A Systematic Analysis of the Memory term in Coarse-Grained models: the case of the Markovian Approximation

The systematic development of Coarse-Grained (CG) models via the Mori-Zwanzig projector operator formalism requires the explicit description of several terms, including a deterministic drift term, a dissipative memory term and a random fluctuation term. In many applications, the memory and fluctuation terms are related by the fluctuation-dissipation relation and are, in general, more challenging to derive than the drift term. In this work we analyse an approximation of the memory term and propose a rational basis for a data-driven approach to an approximation of the memory and fluctuating terms which can be considered included in the class of the Markovian ones.Comment: 39 pages, 2 Figure

Molecular epidemiology of measles in Liguria, Italy: a tool for the elimination of the infection

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Performance testing of two new one-step real time PCR assays for detection of human influenza and avian influenza viruses isolated in humans and Respiratory Syncytial Virus

Introduction and Methods. Two real time one-step RT-PCRassays were developed for simultaneous detection and typingof influenza A and B viruses and detection of Respiratory Syncytial Virus (RSV). As regard influenza, primers were designedto amplify specific sequences of gene M of A/H1N1, A/H3N2,A/H5N1, A/H7N7 and A/H9N2 viruses and of gene NP of typeB viruses belonging both Yamagata and Victoria lineage. Specificity, analytical and clinical sensitivity, dynamic range, linearity of the new assays were evaluated.Results. Dynamic ranges for Influenza A and B, and RSV,were at least five logs and linearity was conserved. In orderto evaluate the specificity, 80 nasopharyngeal swabs resulting Influenza and RSV negative by multiplex nested PCR andcell culture, were tested and 79 resulted negative. The detection limits for influenza A and B, calculated by 95% probit,was 0,008 and 0,09 PFU, respectively, resulting more sensible than nested PCR. A total of 75 specimens (10 A/H1N1,

A systematic analysis of the memory term in coarse-grained models: The case of the Markovian approximation

Copyright © The Author(s), 2022. The systematic development of coarse-grained (CG) models via the Mori–Zwanzig projector operator formalism requires the explicit description of a deterministic drift term, a dissipative memory term and a random fluctuation term. The memory and fluctuating terms are related by the fluctuation–dissipation relation and are more challenging to sample and describe than the drift term due to complex dependence on space and time. This work proposes a rational basis for a Markovian data-driven approach to approximating the memory and fluctuating terms. We assumed a functional form for the memory kernel and under broad regularity hypothesis, we derived bounds for the error committed in replacing the original term with an approximation obtained by its asymptotic expansions. These error bounds depend on the characteristic time scale of the atomistic model, representing the decay of the autocorrelation function of the fluctuating force; and the characteristic time scale of the CG model, representing the decay of the autocorrelation function of the momenta of the beads. Using appropriate parameters to describe these time scales, we provide a quantitative meaning to the observation that the Markovian approximation improves as they separate. We then proceed to show how the leading-order term of such expansion can be identified with the Markovian approximation usually considered in the CG theory. We also show that, while the error of the approximation involving time can be controlled, the Markovian term usually considered in CG simulations may exhibit significant spatial variation. It follows that assuming a spatially constant memory term is an uncontrolled approximation which should be carefully checked. We complement our analysis with an application to the estimation of the memory in the CG model of a one-dimensional Lennard–Jones chain with different masses and interactions, showing that even for such a simple case, a non-negligible spatial dependence for the memory term exists.Leverhulme Trust through Early Career Fellowship ECF-2016-52

Assessment of knowledge, attitudes, and propensity towards HPV vaccine of young adult students in Italy

Background: Human Papillomavirus (HPV) is a common sexually transmitted infection (STI), representing the main cause of genital warts and cervical cancer. This cross-sectional study evaluated knowledge and attitudes about HPV infection, related diseases, and prevention and propensity towards HPV vaccine among undergraduate students. Methods: An online and written survey about HPV and its prevention, targeted to young adults of both genders, was addressed to students attending health sciences and other schools at Universities of Genoa and Bari. Results: The overall median knowledge and attitude scores were 56.3% (25\u201375 p = 40\u201368.8%) and four out of five (25\u201375 p = 4\u20135), respectively. In the multivariate analysis, attending a health sciences university, using social networks 642 h a day, a history of STI, having heard about HPV and HPV vaccine previously resulted as predictors of higher knowledge scores. Having heard about HPV previously also predicted a high attitude score, together with a perceived economic status as good. Having Italian and healthcare worker parents, being employed, and following a specific diet, instead, predicted lower attitude score. Conclusions: Poor knowledge and good attitudes were found among undergraduates about HPV. In order to increase HPV vaccine compliance and the counselling skills of future healthcare workers, the improvement of training on HPV is needed

Molecular epidemiology and case-control approaches for management of an outbreak of hepatitis A in Liguria, Italy

Introduction and methods. Hepatitis A remains an important public health problem in low endemicity areas, because of the social and economic high burden of cyclical outbreaks. In this study we described an outbreak of HAV infection occurred in the city of Genoa and in its proximity and the viral circulation in the post-epidemic period. In order to identify risk factors associated to the illness and to determine the source of infection and the dynamics of virus evolution, we conducted an epidemiological and molecular investigation by a case-control study and by sequence analysis of high variable regions of the genome. Results. From May to October 2005, 58 HAV hepatitis cases were notified. The case-control study showed that beach establishment attending is strongly associated with HAV hepatitis (OR = 24.5, p-value inf. 0.01), at multivariate analysis. The profile of epidemic curve, the clinical onset of primary cases who occurred in few weeks and the geographic distribution of cases clearly indicated a common exposure to a point source: the outbreak can be probably associated with a contaminated food product dispensed in the affected area. The outbreak has been mainly caused by a single variant, confirming the common exposure to a point source; this variant previously circulated within homosexual man (MSM) network in Northern Europe. During the outbreak and in the following months, different variants originating from Southeast Asia, Southern America and Northern Africa, have co-circulated: all these cases were related to international travel and none of these had determined secondary cases. Discussion. The epidemiological picture of hepatitis A in Liguria is characterized by a wide heterogeneity of circulating HAV strains. This pattern could be associated with the increase of imported cases and transmission within network of persons with similar risk factors. Molecular approach coupled to descriptive and analytical epidemiological studies appeared un-replaceable tools for management and control of HAV outbreaks, because of their capacity to recognize infection origin, transmission patterns and dynamics of virus evolution

Effect of the 2020/21 season influenza vaccine on SARS-CoV-2 infection in a cohort of Italian healthcare workers

Objectives: Healthcare workers (HCWs) are a priority group for seasonal influenza vaccination (SIV). The 2020/21 SIV campaign was conducted during the second wave of the COVID-19 pandemic. Vaccines, including SIV, may exert non-specific protective effects on other infectious diseases which may be ascribable to the concept of trained immunity. The aim of this study was to explore the association between 2020/21 SIV and SARS-CoV-2 positivity in a cohort of Italian HCWs. Methods: In this observational study, a cohort of HCWs employed by a large (ca 5000 employees) referral tertiary acute-care university hospital was followed up retrospectively until the start of the COVID-19 vaccination campaign. The independent variable of interest was the 2020/21 SIV uptake. Both egg-based and cell culture-derived quadrivalent SIVs were available. The study outcome was the incidence of new SARS-CoV-2 infections, as determined by RT-PCR. Multivariable Cox regression was applied in order to discern the association of interest. Results: The final cohort consisted of 2561 HCWs who underwent ≥1 RT-PCR test and accounted for a total of 94,445 person-days of observation. SIV uptake was 35.6%. During the study period, a total of 290 new SARS-CoV-2 infections occurred. The incidence of new SARS-CoV-2 was 1.62 (95% CI: 1.22–2.10) and 3.91 (95% CI: 3.43–4.45) per 1000 person-days in vaccinated and non-vaccinated HCWs, respectively, with an adjusted non-proportional hazard ratio of 0.37 (95% CI: 0.22–0.62). E-values suggested that unmeasured confounding was unlikely to explain the association. Conclusions: A lower risk of SARS-CoV-2 infection was observed among SIV recipients

Current take on systemic sclerosis patients’ vaccination recommendations

Systemic sclerosis (SSc) is a rare autoimmune inflammatory rheumatic disease. The prevalence of SSc ranges from 7 to 700 cases per million worldwide. Due to multiple organ involvement and constant inflammatory state, this group of patients presents an increased risk of infectious diseases. This paper aimed to gather the up-to-date evidence on vaccination strategies for patients with SSc and to be a useful tool for the prevention and management of infectious diseases. The authors conducted a scoping review in which each paragraph presents data on a specific vaccine’s safety, immuno-genicity, and efficacy. The work deals with the following topics: SARS-CoV-2, seasonal influenza, S. pneumoniae, HAV, HBV, HZV, N. meningitidis, H. influenzae, HPV, and diphtheria-tetanus-pertussis

Pregnancy and neonatal outcomes among a cohort of HIV-infected women in a large Italian teaching hospital : a 30-year retrospective study

The primary study objective was to investigate three decades from 1985 to 2014 of changes in pregnancies among HIV-infected women. The secondary objective was to assess risk factors associated with preterm delivery and severe small-for-gestational-age (SGA) infants in HIV-infected women. A retrospective review of deliveries among pregnant HIV-infected women at the University of Genoa and IRCCS San Martino-IST in Genoa between 1985 and 2014 was performed. Univariate and multivariable analyses were used to study the variables associated with neonatal outcomes. Overall, 262 deliveries were included in the study. An increase in median age (26 years in 1985-1994 vs. 34 years in 2005-2014), in the proportion of foreigners (none in 1985-1994 vs. 27/70 (38\ub76%) in 2005-2014), and a decrease in intravenous drug use (75\ub72% (91/121) in 1985-1994 vs. 12\ub79% (9/70) in 2005-2014) among pregnant HIV-infected women was observed. Progressively, HIV infections were diagnosed sooner (prior to pregnancy in 80% (56/70) of women in the last decade). An increase in combined antiretroviral therapy (cART) prescription during pregnancy (50% (27/54) in 1995-2004 vs. 92\ub72% (59/64) in 2005-2014) and in HIV-RNA <50 copies/ml at delivery (19\ub72% (5/26) in 1995-2004 vs. 82\ub73% (53/64) in 2005-2014) was observed. The rate of elective caesarean section from 1985 to 1994 was 9\ub71%, which increased to 92\ub73% from 2004 to 2015. Twelve (10\ub71%) mother-to-child transmissions (MTCT) occurred in the first decade, and six (8\ub73%) cases occurred in the second decade, the last of which was in 2000. Preterm delivery (<37 weeks gestation) was 5% (6/121) from 1985 to 1994 and increased to 17\ub71% (12/70) from 2005 to 2014. In univariate and multivariable logistic regression analyses, advancing maternal age and previous pregnancies were associated with preterm delivery (odds ratio (OR) 2\ub77; 95% confidence intervals (CI) 1-7\ub78 and OR 2\ub76; 95% CI 1\ub71-6\ub77, respectively). In the logistic regression analysis, use of heroin or methadone was found to be the only risk factor for severe SGA (OR 3\ub71; 95% CI 1\ub74-6\ub78). In conclusion, significant changes in demographic, clinical and therapeutic characteristics of HIV-infected pregnant women have occurred over the last 30 years. Since 2000, MTCT has decreased to zero. An increased risk of preterm delivery was found to be associated with advancing maternal age and previous pregnancies but not with cART. The use of heroin or methadone has been confirmed as a risk factor associated with severe SGA

Prevalence of Pneumococcal Serotypes in Community-Acquired Pneumonia among Older Adults in Italy: A Multicenter Cohort Study.

Pneumococcal community-acquired pneumonia (CAP) is a leading cause of mortality. Following the introduction of pneumococcal conjugate vaccines (PCVs) in children, a decrease in the burden of the disease was reported. In parallel, an increase in non-vaccine serotypes was also noted. The objective of this study was to assess the current serotype-specific epidemiology of pneumococci among Italian older adults hospitalized for CAP. A prospective study was conducted between 2017 and 2020 in four Italian regions. Subjects aged ≥65 years hospitalized with confirmed CAP were tested for pneumococci using both pneumococcal urinary antigen and serotype-specific urine antigen tests able to identify all 24 serotypes included in the available vaccines. Of the 1155 CAP cases, 13.1% were positive for pneumococci. The most prevalent serotypes were 3 (2.0%), 8 (1.7%), 22F (0.8 %) and 11A (0.7%). These serotypes are all included in the newly licensed PCV20. The serotypes included in PCV13, PCV15 and PCV20 contributed to 3.3%, 4.4% and 7.5% of the CAP cases, respectively. In the context of a low PCV13 coverage among older adults and a high PCV coverage in children, a substantial proportion of CAP is caused by PCV13 serotypes. Higher valency PCV15 and PCV20 may provide additional benefits for the prevention of CAP in vaccinated older adults