Well-posedness for a diffusion–reaction compartmental model simulating the spread of COVID-19

This paper is concerned with the well-posedness of a diffusion–reaction system for a susceptible-exposed-infected-recovered (SEIR) mathematical model. This model is written in terms of four nonlinear partial differential equations with nonlinear diffusions, depending on the total amount of the SEIR populations. The model aims at describing the spatio-temporal spread of the COVID-19 pandemic and is a variation of the one recently introduced, discussed, and tested in a paper by Viguerie et al (2020). Here, we deal with the mathematical analysis of the resulting Cauchy–Neumann problem: The existence of solutions is proved in a rather general setting, and a suitable time discretization procedure is employed. It is worth mentioning that the uniform boundedness of the discrete solution is shown by carefully exploiting the structure of the system. Uniform estimates and passage to the limit with respect to the time step allow to complete the existence proof. Then, two uniqueness theorems are offered, one in the case of a constant diffusion coefficient and the other for more regular data, in combination with a regularity result for the solutions. © 2023 The Authors. Mathematical Methods in the Applied Sciences published by John Wiley & Sons, Ltd.

The Impact of Covid-19 on Breast Cancer Newly Diagnoses and Survival: Real World Data from 12912 Cases

Background: Studies evaluating COVID-19 in cancer patients beyond the effects of the infection itself are generally from single institutions, voluntary surveillance registries, or surveys. To extend the limited evidence available, we analyzed both the incidence and one-year mortality of breast cancer (BC) female patients at a population level in Lombardy, the first Italian region affected by the pandemic and the most populous one. Method(s): The regional COVID-19 database, including all SARS-CoV2 cases based on a positive swab result, was integrated with the Regional Health Information System, collecting data from 10 million habitants on primary medical care;hospitalization;pharmaceuticals;and survival status. From the database, we extracted data of newly-diagnosed not previously treated BC patients, including patient characteristics and comorbidities (respiratory insufficiency, diabetes, chronic kidney disease, cerebral vasculopathy, hypertension and cardiovascular disease), BC stage, and treatment. Result(s): The study population consisted of 12912 newlydiagnosed/ not previously treated BC patients, 7349 in 2019 and 5563 in 2020. There were two drops of newly diagnosed cases, one in the first wave (March-May 2020;-37.2%), the other in the second wave (October-December 2020;-15.8%). No major differences were found between characteristics of cases occurring in 2019 and 2020;with the exception of a reduced use of both chemotherapy (86.2% vs 53.4%) and radiotherapy (65.7% vs 42.1%) in 2020. One-year overall survival was 97.6% in 2020 vs 98.3% in 2019, Hazard Ratio [HR] (95% Confidence Interval [95%CI]): 1.51 (1.18-1.93);p=0.0010 at univariate analysis;HR 0.91 (0.71-1.17), p= 0.47, after adjusting for age, stage, BC treatment and comorbidities at multivariable analysis. COVID-19 occurred in 250 of 5563 (4.5%) newly-diagnosed BC cases in 2020. Notably, the time-dependent COVID-19 effect was significantly associated with mortality (multivariable Cox analysis HR 2.25 (1.35-3.74);p=0.0018) even after adjusting for age, stage, treatment and comorbidities. Conclusion(s): Breast cancer incidence and survival were both reduced in 2020, and COVID-19 was an independent predictor of death in BC patients. While follow-up is ongoing to assess long sequelae of COVID-19, these results encourage prevention of infection regardless of BC stage;and at the same time warn against suboptimal treatment and overlooking new diagnoses to ensure a favourable prognostic outcome.

Monitoring the Safety of Medicines and Vaccines in Times of Pandemic: Practical, Conceptual, and Ethical Challenges in Pharmacovigilance

In this paper, we analyse some of the challenges that pharmacovigilance, the science of detecting and assessing possible adverse reactions from medical interventions, is facing during the COVID-19 pandemic. In particular, we consider the issue of increased uncertainty of the evidence and the issue of dealing with an unprecedented amount of data. After presenting the technical advances implemented in response to these two challenges, we offer some conceptual reflections around such practical changes. We argue that the COVID-19 emergency represents a chance to push forward critical thinking in the field of pharmacovigilance, and that contributions from epistemology, ethics and philosophy of science are necessary to increase resilience in the face of this and future health emergencies. © 2021 University of Sassari

Being a nurse in medical oncology during the covid19 epidemic

Background: Until February 21, 2020, Covid 19 was a disease known exclusively in China. Since that date, our working life has changed considerably. The number of cancer patients has not changed and their needs have always been fulfilled without interruption. Our department has not stopped its activity and the staff have been exposed to the risk of contagion because patients were not able to access the preventive tampon. Method: Our department has followed the regional and internal directives issued by the Health Department in conjunction with those issued by the Istituto Superiore di Sanita. The staff have protected themselves with PPE such as masks of different types, gloves, sanitization and body temperature monitoring. The same protection methods have been used for patients. In order to avoid our patients' unchecked access to the department, a doorbell has been installed to signal their arrival. We have granted the correct social distancing in the waiting rooms and the shifting in the therapy rooms. Because of the absence of a secretary in our department the staff has had to deal also with the several telephone calls, that in tis period have increased further. Our patients in oral treatment have received medications to continue their treatment for a longer period (two months), all the chemotherapy cycles with a second day (e.g. Folfox-4) have been converted into a single day (Folfox-6 and so on). Periodic checks have been postponed after medical evaluation. Results: During the months of March to May, 1589 chemotherapy cycles were performed. In the same period 49 patients were discharged from the hospital ward. Just first or emergency visits were granted. Conclusions: Our workload has not been reduced. Patients were welcomed with new rules. No one has complained about our organizational changes. In a high turnout department like ours, this has been a stressful period for our staff, because in addition to the infectious risk from Covid the nursing and administrative workload have both increased. The volunteer staff to whom the reception is usually delegated remained at home and so did the psychological and nutritional support. From a psychological point of view, this period was not without emotional consequences. None of the staff fell ill, while some of 44 cancer patients tested positive were discovered during our work. 21 of them died.