integrated disease control tactics every period T. For periodic control strategy, if we aim to control the disease such that the maximum number of infectives is relatively small, our results show that the periodic pulse vaccination is optimal in terms of cost.

Resonances and time operator for the cusp map

A stochastic model for the spread of an SIS epidemic among a population consisting of N individuals, each having heterogeneous infectiousness and/or susceptibility, is considered and its behavior is analyzed under the practically relevant situation when N is small. The model is formulated as a finite time-homogeneous continuous-time Markov chain X. Based on an appropriate labeling of states, we first construct its infinitesimal rate matrix by using an iterative argument, and we then present an algorithmic procedure for computing steady-state measures, such as the number of infected individuals, the length of an outbreak, the maximum number of infectives, and the number of infections suffered by a marked individual during an outbreak. The time till the epidemic extinction is characterized as a phase-type random variable when there is no external source of infection, and its Laplace–Stieltjes transform and moments are derived in terms of a forward elimination backward substitution solution. The inverse iteration method is applied to the quasi-stationary distribution of X, which provides a good approximation of the process X at a certain time, conditional on non-extinction, after a suitable waiting time. The basic reproduction number R0 is defined here as a random variable, rather than an expected value.

On superinfection in malaria.

The task of proving or disproving that there is superinfection of human beings in malaria has been unresolved since the concept of superinfection was introduced by Macdonald (1950). We present a method of analysis the results of which indicate that there is superinfection in children up to the age of about five years, but not in older human hosts. We use maximum-likelihood estimation in an extension of ideas introduced by Bekessy, Molineaux, & Storey (1976). The estimation is based on a model for the infection of human hosts with variable degree of superinfection. This model contains a parameter S that equals the maximum number of infections in the host. In the absence of superinfection, S = 1, while S = infinity in the unlimited superinfection assumed by Macdonald. The estimation of S in a number of age bands allows us to identify the age bands where superinfection occurs.

Optimal control of a deterministic epidemic

Optimal control by immunization of a general deterministic model of an epidemic is examined when cost is measured by the maximum number of infectives plus a measure of the control effort expended. Results guaranteeing that the optimal control has one switch are presented, as are conditions under which the optimal control is to allow the epidemic to run its course unchecked. Optimal control by more efficient removal of infectives is also considered.

Optimal control policies for reducing the maximum size of a closed epidemic—II. Stochastic dynamics

We study the optimal control through immunization of the stochastic version of the Kermack-McKendrick model of an epidemic in a closed population. Costs are taken as the maximum number of infectives during the course of the epidemic, plus an integral functional of the expended immunization effort; the aim is to find a stationary policy which minimizes the expected cost, starting from any point in the epidemic state space. Optimal policies are of the bang-bang type, but require considerable computation in even moderately large populations. The accuracy of several sub-optimal policies which are easier to calculate is investigated.