Multidrug-Resistant Bacterial Colonization and Infections in Large Retrospective Cohort of Mechanically Ventilated COVID-19 Patients1.

Few data are available on incidence of multidrug-resistant organism (MDRO) colonization and infections in mechanically ventilated patients, particularly during the COVID-19 pandemic. We retrospectively evaluated all patients admitted to the COVID-19 intensive care unit (ICU) of Hub Hospital in Milan, Italy, during October 2020‒May 2021. Microbiologic surveillance was standardized with active screening at admission and weekly during ICU stay. Of 435 patients, 88 (20.2%) had MDROs isolated ≤48 h after admission. Of the remaining patients, MDRO colonization was diagnosed in 173 (51.2%), MDRO infections in 95 (28.1%), and non-MDRO infections in 212 (62.7%). Non-MDRO infections occurred earlier than MDRO infections (6 days vs. 10 days; p<0.001). Previous exposure to antimicrobial drugs within the ICU was higher in MDRO patients than in non-MDRO patients (116/197 [58.9%] vs. 18/140 [12.9%]; p<0.001). Our findings might serve as warnings for future respiratory viral pandemics and call for increased measures of antimicrobial stewardship and infection control.

Unexpectedly High Frequency of Enterococcal Bloodstream Infections in Coronavirus Disease 2019 Patients Admitted to an Italian ICU: An Observational Study.

OBJECTIVES: We aimed to assess the frequency of ICU-acquired bloodstream infections in coronavirus disease 2019 patients. DESIGN: Retrospective observational study. SETTING: The emergency expansion of an ICU from eight general beds to 30 coronavirus disease 2019 beds. PARTICIPANTS: Patients with coronavirus disease 2019 admitted to the ICU of Luigi Sacco Hospital (Milan, Italy) for greater than or equal to 48 hours between February 21, 2020, and April 30, 2020. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The frequency of bloodstream infections per 1,000 days of ICU stay was calculated in 89 coronavirus disease 2019 patients, and the cumulative probability of bloodstream infection was estimated using death and ICU discharge as competing events. Sixty patients (67.4%) experienced at least one of the 93 recorded episodes of bloodstream infection, a frequency of 87 per 1,000 days of ICU stay (95% CI, 67-112).The patients who experienced a bloodstream infection had a higher Sequential Organ Failure Assessment score upon ICU admission (9.5; interquartile range, 8-12 vs 8, interquartile range, 5-10; p = 0.042), a longer median ICU stay (15 d; interquartile range, 11-23 vs 8, interquartile range, 5-12; p < 0.001), and more frequently required invasive mechanical ventilation (98.3% vs 82.8%; p = 0.013) than those who did not. The median time from ICU admission to the first bloodstream infection episode was 10 days. Gram-positive bacteria accounted for 74 episodes (79.6%), with Enterococcus species being the most prevalent (53 episodes, 55.8%). Thirty-two isolates (27.3%) showed multidrug resistance. CONCLUSIONS: Coronavirus disease 2019 seemed to increase the frequency of bloodstream infections (particularly Enterococcus-related bloodstream infection) after ICU admission. This may have been due to enteric involvement in patients with severe coronavirus disease 2019 and/or limitations in controlling the patient-to-patient transmission of infectious agents in extremely challenging circumstances.

An unusual case of pleural effusion.

CASE PRESENTATION: A 63-year-old man presented with fever, thoracalgia, weight loss, diffuse lymphadenopathy, and a massive pleural effusion. Extensive laboratory and radiologic investigations for possible autoimmune, infectious, hematologic, and neoplastic conditions all resulted negative. A lymph node biopsy showed a granulomatous necrotizing lymphadenitis, suspicious for tuberculosis. Although mycobacterium tuberculosis (MT) was never isolated and tuberculin skin test resulted negative, diagnosis of extrapulmonary tuberculosis was made and anti-tubercular therapy was started. Despite the strict adherence to 5 months of treatment, he returned to the emergency ward complaining of fever, chest pain and pleural effusion; total-body CT and PET scans demonstrated a progression of new disseminated nodular consolidations. DIAGNOSTIC WORK-UP: Microscopic and cultural search for MT and other micro-organisms resulted again negative on urine, stool, blood, pleural fluid, and spinal lesion biopsy. We therefore started considering alternative diagnosis for necrotizing granulomatosis, including multidrug-resistant tuberculosis, Wegener granulomatosis, Churg Strauss syndrome, necrobiotic nodules of rheumatoid arthritis, lymphomatoid granulomatosis and Necrotizing Sarcoid Granulomatosis (NSG). Having already rejected other autoimmune, hematological, and neoplastic disorders, NSG resulted the most consistent hypothesis. With an expert we thus re-examined histological specimens that were suggestive for an atypical presentation of sarcoidosis. Steroid therapy was initiated, achieving symptoms improvement. DISCUSSION: Sarcoidosis is a rare condition that can be challenging to diagnose, due to its variability in clinical presentation, often mimicking alternative conditions like disseminated tuberculosis. A high degree of suspicion and an experienced lab in anatomical pathology are essential for final diagnosis.

Genomic Characterization of Carbapenem-Resistant Acinetobacter baumannii (CRAB) in Mechanically Ventilated COVID-19 Patients and Impact of Infection Control Measures on Reducing CRAB Circulation during the Second Wave of the SARS-CoV-2 Pandemic in Milan, Italy.

COVID-19 has significantly affected hospital infection prevention and control (IPC) practices, especially in intensive care units (ICUs). This frequently caused dissemination of multidrug-resistant organisms (MDROs), including carbapenem-resistant Acinetobacter baumannii (CRAB). Here, we report the management of a CRAB outbreak in a large ICU COVID-19 hub Hospital in Italy, together with retrospective genotypic analysis by whole-genome sequencing (WGS). Bacterial strains obtained from severe COVID-19 mechanically ventilated patients diagnosed with CRAB infection or colonization between October 2020 and May 2021 were analyzed by WGS to assess antimicrobial resistance and virulence genes, along with mobile genetic elements. Phylogenetic analysis in combination with epidemiological data was used to identify putative transmission chains. CRAB infections and colonization were diagnosed in 14/40 (35%) and 26/40 (65%) cases, respectively, with isolation within 48 h from admission in 7 cases (17.5%). All CRAB strains belonged to Pasteur sequence type 2 (ST2) and 5 different Oxford STs and presented blaOXA-23 gene-carrying Tn2006 transposons. Phylogenetic analysis revealed the existence of four transmission chains inside and among ICUs, circulating mainly between November and January 2021. A tailored IPC strategy was composed of a 5-point bundle, including ICU modules' temporary conversion to CRAB-ICUs and dynamic reopening, with limited impact on ICU admission rate. After its implementation, no CRAB transmission chains were detected. Our study underlies the potentiality of integrating classical epidemiological studies with genomic investigation to identify transmission routes during outbreaks, which could represent a valuable tool to ensure IPC strategies and prevent the spread of MDROs. IMPORTANCE Infection prevention and control (IPC) practices are of paramount importance for preventing the spread of multidrug-resistant organisms (MDROs) in hospitals, especially in the intensive care unit (ICU). Whole-genome sequencing (WGS) is seen as a promising tool for IPC, but its employment is currently still limited. COVID-19 pandemics have posed dramatic challenges in IPC practices, causing worldwide several outbreaks of MDROs, including carbapenem-resistant Acinetobacter baumannii (CRAB). We present the management of a CRAB outbreak in a large ICU COVID-19 hub hospital in Italy using a tailored IPC strategy that allowed us to contain CRAB transmission while preventing ICU closure during a critical pandemic period. The analysis of clinical and epidemiological data coupled with retrospective genotypic analysis by WGS identified different putative transmission chains and confirmed the effectiveness of the IPC strategy implemented. This could be a promising approach for future IPC strategies.

Prognostic Value of Mid-Region Proadrenomedullin and In Vitro Interferon Gamma Production for In-Hospital Mortality in Patients with COVID-19 Pneumonia and Respiratory Failure: An Observational Prospective Study.

Coagulopathy and immune dysregulation have been identified as important causes of adverse outcomes in coronavirus disease (COVID-19). Mid-region proadrenomedullin (MR-proADM) is associated with endothelial damage and has recently been proposed as a prognostic factor in COVID-19. In non-COVID-19 immunocompromised patients, low in vitro interferon gamma (IFNγ) production correlates with infection risk and mortality. This prospective, monocentric, observational study included adult patients consecutively admitted with radiologic evidence of COVID-19 pneumonia and respiratory failure. MR-proADM and in vitro IFNγ production were measured at T0 (day 1 from admission) and T1 (day 7 from enrollment). One hundred patients were enrolled. Thirty-six percent were females, median age 65 (Q1−Q3 54.5−75) years, and 58% had ≥1 comorbidity. Only 16 patients had received COVID-19 vaccination before hospitalization. At admission, the median PaO2:FiO2 ratio was 241 (157−309) mmHg. In-hospital mortality was 13%. MR-proADM levels differed significantly between deceased and survivors both at T0 (1.41 (1.12−1.77) nmol/L vs. 0.79 (0.63−1.03) nmol/L, p < 0.001) and T1 (1.67 (1.08−1.96) nmol/L vs. 0.66 (0.53−0.95) nmol/L, p < 0.001). In vitro IFNγ production at T0 and T1 did not vary between groups. When only the subset of non-vaccinated patients was considered, both biomarkers at T1 resulted significantly associated with in-hospital mortality. AUROC for MR-proADM at T0 to predict in-hospital mortality was 0.87 (95%CI 0.79−0.94), with the best cut-off point at 1.04 nmol/L (92% sensitivity, 75% specificity and 98% negative predictive value). In patients with COVID-19 pneumonia and different degrees of respiratory failure, MR-proADM at admission and during hospitalization resulted strongly associated with in-hospital mortality. Low in vitro IFNγ production after the first week of hospitalization was associated with mortality in non-vaccinated patients possibly identifying the subgroup characterized by a higher degree of immune suppression.

Safety Profile and Outcomes of Early COVID-19 Treatments in Immunocompromised Patients: A Single-Centre Cohort Study.

BACKGROUND: Early treatment with remdesivir (RMD) or monoclonal antibodies (mAbs) could be a valuable tool in patients at risk of severe COVID-19 with unsatisfactory responses to vaccination. We aim to assess the safety and clinical outcomes of these treatments among immunocompromised subjects. METHODS: We retrospectively reviewed all nonhospitalized patients who received an early treatment with RMD or mAbs for COVID-19, from 25 November 2021 to 25 January 2022, in a large tertiary hospital. Outcomes included frequency of adverse drug reaction (ADR), duration of symptoms and molecular swab positivity, emergency department access, hospital or intensive care unit admission, and mortality in the 14 days following treatment administration. RESULTS: Early treatments were administered to 143 patients, 106/143 (74.1%) immunocompromised, including 41 solid organ and 6 hematopoietic stem cell transplant recipients. Overall, 23/143 (16.1%) subjects reported ADRs. Median time from treatment start to SARS-CoV-2 nasopharyngeal swab negativity and symptom resolution was 10 (IQR 6-16) and 2.5 days (IQR 1.0-6.0), respectively, without differences between immunocompromised and nonimmunocompromised patients. In the 14 days after treatment administration, 5/143 patients (3.5%) were hospitalized and one died as a result of causes related to COVID-19, all of them were immunocompromised. CONCLUSIONS: RMD and mAbs have minimal ADRs and favourable outcomes in immunocompromised patients.

Are direct-acting antivirals safe and effective in hepatitis C virus-cryoglobulinemia? virological, immunological, and clinical data from a real-life experience.

OBJECTIVES: Hepatitis C virus (HCV) is the major cause of cryoglobulinemia. Direct-acting antivirals (DAAs) have markedly changed the therapeutic outcomes in the treatment of patients with HCV. We evaluate the efficacy, safety, immunological, and clinical response of different DAA regimens in HCV-cryoglobulinemia. PATIENTS AND METHODS: Ninety-three cryoglobulinemic patients, divided into symptomatic [symptomatic cryoglobulinemic patients (SCP; n=35)] and asymptomatic [nonsymptomatic cryoglobulinemic patients (NSCP; n=60)], underwent DAAs. Eighty-nine comparable noncryoglobulinemic patients were selected as a control group. We evaluated the sustained virological response (SVR), the adverse effects, and the immune and symptomatic response. RESULTS: Percentages of patients who achieved SVR and experienced adverse effects were not statistically different between the three groups (100, 95, 93.3% and 57.1, 53.3, 48.3%). In 68.5% of SCP and in 76.7% of NSCP, cryoglobulins disappeared at SVR. No risk factor was associated with the persistence of cryoglobulins. An increase was observed both in C4 (P=0.002; P=0.018) and in C3 (P=0.0037; P=0.031) in SCP and NSCP. About 70% of symptomatic patients showed a complete or partial symptomatic remission: persistence of symptoms is correlated to the type of clinical picture. CONCLUSION: DAA regimens are safe and effective in patients with HCV-cryoglobulinemia. The achievement of SVR is necessary, but not sufficient, to achieve a complete immunological and clinical response.

Improvement of ALT decay kinetics by all-oral HCV treatment: Role of NS5A inhibitors and differences with IFN-based regimens.

BACKGROUND: Intracellular HCV-RNA reduction is a proposed mechanism of action of direct-acting antivirals (DAAs), alternative to hepatocytes elimination by pegylated-interferon plus ribavirin (PR). We modeled ALT and HCV-RNA kinetics in cirrhotic patients treated with currently-used all-DAA combinations to evaluate their mode of action and cytotoxicity compared with telaprevir (TVR)+PR. STUDY DESIGN: Mathematical modeling of ALT and HCV-RNA kinetics was performed in 111 HCV-1 cirrhotic patients, 81 treated with all-DAA regimens and 30 with TVR+PR. Kinetic-models and Cox-analysis were used to assess determinants of ALT-decay and normalization. RESULTS: HCV-RNA kinetics was biphasic, reflecting a mean effectiveness in blocking viral production >99.8%. The first-phase of viral-decline was faster in patients receiving NS5A-inhibitors compared to TVR+PR or sofosbuvir+simeprevir (p<0.001), reflecting higher efficacy in blocking assembly/secretion. The second-phase, noted δ and attributed to infected-cell loss, was faster in patients receiving TVR+PR or sofosbuvir+simeprevir compared to NS5A-inhibitors (0.27 vs 0.21 d-1, respectively, p = 0.0012). In contrast the rate of ALT-normalization, noted λ, was slower in patients receiving TVR+PR or sofosbuvir+simeprevir compared to NS5A-inhibitors (0.17 vs 0.27 d-1, respectively, p<0.001). There was no significant association between the second-phase of viral-decline and ALT normalization rate and, for a given level of viral reduction, ALT-normalization was more profound in patients receiving DAA, and NS5A in particular, than TVR+PR. CONCLUSIONS: Our data support a process of HCV-clearance by all-DAA regimens potentiated by NS5A-inhibitor, and less relying upon hepatocyte death than IFN-containing regimens. This may underline a process of "cell-cure" by DAAs, leading to a fast improvement of liver homeostasis.