Severity Of Associated Disease Research Articles

Defining the pknH Transcriptional Network in the Animal Tuberculosis bacillus, Mycobacterium bovis

The Mycobacterium tuberculosiscomplex (MTBC) is a group of bacteria that show more than 99% genetic identity, yet they diverge in their host preference and the severity of associated disease. Mycobacterium bovis causes the disease in cattle and poses an economic challenge, with the cost of Irelands TB Eradication Scheme predicted to exceed €90 million in 2020. The aim was to focus on the RD900 and pknH gene network in MTBC members. ThepknH gene encodes a transmembrane serine threonine protein kinase, that plays a role in the regulation of signalling pathways in the mycobacterial cell and has been linked to virulence. The RD900 or “region of difference 900” contains the tbD2 and pknH2 genes. The part of the genome that contains this region varies substantially across MTBC members. The results of RNA-seq analysis showed that there are statistically significant levels of differential gene expression in wildtype and knock-in M. bovis strains. The RD900 analysis across the MTBC showed that there is variation in this important genomic region. Analysis carried out by Mata et al. 2020, showed that this RD900 region had been independently lost in different MTBC lineages and strains. M. bovis has retained the RD900 region and this is believed to be linked to its increased virulence. The majority of the M . africanum strains were found to possess the standard pknH, tbD2, pknH2, embR gene arrangement as is found in M. africanum GM041182, the strain that is typically used as a reference. Based on work of Mata et al., 2020.

Atlantic salmon farms are a likely source of Tenacibaculum maritimum infection in migratory Fraser River sockeye salmon

Juvenile sockeye salmon (Oncorhynchus nerka) in British Columbia migrate past numerous Atlantic salmon (Salmo salar) farms from which they may acquire infectious agents. We analyse patterns of molecular detection in juvenile sockeye for the bacterium Tenacibaculum maritimum, known to cause disease in fish globally and to cause mouthrot disease in farmed Atlantic salmon in British Columbia. Our data show a clear peak in T. maritimum detections in the Discovery Islands region of British Columbia, where sockeye migrate close to salmon farms. Using well-established differential equation models to describe sockeye migration and bacterial infection, fit to detection data, we assessed support for multiple hypotheses describing farm- and background-origin infection. Our best models (with 99.8% empirical support) describe constant background infection pressure, except around Discovery Islands salmon farms, where farm-origin infection pressure peaked at 12.7 (approximate 95% CI: 4.5 to 31) times background levels. Given the severity of associated disease in related species and the imperilled nature of Fraser River sockeye, our results suggest the need for a more precautionary approach to managing farm–wild interactions in sockeye salmon.

Mathematical modeling of COVID-19 pandemic in India using Caputo-Fabrizio fractional derivative

The range of effectiveness of the novel corona virus, known as COVID-19, has been continuously spread worldwide with the severity of associated disease and effective variation in the rate of contact. This paper investigates the COVID-19 virus dynamics among the human population with the prediction of the size of epidemic and spreading time. Corona virus disease was first diagnosed on January 30, 2020 in India. From January 30, 2020 to April 21, 2020, the number of patients was continuously increased. In this scientific work, our main objective is to estimate the effectiveness of various preventive tools adopted for COVID-19. The COVID-19 dynamics is formulated in which the parameters of interactions between people, contact tracing, and average latent time are included. Experimental data are collected from April 15, 2020 to April 21, 2020 in India to investigate this virus dynamics. The Genocchi collocation technique is applied to investigate the proposed fractional mathematical model numerically via Caputo-Fabrizio fractional derivative. The effect of presence of various COVID parameters e.g. quarantine time is also presented in the work. The accuracy and efficiency of the outputs of the present work are demonstrated through the pictorial presentation by comparing it to known statistical data. The real data for COVID-19 in India is compared with the numerical results obtained from the concerned COVID-19 model. From our results, to control the expansion of this virus, various prevention measures must be adapted such as self-quarantine, social distancing, and lockdown procedures.

Effectiveness of Isolation and Contact Tracing for Containment and Slowing Down a COVID-19 Epidemic: A Modelling Study

Background: Novel coronavirus (SARS-CoV-2) is extending its range of transmission in all parts of the world, with substantial variation in rates of transmission and severity of associated disease. Methods: We evaluated whether and under which conditions it is possible to control and slow down a COVID-19 epidemic in the early stages by isolation and contact tracing. We used a stochastic transmission model in which every person generates novel infections according to a probability distribution that is affected by the incubation period distribution (time from infection to symptoms), distribution of the latent period (time from infection to a person becoming infectious), and overall transmissibility. The model distinguishes between close contacts (e.g., within a household) and other contacts in the population. Findings: The analyses showed that transmissibility and the duration of the latent period relative to the duration of incubation period have strong impact on the controllability of the disease. Delays in diagnosis of cases and proportion of asymptomatic cases are key factors for containment and slowing down the epidemic. Interpretation: Isolation and contact tracing can be an effective means to control early epidemics, but only if transmissibility as measured by R0 is in the lower ranges of reported values. Timeliness as well as completeness of tracing and diagnosis of cases are paramount to achieve containment and effective slowing down of the epidemic growth rate. Funding Statement: This research was funded by the Dutch Ministry of Health, Welfare and Sport and by ZonMw project number 91216062. Declaration of Interests: The authors declare no competing interests.

Enfermedad pulmonar por Mycobacterium kansasii. Análisis de 39 casos

To study the epidemiological, clinical, radiological, and microbiological characteristics as well as clinical course and response to treatment of patients with lung disease due to Mycobacterium kansasii. All cases of lung disease caused by M. kansasii diagnosed between 1993 and 1998 in Santa Marina Hospital in Bilbao (Spain) were reviewed. The nurse identified 39 cases of lung disease caused by M. kansasii. The incidence in our practice is growing. Most patients were men (97.4%). Mean patient age was 55.9 years. Relevant features of patients' case histories were lung tuberculosis (38.4%), chronic airflow limitation (28.2%) and smoking (87%). Most patients lived in urban settings (94.8%). The most frequent symptoms were cough (87%) and general malaise (72%). Hemoptysis occurred in 31%. Chest images showed mainly a localized alveolar pattern (69%). Cavitation was present in 76.9%. Bacilli were observed in 76.9%. Antibiograms (for 30 cases) showed resistance to the following drugs: rifampicin 3.3%, isoniazid (1 microgram/ml 10%, isoniazid (0.2 microgram/ml 100%, ethambutol 6.6%, streptomycin 90%, pyrazinamide 90%. Eight patients (22% of 36) died; all had severe associated disease. In 33% of the 21 patients with cavitation, closure was not achieved according to follow-up images. Follow-up microbiological tests revealed one case (2.7% of 36 patients) of treatment failure and four cases (15.3% of 26 patients) of relapse. The number of patients with lung disease due to M. kansasii has increased significantly in recent years in our hospital. The mortality rate in these patients was high, but we believe it is explained by the severity of associated disease. The 15.3% rate of relapse calls for long-term follow-up of such patients.

An HTLV-I/II Vaccine: From Animal Models to Clinical Trials?

A human T-lymphotropic virus type I/II (HTLV-I/II) vaccine is necessary in view of two etiologically related, life-threatening diseases, namely, adult T-cell leukemia/lymphoma and tropical spastic paraparesis/HTLV-I-associated myelopathy. When the risk of developing autoimmune diseases such as uveitis, polymyositis, and arthritis is included, one can estimate the life-long risk of infected individuals to develop an HTLV associated pathology as approximately 10%. The populations at risk are, in a large majority, from developing countries but the epidemic of HTLV-II infection in intravenous drug users (IVDU) represents a possible reservoir for dissemination in the general population. The number of HTLV-I-infected individuals (15 to 25 million), together with the severity of associated disease, justifies the development of a vaccine. Different vaccine preparations have been developed, using mostly recombinant pox and adenoviruses, but DNA plasmid technology will soon become a feasible approach. Various animal models exist for experimental viral infections, involving rats, rabbits, or monkeys, but up to now, neither hematological nor neurological disorders have been induced by HTLV infection in such animal models. For long-term protection from HTLV-I-associated diseases, vaccination should induce both neutralizing antibodies and specific cell-mediated immunity. This will require the incorporation of both env and gag coding sequences in the vaccine preparations. Preventive clinical trials may involve different cohorts of seronegative young girls from endemic areas prior to sexual activity and IVDU in the industrialized world. In parallel, one should consider therapeutic vaccine trials in HTLV-I-positive mothers and IVDU to protect them against disease development. The observed rate of seroconversion in these different cohorts makes such trials feasible.