Durability of anti-spike antibodies after vaccination with mRNA SARS-CoV-2 vaccine is longer in subjects with previous infection: could the booster dose be delayed?

PURPOSE: The long-term effectiveness of BNT162b2/Pfizer vaccine remains undetermined. This observational prospective study was designed to verify durability of antibodies against the viral receptor-binding domain (RBD) spike (S)-protein (RBD S-Protein IgG) after the second-dose administration of the vaccine among Health Care Workers (HCWs). METHODS: In all HCWs at the Poliambulanza Foundation Hospital Brescia (Italy) were quantified the levels of RBD S-Protein IgG (Abbott Diagnostics) at 45 and 240 days after the second-dose vaccine. Previous infection was defined as antibodies against SARS-CoV-2 nucleocapsid positivity (Abbott Diagnostics) before vaccination. The Mann-Whitney U test was used to compare mean levels of RBD S-Protein IgG among previously infected and uninfected HCWs. RESULTS: The mean level of the RBD S-protein IgG detected 45 days after the second dose of the vaccine was 30,041 AU/mL (95% CI 145-80,000) for the 250 previously infected HCWs and it was significantly higher (p < 0.001) than that observed in the 1121 previously uninfected subject with the mean level of 10,604 AU/mL (95% CI 165-62,241). Similarly, at 240 days in previously infected subjects the antibody titer was of 8145 AU/mL (95% CI 347-80,000) and significantly higher (p < 0.001) than that observed in the 1121 previously uninfected HCWs with a mean antibody level of 1271 AU/mL (95% CI 50-80,000). When comparing the change in mean antibody levels overtime, the previously infected HCWs presented a 72.9% reduction in RBD S-protein IgG while in the previously uninfected HCWs the reduction was 88.0%. In addition, in the HCWs group without previous infection we reported 53 new SARS-CoV-2 infections and they had a mean level of RBD S-protein IgG antibodies of 1039 AU/mL (95% CI 157-4237) at 240 days. No new infections were found in previously SARS-CoV-2 infected subjects. CONCLUSIONS: We report that the mean level of post vaccinal RBD S-protein IgG was significantly higher in the previously infected HCWs than in previously uninfected subjects at 45 and 240 days after the second-dose vaccine. Moreover, our data suggest that the risk of a new SARS-CoV-2 infection was higher in the previously uninfected HCWs than in those who had already contracted natural viral infection. The limitations of this study prevent us to draw definitive conclusions on the antibody titers and on the role of a previous SARS-CoV-2 infection in influencing the levels of post-vaccine RBD S-protein IgG. The booster dose of the vaccine could be delayed after the second dose in previously naturally infected subject and it could have an important strategic impact on the organization of the future COVID-19 vaccination campaign.

Current features of infective endocarditis in persons on hemodialysis: a prevalence study with case control design from the prospective multicenter SEI cohort.

PURPOSE: Persons on hemodialysis (HD) are at high risk of infective endocarditis (IE). In non-comparative retrospective studies, a higher rate of mortality was reported in IE on HD. We assessed risk factors, clinical characteristics, and outcomes of IE in HD. METHODS: This was a prevalence study with a case control methodology on a set of data from the prospectively followed cohort of the Studio Endocarditi Italiano (SEI), conducted between 2004 and 2011. Included were 42 consecutive cases of IE HD subjects and 126 controls not on HD, matched for age, sex, type of IE, and heart side involved. Clinical, echocardiographic, microbiological features, and disease complications and therapeutic modalities were assessed. RESULTS: HD patients were more often diabetics (42.9 vs 18.2 % in no-HD; p = 0.007) and immune-suppressed (16.7 vs 3.2 %; p = 0.02), and had a higher rate of predisposing cardiac conditions (45 vs 25 %; p = 0.031). A higher prevalence of health care-related acquisition and a shorter diagnostic delay was observed in IE on HD, that was more likely to be caused by staphylococci and less by streptococci (p < 0.002). Cardiac surgery was performed in 38 % of HD patients and 36.5 % of no-HD patients (p = 0.856). Complications were similar and in-hospital mortality did not differ significantly (26.2 % in HD vs 15.9 % in no-HD; p = 0.168). CONCLUSIONS: IE in persons on HD is characterized by distinctive clinical features, including a higher prevalence of some important comorbidities. Inconsistent with prior studies, we could not confirm a higher rate of complications and mortality in HD patients with IE.

Predicting the occurrence of embolic events: an analysis of 1456 episodes of infective endocarditis from the Italian Study on Endocarditis (SEI).

BACKGROUND: Embolic events are a major cause of morbidity and mortality in patients with infective endocarditis. We analyzed the database of the prospective cohort study SEI in order to identify factors associated with the occurrence of embolic events and to develop a scoring system for the assessment of the risk of embolism. METHODS: We retrospectively analyzed 1456 episodes of infective endocarditis from the multicenter study SEI. Predictors of embolism were identified. Risk factors identified at multivariate analysis as predictive of embolism in left-sided endocarditis, were used for the development of a risk score: 1 point was assigned to each risk factor (total risk score range: minimum 0 points; maximum 2 points). Three categories were defined by the score: low (0 points), intermediate (1 point), or high risk (2 points); the probability of embolic events per risk category was calculated for each day on treatment (day 0 through day 30). RESULTS: There were 499 episodes of infective endocarditis (34%) that were complicated by ≥ 1 embolic event. Most embolic events occurred early in the clinical course (first week of therapy: 15.5 episodes per 1000 patient days; second week: 3.7 episodes per 1000 patient days). In the total cohort, the factors associated with the occurrence of embolism at multivariate analysis were prosthetic valve localization (odds ratio, 1.84), right-sided endocarditis (odds ratio, 3.93), Staphylococcus aureus etiology (odds ratio, 2.23) and vegetation size ≥ 13 mm (odds ratio, 1.86). In left-sided endocarditis, Staphylococcus aureus etiology (odds ratio, 2.1) and vegetation size ≥ 13 mm (odds ratio, 2.1) were independently associated with embolic events; the 30-day cumulative incidence of embolism varied with risk score category (low risk, 12%; intermediate risk, 25%; high risk, 38%; p < 0.001). CONCLUSIONS: Staphylococcus aureus etiology and vegetation size are associated with an increased risk of embolism. In left-sided endocarditis, a simple scoring system, which combines etiology and vegetation size with time on antimicrobials, might contribute to a better assessment of the risk of embolism, and to a more individualized analysis of indications and contraindications for early surgery.

Role of Cefiderocol in Multidrug-Resistant Gram-Negative Central Nervous System Infections: Real Life Experience and State-of-the-Art.

Cefiderocol is a new molecule effective against multidrug-resistant (MDR) Gram-negative pathogens. Currently, there is limited evidence regarding the use of cefiderocol in central nervous system (CNS) infections. Data on the cerebrospinal fluid penetration rate of cefiderocol are limited and heterogeneous, and there is no consensus on the dosing scheme of cefiderocol to penetrate the blood-brain barrier. We present a case series and a literature review of CNS infections caused by MDR pathogens that were treated with cefiderocol: some of these patients were treated with different dose schemes of cefiderocol and underwent therapeutic drug monitoring both on plasma and cerebrospinal fluid (CSF). The CSF penetration rates and the clinical outcomes were evaluated.

Effect of Corticosteroids on Mortality in Hospitalized COVID-19 Patients Not Receiving Invasive Mechanical Ventilation.

The most beneficial effect of corticosteroid therapy in COVID-19 patients has been shown in subjects receiving invasive mechanical ventilation (IMV), corresponding to a score of 6 on the World Health Organization (WHO) COVID-19 Ordinal Scale for Clinical Improvement (OSCI). The aim of this observational, single-center, prospective study was to assess the association between corticosteroids and hospital mortality in coronavirus disease 2019 (COVID-19) patients who did not receive IMV (OSCI 3-5). Included were 1,311 COVID-19 patients admitted to nonintensive care wards, and they were divided in two cohorts: (i) 480 patients who received corticosteroid therapy and (ii) 831 patients who did not. The median daily dose was of 8 mg of dexamethasone or equivalent, with a mean therapy duration of 5 (3-9) days. The indication to administer or withhold corticosteroids was given by the treating physician. In-hospital mortality was similar between the two cohorts after adjusting for possible confounders (adjusted odds ratio (ORadj) 1.04, 95% confidence interval (CI), 0.81-1.34, P = 0.74). There was also no difference in Intensive Care Unit (ICU) admission (ORadj 0.81, 95% CI, 0.56-1.17, P = 0.26). COVID-19 patients with noninvasive mechanical ventilation (NIMV) had a lower risk for ICU admission if they received steroid therapy (ORadj 0.58, 95% CI, 0.35-0.94, P = 0.03). In conclusion, corticosteroids were overall not associated with a difference in hospital mortality for patients with COVID-19 with OSCI 3-5. In the subgroup of patients with NIMV (OSCI 5), corticosteroids reduced ICU admission, whereas the effect on mortality requires further studies.

Pulmonary thromboembolism in hospitalised COVID-19 patients at moderate to high risk by Wells score: a report from Lombardy, Italy.

OBJECTIVES: To present a single-centre experience on CT pulmonary angiography (CTPA) for the assessment of hospitalised COVID-19 patients with moderate-to-high risk of pulmonary thromboembolism (PTE). METHODS: We analysed consecutive COVID-19 patients (RT-PCR confirmed) undergoing CTPA in March 2020 for PTE clinical suspicion. Clinical data were retrieved. Two experienced radiologists reviewed CTPAs to assess pulmonary parenchyma and vascular findings. RESULTS: Among 34 patients who underwent CTPA, 26 had PTE (76%, 20 males, median age 61 years, interquartile range 54-70), 20/26 (77%) with comorbidities (mainly hypertension, 44%), and 8 (31%) subsequently dying. Eight PTE patients were under thromboprophylaxis with low-molecular-weight heparin, four PTE patients had lower-limbs deep vein thrombosis at ultrasound examination (performed in 33/34 patients). Bilateral PTE characterised 19/26 cases, with main branches involved in 10/26 cases. Twelve patients had a parenchymal involvement >75%, the predominant pneumonia pattern being consolidation in 10/26 patients, ground glass opacities in 9/26, crazy paving in 5/26, and both ground glass opacities and consolidation in 2/26. CONCLUSION: COVID-19 patients are prone to PTE. ADVANCES IN KNOWLEDGE: PTE, potentially attributable to an underlying thrombophilic status, may be more frequent than expected in COVID-19 patients. Extension of prophylaxis and adaptation of diagnostic criteria should be considered.

Bacterial Blood Stream Infections Negatively Impact on Outcome of Patients Treated with Allogeneic Stem Cell Transplantation: 6 Years Single-Centre Experience.

BACKGROUND: Blood stream infections (BSIs) represent a major complication of allo-SCT and are a major cause of morbidity and mortality during and after bone marrow aplasia. OBJECTIVES: The objective of this study was to describe the incidence and outcome of BSIs in a cohort of patients submitted to allo-SCT, in order to track changes of the epidemiology and bacteria resistance. METHODS: We retrospectively analyzed the microbiological data of 162 patients allotransplanted in Brescia University Hospital, over a period of 6 years. RESULTS: Eighty patients experienced a BSIs for a total of 119 isolates. In 77 cases (65%) a Gram positive bacteria was isolated, being coagulase negative Staphilococci the most frequent species (77% of the cases). In 42 cases (35%) a Gram negative bacteria was isolated (E. coli 57% and P. aeruginosa 24%). Fluoroquinolones resistance was frequent (90% for S. epidermidis, 92% for E. coli, 90% for P. aeruginosa). Methycillin resistance of S. epidermidis was 100%, 76% of E. coli were ESBL positive and among P. aeruginosa resistance to carbapenems was 40%. The 2 years overall survival of patients with BSIs vs patients without BSIs was 46% vs 60% (HR1,48, p=0,07). P. aeruginosa and E. coli were the species with the highest mortality (50% and 33%, respectively). CONCLUSIONS: These data confirm that BSIs, mainly sustained by Gram positive bacteria, are frequent in allotransplanted patients (50% of the cases) and may influence the outcome of allotransplanted patients, being antibiotics resistance highly frequent among these bacteria.

Pharmacokinetic-pharmacodynamic aspects of antimicrobial prophylaxis with teicoplanin in patients undergoing major vascular surgery.

A prospective, two-arm, open study assessing plasma exposure to teicoplanin with two different prophylactic regimens (Group A (n = 23), 800 mg pre-operatively versus Group B (n = 24), 400 mg pre-operatively plus two doses of 200 mg 24 h apart) was carried out in patients undergoing major vascular surgery. The intent was to define the feasibility and the possible advantages of the single pre-operative high dose in ensuring therapeutically effective plasma concentrations (>10 mg/L) of teicoplanin even during long-lasting operations. At the end of the intervention, mean teicoplanin concentrations (+/-S.D.) were 14.05 +/- 5.13 mg/L and 5.39 +/- 2.13 mg/L in Groups A and B, respectively. At 24 h, average teicoplanin levels were 5.10 +/- 1.25 mg/L and 2.08 +/- 0.73 mg/L in Groups A and B, respectively; at 48 h they declined to 2.86 +/- 0.70 mg/L in Group A, whereas they rose to 2.67 +/- 0.82 mg/L after administration of 2.63 +/- 0.51 mg/kg at 24 h in Group B. Single pre-operative high-dose teicoplanin may ensure effective plasma levels even in cases of very long-lasting operations (>8 h) with no need for intraoperative re-dosing and may enable more appropriate prophylactic exposure than that achievable with the same total dose given in three administrations 24 h apart.

A randomised, open label, controlled trial on the effect of interferon plus amantadine compared with interferon alone for treatment of chronic hepatitis C.

BACKGROUND: Combination of the antiviral drug amantadine with interferon (IFN) may be more effective than IFN monotherapy for treatment of chronic hepatitis C. METHODS: We randomised 93 patients with chronic hepatitis C to IFNIFN 6 MU 3 times/week for 24 weeks, followed by IFN 3 MU 3 times/week for further 24 weeks given in combination with amantadine 100 mg t.i.d. (regimen A, n=48) or as monotherapy (regimen B, n=45). Control liver biopsies were obtained 6 months post treatment. RESULTS: At the end of the trial a similar proportion of patients had normal serum ALT levels (35% for regimen A, and 44% for regimen B) as measured by intention to treat criteria. Sustained biochemical response at 6 months post treatment was 15 and 20%, and sustained virological response was 10 and 20% for regimen A and B, respectively. The effect on liver histology was also similar: the inflammatory components of the Knodell score decreased by 1.3+/-0.6 points for regimen A and by 1.6+/-0.6 for regimen B, and score for fibrosis remained unchanged with both regimens. CONCLUSIONS: Combination of IFN therapy with amantadine does not enhance the effect of IFN as shown by biochemical, virological and histological criteria.

Effect of HAART on SEN virus infected HIV positive patients.

Since it has been demonstrated that concomitant infections could influence the outcome of antiviral treatment, we investigated whether the presence of SENV infection may interfere with highly active antiretroviral therapy (HAART) in HIV+ coinfected patients. In spite of persistent fluctuations in SENV-A positivity we could not find any correlation between SENV-DNA and the immunological and virologic parameters found in the patients, suggesting SENV has no apparent clinical relevance during highly active antiretroviral therapy.

Linezolid and clindamycin improve the outcome of severe, necrotizing pneumonia due to community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA).

The last decade has been characterized by the emergence of CA-MRSA strains associated with the production of Panton-Valentine leukocidin. We report a case of necrotizing pneumonia and septic shock caused by CA-MRSA, in which early recognition of the syndrome and appropriate treatment with two toxin-suppressing antibiotics improved the patient's outcome.

Fatal disseminated toxoplasmosis during primary HIV infection.

Toxoplasmosis is a well recognized manifestation of AIDS, but the disseminated disease is a rare condition and it has not been associated to HIV seroconversion to our knowledge. We describe a fatal episode of disseminated T. gondii acute infection with massive organ involvement during primary HIV infection. The serological data demonstrate primary T. gondii infection. The avidity index for HIV antibodies supports recent HIV-1 infection.