Occurrence of SARS-CoV-2 infection among healthcare personnel: results from an early systematic review and meta-analysis

Abstract

Background: SARS-CoV-2 infection has become a global public health concern globally. Even though Healthcare Workers (HCWs) are supposedly at increased risk for SARS-CoV-2 infection, to date no pooled evidence has been collected.

Materials and methods: We searched online electronic databases (PubMed, Embase, medRxiv.org for pre-prints) for all available contribution (up to May 20, 2019). Two Authors independently screened articles and extracted the data. The pooled prevalence of SARS-CoV-2 was analyzed using the random-effects model. The possible sources of heterogeneity were analyzed through subgroup analysis, and meta-regression.

Results: The overall pooled prevalence of SARS-CoV-2 was 3.5% (95%CI 1.8-6.6) for studies based on molecular assays, 5.5% (95%CI 2.1-14.1) for studies based on serological assays, and 6.5% (95%CI 2.5-15.6) for point-of-care capillary blood tests. Among subgroups, serological tests identified higher risk for SARS-CoV-2 seropositivity 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 tests (t -3.3526, p-value 0.002648).

Conclusions: The overall pooled 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 warranted.

Figure 1.

The process of studies retrieval and inclusion adopted in the present systematic review and meta-analysis.

Figure 2.

Forest plot for occurrence of SARS-CoV-2 infection among healthcare professionals, studies reporting data form RT-qPCR tests broken down by reporting country. Pooled prevalence was 3.5% (95%CI 1.8–6.6), with significant heterogeneity among retrieved studies (I2 99%, p < 0.01).

Figure 3.

Forest plot for occurrence of SARS-CoV-2 infection among healthcare professionals, studies reporting data form serological tests broken down by reporting country. Pooled prevalence was 5.5% (95%CI 2.1–14.1), with significant heterogeneity among retrieved studies (I2 97%, p < 0.01).

Figure 4.

Forest plot for occurrence of SARS-CoV-2 infection among healthcare professionals, studies reporting data from point-of-care tests broken down by reporting country. Mean prevalence was 6.5% (95%CI 2.5–15.6), with significant heterogeneity among retrieved studies (I2 92%, p < 0.01).

Figure 5.

Odds Ratio (OR) for SARS-CoV-2 positive status in Physicians vs. Nurses, as assessed by RT-PCR (a) and serological status (b). Note: as only one point-of-care test (i.e. Comar et al.) was eventually included, it was assessed alongside conventional serological tests.

Figure 6.

Funnel plot of studies dealing with SARS-CoV-2 occurrence in healthcare workers. Overall, available studies showed high heterogeneity, that were eventually confirmed at regression test only for RT-qPCR (t = -3.3526, df = 24, p-value = 0.002648), while no heterogeneity was reported for studies based on serology (t = -2.3591, df = 7, p-value = 0.05041) or point-of-care tests (t = -1.7229, df = 2, p-value = 0.227). Focusing on comparisons between SARS-CoV-2 infection in Physicians vs. nurses, no significant asymmetry was identified either at visual inspection or by regression analysis for RT-qPCR studies ( d), t = -0.7664, df = 5, p-value = 0.478), and studies based on antibody assays ( e), t = -1.134, df = 2, p-value = 0.3744).