A small volume procedure for viral concentration from water

Development and validation of a 3D printed antiviral ventilator filter - a comparative study

BACKGROUND

The current coronavirus infectious disease 2019 (COVID-19) pandemic has caused unexpected pressure on medical supplies, interrupting supply chains and increasing prices. The supply of antiviral filters which form an essential part of the ventilator circuit have been affected by these issues. Three-dimensional (3D) printing may provide a solution to some of these issues.

METHODS

We designed and tested 3D printed heat and moisture exchange (HME) and antiviral casing. For each casing we tested two different filter materials derived from a sediment water filter cartridge or 1.5-μm glass fiber filter paper. A polyurethane sponge was used for the HME. Each design was tested for circuit leak, circuit compliance, peak inspiratory pressure and casing integrity using methylene blue dye.

RESULTS

We designed, produced, and tested two different types of antiviral filters with six different internal configurations. Overall, we tested 10 modified filter designs and compared them with the original commercial filter. Except for the combination of 1.5-μm filter paper and 5 mm sponge peak inspiratory pressure and circuit compliance of the filters produced were within the operating limits of the ventilator. All In addition, all filters passed the dye test.

CONCLUSIONS

Our filter may be of particular importance to those working in low middle-income countries unable to compete with stronger economies. Our design relies on products available outside the healthcare supply chain, much of which can be purchased in grocery stores, hardware stores, or industrial and academic institutions. We hope that these HMEs and viral filters may be beneficial to clinicians who face critical supply chain issues during the COVID-19 pandemic.

Water-Mediated Transmission of Plant, Animal, and Human Viruses

Viruses represent the most abundant and diverse of the biological entities in environmental waters, including the seas and probably also freshwater systems. They are important players in ecological networks in waters and influence global biochemical cycling and community composition dynamics. Among the many diverse viruses from terrestrial environments found in environmental waters, some are plant, animal, and/or human pathogens. The majority of pathogenic viral species found in waters are very stable and can survive outside host cells for long periods. The occurrence of such viruses in environmental waters has raised concerns because of the confirmation of the infectivity of waterborne viruses even at very low concentrations. This chapter focuses mainly on the survival of human, animal, and plant pathogenic viruses in aqueous environments, the possibility of their water-mediated transmission, the ecological implications of viruses in water, the methods adapted for detecting such viruses, and how to minimize the risk of viruses spreading through water.