COVID-19 disease is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which originated in Wuhan, China and spread with an astonishing rate across the world. The transmission routes of SARS-CoV-2 are still debated, but recent evidence strongly suggests that COVID-19 could be transmitted via air in poorly ventilated places. Some studies also suggest the higher surface stability of SARS-CoV-2 as compared to SARS-CoV-1. It is also possible that small viral particles may enter into indoor environments from the various emission sources aided by environmental factors such as relative humidity, wind speed, temperature, thus representing a type of an aerosol transmission. Here, we explore the role of relative humidity in airborne transmission of SARS-CoV-2 virus in indoor environments based on recent studies around the world. Humidity affects both the evaporation kinematics and particle growth. In dry indoor places i.e., less humidity (< 40% RH), the chances of airborne transmission of SARS-CoV-2 are higher than that of humid places (i.e., > 90% RH). Based on earlier studies, a relative humidity of 40-60% was found to be optimal for human health in indoor places. Thus, it is extremely important to set a minimum relative humidity standard for indoor environments such as hospitals, offices and public transports for minimization of airborne spread of SARS-CoV-2.

The second wave of COVID-19 due to Delta (B.1.617.2) variant led to the rapid rise of total coronavirus and COVID-associated mucormycosis cases reported from India. Hence, the current perspective explores the possible causes of rapid upsurge in COVID-associated mucormycosis cases, which was accounted for over 70% of global cases. The five most probable factors associated with the increase of mucormycosis in COVID-19 patients include diabetes mellitus, steroids overdose, high iron levels, immuno-suppression, combined with other possible factors such as unhygienic conditions, prolonged hospitalization, use of ventilators and leaky humidifiers in oxygen cylinders, creates an ideal environment for contracting mucormycosis. However, these cases could be brought down by disseminating simple preventive measures and creating awareness among the medical society and general public on this rare and deadly contagion of COVID-associated mucormycosis. The identification of the early symptoms will help to restrict the spread of lethal fungal diseases. Further, a collaborative team of surgeons, ophthalmologists, physicians, otolaryngologists specialists would be required in the hospital wards to proceed with quick surgeries on severely impacted patients.

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