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Introduction: Registration studies have shown high efficacy of BNT162b2 mRNA COVID-19 vaccine. We evaluated vaccine effectiveness (VE) of BNT162b2 mRNA COVID-19 vaccine in a cohort of healthcare workers (HCWs) of a large hospital in Milan, Lombardy, Italy. Material and Methods: Follow-up started on 27 December 2020 (beginning of the vaccination campaign). HCWs without history of SARS-CoV-2 infection before the start date and with at least a nasopharyngeal test afterwards were included. Vaccination was treated as a time-dependent variable. For selected periods after vaccination we calculated incidence rate ratios (IRR) and 95% confidence intervals (CI) of infection with a Poisson regression model adjusted for gender, age, occupation, and 30-day periods, and then VE as (1 – IRR)x100 using unvaccinated person-time as reference. Databases were closed on 27 September 2021. The study was approved by the hospital’s ethics committee (Milano Area 2, Prot. No. 828_2021bis). Results and Conclusions: We included 3,809 HCWs, 131 still unvaccinated and 3,678 vaccinated (3,576 with two doses). We identified 134 infections (62% symptomatic). Adjusted VE was 77% (CI: 43-91) from day 14 after the first vaccine dose and 87% (CI: 79-92) at least 7 days after the second dose. After full vaccination schedule VE was 89% (CI: 82-94) for symptomatic and 77% (CI: 45-90) for asymptomatic infections. In conclusion, we found high effectiveness of BNT162b2 vaccine in reducing incidence of both symptomatic and asymptomatic infections. The follow-up is continuing to assess long-term effectiveness, also considering emerging SARS-CoV-2 variants.
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Introduction: The role of air pollution on SARS-CoV-2 infection is still unclear. We aimed to verify this association in a cohort of healthcare workers (HCWs), a group identified as at high risk since the beginning of the pandemic. Material and Methods: We included HCWs who performed a nasopharyngeal swab (NS) for detection of SARS-CoV-2 at the Policlinico Hospital (Milan, Italy) in February-December 2020. Daily average concentrations of particulate matter ≤2.5 μm (PM2.5) and nitrogen dioxide (NO2) were assigned to each worker’s residential address and treated as time-dependent variables. We generated person-days at risk and applied multivariable Poisson regression models adjusted for age, sex, BMI, smoke, job title and province to evaluate incidence rate ratios (IRR) and 95% confidence interval (CI) of positive NS. The association between air pollution and anti-nucleocapside antibodies was assessed among swab-positive workers through multivariable linear regression models. The study was approved by the hospital Ethics Committee (828_2021bis). Results: 635 (17%) positive swabs were recorded among 3,712 included HCWs. A 10 μg/m3 increase in PM2.5 and NO2 average concentrations in the five days preceding NS was associated with a higher risk of testing positive [IRR: 1.11 (CI: 1.02;1.21) and 1.10 (1.03;1.18), respectively]. Among swab-positive HCWs, we observed a 49% decrease in antibody titer (CI: -60;-36) associated with a 10 μg/m3 increase in PM2.5 mean levels in the month preceding NS. Conclusions: Our study suggests a potential role of air pollution exposure in influencing the immune response to SARS-CoV-2 infection.
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Introduction Randomized controlled trials showed efficacy of vaccines against coronavirus disease 19 (COVID-19). There is the need to quantify vaccine effectiveness in real-word contexts, including people at high risk of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), such as health care workers (HCWs). Objectives To evaluate vaccine effectiveness among hospital HCWs. Methods We performed a cohort study among HCWs of a large University hospital in Milan, Lombardy, Italy by merging routinely collected data on demographics, COVID-19 vaccination, and polymerase chain-reaction (PCR) tests performed on nasopharyngeal swabs. Follow-up started on December 27, 2020 (start of vaccination campaign). We included HCWs never PCR-positive before the start date and with at least a PCR test afterwards. Vaccination was treated as a time-dependent variable by calculating person-years (PY) at risk before and after vaccine doses. Subjects contributed PY until first positive PCR test (cases) or last test for never positive HCWs (to avoid immortal time bias). We calculated infection rates (cases per 1000 PY), rate ratios (RR, with a Poisson regression model adjusted for gender, age, occupation and 30-day periods), vaccine effectiveness (VE = (1-RR)x100) and 95% confidence intervals (CI) taking never vaccinated HCWs as reference. Results As of May 10, there were 3,152 vaccinated (97% with BNT162b2, 140 with one dose, 2,679 with two doses) and 333 non-vaccinated. We counted 29 infected cases (rate 385) among non-vaccinated, 6 (rate 65) from day 14 after the first dose (VE 79%, CI 49-92%), and 24 (rate 65) from day 7 after the second dose (VE 89%, CI 80-94%). Most cases after vaccination were asymptomatic or mildly symptomatic. Conclusion In these preliminary analysis we found high effectiveness of COVID-19 vaccine in HCWs in our hospital. Further work is needed to assess long-term effectiveness and to better plan future preventive strategies among this high-risk occupational group.
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Background and aim: Gastrointestinal infections represent a risk factor for functional gastrointestinal and somatoform extraintesti-nal disorders. We investigated the prevalence and relative risk (RR) of gastrointestinal and somatoform symptoms five months after SARS-CoV-2 infection compared with a control cohort. Materials and methods: 378 subjects, age range 18-60 years, were stu-died. 177 SARS-CoV-2 infected patients and 201 controls responded to an online questionnaire about symptoms and signs during the acute phase of the infection and after 4.8±0.3 months. 13 and 18 patients were respectively excluded because of a previous gastrointestinal dise-ase. Presence and severity of gastrointestinal symptoms, somatization, anxiety and depression were recorded with a structured standardized questionnaire, including the Structured Assessment of Gastrointestinal Symptoms (SAGIS) questionnaire, the Symptom Check List (SCL)-12 for somatization and the Hospital Anxiety and Depression Scale (HADS). Stool form through Bristol Stool scale and a yes/no question summari-zing the Rome IV criteria for Irritable Bowel Syndrome (IBS) were also recorded. Any association between exposure to infection and symp-toms was evaluated by calculating crude and adjusted RR values and score differences with 95% confidence intervals (CI). Results: Fever, dyspnea, loss of smell/taste/weight, diarrhea, myal-gia, arthralgia and asthenia were reported by more than 40% of patients during the acute phase. Abdominal pain/discomfort, diar-rhea/incontinence and gastroesophageal reflux disease/regurgita-tion symptoms persisted after SARS-CoV-2 infection, but with very low severity;the relative increase on the mean score of each domain was minimal (score difference up to +0.16). Compared with con-trols, adjusted RRs for loose stools, chronic fatigue and somatization were increased after infection: 1.88 (95% CI 0.99–3.54), 2.24 (95% CI 1.48–3.37), 3.62 (95% CI 1.01–6.23) respectively. The prevalence of IBS and HADS scores tended to be greater in patients than in con-trols. Gastrointestinal sequelae were greater in patients with diar-rhea during the acute phase. Conclusions: Mild gastroenterological symptoms persist five months after SARS-CoV-2 infection, in particular in patients report-ing diarrhea in the acute phase. Infected patients are at increased risk of chronic fatigue and somatoform disorders, thus supporting the hypothesis that both functional gastrointestinal and somato-form disorders may have a common biological orig
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Background: Coronavirus Disease (COVID-19) could be considered as a human model of marked inflammation combined with severe hypoxia. In this setting, both erythropoiesis and iron metabolism appear to be profoundly affected by inflammatory and hypoxic stimuli, which act in the opposite direction. In patients with SARS-CoV-2 infection, Hb levels tend to be relatively high even in the context of severe disease and marked inflammation. A better understanding of erythropoiesis and iron metabolism in COVID-19 could contribute to elucidate the relationship between hypoxia and inflammation on erythropoietic control. Aims: To investigate the prevalence of anemia, the alterations of iron homeostasis,and the relationship between inflammation,hypoxia and erythropoiesis in a cohort of COVID-19 patients admitted both to medical wards and intensive care unit (ICU). Methods: We retrospectively analyzed data of 303 patients with COVID- 19 (178 subjects admitted to medical wards and 125 subjects admitted to the ICU). Biochemical parameters were collected on admission (T0), after 7 days of hospitalization (T1) and at discharge/death (T2). Results: The median age of the patients was 62 years (53-71) and 72% were males. ICU patients had lower mean Hb levels compared to non- ICU patients (11.3±1.8 vs 12.8±1.8 g/dL at T0, 10.2±1.6 vs 12.2±1.9 g/ dL at T1, 10±1.4 vs 12±1.7 g/dL at T2;p<0.001). Mean Hb concentration did not fall under 12 g/dl in the non-ICU group and under 10 g/ dl in the ICU group during hospitalization. Hb decreased by approximately 1 g/dl in both cohorts during the first 7 days of hospitalization, then remained stable until discharge. ICU patients also showed increased inflammatory markers and ferritin levels (1401 vs 839 mcg/l at T0, p<0.001;913 vs 832 mcg/L at T1, p ns;764 vs 651 mcg/L at T2, p ns). There were no significant differences in other iron parameters between groups. Hypoxia was a prominent feature of ICU patients (P/F ratio 91 vs 224, p<0.001). Patients who were anemic on admission maintained relatively constant Hb concentrations from T0 to T2 (10.8 g/dL at T0, 10.2 g/dL at T1 and 10.4 g/dL at T2), thus remaining in a range of mild to moderate anemia. Conversely, the non-anemic group displayed a greater reduction of Hb levels (13.7 g/dl at T0, 12.7 g/dl at T1, 12 g/dl at T2). Anemic subjects were more hypoxic than non-anemic patients (P/F 151 vs 292 at T0, p<0.001) and showed significantly higher levels of CRP (10.8 vs 6.6 mg/dL), IL-6 (60.3 vs 47.7 ng/L) and leukocyte count (7290 vs 6130 x109/L). Ferritin was higher in anemic patients at T0 and T1 (1220 vs 926 mcg/L and 852 vs 896 mcg/L, p ns), decreasing more at T2 (655 vs 763 mcg/L, p ns). Median hepcidin levels, which were available for a limited subset of non- ICU patients, were elevated during the whole period: 233 ng/mL at T0, 95 ng/mL at T1 and 60 ng/mL at T2. Summary/Conclusion: In patients with SARS-CoV-2 infection, two main factors influence erythropoiesis and iron homeostasis: systemic inflammation and profound hypoxia. Markedly high ferritin and hepcidin levels reflect a strong inflammatory response. However, COVID-19 patients tend to have disproportionately high Hb levels in the contest of the inflammatory milieu. The absolute reduction in Hb levels is more prominent in patients who displayed normal Hb on admission. Conversely, anemic and profoundly hypoxic subjects show constant mean Hb levels over time. Thus, we can hypothesize that the erythropoietic drive provided by hypoxia could counterbalance the effect of inflammation on hepcidin regulation, preventing Hb levels from falling dramatically during hospitalization.
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OBJECTIVES: The management of healthcare workers (HCWs) exposed to confirmed cases of coronavirus disease 2019 (COVID-19) is still a matter of debate. We aimed to assess in this group the attack rate of asymptomatic carriers and the symptoms most frequently associated with infection. METHODS: Occupational and clinical characteristics of HCWs who underwent nasopharyngeal swab testing for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in a university hospital from 24 February 2020 to 31 March 2020 were collected. For those who tested positive and for those who tested positive but who were asymptomatic, we checked the laboratory and clinical data as of 22 May to calculate the time necessary for HCWs to then test negative and to verify whether symptoms developed thereafter. Frequencies of positive tests were compared according to selected variables using multivariable logistic regression models. RESULTS: There were 139 positive tests (8.8%) among 1573 HCWs (95% confidence interval, 7.5-10.3), with a marked difference between symptomatic (122/503, 24.2%) and asymptomatic (17/1070, 1.6%) workers (p < 0.001). Physicians were the group with the highest frequency of positive tests (61/582, 10.5%), whereas clerical workers and technicians had the lowest frequency (5/137, 3.6%). The likelihood of testing positive for COVID-19 increased with the number of reported symptoms; the strongest predictors of test positivity were taste and smell alterations (odds ratio = 76.9) and fever (odds ratio = 9.12). The median time from first positive test to a negative test was 27 days (95% confidence interval, 24-30). CONCLUSIONS: HCWs can be infected with SARS-CoV-2 without displaying any symptoms. Among symptomatic HCWs, the key symptoms to guide diagnosis are taste and smell alterations and fever. A median of almost 4 weeks is necessary before nasopharyngeal swab test results are negative.