Kori N, Periyasamy P, Ng BH, Satariah Ali UK, Zainol Rashid NZ. Aerosolised COVID-19 Transmission Risk: Surgical or N95 Masks? Infect Control Hosp Epidemiol. 2020 Sep 15:1-8. doi: 10.1017/ice.2020.465. Epub ahead of print. PMID: 32928321.

Based on available evidence, the COVID-19 virus is thought to spread through close contact and droplet transmission. However, some have debated that it could be airborne. Airborne transmission occurs when particles of less than 0.5 μm within droplets spread through exhaled air via a process called aerosolisation. These particles can remain in the air for long periods and can disseminate over distances further than 1 meter. In the context of COVID-19, airborne particles can occur during certain aerosolised-generating-procedures (AGP). WHO underlines the use of N95 respirators or equivalent as part of personal protective equipment (PPE) for healthcare workers (HCW) managing COVID-19 positive patients when aerosolised-generating-procedures (AGP) are being conducted.This retrospective observational study describes the result of COVID-19 reverse transcriptase polymerase chain reaction (RT-PCR) in health care workers (HCW) wearing different form of personal protective equipment (PPE) who had had close contact with a confirmed COVID-19 patient during performing such procedures. All HCWs were quarantined for 14 days after the exposure. COVID-19 RT-PCR nasopharyngeal swabs were performed at different intervals. Little is known about the effectiveness of different types of personal protective equipment (PPE) for preventing SARS-CoV-2 in HCWs. We describe the clinical outcome of HCWs exposed to sudden acute respiratory infection patient before the diagnosis of COVID-19 was known