Actually, it ranged from 0 in an early study from Singapore, to 37

Actually, it ranged from 0 in an early study from Singapore, to 37.9% (44) in a study from Madrid (Spain)(40), with a crude estimate of 1117 SARS-CoV-2 positive cases out of 9051 sampled HCWs (12.3%) for prospective studies, and 1015 positive cases out of 15983 samples (6.4%, chi squared test p value 0.001) for retrospective ones. in physicians than in nurses (OR 1.436, 95%CI 1.026 to 2.008). Regression analysis indicated the possible presence of publication bias only for molecular assessments (t -3.3526, p-value 0.002648). Conclusions. The overall pooled ANGPT2 prevalence of SARS-CoV-2 was lower than previously expected, but available studies were affected by significant heterogeneity, and the molecular studies by significant publication bias. Therefore, further high-quality research in the field is usually warranted. (www.actabiomedica.it) bundle (version 4.9-9), functions for pooling of prevalence, and for binary comparison and calculation of the OR. The meta package is an open-source add-on for conducting meta-analyses. Results In the beginning, 1238 entries were identified, including a total of 353 articles CTP354 from MedLine/EMBASE and 885 medRxiv preprints: eventually, 49 abstracts were screened. After applying the inclusion and exclusion criteria (Physique 1) and removing duplicated studies, 32 articles (15 of them as preprint) were included in the analyses and summarized, encompassing a total of 39 estimates, and more precisely: 26 estimates based on RT-qPCR assays (20C45), 4 on POCT (32,36,46,47), 9 estimates based on ser Open in a separate window Physique 1. The process of studies retrieval and inclusion adopted in the present systematic evaluate and meta-analysis. In the majority of the studies, estimates were based either on RT-qPCR, or on serological assessment, while only one study based the estimates of SARS-CoV-2 positivity on POCT alone(47). Moreover, four studies were sequentially based on initial serological assessment followed by RT-qPCR (30,33,41), and one study on POCT followed by confirmatory RT-qPCR (32). One further study included initial POCT assessment, followed by serology and eventually RT-qPCR, for a total of three estimates (36). CTP354 Eventually, the final sample included a total of 25,900 HCWs. The majority of the studies were prompted after March 2020: overall, only 5 studies and 5 estimates were prompted before March 2020 (20,25,37,42,44), while 26 studies were started in-between the 9th and the 13th week of 2020. Focusing CTP354 on the geographical origin of the HCWs, the majority of studies (No. = 23) and available estimates (No. = 29) were based on European countries (22C25,27C30,32C36,38C41,45,47,48,50), with only 3 studies (3 estimates) each from China (20,26,37) and Japan (43,46,49), 2 studies (2 estimates) from the USA (21,42), 1 study (1 estimate) from Singapore (44). Pooled estimates for SARS-CoV-2 prevalence are summarized in Physique 2, ?,33 and ?and44. Open in a separate window Physique 2. Forest plot for occurrence of SARS-CoV-2 contamination among healthcare professionals, studies reporting data form RT-qPCR tests broken down by reporting country. Pooled prevalence was 3.5% (95%CI 1.8C6.6), with significant heterogeneity among retrieved studies (I2 99%, p 0.01). Open in a separate window Physique 3. Forest plot for occurrence of SARS-CoV-2 contamination among healthcare professionals, studies reporting data form serological tests broken down by reporting country. CTP354 Pooled prevalence was 5.5% (95%CI 2.1C14.1), with significant heterogeneity among retrieved studies (I2 97%, p 0.01). Open in a separate window Physique 4. Forest plot for occurrence of SARS-CoV-2 contamination among healthcare professionals, studies reporting data from point-of-care assessments broken down by reporting country. Mean prevalence was 6.5% (95%CI 2.5C15.6), with significant heterogeneity among retrieved studies (I2 92%, p 0.01). Open in a separate window Physique 5. Odds Ratio (OR) for SARS-CoV-2 positive status in Physicians vs. Nurses, as assessed by RT-PCR (a) and serological status (b). Notice: as only one point-of-care test (i.e. Comar et al.) was eventually included, it was assessed alongside standard serological tests. Focusing on RT-qPCR based reports (Physique 2), not only sample size (range 28 to 2085), but also CTP354 reported prevalence was quite heterogenous. Actually, it ranged from 0 in an early study from Singapore, to 37.9% (44) in a study from Madrid (Spain)(40), with a crude estimate of 1117 SARS-CoV-2 positive cases out of 9051 sampled HCWs (12.3%) for prospective studies, and 1015 positive cases out of 15983 samples (6.4%, chi squared test p value 0.001) for retrospective ones. However, reflecting the high heterogeneity of retrieved studies (I2 98%, p 0.01), the random effect model retrieved a pooled estimate of 3.0% (95%CI 0.8-10.1) for prospective studies, and 3.8% (95%CI, 1.8-7.8) for retrospective ones, and summary estimate of 3.5%.