How to Reduce Virus Cross-Contamination of Medical Vacuum Suction Pumps with Virus and Bacteria Filters


  • The following virus types count as coronaviruses: SARS-CoV in 2003; HCoV NL63 in 2004; HKU1 in 2005, MERS-CoV in 2012; SARS-CoV-2 in 2019 (name of disease according to WHO: COVID-19)1
  • All the viruses mentioned above have approx. 0.12 µm in diameter
  • Medela virus filters have been tested using testbacteriophage Phi X17 4 with a diameter of approximately 0.036 µm
  • Filtration Efficiency of Medela virus filters is greater than 99.99984 % (= probability <1 virus out of 1 '000'000 goes through the filter)

This means using Medela pumps in conjunction with Medela virus and bacteria filters can effectively prevent coronavirus cross-contamination.

  • Note: Medela bacteria filter can prevent bacteria - with a diameter of 0.8 to 1.2 µm – cross-contamination. However, the Medela bacteria filters will not be sufficient to filter and hence not prevent cross-contamination with SARS-CoV-2.
  • As an additional information: According to the NBC report2, it is recommended by CDC (Centers for Disease Control and Prevention) to use masks for virus protection that filter particles of a size of 0.3 microns.

The graph below provides evidence for the statements above:

200226_PVS_Filters_Graph_Particles Covered by Filters Overview


1 The Editors of Encyclopaedia Britannica. Coronavirus. Virus Group. 2020. Internet: (retrieved 16.03.2020).

2 Edwards E, Miller SG. What ist he coronavirus? Here’s what we know about it. 2020. Internet: (retrieved 16.03.2020).