A comparison of centrality measures and their role in controlling the spread in epidemic networks

The ranking of nodes in a network according to their centrality or "importance” is a classic problem that has attracted the interest of different scientific communities in the last decades. The current COVID-19 pandemic has recently rejuvenated the interest in this problem, as it informs the selection of which individuals should be tested in a population of asymptomatic individuals, or which individuals should be vaccinated first. Motivated by these issues, in this paper we review some popular methods for node ranking in undirected unweighted graphs, and compare their performance in a benchmark realistic network that takes into account the community-based structure of society. In particular, we use the information of the relevance of individuals in the network to take a control decision, i.e., which individuals should be tested, and possibly quarantined. Finally, we also review the extension of these ranking methods to weighted graphs, and explore the importance of weights in a contact network by exhibiting a toy model and comparing node rankings for this case in the context of disease spread. [ FROM AUTHOR] Copyright of International Journal of Control is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

When a Neglected Tropical Disease Goes Global: Knowledge, Attitudes and Practices of Italian Physicians towards Monkeypox, Preliminary Results.

Monkeypox (MPX) has been regarded as a neglected tropic disease of Western and Central Africa since the early 70s. However, during May 2022, an unprecedent outbreak of MPX has involved most of European Countries, as well as North and South America. While the actual extent of this outbreak is being assessed by health authorities, we performed a pilot study on specific knowledge, attitudes, and practices (KAP) in a sample of Italian medical professionals (24-30 May 2022; 10,293 potential recipients), focusing on Occupational Physicians (OP), Public Health Professionals (PH), and General Practitioners (GP), i.e., medical professionals more likely involved in the early management of incident cases. More specifically, we inquired into their attitude on the use of variola vaccine in order to prevent MPX infection. From a total of 566 questionnaire (response rate of 5.5%), 163 participants were included in the final analyses. Knowledge status was quite unsatisfying, with substantial knowledge gaps on all aspect of MPX. In turn, analysis of risk perception suggested a substantial overlooking of MPX as a pathogen, particularly when compared to SARS-CoV-2, TB, HIV, and HBV. Overall, 58.6% of respondents were somehow favorable to implement variola vaccination in order to prevent MPX, and the main effectors of this attitude were identified in having been previously vaccinated against seasonal influenza (adjusted Odds Ratio [aOR] 6.443, 95% Confidence Interval [95%CI] 1.798-23.093), and being favorable to receive variola vaccine (aOR 21.416; 95%CI 7.290-62.914). In summary, the significant extent of knowledge gaps and the erratic risk perception, associated collectively stress the importance of appropriate information campaigns among first-line medical professionals.

Respiratory Syncytial Virus: Knowledge, Attitudes and Beliefs of General Practitioners from North-Eastern Italy (2021).

Respiratory syncytial virus (RSV) is a lead cause of morbidity and hospitalizations in infants. RSV vaccines are currently under development, and preventive options are limited to monoclonal antibodies (mAb). We assessed the knowledge, attitudes and practices for RSV in a sample of general practitioners (GPs) from north-eastern Italy (2021), focusing on the risk perception for infants (age < 8 years) and its potential effectors. We administered an internet survey to 543 GPs, with a response rate of 28.9%. Knowledge status was unsatisfactory, with substantial knowledge gaps found on the epidemiology of RSV and its prevention through mAb. The main effectors of risk perception were identified as having a background in pediatrics (adjusted odds ratio (aOR): 55.398 and 95% confidence interval (95% CI): 6.796-451.604), being favorable towards RSV vaccines when available (aOR: 4.728, 95% CI: 1.999-11.187), while having previously managed an RSV case (aOR: 0.114, 95% CI: 0.024-0.552) and previously recommended hospitalization for cases (aOR: 0.240, 95% CI: 0.066-0.869) were identified as negative effectors. In summary, the significant extent of knowledge gaps and the erratic risk perception, associated with the increasing occurrence in RSV infections, collectively stress the importance of appropriate information campaigns among primary care providers.

Excess Mortality on Italian Small Islands during the SARS-CoV-2 Pandemic: An Ecological Study.

Small islands have been considered at an advantage when dealing with infectious diseases, including COVID-19, but the evidence is still lacking. Crude mortality rates (CMRs) and excess mortality rates (EMRs) were calculated for 35 municipalities on the Italian small islands for 2020 and 2021, and the corresponding estimates were compared to those of the parent provinces and the national estimates. Notification rates for COVID-19 were retrieved, but detailed data at the municipality level were not available. A relatively low CMR (1.069 per 100 per year, 95% confidence interval [95% CI] 0.983-1.164) was identified in 2020, compared to 1.180, 95% CI 1.098-1.269 for 2021. EMRs of small islands ranged between -25.6% and +15.6% in 2020, and between -13.0% and +20.9% in 2021, with an average gain of +0.3% (95% CI -5.3 to +5.8) for the entirety of the assessed timeframe, and no substantial differences between 2020 and 2021 (pooled estimates of -4.1%, 95% CI -12.3 to 4.1 vs. 4.6%, 95% CI -3.1 to 12.4; p = 0.143). When dealing with COVID-19 notification rates, during the first wave, parent provinces of Italian small islands exhibited substantially lower estimates than those at the national level. Even though subsequent stages of the pandemic (i.e., second, third, and fourth waves) saw a drastic increase in the number of confirmed cases and CMR, estimates from small islands remained generally lower than those from parent provinces and the national level. In regression analysis, notification rates and mortality in the parent provinces were the main effectors of EMRs in the small islands (ß = 0.469 and ß = 22.768, p < 0.001 and p = 0.007, respectively). Contrarily, the management of incident cases in hospital infrastructures and ICUs was characterized as a negative predictor for EMR (ß = -11.208, p = 0.008, and -59.700, p = 0.003, respectively). In summary, the study suggests a potential role of small geographical and population size in strengthening the effect of restrictive measures toward countering the spread and mortality rate of COVID-19.

Antigen Detection Tests for SARS-CoV-2: a systematic review and meta-analysis on real world data.

Background and aim Rapid antigen detection (RAD) tests on nasopharyngeal specimens have been recently made available for SARS-CoV-2 infections, and early studies suggested their potential utilization as rapid screening and diagnostic testing. The present systematic review and meta-analysis was aimed to assess available evidence and to explore the reliability of antigenic tests in the management of the SARS-CoV-2 pandemic. MATERIALS AND METHODS: We reported our meta-analysis according to the PRISMA statement. We searched Pubmed, Embase, and pre-print archive medRxiv.og for eligible studies published up to November 5th, 2020. Raw data included true/false positive and negative tests, and the total number of tests. Sensitivity and specificity data were calculated for every study, and then pooled in a random-effects model. Heterogeneity was assessed using the I2 measure. Reporting bias was assessed by means of funnel plots and regression analysis. RESULTS: Based on 25 studies, we computed a pooled sensitivity of 72.8% (95%CI 62.4-81.3), a specificity of 99.4% (95%CI 99.0-99.7), with high heterogeneity and risk of reporting bias. More precisely, RAD tests exhibited higher sensitivity on samples with high viral load (i.e. <25 Cycle Threshold; 97.6%; 95%CI 94.1-99.0), compared to those with low viral load (≥25 Cycle Threshold; 43.6%; 95% 27.6-61.1). DISCUSSION: As the majority of collected reports were either cohort or case-control studies, deprived of preventive power analysis and often oversampling positive tests, overall performances may have been overestimated. Therefore, the massive referral to antigenic tests in place of RT-qPCR is currently questionable, and also their deployment as mass screening test may lead to intolerable share of missing diagnoses. On the other hand, RAD tests may find a significant role in primary care and in front-line settings (e.g. Emergency Departments). (www.actabiomedica.it).

SARS-CoV-2-Legionella Co-Infections: A Systematic Review and Meta-Analysis (2020-2021).

Legionnaires' Disease (LD) is a severe, sometimes fatal interstitial pneumonia due to Legionella pneumophila. Since the inception of the SARS-CoV-2 pandemic, some contradictory reports about the effects of lockdown measures on its epidemiology have been published, but no summary evidence has been collected to date. Therefore, we searched two different databases (PubMed and EMBASE) focusing on studies that reported the occurrence of LD among SARS-CoV-2 cases. Data were extracted using a standardized assessment form, and the results of such analyses were systematically reported, summarized, and compared. We identified a total of 38 articles, including 27 observational studies (either prospective or retrospective ones), 10 case reports, and 1 case series. Overall, data on 10,936 SARS-CoV-2 cases were included in the analyses. Of them, 5035 (46.0%) were tested for Legionella either through urinary antigen test or PCR, with 18 positive cases (0.4%). A pooled prevalence of 0.288% (95% Confidence Interval (95% CI) 0.129-0.641), was eventually calculated. Moreover, detailed data on 19 co-infections LD + SARS-CoV-2 were obtained (males: 84.2%; mean age: 61.9 years, range 35 to 83; 78.9% with 1 or more underlying comorbidities), including 16 (84.2%) admissions to the ICU, with a Case Fatality Ratio of 26.3%. In summary, our analyses suggest that the occurrence of SARS-CoV-2-Legionella infections may represent a relatively rare but not irrelevant event, and incident cases are characterized by a dismal prognosis.

Hysteresis-based supervisory control with application to non-pharmaceutical containment of COVID-19.

The recent COVID-19 outbreak has motivated an extensive development of non-pharmaceutical intervention policies for epidemics containment. While a total lockdown is a viable solution, interesting policies are those allowing some degree of normal functioning of the society, as this allows a continued, albeit reduced, economic activity and lessens the many societal problems associated with a prolonged lockdown. Recent studies have provided evidence that fast periodic alternation of lockdown and normal-functioning days may effectively lead to a good trade-off between outbreak abatement and economic activity. Nevertheless, the correct number of normal days to allocate within each period in such a way to guarantee the desired trade-off is a highly uncertain quantity that cannot be fixed a priori and that must rather be adapted online from measured data. This adaptation task, in turn, is still a largely open problem, and it is the subject of this work. In particular, we study a class of solutions based on hysteresis logic. First, in a rather general setting, we provide general convergence and performance guarantees on the evolution of the decision variable. Then, in a more specific context relevant for epidemic control, we derive a set of results characterizing robustness with respect to uncertainty and giving insight about how a priori knowledge about the controlled process may be used for fine-tuning the control parameters. Finally, we validate the results through numerical simulations tailored on the COVID-19 outbreak.

Mandate or Not Mandate: Knowledge, Attitudes, and Practices of Italian Occupational Physicians towards SARS-CoV-2 Immunization at the Beginning of Vaccination Campaign.

Vaccinations used to prevent coronavirus disease (COVID-19)-the disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-are critical in order to contain the ongoing pandemic. However, SARS-CoV-2/COVID-19 vaccination rates have only slowly increased since the beginning of the vaccination campaign, even with at-risk workers (e.g., HCWs), presumptively because of vaccine hesitancy. Vaccination mandates are considered instrumental in order to rapidly improve immunization rates (but they minimize the impact of vaccination campaigns). In this study, we investigated the acceptance (i.e., knowledge, attitudes, and practices) from occupational physicians (OPs)) in regard to SARS-CoV-2/COVID-19 vaccination mandates. A total of 166 OPs participated in an internet-based survey by completing structured questionnaires. Adequate, general knowledge of SARS-CoV-2/COVID-19 was found in the majority of OPs. High perception of SARS-CoV-2 risk was found in around 80% of participants (79.5% regarding its occurrence, 81.9% regarding its potential severity). SARS-CoV-2/COVID-19 vaccination was endorsed by 90.4% of respondents, acceptance for SARS-CoV-2 vaccine was quite larger for mRNA formulates (89.8%) over adenoviral ones (59.8%). Endorsement of vaccination mandates was reported by 60.2% of respondents, and was more likely endorsed by OPs who exhibited higher concern for SARS-CoV-2 infection occurrence (odds ratio 3.462, 95% confidence intervals 1.060-11.310), who were likely to accept some sort of payment/copayment for SARS-CoV-2/COVID-19 vaccination (3.896; 1.607; 9.449), or who were more likely to believe HCWs not vaccinates against SARS-CoV-2 as unfit for work (4.562; 1.935; 10.753). In conclusion, OPs exhibited wide acceptance of SARS-CoV-2/COVID-19 vaccinations, and the majority endorsed vaccination mandates for HCWs, which may help improve vaccination rates in occupational settings.

Consequences of COVID19-pandemic lockdown on Italian occupational physicians' psychosocial health.

COVID-19 was declared a pandemic on March 12, 2020. Italy has been the most affected country in the world, right after China. Healthcare workers (HCWs) were among the hardest hit by this event from both a working and psychological point of view. The aim of this web-based cross-sectional study is to assess the consequences of the COVID-19 pandemic on Italian Occupational Physicians' well-being and psychological distress, in relation to demographic and occupational characteristic, lifestyle and habits during the lockdown period. We conducted a web-based cross-sectional survey questionnaire from April 1 to April 21st, 2020. To evaluate the level of psychological distress and the level of well-being, the general Health Questionnaire-12 (GHQ-12) and the WHO-5 Wellbeing Index were utilized. Since the statistical assumptions were respected, we proceeded with an analysis of variance (ANOVA) to ascertain the differences between the averages of the scores of the GHQ-12. Doctors who live in the most affected regions have a prevalence of psychological distress higher than their colleagues from the rest of Italy. ANOVA shows significant differences relating to the female gender, and to the life changes provoked by the lockdown for example not feeling sheltered at home or suffering from loneliness. This study showed a high prevalence of psychological distress in occupational physicians. To prevent the occurrence of mental disorders among Occupational Physicians, it is urgent to put in place policies of psychological support and well-being preservation.

Post-lockdown abatement of COVID-19 by fast periodic switching.

COVID-19 abatement strategies have risks and uncertainties which could lead to repeating waves of infection. We show-as proof of concept grounded on rigorous mathematical evidence-that periodic, high-frequency alternation of into, and out-of, lockdown effectively mitigates second-wave effects, while allowing continued, albeit reduced, economic activity. Periodicity confers (i) predictability, which is essential for economic sustainability, and (ii) robustness, since lockdown periods are not activated by uncertain measurements over short time scales. In turn-while not eliminating the virus-this fast switching policy is sustainable over time, and it mitigates the infection until a vaccine or treatment becomes available, while alleviating the social costs associated with long lockdowns. Typically, the policy might be in the form of 1-day of work followed by 6-days of lockdown every week (or perhaps 2 days working, 5 days off) and it can be modified at a slow-rate based on measurements filtered over longer time scales. Our results highlight the potential efficacy of high frequency switching interventions in post lockdown mitigation. All code is available on Github at https://github.com/V4p1d/FPSP_Covid19. A software tool has also been developed so that interested parties can explore the proof-of-concept system.

Kemeny-based testing for COVID-19.

Testing, tracking and tracing abilities have been identified as pivotal in helping countries to safely reopen activities after the first wave of the COVID-19 virus. Contact tracing apps give the unprecedented possibility to reconstruct graphs of daily contacts, so the question is: who should be tested? As human contact networks are known to exhibit community structure, in this paper we show that the Kemeny constant of a graph can be used to identify and analyze bridges between communities in a graph. Our 'Kemeny indicator' is the value of the Kemeny constant in the new graph that is obtained when a node is removed from the original graph. We show that testing individuals who are associated with large values of the Kemeny indicator can help in efficiently intercepting new virus outbreaks, when they are still in their early stage. Extensive simulations provide promising results in early identification and in blocking the possible 'super-spreaders' links that transmit disease between different communities.

Point-of-Care Diagnostic Tests for Detecting SARS-CoV-2 Antibodies: A Systematic Review and Meta-Analysis of Real-World Data.

SARS-CoV-2 is responsible for a highly contagious infection, known as COVID-19. SARS-CoV-2 was discovered in late December 2019 and, since then, has become a global pandemic. Timely and accurate COVID-19 laboratory testing is an essential step in the management of the COVID-19 outbreak. To date, assays based on the reverse-transcription polymerase chain reaction (RT-PCR) in respiratory samples are the gold standard for COVID-19 diagnosis. Unfortunately, RT-PCR has several practical limitations. Consequently, alternative diagnostic methods are urgently required, both for alleviating the pressure on laboratories and healthcare facilities and for expanding testing capacity to enable large-scale screening and ensure a timely therapeutic intervention. To date, few studies have been conducted concerning the potential utilization of rapid testing for COVID-19, with some conflicting results. Therefore, the present systematic review and meta-analysis was undertaken to explore the feasibility of rapid diagnostic tests in the management of the COVID-19 outbreak. Based on ten studies, we computed a pooled sensitivity of 64.8% (95%CI 54.5-74.0), and specificity of 98.0% (95%CI 95.8-99.0), with high heterogeneity and risk of reporting bias. We can conclude that: (1) rapid diagnostic tests for COVID-19 are necessary, but should be adequately sensitive and specific; (2) few studies have been carried out to date; (3) the studies included are characterized by low numbers and low sample power, and (4) in light of these results, the use of available tests is currently questionable for clinical purposes and cannot substitute other more reliable molecular tests, such as assays based on RT-PCR.