Effect of SARS-CoV-2 shedding rate distribution of individuals during their disease days on the estimation of the number of infected people. Application of wastewater-based epidemiology to the city of Thessaloniki, Greece.

During the COVID-19 pandemic, wastewater-based epidemiology has proved to be an important tool for monitoring the spread of a disease in a population. Indeed, wastewater surveillance was successfully used as a complementary approach to support public health monitoring schemes and decision-making policies. An essential feature for the estimation of a disease transmission using wastewater data is the distribution of viral shedding rate of individuals in their personal human wastes as a function of the days of their infection. Several candidate shapes for this function have been proposed in literature for SARS-CoV-2. The purpose of the present work is to explore the proposed function shapes and examine their significance on analyzing wastewater SARS-CoV-2 shedding rate data. For this purpose, a simple model is employed applying to medical surveillance and wastewater data of the city of Thessaloniki during a period of Omicron variant domination in 2022. The distribution shapes are normalized with respect to the total virus shedding and then their basic features are investigated. Detailed analysis reveals that the main parameter determining the results of the model is the difference between the day of maximum shedding rate and the day of infection reporting. Since the latter is not part of the distribution shape, the major feature of the distribution affecting the estimation of the number of infected people is the day of maximum shedding rate with respect to the initial infection day. On the contrary, the duration of shedding (total number of disease days) as well as the exact shape of the distribution are by far less important. The incorporation of such wastewater surveillance models in conventional epidemiological models - based on recorded disease transmission data- may improve predictions for disease spread during outbreaks.

Relating SARS-CoV-2 shedding rate in wastewater to daily positive tests data: A consistent model based approach.

During the COVID-19 pandemic, wastewater-based epidemiology (WBE) has been engaged to complement medical surveillance and in some cases to also act as an early diagnosis indicator of viral spreading in the community. Most efforts worldwide by the scientific community and commercial companies focus on the formulation of protocols for SARS-CoV-2 analysis in wastewater and approaches addressing the quantitative relationship between WBE and medical surveillance are lacking. In the present study, a mathematical model is developed which uses as input the number of daily positive medical tests together with the highly non-linear shedding rate curve of individuals to estimate the evolution of global virus shedding rate in wastewater along calendar days. A comprehensive parametric study by the model using as input actual medical surveillance and WBE data for the city of Thessaloniki (~700,000 inhabitants, North Greece) during the outbreak of November 2020 reveals the conditions under which WBE can be used as an early warning tool for predicting pandemic outbreaks. It is shown that early warning capacity is different along the days of an outbreak and depends strongly on the number of days apart between the day of maximum shedding rate of infected individuals in their disease cycle and the day of their medical testing. The present data indicate for Thessaloniki an average early warning capacity of around 2 days. Moreover, the data imply that there exists a proportion between unreported cases (asymptomatic persons with mild symptoms that do not seek medical advice) and reported cases. The proportion increases with the number of reported cases. The early detection capacity of WBE improves substantially in the presence of an increasing number of unreported cases. For Thessaloniki at the peak of the pandemic in mid-November 2020, the number of unreported cases reached a maximum around 4 times the number of reported cases.

Sorption of beryllium in cementitious systems relevant for nuclear waste disposal: Quantitative description and mechanistic understanding.

Beryllium has applications in fission and fusion reactors, and it is present in specific streams of radioactive waste. Accordingly, the environmental mobility of beryllium needs to be assessed in the context of repositories for nuclear waste. Although cement is widely used in these facilities, Be(II) uptake by cementitious materials was not previously investigated and was hence assumed negligible. Sorption experiments were performed under Ar-atmosphere. Ordinary Portland cement, low pH cement, calcium silicate hydrated (C-S-H) phases and the model system TiO2 were investigated. Sorption kinetics, sorption isotherms and distribution ratios (Rd, in kg⋅L-1) were determined for these systems. Molecular dynamics were used to characterize the surface processes driving Be(II) uptake. A strong uptake (5 ≤ log Rd ≤ 7) is quantified for all investigated cementitious systems. Linear sorption isotherms are observed over three orders of magnitude in [Be(II)]aq, confirming that the uptake is controlled by sorption processes and that solubility phenomena is not relevant within the investigated conditions. The analogous behaviour observed for cement and C-S-H support that the latter are the main sink of beryllium. The two step sorption kinetics is explained by a fast surface complexation process, followed by the slow incorporation of Be(II) in C-S-H. Molecular dynamics indicate that Be(OH)3- and Be(OH)42- are sorbed to the C-S-H surface through Ca-bridges. This work provides a comprehensive quantitative and mechanistic description of Be(II) uptake by cementitious materials, whose retention properties can be now reliably assessed for a wide range of boundary conditions of relevance in nuclear waste disposal.

First report of fatal autochthonous angiostrongylosis in a dog in Greece.

Canine angiostrongylosis caused by Angiostrongylus vasorum is a life-threatening disease which is emerging in regions of Europe. Thus, there is the merit for a continuous epidemiological surveillance in dog populations. This is the first description of a clinical autochthonous case of canine angiostrongylosis in Greece. A 7-month-old, male, mixed-breed dog was presented with progressively worsening anorexia, respiratory distress, coughing, bleeding diathesis and succumbed four days post admission. Gross post mortem examination revealed numerous nodular fistulated lesions in the lungs, and pulmonary cytology and histopathology showed a verminous pyogranulomatous pneumonia. The definitive diagnosis was based on the morphological identification of first stage larvae (L1) retrieved in the feces by the Baermann method, the detection of the circulating antigen by an in-clinic test and the molecular identification of L1. This report underlines the epidemiological and clinical implications, as well as the infection risks when the index of clinical suspicion is low and the disease is unexpected in a country.

Use of tourniquet does not increase serum concentration of inflammatory mark-ers following total knee arthroplasty during the first 24 postoperative hours.

BACKGROUND: The literature on the systemic inflammatory reaction following tourniquet-induced ischemia and reperfusion in elective orthopedic surgery is limited. METHODS: This prospective comparative study compared the levels of clinically relevant cytokines and peripheral blood counts and major complications in patients undergoing total knee arthroplasty (TKA) with or without a tourniquet during the first postoperative day. Forty-three patients undergoing primary TKA for degenerative osteoarthritis were divided into two groups; 21 patients were operated on using (TG group) and 22 (NTG group) without using a tourniquet. Proinflammatory cytokines interleukin-1b, interleukin-6, anti-inflammatory cytokine interleukin-10, intercellular and vascular adhesion molecules, C-reactive protein, and full blood count were evaluated preoperatively and at one, three, six, and 24 hours postoperatively in both groups. RESULTS: Demographics, American Society of Anesthesiologists score, surgery duration, osteoarthritis grade, and other preoperative variable values were comparable between groups. The average tourniquet time was 67.8 minutes. The majority of testing variables did not demonstrate significant postoperative differences between groups. However, the mean IL-6 value was non-significantly higher for the TG than the NTG group during the first six postoperative hours. It demonstrated a trend to significance at the end of the first postoperative day. The mean hemoglobin and hematocrit levels were significantly higher for the NTG group at the sixth postoperative hour. CONCLUSIONS: The tourniquet use may affect the systemic inflammatory response. Patients undergoing TKA with or without a tourniquet demonstrated a similar systemic inflammatory response. However, reperfusion following approximately 70 minutes of tourniquet ischemia is a safe practice. HIPPOKRATIA 2021, 25 (1):31-37.

A physicochemical model for rationalizing SARS-CoV-2 concentration in sewage. Case study: The city of Thessaloniki in Greece.

Detection of SARS-CoV-2 in sewage has been employed by several researchers as an alternative early warning indicator of virus spreading in communities, covering both symptomatic and asymptomatic cases. A factor that can seriously mislead the quantitative measurement of viral copies in sewage is the adsorption of virus fragments onto the highly porous solids suspended in wastewater, making them inaccessible. This depends not only on the available amount of suspended solids, but also on the amount of other dissolved chemicals which may influence the capacity of adsorption. On this account, the present work develops a mathematical framework, at various degrees of spatial complexity, of a physicochemical model that rationalizes the quantitative measurements of total virus fragments in sewage as regards the adsorption of virus onto suspended solids and the effect of dissolved chemicals on it. The city of Thessaloniki in Greece is employed as a convenient case study to determine the values of model variables. The present data indicate the ratio of the specific absorption (UV254/DOC) over the dissolved oxygen (DO) as the parameter with the highest correlation with viral copies. This implies a strong effect on viral inaccessibility in sewage caused (i) by the presence of humic-like substances and (ii) by virus decay due to oxidation and metabolic activity of bacteria. The present results suggest days where many fold corrections in the measurement of viral copies should be applied. As a result, although the detected RNA load in June 2020 is similar to that in April 2020, virus shedding in the city is about 5 times lower in June than in April, in line with the very low SARS-CoV-2 incidence and hospital admissions for COVID-19 in Thessaloniki in June.

First case of Serratia liquefaciens isolated from urinary tract infection in sows and associated clinicopathological and pathological findings.

An incident of sudden deaths in the breeding stock was reported from a farrow-to-finish commercial pig farm in Greece. The 8·4% of sows during lactation and gestation period presented anorexia, fever, haematuria, return-to-oestrus and sudden deaths (mortality rate: 2·3%). Blood and urine samples were collected from four diseased sows. Furthermore, swabs from urine bladders were collected from two dead sows and four culled sows at the slaughterhouse. Blood testing demonstrated mild leucocytosis and absence of azotaemia. Urinalysis revealed haematuria, proteinuria, bilirubinuria and active urine sediment with bacilli, epithelial cells and leucocytes, crystals and granular casts. Histopathological evaluation of the bladder demonstrated chronic active polypoid cystitis. The bacterial culture revealed the presence of Serratia liquefaciens. The antibiotic susceptibility testing showed high resistance to the most common antibiotics, with the highest sensitivity of the isolate towards quinolones. After the administration of a single dose of 7·5 mg kg-1 body weight enrofloxacin intramuscularly, the mortality rate decreased to less than 0·5% along with a remarkable reduction in the severity of clinical signs. Based on our findings, S. liquefaciens induced severe clinical signs and deaths in sows, mainly due to urinary infection. Inadequate water sanitation might have been responsible for increased exposure to S. liquefaciens. SIGNIFICANCE AND IMPACT OF THE STUDY: In this study, the isolation of Serratia liquefaciens from the urinary tract of pigs associated with clinical signs and increased mortality was described for the first time. Serratia liquefaciens is an important cause of hospital-acquired human infections. The isolate in this study was resistant to the most common antibiotics. Therefore, the use of quinolones which are drugs of last resort for treatment of infections was the only therapeutic option. The presence of the resistant bacterium in the urinary tract raises concerns for its zoonotic potential.

Correction to: Conducting an observational study during an economic crisis: analysis of the treatment and follow-up phase of Greek patients participating in the ExFOS study.

Unfortunately in the original publication, the affiliation of the author N. Papaioannou was incorrectly provided.

Conducting an observational study during an economic crisis: analysis of the treatment and follow-up phase of Greek patients participating in the ExFOS study.

OBJECTIVE: We present the subanalysis of the Greek cohort of the Extended Forsteo Observational Study (ExFOS), a multicenter, non-interventional, prospective, observational study evaluating the effect of teriparatide on fractures, back pain (BP), health-related quality of life (HR-QoL), and safety and compliance, in patients with osteoporosis treated for up to 24 months, with a post-treatment follow-up of at least 18 months. DESIGN: A total of 439 osteoporotic patients (92.2% female) were enrolled in Greece. New or worsened fractures, based on their physicians' assessment, as well as patients' self-assessment of HR-QoL and BP, compliance, and safety profile, were captured by validated questionnaires. RESULTS: In the ExFOS Greek cohort, fracture rates were low and mean bone mineral density (BMD) was numerically improved. Compliance with teriparatide remained high throughout the study, with 81.5% of subjects completing treatment. Only 0.7% of patients reported discontinuation due to adverse effects. A sustainable improvement in patient-perceived BP and HRQoL throughout treatment and follow-up was similar to that achieved by the European Forsteo Observational Study (EFOS). A lower than expected percentage of patients using antiresorptives following teriparatide was recorded. CONCLUSIONS: ExFOS reproduces the outcomes of EFOS, with a 6.5-year time interval between studies, in comparable cohorts of osteoporotic patients. Data should be interpreted in the context of observational study data collection, although summary statistics computed at each time point may overstate drug effect.

Factors associated with high 24-month persistence with denosumab: results of a real-world, non-interventional study of women with postmenopausal osteoporosis in Germany, Austria, Greece, and Belgium.

Persistence with osteoporosis therapy is vital for fracture prevention. This non-interventional study of postmenopausal women receiving denosumab in Germany, Austria, Greece, and Belgium found that persistence with denosumab remains consistently high after 24 months in patients at high risk of fracture. PURPOSE: Continued persistence with osteoporosis therapy is vital for fracture prevention. This non-interventional study of clinical practice evaluated medication-taking behavior of postmenopausal women receiving denosumab in Germany, Austria, Greece, and Belgium and factors influencing persistence. METHODS: Subcutaneous denosumab (60 mg every 6 months) was assigned according to prescribing information and local guidelines before and independently of enrollment; outcomes were recorded during routine practice for up to 24 months. Persistence was defined as receiving the subsequent injection within 6 months + 8 weeks of the previous injection and adherence as administration of subsequent injections within 6 months ± 4 weeks of the previous injection. Medication coverage ratio (MCR) was calculated as the proportion of time a patient was covered by denosumab. Associations between pre-specified baseline covariates and 24-month persistence were assessed using multivariable logistic regression. RESULTS: The 24-month analyses included 1479 women (mean age 66.3-72.5 years) from 140 sites; persistence with denosumab was 75.1-86.0%, adherence 62.9-70.1%, and mean MCR 87.4-92.4%. No covariate had a significant effect on persistence across all four countries. For three countries, a recent fall decreased persistence; patients were generally older with chronic medical conditions. In some countries, other covariates (e.g., older age, comorbidity, immobility, and prescribing reasons) decreased persistence. Adverse drug reactions were reported in 2.3-6.9% patients. CONCLUSIONS: Twenty-four-month persistence with denosumab is consistently high among postmenopausal women in Europe and may be influenced by patient characteristics. Further studies are needed to identify determinants of low persistence.

Myelin Sheath Development in the Maxillary Nerve of the Newborn Pig.

Myelination, the ensheathing of neuronal axons by myelin, is important for the proper function of both central and peripheral nervous systems. Various studies have investigated the quantitative parameters of myelination in certain species. Pigs are among the species of which their use as laboratory animals in neuroscience research increased the past few decades. However, there is limited data regarding the myelination process in the pig. Moreover, the maxillary nerve is crucial for Pseudorabies Virus (PrV) neuropathogenesis. In this context, a quantitative analysis of various myelination parameters of the maxillary nerve was performed, during the first 5 weeks of porcine post-natal development, the time period, which exhibits the highest interest for PrV neuropathogenesis. The evaluation was conducted in four groups of uninfected pigs, at the time of birth (group 0w), at the age of 1 week (group 1w), 3 weeks (group 3w) and 5 weeks (group 5w), using toluidine blue staining, immunofluorescence and electron microscopy. Axon and fibre diameter, perimeter and surface, myelin sheath thickness and g-ratio were measured on histological sections transverse to the longitudinal axis of the maxillary nerve. The thickness of myelin sheath was 0.76 µm for group 0w, 0.94 µm for group 1w, 0.98 µm for group 3w and 1.03 µm for group 5w. The g-ratio was 0.529, 0.540, 0.542 and 0.531 for the respective animal groups. The results of this study contribute to the understanding of the myelination process in the pig will be used for the study of PrV effects on the myelination development of newborn piglets' maxillary nerve and may shed new light to their vulnerability to the virus.

Thalassemia-associated osteoporosis: a systematic review on treatment and brief overview of the disease.

Thalassemia-associated osteoporosis constitutes a major complication in patients with thalassemia. This review presents the existing studies on the treatment of thalassemia-associated osteoporosis and discusses the management of this debilitating complication. A brief presentation of the disease characteristics and pathogenetic mechanisms is also provided. The life expectancy of patients with thalassemia has increased markedly in recent years resulting in the aging of the population and the emergence of new comorbidities. The majority of patients with thalassemia have low bone mineral density and experience lifelong fracture rates as high as 71 %. The pathogenesis of thalassemia-associated osteoporosis (TAO) is multifactorial with anemia and iron overload playing crucial role in its development. Data concerning the prevention and treatment of TAO are extremely limited. We performed a literature research in Pubmed and Scopus to identify interventional studies evaluating the effects of various agents on TAO. Seventeen studies were retrieved. We present the results of these studies as well as a brief overview of TAO including presentation, pathogenesis, and management. Most of the studies identified are of poor quality, are not randomized controlled, and include small number of participants. There are no data concerning effects on fracture rates. Bisphosphonates are the most widely studied agents and among them zoledronic acid is the most well studied. Hormone replacement treatment (HRT) shows beneficial but small effects. Denosumab and strontium ranelate have each been evaluated in only a single study, while there are no data about the effects of anabolic agents. Given the increased life expectancy and the increase in fracture rates with age, more data about the management of TAO are warranted. Moreover, due to the need for lifelong management starting at young age, careful treatment plans which may include sequential treatment may often be required. However, currently, there are no relevant data available.

Differences of bone mineral mass, volumetric bone mineral density, geometrical and structural parameters and derived strength of the tibia between premenopausal and postmenopausal women of different age groups: a peripheral Quantitative Computed Tomography (pQCT) study.

Menopause constitutes a significant cause of bone loss, and it is currently debated whether bone mass is preserved or begins to decline substantially before that time in women. We used pQCT of the tibia to estimate differences of bone mineral mass, bone geometry and derived strength between premenopausal and postmenopausal Caucasian women of different age-groups per decade of age (20-79y). For each individual, we assessed total, trabecular and cortical bone mineral content (BMC, mg) and volumetric bone mineral density (BMD, mg/cm3); total and cortical cross-sectional areas (CSA, mm2); periosteal circumference (PERI_C, mm); endosteal circumference (ENDO_C, mm); mean cortical thickness (CRT_THK, mm); and Stress-Strain Index (SSI) . Comparisons were made both between premenopausal (N=84) and postmenopausal (N=231) women as distinct groups, and among women of the different age-groups. Our results indicated that premenopausal women had significantly higher trabecular and cortical BMC and vBMD, with higher cortical CSA, CRT_THK and SSI than postmenopausal women. Moreover, significant differences of trabecular but not cortical BMC, vBMD or SSI were found between women of the younger (<48y) age-groups. PERI_C, ENDO_C displayed lower values in the 20-29y group and higher values in the 70-79y group, denoting significant differences of bone geometry with aging.

Persistence, adherence, and medication-taking behavior in women with postmenopausal osteoporosis receiving denosumab in routine practice in Germany, Austria, Greece, and Belgium: 12-month results from a European non-interventional study.

UNLABELLED: Persistence with and adherence to osteoporosis therapy are critical for fracture reduction. This non-interventional study is evaluating medication-taking behavior of women with postmenopausal osteoporosis (PMO) receiving denosumab in Germany, Austria, Greece, and Belgium. Patients were representative of the PMO population and highly persistent with and adherent to denosumab at 12 months. INTRODUCTION: Persistence with and adherence to osteoporosis therapy are important for optimal treatment efficacy, namely fracture reduction. This ongoing, non-interventional study will evaluate medication-taking behavior of women with postmenopausal osteoporosis (PMO) receiving denosumab in routine practice in four European countries. METHODS: The study enrolled women who had been prescribed subcutaneous denosumab (60 mg every 6 months) in accordance with prescribing information and local guidelines. Persistence was defined as receiving the subsequent injection within 6 months + 8 weeks of the previous injection. Adherence was defined as receiving two consecutive injections within 6 months ± 4 weeks of each other. Medication coverage ratio (MCR) was calculated using the time a patient was covered with denosumab, as assessed from prescription records. Treatment was assigned prior to and independently of enrollment; outcomes are recorded during routine practice. RESULTS: These planned 12-month interim analyses included data from 1500 patients from 141 sites. Mean age was 66.4-72.4 years, mean baseline total hip T-scores ranged from -2.0 to -2.1 and femoral neck T-scores from -2.2 to -2.6, and 30.7-62.1% of patients had prior osteoporotic fracture. Persistence was 87.0-95.3%, adherence 82.7-89.3%, and MCR 91.3-95.4%. In a univariate analysis, increased age, decreased mobility, and increased distance to the clinic were associated with significantly decreased persistence; parental history of hip fracture was associated with significantly increased persistence. CONCLUSIONS: These data extend the real-world evidence regarding persistence with and adherence to denosumab, both of which are critical for favorable clinical outcomes, including fracture risk reduction.

Denosumab compared with risedronate in postmenopausal women suboptimally adherent to alendronate therapy: efficacy and safety results from a randomized open-label study.

Denosumab has been shown to reduce new vertebral, nonvertebral, and hip fractures in postmenopausal women with osteoporosis. In subjects who were treatment-naïve or previously treated with alendronate, denosumab was associated with greater gains in bone mineral density (BMD) and decreases in bone turnover markers when compared with alendronate-treated subjects. This trial was designed to compare the efficacy and safety of denosumab with risedronate over 12 months in postmenopausal women who transitioned from daily or weekly alendronate treatment and were considered to be suboptimally adherent to therapy. In this randomized, open-label study, postmenopausal women aged ≥55 years received denosumab 60 mg subcutaneously every 6 months or risedronate 150 mg orally every month for 12 months. Endpoints included percentage change from baseline in total hip BMD (primary endpoint), femoral neck, and lumbar spine BMD at month 12, and percentage change from baseline in sCTX-1 at months 1 and 6. Safety was also assessed. A total of 870 subjects were randomized (435, risedronate; 435, denosumab) who had a mean (SD) age of 67.7 (6.9) years, mean (SD) BMD T-scores of -1.6 (0.9), -1.9 (0.7), and -2.2 (1.2) at the total hip, femoral neck, and lumbar spine, respectively, and median sCTX-1 of 0.3 ng/mL at baseline. At month 12, denosumab significantly increased BMD compared with risedronate at the total hip (2.0% vs 0.5%), femoral neck (1.4% vs 0%), and lumbar spine (3.4% vs 1.1%; p<0.0001 at all sites). Denosumab significantly decreased sCTX-1 compared with risedronate at month 1 (median change from baseline of -78% vs -17%; p<0.0001) and month 6 (-61% vs -23%; p<0.0001). Overall and serious adverse events were similar between groups. In postmenopausal women who were suboptimally adherent to alendronate therapy, transitioning to denosumab was well tolerated and more effective than risedronate in increasing BMD and reducing bone turnover.

Early changes in biochemical markers of bone formation during teriparatide therapy correlate with improvements in vertebral strength in men with glucocorticoid-induced osteoporosis.

UNLABELLED: Changes of the bone formation marker PINP correlated positively with improvements in vertebral strength in men with glucocorticoid-induced osteoporosis (GIO) who received 18-month treatment with teriparatide, but not with risedronate. These results support the use of PINP as a surrogate marker of bone strength in GIO patients treated with teriparatide. INTRODUCTION: To investigate the correlations between biochemical markers of bone turnover and vertebral strength estimated by finite element analysis (FEA) in men with GIO. METHODS: A total of 92 men with GIO were included in an 18-month, randomized, open-label trial of teriparatide (20 µg/day, n = 45) and risedronate (35 mg/week, n = 47). High-resolution quantitative computed tomography images of the 12th thoracic vertebra obtained at baseline, 6 and 18 months were converted into digital nonlinear FE models and subjected to anterior bending, axial compression and torsion. Stiffness and strength were computed for each model and loading mode. Serum biochemical markers of bone formation (amino-terminal-propeptide of type I collagen [PINP]) and bone resorption (type I collagen cross-linked C-telopeptide degradation fragments [CTx]) were measured at baseline, 3 months, 6 months and 18 months. A mixed-model of repeated measures analysed changes from baseline and between-group differences. Spearman correlations assessed the relationship between changes from baseline of bone markers with FEA variables. RESULTS: PINP and CTx levels increased in the teriparatide group and decreased in the risedronate group. FEA-derived parameters increased in both groups, but were significantly higher at 18 months in the teriparatide group. Significant positive correlations were found between changes from baseline of PINP at 3, 6 and 18 months with changes in FE strength in the teriparatide-treated group, but not in the risedronate group. CONCLUSIONS: Positive correlations between changes in a biochemical marker of bone formation and improvement of biomechanical properties support the use of PINP as a surrogate marker of bone strength in teriparatide-treated GIO patients.