Efficacy of face-masks used in Uganda: a laboratory-based inquiry during the COVID-19 pandemic

Mboowa, G.; Semugenze, D.; Nakabuye, H.; Bulafu, D.; Aruhomukama, D.

Background With shortages of face-masks continuing to be reported worldwide, critical questions like whether or not there is an adequate alternative to commercially manufactured face-masks continue to linger especially in low- and middle- income settings. This study aimed at addressing this through testing and comparing various materials and forms of face-masks for filtration efficiency, breathability, microbial cleanliness, distance-dependent fitness, and re-usability of different face-masks procured from face-mask vendors in Kampala, Uganda. Methods This was a laboratory-based descriptive study that applied new protocols and already existing protocols with substantive modifications to ten different types of face-mask types each in quadruplicate to achieve each specified aim. Results Surgical face-masks had better filtration efficiency, distance-dependent fitness and breathability compared to other face-masks tested. Decontamination of these face-masks with 70% ethanol negatively affected their efficacy. Locally-made double layered face-masks had better: filtration efficiency, distance-dependent fitness and breathability compared to other locally-made cloth face-masks, and re-usability compared to all the face-mask types that had been tested. Discussion/conclusions Locally-made double layered cloth face-masks could serve as alternative face-masks especially for populations in low- and middle- income settings like Uganda while allowing restricted use of surgical face-masks and other respirators like the KN95 to high-risk groups only.