Patterns of Transmitted Drug Resistance Mutations and HIV-1 Subtype Dynamics in ART-Naïve Individuals in Veneto, Italy, from 2017 to 2024.

This study investigates the prevalence and patterns of transmitted drug resistance mutations (TDRMs) and HIV-1 subtypes among antiretroviral therapy (ART) naïve individuals in Veneto, Italy, from 2017 to 2024. This research aims to understand the dynamic landscape of TDRMs and HIV-1 genetic diversity to inform treatment strategies effectively. We included all adult ART-naïve people with HIV (PWH) from seven infectious disease units in Veneto, Italy. We collected the genotypic resistance testing conducted to predict drug susceptibility and subtype distribution using the Stanford HIVdb algorithm. We included 762 PWH, showing a slight but statistically significant decline in the B subtype among Italian PWH (p = 0.045) and an increase in non-B subtypes among foreigners, though it was not statistically significant (p = 0.333). The most frequent mutations were in Non-nucleoside Reverse Transcriptase Inhibitors (NNRTIs), especially in non-B subtypes, with a notable rise from 10.7% in 2017-2019 to 15.5% in 2020-2024. Notably, TDRMs were consistently detected, highlighting an ongoing challenge despite the stable prevalence observed over the years. In addition, the data revealed a concerning rise in mutations against newer drug classes, such as integrase inhibitors. Conclusively, the study underscores the necessity of continuous surveillance of HIV subtypes and resistance patterns to adapt ART regimens optimally. Despite the stable levels of drug resistance, the emergence of resistance against newer drugs necessitates ongoing vigilance and possible adjustment in treatment protocols to enhance clinical outcomes and manage HIV drug resistance effectively.

Kaposi sarcoma and vertebral involvement in people with HIV: a case report and systematic literature review.

BACKGROUND: Kaposi Sarcoma (KS) has been historically associated with HIV, especially in people with advanced immunosuppression. Its prevalence decreased over time, but management remains difficult especially when the diagnosis is late and there is a visceral involvement. Bone localization, and particularly the vertebral one, is rare. We herein present a case of vertebral localizations of KS and performed a review literature to assess demographic, clinical characteristics and treatment outcomes in people with HIV. METHODS: The systematic review was carried out by following the PRISMA guidelines and registering the protocol in PROSPERO database (n. registration: CRD42024548626). We included all cases of vertebral localizations of KS from January 1rst 1981 to December 31rst, 2023. RESULTS: Twenty-two cases, including ours, were ever reported in people with HIV, mostly males (95.4%), with a median age of 35 years (IQR: 32-44), median CD4+ T cell count of 80 cell/mm3 (IQR 13-111), 31.8% with high HIV viral load. Five people received HIV and KS diagnosis simultaneously. In all cases, but one, there were multiple sites involved. Most spine lesions were localized at thoracic and lumbar levels (59.1%), causing pathological fractures in 2 cases. Chemotherapy and radiotherapy were performed in 50% and 18.2% cases, respectively. 22.7% persons died, stability and improvement/disease regression were reported for 13.6% and 22.7% persons, respectively, while 9.9% had a significant disease progression and a person was lost to follow-up. CONCLUSIONS: Despite progresses in treatment, late presentation of KS, especially with spine involvement may have a poor prognosis. More efforts are needed to promote access to HIV testing, especially when indicating conditions are present.

Assessing ChatGPT's theoretical knowledge and prescriptive accuracy in bacterial infections: a comparative study with infectious diseases residents and specialists.

OBJECTIVES: Advancements in Artificial Intelligence(AI) have made platforms like ChatGPT increasingly relevant in medicine. This study assesses ChatGPT's utility in addressing bacterial infection-related questions and antibiogram-based clinical cases. METHODS: This study involved a collaborative effort involving infectious disease (ID) specialists and residents. A group of experts formulated six true/false, six open-ended questions, and six clinical cases with antibiograms for four types of infections (endocarditis, pneumonia, intra-abdominal infections, and bloodstream infection) for a total of 96 questions. The questions were submitted to four senior residents and four specialists in ID and inputted into ChatGPT-4 and a trained version of ChatGPT-4. A total of 720 responses were obtained and reviewed by a blinded panel of experts in antibiotic treatments. They evaluated the responses for accuracy and completeness, the ability to identify correct resistance mechanisms from antibiograms, and the appropriateness of antibiotics prescriptions. RESULTS: No significant difference was noted among the four groups for true/false questions, with approximately 70% correct answers. The trained ChatGPT-4 and ChatGPT-4 offered more accurate and complete answers to the open-ended questions than both the residents and specialists. Regarding the clinical case, we observed a lower accuracy from ChatGPT-4 to recognize the correct resistance mechanism. ChatGPT-4 tended not to prescribe newer antibiotics like cefiderocol or imipenem/cilastatin/relebactam, favoring less recommended options like colistin. Both trained- ChatGPT-4 and ChatGPT-4 recommended longer than necessary treatment periods (p-value = 0.022). CONCLUSIONS: This study highlights ChatGPT's capabilities and limitations in medical decision-making, specifically regarding bacterial infections and antibiogram analysis. While ChatGPT demonstrated proficiency in answering theoretical questions, it did not consistently align with expert decisions in clinical case management. Despite these limitations, the potential of ChatGPT as a supportive tool in ID education and preliminary analysis is evident. However, it should not replace expert consultation, especially in complex clinical decision-making.

Use of Cefiderocol in Adult Patients: Descriptive Analysis from a Prospective, Multicenter, Cohort Study.

INTRODUCTION: Cefiderocol is a siderophore cephalosporin showing activity against various carbapenem-resistant Gram-negative bacteria (CR-GNB). No data currently exist about real-world use of cefiderocol in terms of types of therapy (e.g., empirical or targeted, monotherapy or combined regimens), indications, and patient characteristics. METHODS: In this multicenter, prospective study, we aimed at describing the use of cefiderocol in terms of types of therapy, indications, and patient characteristics. RESULTS: Cefiderocol was administered as empirical and targeted therapy in 27.5% (55/200) and 72.5% (145/200) of cases, respectively. Overall, it was administered as monotherapy in 101/200 cases (50.5%) and as part of a combined regimen for CR-GNB infections in the remaining 99/200 cases (49.5%). In multivariable analysis, previous isolation of carbapenem-resistant Acinetobacter baumannii odds ratio (OR) 2.56, with 95% confidence interval (95% CI) 1.01-6.46, p = 0.047] and previous hematopoietic stem cell transplantation (OR 8.73, 95% CI 1.05-72.54, p = 0.045) were associated with administration of cefiderocol as part of a combined regimen, whereas chronic kidney disease was associated with cefiderocol monotherapy (OR 0.38 for combined regimen, 95% CI 0.16-0.91, p = 0.029). Cumulative 30-day mortality was 19.8%, 45.0%, 20.7%, and 22.7% in patients receiving targeted cefiderocol for infections by Enterobacterales, A. baumannii, Pseudomonas aeruginosa, and any metallo-ß-lactamase producers, respectively. CONCLUSIONS: Cefiderocol is mainly used for targeted treatment, although empirical therapies account for more than 25% of prescriptions, thus requiring dedicated standardization and guidance. The almost equal distribution of cefiderocol monotherapy and cefiderocol-based combination therapies underlines the need for further study to ascertain possible differences in efficacy between the two approaches.

Weight excess and obesity are associated with binge eating behaviours in people with HIV.

OBJECTIVE: Binge eating (BE) is a mental health disorder related to weight gain (WG), whose prevalence/correlation with weight excess in people with HIV (PWH) have been scarcely investigated.Design: A cross-sectional study of PWH who underwent the validated Binge eating scale (BES) questionnaire. METHODS: We included adult PWH during routine visits from October 2022 to February 2023. The BES questionnaire was administered with the support of a psychiatrist (score <17 BE very unlikely, BE≥17 possible/very likely). We performed a logistic regression for the binary outcome BES≥17 and being overweighted/obese as effect measure of risk association, and then adjusted for possible confounders (as integrase inhibitor exposure) and performed a sensitivity analysis fitting the regression model including and excluding depression (which may drive BE). RESULTS: We included 1204 PWH, 75.2% males, median age 53 years (IQR:44-60), 95.6% with undetectable HIV-RNA. As for BMI, we had overweight and obesity in 35.1% and 19.4% cases. Considering BES, 1089 (90.4%) PWH had a score<17, 115 (9.6%) ≥17. Multivariable analysis showed that obesity (OR = 6.21, p�< 0.0001), overweight (OR = 2.21, p = 0.006) and depression (OR�=�1.98, p�=�0.028) were significantly associated with high BES score. By excluding depression, our results were confirmed, and obesity/overweight remained significantly associated with BE (obesity OR = 6.58, p < 0.0001, overweight OR = 2.17, p = 0.023). CONCLUSIONS: BE should be considered among possible causes of WG in PWH. Our results push towards an in-depth study of this topic for a better understanding of the phenomenon in PWH, possibly identifying subgroups of this population who could benefit from a psychoeducational/psychological intervention to preventing WG.

Impact of switching to injectables cabotegravir and rilpivirine on sleep disturbances in a cohort of people living with HIV.

BACKGROUND: Recently, injectable cabotegravir/rilpivirine (ICAB/RPV) became available for HIV treatment. However, there are no real-life data on the impact of switching to ICAB/RPV on sleep disturbances (SD). Therefore, we aimed at assessing and investigating this aspect in our cohort. METHODS: A SD multidimensional assessment (Epworth Sleepiness scale, Insomnia severity Index, Berlin Questionnaire, and Pittsburg Sleep Quality Index, PSQI) was performed to all people who consented before starting ICAB/RPV and 12 wk after the switch. Demographics, life-style habits, laboratory, and clinical data were collected from medical health records. RESULTS: To June 2023, 46 people were included, 76.1% males, with a median age of 48.5 (IQR: 41-57), 50% had multimorbidity, 13% was on polypharmacy. Median age with HIV and CD4 + T cell count nadir were 10 (5-19.5) years and 360 (205-500) cell/mm3, respectively. The reason to start a long-acting strategy was person's choice in all cases. Baseline antiretroviral regimens were mostly: tenofovir alafenamide/emtricitabine/rilpivirine (39.1%) and dolutegravir/lamivudine (32.6%). No significant changes were observed in any of the scores for each questionnaire, but for a worsening PSQI. 37% people reported a subjectively improved sleep quality, even if statistically significant changes were not observed in almost all the sleep parameters. CONCLUSIONS: To the best of our knowledge, this is the first study exploring impact of switching to ICAB/RPV on SD. Despite integrase inhibitor have been associated with SD, we did not observed a negative impact on sleep quality after the switch to ICAB/RPV. More studies and with larger number of people are necessary to confirm our results.

Achievement of Primary Prevention Cardiometabolic Targets in Women with HIV: An Urgent Call to Action to Pursue Cardiovascular Health.

BACKGROUND: Cardiometabolic health has become crucial, especially for women with HIV (WWH). We assessed the achievement of targets for hypertension, dyslipidemia, and diabetes (H/Dy/DT) in primary prevention in a WWH cohort. METHODS: Cross-sectional analysis including all WWH in our clinic, excluding those who had a myocardial infarction. H/Dy/DT achievement was assessed by both EACS guidelines and individual cardiovascular risk, CVR (measured by ESC calculator), using logistic regression to evaluate differences in H/Dy/DT achievement between migrant and Italian women. RESULTS: We included 292 WWH, 55.5% Italian and 44.5% migrant women; the median age was 50 (IQR:42-58) years, 94.5% had undetectable HIV-RNA, 55.1% had a high level of education, 27.1% were smokers, and 19.2% did regularly physical exercise. Overall, 76%, 19%, and 5% of women presented a low, a high, and a very high CVR, respectively. Among Italians, 28.4% and 6.2% women presented a high and a very high CVR, respectively. Considering migrants, 7.7% and 3.8% women presented a high and a very high CVR, respectively. Overall, among migrant women, those with a high CVR were more likely to be not at target than those with a low risk (especially for LDL-c and blood pressure among people on treatment), despite the fact that we did not detect a statistically significant difference. By contrast, migrants were more likely to achieve glycemic targets than Italians (p = 0.032). CONCLUSIONS: H/Dy/DT target achievement is suboptimal, especially in migrants. A more aggressive pharmacological treatment, also assessing adherence to medical prescriptions, and promotion of healthy lifestyle should be urgently implemented, possibly redrawing the current model of care.

Gram-negative bacterial colonizations before bilateral lung transplant. The impact of 'targeted' versus 'standard' surgical prophylaxis.

BACKGROUND: Infections are one of the most common causes of death after lung transplant (LT). However, the benefit of 'targeted' prophylaxis in LT recipients pre-colonized by Gram-negative (GN) bacteria is still unclear. METHODS: All consecutive bilateral LT recipients admitted to the Intensive Care Unit of the University Hospital of Padua (February 2016-2023) were retrospectively screened. Only patients with pre-existing GN bacterial isolations were enrolled and analyzed according to the antimicrobial surgical prophylaxis ('standard' vs. 'targeted' on the preoperative bacterial isolation). RESULTS: One hundred eighty-one LT recipients were screened, 46 enrolled. Twenty-two (48%) recipients were exposed to 'targeted' prophylaxis, while 24 (52%) to 'standard' prophylaxis. Overall prevalence of postoperative multi-drug resistant (MDR) GN bacteria isolation was 65%, with no differences between the two surgical prophylaxis (p = 0.364). Eleven (79%) patients treated with 'standard' prophylaxis and twelve (75%) with 'targeted' therapy reconfirmed the preoperative GN pathogen (p = 0.999). The prevalence of postoperative infections due to MDR GN bacteria was 50%. Of these recipients, 4 belonged to the 'standard' and 11 to the 'targeted' prophylaxis (p = 0.027). CONCLUSIONS: The administration of a 'targeted' prophylaxis in LT pre-colonized recipients seemed not to prevent the occurrence of postoperative MDR GN infections.

Kaposi's Sarcoma: Evaluation of Clinical Features, Treatment Outcomes, and Prognosis in a Single-Center Retrospective Case Series.

Kaposi's sarcoma (KS) is a rare angioproliferative tumor classified in four different clinical-epidemiological forms. The diagnosis is based on histopathological and immunohistochemical analyses. The treatment is heterogeneous and includes several local and systemic therapeutic strategies. Methods: This is a retrospective cohort study including 86 KS patients treated between 1993 and 2022 at the University Hospital of Padua (AOPD) and at the Veneto Institute of Oncology (IOV). The data were extracted from an electronic database. Survival curves were generated using the Kaplan-Meier method, and Cox regression models were employed to explore associations with overall and disease-free survival. The male sex (89.53%), classical variant (43.02%), and cutaneous involvement (77.9%) were predominant. More than 61.6% of patients received a single treatment. Surgery, antiretroviral therapy, and chemotherapy were the mostly adopted approaches. A persistent response was observed in approximately 65% of patients, with a 22% relapse rate (at least 2 years). The overall survival ranges from 90 to 70% at 2 to 10 years after the diagnosis. Iatrogenic KS demonstrated a higher mortality (52.9%). This study reflects our experience in the management of KS. Comorbidities are very frequent, and treatments are heterogeneous. A multidisciplinary approach involving multiple referral specialists is essential for the appropriate management of this disease during diagnosis, treatment, and follow-up.

PRESTIGIO RING: "An 80-year-old man living with HIV resistant to all four antiretroviral classes and desiring treatment simplification".

People aging with 4 antiretroviral class resistant HIV are a very challenging population. It is difficult to build up a fully suppressive regimen, and the high prevalence of comorbidities and polypharmacy may cause drug-drug interactions and put adherence at risk. We herein present the case of an 80-year-old man, participating in the PRESTIGIO registry, asking for a reduction in his antiretroviral burden while on polypharmacy for his comorbidities.

Fungal Infections and Colonization after Bilateral Lung Transplant: A Six-Year Single-Center Experience.

Fungal infections (FIs) are one of the leading causes of morbidity and mortality within the first year of lung transplant (LT) in LT recipients (LTRs). Their prompt identification and treatment are crucial for a favorable LTR outcome. The objectives of our study were to assess (i) the FI incidence and colonization during the first year after a bilateral LT, (ii) the risk factors associated with FI and colonization, and (iii) the differences in fungal incidence according to the different prophylactic strategies. All bilateral LTRs admitted to the intensive care unit of Padua University Hospital were retrospectively screened, excluding patients <18 years of age, those who had been re-transplanted, and those who had received ventilation and/or extracorporeal membrane oxygenation before LT. Overall, 157 patients were included. A total of 13 (8%) patients developed FI, and 36 (23%) developed colonization, which was mostly due to Aspergillus spp. We did not identify independent risk factors for FI. Groups of patients receiving different prophylactic strategies reported a similar incidence of both FI and colonization. The incidence of FI and fungal colonization was 8% and 23%, respectively, with no differences between different antifungal prophylaxes or identified predisposing factors. Further studies with larger numbers are needed to confirm our results.

Circulating haematopoietic stem cells and long-term outcomes of COVID-19.

BACKGROUND AND AIMS: An acute depletion of circulating haematopoietic stem/progenitor cells (HSPCs) occurs during COVID-19, especially among patients with a poorer disease course. We herein examined whether HSPCs levels at hospital admission for COVID-19 predict 1-year mortality and the long-COVID syndrome. MATERIALS AND METHODS: Patients hospitalized for COVID-19 in an infectious disease ward were consecutively enrolled. Circulating HSPC levels were assessed by flow cytometry as cells expressing CD34 and/or CD133. Follow-up was performed for 12 months after hospitalization through the review of electronic medical records and demographic local registers. RESULTS: The study included 100 patients, 36 of whom reported symptoms of long-COVID and 20 died during follow-up. The reduction of 1-SD of HSPCs was associated with a 3- to 5-fold increase in the risk of 1-year mortality. Age, admission hyperglycaemia, C-reactive protein peak, liver enzymes, the need of high-flow oxygen and/or invasive ventilation were predictors of mortality at univariate analysis. Among pre-existing comorbidities, coronary heart disease and chronic kidney disease, but not diabetes, were associated with 1-year mortality. In multivariate analyses, HSPCs remained significantly associated with 1-year mortality independently of confounders. The development of pneumonia an in-hospital treatment with glucocorticoids and convalescent plasma were associated with long-COVID symptoms at follow-up. HSPCs, diabetes and other comorbidities were not predictors of long-COVID. CONCLUSIONS: In a cohort of patients hospitalized for COVID-19, lower HSPC levels at the time of admission were independent predictors of 1-year mortality. However, COVID-19 severity, but not HSPC level, was significantly associated with the development of long-COVID symptoms.

Trauma Shaping the Psychopathological Correlates of Patients with Long-COVID: A 6-Months Longitudinal Study with Repeated Measures Mixed Models.

This research aimed at investigating how the experience of trauma can influence the psychological correlates of long-COVID over time in a clinical sample of patients hospitalized because of COVID-19. Through a longitudinal research design, 70 post-acute patients with COVID-19 were followed-up after hospital discharge in 3-time points up to 6 months and completed the Post-traumatic Stress Disorder Checklist for DSM-5 (PCL-5) and the Symptoms Checklist-90-Revised (SCL-90 R). Repeated measures mixed models with random intercept were used to evaluate the effect of trauma (yes/no) over time (T1, T2, T3) on the SCL-90-R scales. Results showed that patients with trauma display significantly worse psychological outcomes in all the SCL-90-R dimensions [all padj < .05 for the principal effects of trauma(y)], especially in symptoms of depression [time 2 vs time 1*trauma(y): b = -3.86, 95%CI (-7.18, -0.53), padj = .035; time 3 vs time 1*trauma(y): b = -4.77, 95%CI (-8.10, -1.45), padj = .011], anxiety [time 3 vs time 1*trauma(y): b = -4.54, 95%CI (-7.72, -1.37), padj = .011], and obsessive-compulsive difficulties [time 3 vs time 1*trauma(y): b = -4.03, 95%CI (-7.20, -0.86), padj = .027]. These findings shed light on the long-term psychological consequences of COVID-19 among hospitalized patients and highlight the key role of trauma, suggesting its assessment to tailor psychological interventions.

Real-Life Experience on Dolutegravir and Lamivudine as Initial or Switch Therapy in a Silver Population Living with HIV.

BACKGROUND: Clinical trials and real-life studies have granted the efficacy and safety of dolutegravir and lamivudine (DTG/3TC) in naïve and experienced people living with HIV (PLWH), but there are no long-term data in elderly people. We herein describe our real-life cohort of PLWH who were ≥65 years of age (PLWH ≥ 65) who started or were switched to DTG/3TC, single-tablet regimen, or DTG plus 3TC. METHODS: We considered laboratory/clinical parameter changes from the baseline to the last follow-up time point available for each person by the paired Wilcoxon test and analyzed factors associated with virological failure (VF) and discontinuation. RESULTS: We included 112 PLWH with a median age of 66 (IQR: 65-70) years, 77.6% males; 84.8% of people had multimorbidity, 34.8% were on polypharmacy, and only 5.4% were naïve to treatment. Reasons to be switched to DTG/3TC were: abacavir removal (38.7%), treatment simplification (33.1%), and PI discontinuation (28.2%). The median treatment durability was 6 (IQR: 5.4-7) years. No significant changes were detected in metabolic, renal, immunological, or cardiovascular biomarkers during follow-up. HIV RNA undetectability was maintained in 104 (92.8%) individuals for whom follow-up evaluation was available. We observed eight discontinuations (two deaths, two VFs, two early intolerances, one significant weight gain, and one switch to long-acting therapy). No factors were significantly associated with VF or discontinuation. CONCLUSIONS: This is the first study on DTG/3TC in PLWH ≥ 65 with a follow-up longer than 5 years. DTG/3TC was found to be safe and effective, neutral on metabolic parameters, and with a low discontinuation rate for toxicity or VF.

Comprehensive bronchoalveolar lavage characterization in COVID-19 associated acute respiratory distress syndrome patients: a prospective cohort study.

COVID-19-related acute respiratory distress syndrome (CARDS) is associated with high mortality rates. We still have limited knowledge of the complex alterations developing in the lung microenvironment. The goal of the present study was to comprehensively analyze the cellular components, inflammatory signature, and respiratory pathogens in bronchoalveolar lavage (BAL) of CARDS patients (16) in comparison to those of other invasively mechanically ventilated patients (24). In CARDS patients, BAL analysis revealed: SARS-CoV-2 infection frequently associated with other respiratory pathogens, significantly higher neutrophil granulocyte percentage, remarkably low interferon-gamma expression, and high levels of interleukins (IL)-1ß and IL-9. The most important predictive variables for worse outcomes were age, IL-18 expression, and BAL neutrophilia. To the best of our knowledge, this is the first study that was able to identify, through a comprehensive analysis of BAL, several aspects relevant to the complex pathophysiology of CARDS.

Cefiderocol-Based versus Colistin-Based Regimens for Severe Carbapenem-Resistant Acinetobacter baumannii Infections: A Propensity Score-Weighted, Retrospective Cohort Study during the First Two Years of the COVID-19 Pandemic.

BACKGROUND: A large increase in multi-drug-resistant Acinetobacter baumannii, especially carbapenem-resistant strains, occurred during the first two years of the COVID-19 pandemic, posing important challenges in its treatment. Cefiderocol appeared to be a good option for the treatment of Carbapenem-resistant Acinetobacter baumannii (CR-Ab), but to date, the guidelines and evidence available are conflicting. METHODS: We retrospectively included a group of patients with CR-Ab infections (treated with colistin- or cefiderocol-based regimens) at Padua University Hospital (August 2020-July 2022) and assessed predictors of 30-day mortality, and differences in microbiological and clinical treatment. To evaluate the difference in outcomes, accounting for the imbalance in antibiotic treatment allocation, a propensity score weighting (PSW) approach was adopted. RESULTS: We included 111 patients, 68% males, with a median age of 69 years (IQR: 59-78). The median duration of antibiotic treatment was 13 days (IQR:11-16). In total, 60 (54.1%) and 51 (45.9%) patients received cefiderocol- and colistin-based therapy, respectively. Notably, 53 (47.7%) patients had bloodstream infections, while 58 (52.3%) had pneumonia. Colistin was combined in 96.1%, 80.4%, and 5.8% of cases with tigecycline, meropenem, and fosfomycin, respectively. Cefiderocol was combined in 13.3%, 30%, and 18.3% of cases with fosfomycin, tigecycline, and meropenem, respectively. At the baseline, the two treatment groups significantly differed in age (patients treated with colistin were significantly older), the prevalence of diabetes and obesity (more frequent in the group treated with colistin), length of stay (longer in the group receiving cefiderocol), and type of infection (BSI were more frequent in the group receiving cefiderocol). The proportion of patients who developed acute kidney injury was significantly higher in the colistin group. By using PSW, no statistically significant differences emerged for mortality or clinical and microbiological cure between the two groups. No independent predictors were detected for hospital mortality or clinical cure, while for the length of stay, the only selected predictor was age, with a non-linear effect (p-value 0.025 for non-linearity) on the prolongation of hospital stay of 0.25 days (95% CI 0.10-0.39) at increasing ages (calculated over the IQR). CONCLUSIONS: Cefiderocol treatment did not differ in terms of main outcomes and safety profile from colistin-based regimens. More prospective studies with a larger number of patients are required to confirm our results.

Epidemiological and Clinical Features of SARS-CoV-2 Variants Circulating between April-December 2021 in Italy.

SARS-CoV-2 is constantly evolving, leading to new variants. We analysed data from 4400 SARS-CoV-2-positive samples in order to pursue epidemiological variant surveillance and to evaluate their impact on public health in Italy in the period of April-December 2021. The main circulating strain (76.2%) was the Delta variant, followed by the Alpha (13.3%), the Omicron (5.3%), and the Gamma variants (2.9%). The B.1.1 lineages, Eta, Beta, Iota, Mu, and Kappa variants, represented around 1% of cases. There were 48.2% of subjects who had not been vaccinated, and they had a lower median age compared to the vaccinated subjects (47 vs. 61 years). An increasing number of infections in the vaccinated subjects were observed over time, with the highest proportion in November (85.2%). The variants correlated with clinical status; the largest proportion of symptomatic patients (59.6%) was observed with the Delta variant, while subjects harbouring the Gamma variant showed the highest proportion of asymptomatic infection (21.6%), albeit also deaths (5.4%). The Omicron variant was only found in the vaccinated subjects, of which 47% had been hospitalised. The diffusivity and pathogenicity associated with the different SARS-CoV-2 variants are likely to have relevant public health implications, both at the national and international levels. Our study provides data on the rapid changes in the epidemiological landscape of the SARS-CoV-2 variants in Italy.