Harmony COVID-19: A ready-to-use kit, low-cost detector, and smartphone app for point-of-care SARS-CoV-2 RNA detection

Description

Summary of RT-LAMP based technologies that have received the US FDA emergency use authorization as of July 15 th , 2021. Note that multiple tests were previously approved but recently removed from the list. Information was gathered from the package inserts and patents. Some aspects of the tests are not available, so listed as not available (N/A).   Sample transfer methods at the POC Volumetric transfer pipettes are used in POC tests, but we have not identified a unified dispenser used in commercial pathogen tests. A unified dispenser integrating the swab and the buffer container in a single unit could reduce opportunities for sample mix-up when multiple samples are processed simultaneously. A simple workflow is crucial, especially in busy settings like clinics. However, in our hands, the in-house built dispenser led to variable dispensed fluid volumes and had a higher failure rate than those of the transfer pipette method. While the unified dispenser has many attractive features, we would not recommend using this in-house assembled dispenser unit until the method has been optimized to achieve a more accurately dispensed volume. Table. S3. Feedback from the HCWs Among HCWs, 30% (3/10) reported problems dispensing the fluid using the unified system. However, 20% (2/10) of HCWs agreed that the unified dispenser offered an advantage in its similarity to other tools used in healthcare settings, and 30% (3/10) HCWs were concerned about contaminating the sample or the environment with the transfer pipette compared to the unified dispenser system. Only 1/10 (10%) HCW preferred the smallest tube (0.2mL) for either method, and 5/10 (50%) reported that larger (1.5mL) tubes were helpful for the unified system, while 40% (4/10) of HCWs said receptacle size did not make a difference when using the transfer pipette, and none reported preference for tube size when using the unified dispenser system. HCWs reported higher confidence in correctly completing the second kit compared to the first kit of each method, indicating a similar learning curve.

(A) User preference for reaction tube size
Note: Cells with 0% response were left empty to aid data visualization.

(B) User responses to survey questions during sample transfer usability testing.
Users were asked to provide their response on a Likert scale: (1) Not at all, (2) Slightly, (3) Somewhat, (4) Fairly, (5) Completely. Note: Phrasing of the questions below was slightly modified to be clear outside of the context of the written protocol/survey (original survey here). Cells with 0% response were left empty to aid data visualization.

Question
User response, n (%) (1) How confident were you that you added the correct amount of liquid to each reaction tube using the unified dispenser system?

(30%) (30%) 4 (40%)
How confident were you that you completed the protocol correctly using the unified dispenser system with the first kit?
How confident were you that you completed the protocol correctly using the unified dispenser system with the second kit?
How confident were you that you added the correct amount of liquid to each reaction tube using the transfer pipette?
2 (20%) 2(20%) 6 (60%) How confident were you that you completed the protocol correctly using the transfer pipette with the first kit?

(30%) 4 (40%) (30%)
How confident were you that you completed the protocol correctly using the transfer pipette with the second kit?

(50%) (50%)
How confident were you that you completed the on-screen instructions correctly?

Sample transfer method Reported error
Number of occurrences for the unified dispensing system

Number of occurrences for the transfer pipette
The transfer method was hard to aim at the receiving reaction tube. 1 Transfer method dripped/leaked before dispensing to the reaction tube.
2 The materials were too small or difficult to handle.
3 It was hard to execute specific instructions due to unfamiliarity with the sample transfer device.

1
Challenging to dispense a consistent amount of fluid.