The need of health policy perspective to protect Healthcare Workers during COVID-19 pandemic. A GRADE rapid review on the N95 respirators effectiveness.

Primiano Iannone; Greta Castellini; Daniela Coclite; Antonello Napoletano; Alice Fauci; Laura Iacorossi; Daniela D'Angelo; Cristina Renzi; Giuseppe La Torre; Claudio Mastroianni; Silvia Gianola

March [1] . As of 30 March 2020, a total of 693,224 cases and 33,106 deaths have been reported worldwide [2] . Nosocomial spread and infection of healthcare workers (HCWs) are a major concern. In Italy HCWs are paying a heavy price in addition to their professional and humanitarian efforts, with 8956 cases (more than 9% of total Italian cases [3] ) and 63 deaths[4] among physicians. Protecting HCWs from SARS-CoV-2 is therefore of great importance for individual HCW and for their role in fighting this devastating pandemic effectively. Claims of insufficient protection of HCWs by personal protective equipment, in particular with regards to the use of surgical masks, have fuelled the scientific and social media debate in Italy. In fact, except for aerosol generating procedures requiring higher level of respiratory protection with filtering respirators, WHO considers surgical masks adequate for the routine care of coronavirus disease 2019 (COVID-19) patients [5] . Instead, the Centers for Disease Control (CDC) and the European Center for Disease Control guidelines (ECDC) have a more cautious approach, acknowledging that the exact role of airborne (aerosol) route in the transmission of SARS-CoV-2 is still largely unknown [6, 7] . The direct evidence supporting the WHO guidelines is based on very few case reports on the absence of SARS-CoV-2 in air samples taken in highly protected environments where a rapid dilution of aerosols occurs, the absence of infection of HCWs exposed for a limited time or limited viral loads, or on modelling of epidemiologic patterns of transmission [8] [9] [10] [11] . In contrast, the airborne (aerosol) opportunistic route of transmission has been documented for SARS and MERS caused by closely related coronaviruses responsible of severe nosocomial infections among HCWs. Aerorsol filtering respirators were consequently recommended for SARS during 2002-03 outbreak [12] . It is worth remembering that Canadian Health authorities modified their earlier recommendations in favour of a more strict respiratory protection after the deaths of several HCWs [13] . The presence of SARS-CoV-2 in aerosols has been documented in experimental [14] and real life conditions in crowded, poorly ventilated hospital areas unrelated to aerosol generating procedures [15] .