Detection of Sars-Cov-2 in the air of two hospitals in Hermosillo, Sonora, México, utilizing a low-cost environmental monitoring system

•The SARS-CoV-2 virus could be detected in particulate matter in air using 0.22 μm pore filters.•Virus presence was only observed in areas close to patients in hospitals.•Sampling air for 3 h was sufficient time for virus detection.•The system implemented for air sampling can be used for detecting SARS-CoV-2 in high-risk environments. The best way of preventing the dispersion of an infectious disease is decreasing the transmissibility of the pathogen. To achieve such a goal, it is important to have epidemiological surveillance to retrieve data about its routes of transmission and dispersion. This study investigated the possibility of SARS-CoV-2 detection using filtration through 0.22 μm pores. A filtration system with vacuum pump was used for sampling, and molecular analysis was performed by RT-PCR for detecting the COVID-19 virus. It was found that SARS-CoV-2 could be detected in particulate matter trapped on 0.22 μm filters 3 h after air sampling, and the only contaminated areas were those near patient zones. The results confirm the possibility of finding this virus in floating particulate matter in contaminated zones, with a simple and economic sampling method based on filtration technology through 0.22 μm pores and detection with molecular techniques (RT-PCR). The higher risk zones were those near patients with COVID-19.