Chiara Cassol

Sindbis virus (SINV) is a mosquito borne alphavirus causing seasonal outbreaks in northern Europe, Africa and Russia. Neurological involvement in humans is poorly documented, and detection in cerebrospinal fluid (CSF) has not previously been reported. This study provides the first unequivocal evidence of human CNS involvement by detecting SINV RNA directly in the cerebrospinal fluid of four autochthonous patients presenting with acute neurological symptoms in south eastern Tuscany, Italy, July-August 2025. Utilizing metagenomic Next Generation Sequencing (mNGS), we reconstructed complete viral genomes, strongly supporting a causal relationship between SINV and neurological manifestations. Phylogenetic analysis revealed a complex epidemiological landscape in Italy characterized by the co-circulation of Clade D lineages. Our findings fundamentally expand the clinical spectrum of SINV, demonstrating that it is not merely an arthritogenic pathogen, but a neuroinvasive threat to humans. This highlights the critical need to include SINV in the differential diagnosis of viral CNS infections in endemic areas and underscores the urgency for enhanced European laboratory surveillance.

The rise of HIV‐1 drug resistance to nonnucleoside reverse transcriptase inhibitors (NNRTIs) threatens the long‐term success of NNRTI‐based therapies. Our study aims to describe the circulation of major resistance‐associated mutations (RAMs) for NNRTIs in people living with HIV (PLWH) in Italy from 2000 to 2020. We included 5982 naïves and 28 505 genotypes from 9387 treatment‐experienced PLWH from the Antiviral Response Cohort Analysis (ARCA) cohort. Transmitted drug resistance (TDR) was found in 12.5% and declined from 17.3% in 2000–2003 to 10.9% in 2016–2020 (p = 0.003). Predictors of TDR were viral subtype B [vs. non‐B, adjusted odds ratio (aOR) = 1.94, p < 0.001], zenith viral load (VL) (per 1 log₁₀ higher, aOR = 0.86, p = 0.013), nadir CD4 cell count (per 100 cells/μL increase aOR = 0.95, p = 0.013). At least one RAM for NNRTIs among treatment experienced PLWH was detected in 33.2% and pre‐treatment drug resistance (PDR) declined from 43.4% in 2000–2003 to 20.9% in 2016–2020 (p < 0.001). Predictors of PDR were sexual transmission route (vs. others, aOR = 0.78, p < 0.001), time since HIV diagnosis (per 1 month longer, aOR = 1.002, p < 0.001), viral subtype B (vs. non B, aOR = 1.37, p < 0.001), VL (per 1 log₁₀ higher, aOR = 1.12, p < 0.001), nadir CD4 count (per 100 cells/μL increase, aOR = 0.91, p < 0.001), previous exposure to any NNRTI (aOR = 2.31, p < 0.001) and a more recent calendar year sequence (any time span > 2008 vs. 2000–2003, any aOR p < 0.001). Circulation of RAMs to NNRTIs declined during the last 20 years in Italy. NNRTIs remain pivotal drugs for the management of HIV‐1 due to safety concerns and long‐acting options.

Long-acting (LA) formulations have been designed to improve the quality of life of people with HIV (PWH) by maintaining virologic suppression. However, clinical trials have shown that patient selection is crucial. In fact, the HIV-1 resistance genotype test and the Body Mass Index of individual patients assume a predominant role in guiding the choice. Our work aimed to estimate the patients eligible for the new LA therapy with cabotegravir (CAB) + rilpivirine (RPV). We selected, from the Antiviral Response Cohort Analysis (ARCA) database, all PWH who had at least one follow-up in the last 24 months. We excluded patients with HBsAg positivity, evidence of non-nucleoside reverse transcriptase inhibitor (except K103N) and integrase inhibitor mutations, and with a detectable HIV-RNA (>50 copies/mL). Overall, 4103 patients are currently on follow-up in the ARCA, but the eligible patients totaled 1641 (39.9%). Among them, 1163 (70.9%) were males and 1399 were Caucasian (85.3%), of which 1291 (92%) were Italian born. The median length of HIV infection was 10.2 years (IQR 6.3–16.3) with a median nadir of CD4 cells/count of 238 (106–366) cells/mm³ and a median last available CD4 cells/count of 706 (509–944) cells/mm³. The majority of PWH were treated with a three-drug regimen (n = 1116, 68%). Among the 525 (30.3%) patients treated with two-drug regimens, 325 (18.1%) were treated with lamivudine (3TC) and dolutegravir (DTG) and only 84 (5.1%) with RPV and DTG. In conclusion, according to our snapshot, roughly 39.9% of virologically suppressed patients may be suitable candidates for long-acting CAB+RPV therapy. Therefore, based on our findings, many different variables should be taken into consideration to tailor the antiretroviral treatment according to different individual characteristics.

Despite the high efficacy of direct-acting antivirals (DAAs), the selection of resistance-associated substitutions (RASs) after virological failure of hepatitis C virus (HCV) DAAs can impair the cure of chronic HCV. The aim of the study was to characterize RASs after virological failure of DAAs in Italy over the years. Within the Italian network VIRONET-C, the change in prevalence of NS3/4A-NS5A-NS5B RASs was retrospectively evaluated in patients who failed a DAA regimen over the years 2015-2019. NS3, NS5A and NS5B Sanger sequencing was performed using homemade protocols and the geno2pheno system was used to define HCV-genotype/subtype and predict drug resistance. The changes in the prevalence of RASs over time were evaluated using the chi-square test for trend. Predictors of RASs at failure were analysed by logistic regression. Among 468 HCV-infected patients, HCV genotype 1 was the most prevalent (1b in 154, 33% and 1a in 109, 23%). DAA regimens were: ledipasvir (LDV)/sofosbuvir (SOF) in 131 patients (28%), daclatasvir (DCV)/SOF in 109 (23%), ombitasvir/paritaprevir/ritonavir+dasabuvir (3D) in 89 (19%), elbasvir (EBR)/grazoprevir (GRZ) in 52 (10.5%), velpatasvir (VEL)/SOF in 53 (11%), glecaprevir (GLE)/pibrentasvir (PIB) in 27 (6%) and ombitasvir/paritaprevir/ritonavir (2D) in 7 (1.5%); ribavirin was administered in 133 (28%). The NS5A fasta sequence was available for all patients, NS5B and NS3/4A both for 93%. The prevalence of NS5A and NS3/4A RASs significantly declined from 2015 to 2019; NS5B RAS remained stable. Independent predictors of any RASs included older age and genotype 1a (vs G2 and vs G4). Notably, at least partial susceptibility to all the agents included in the GLE/PIB and VEL/SOF/Voxilaprevir (VOX) combinations was predicted in >95% of cases. As RASs remain common at the failure of DAAs, their identification could play a crucial role in optimizing re-treatment strategies. In Italy RAS prevalence has been decreasing over the years and susceptibility to the latest developed drug combinations is maintained in most cases.

To evaluate incidence of and risk factors for respiratory bacterial colonization and infections within 30 days from lung transplantation (LT). We retrospectively analyzed microbiological and clinical data from 94 patients transplanted for indications other than cystic fibrosis, focusing on the occurrence of bacterial respiratory colonization or infection during 1 month of follow-up after LT. Thirty-three percent of patients developed lower respiratory bacterial colonization. Bilateral LT and chronic heart diseases were independently associated to a higher risk of overall bacterial colonization. Peptic diseases conferred a higher risk of multi-drug resistant (MDR) colonization, while longer duration of aerosol prophylaxis was associated with a lower risk. Overall, 35% of lung recipients developed bacterial pneumonia. COPD (when compared to idiopathic pulmonary fibrosis, IPF) and higher BMI were associated to a lower risk of bacterial infection. A higher risk of MDR infection was observed in IPF and in patients with pre-transplant colonization and infections. The risk of post-LT respiratory infections could be stratified by considering several factors (indication for LT, type of LT, presence of certain comorbidities, and microbiologic assessment before LT). A wider use of early nebulized therapies could be useful to prevent MDR colonization, thus potentially lowering infectious risk.

This study aims to assess the peripheral blood cell count “signature” of Severe Acute Respiratory Syndrome-Coronavirus 2 (SARS-CoV-2) to discriminate promptly between COronaVIrus Disease 19 (COVID-19) and community-acquired pneumonia (CAP). We designed a retrospective case-control study, enrolling 525 patients (283 COVID-19 and 242 with CAP). All patients had a fever and at least one of the following signs: cough, chest pain, or dyspnea. We excluded patients treated with immunosuppressants, steroids, or affected by diseases known to modify blood cell count. COVID-19 patients showed a significant reduction in white blood cells (neutrophils, lymphocytes, monocytes, eosinophils) and platelets. We studied these parameters univariately, combined the significant ones in a multivariate model (AUROC 0.86, Nagelkerke PSEUDO-R2 0.5, Hosmer–Lemeshow p-value 0.9) and examined its discriminative performance in an internally-randomized validation cohort (AUROC 0.84). The cut-off selected according to Youden’s Index (−0.13) showed a sensitivity of 84% and a specificity of 72% in the training cohort, and a sensitivity of 88% and a specificity of 73% in the validation cohort. In addition, we determined the probability of having COVID-19 pneumonia for each Model for possible Early COvid-19 Recognition (MECOR) Score value. In conclusion, our model could provide a simple, rapid, and cheap tool for prompt COVID-19 diagnostic triage in patients with CAP. The actual effectiveness should be evaluated in further, prospective studies also involving COVID-19 patients with negative nasopharyngeal swabs.