Comparison of Nasopharyngeal Swab v. Nasopharyngeal Saline Wash or Saliva Collection in Testing for Respiratory Viruses

Respiratory tract infections (RTIs) are high prevalence community diseases and is the third leading cause of death worldwide. It is estimated that a new infectious disease emerges at a rate of one per year, making early disease detection critically important. Within the past few decades, we have seen an increase in cases of novel respiratory illnesses such as SARS (severe acute respiratory syndrome), H1N1 (Swine Influenza), MERS (Middle East respiratory syndrome), and SARS-COV-2 (severe acute respiratory syndrome coronavirus 2). Rapid diagnosis of RTIs is essential to the management of patients experiencing respiratory symptoms as it drives decision points such as treatment and disposition. There are currently millions of confirmed SARS-COV-2 cases globally. This number is likely underreported given the limitations and barriers to confirmatory testing. This problem is compounded by other RTIs such as influenza and rhinovirus, which are also tested via a nasopharyngeal swab specimen. According to recent updates from the CDC, nasopharyngeal swabbing is the preferred method of specimen collection for SARS-COV-2. The nasopharyngeal swab method is also commonly used in the testing of other viral pathogens such as influenza, respiratory syncytial virus (RSV), rhinovirus, and human parainfluenza. This process can be somewhat invasive and traumatizing for patients as it requires probing (10-20 seconds) of the posterior nasopharynx with a stiff swab applicator. In some cases, this procedure has been known to result in pain and injury. Because of the invasive nature of the procedure, patients often refuse testing or withdraw during the collection process resulting in inadequate specimen procurement. In our effort to streamline the specimen collection process, our team has developed working prototypes of two specimen devices (a NP wash collection device and an Oral Capsule saliva collection device).

• The NP wash device is designed to irrigate the patient's nasopharyngeal passage with 3 ml of sterile saline and recollect the solution for testing. In our preliminary testing, the study device was successful in collecting RNase P from the nasal passages 100% of the time while achieving a mean Cycle Threshold (CT) value of 29.5. Participants in early studies also reported the study device to be more comfortable (0.3/10 pain) than the nasopharyngeal swab (8/10 pain).

• The Oral Capsule device is a soft-hollow device that is inserted into the mouth, overlying their molars. As the patient bites on the device, it generates an intermittent suction force which pulls saliva into the device's specimen chamber. In preliminary testing, the saliva collection device was successful in consistently collecting approximately 1 ml of saliva with 5-10 seconds of use.

The study design of this new protocol will allow the study investigators calculate the study devices' sensitivity and specificity for pathogen testing and test for antibody response from each respective specimen, along with improving enrollment rates. This study will enroll up to 1000 participants from a pool of ED patients who received a nasopharyngeal swab for PCR testing as part of their standard work up. Enrolled patients will provide four specimens 1) saliva drool specimen, 2) Oral Capsule saliva specimen, 3) NP wash specimen, and 4) finger stick serum specimen. Specimens 1, 2, 3 will undergo RPP PCR testing and COVID-19 antibody testing. Specimen 4 will undergo COVID-19 antibody testing. Patients can opt out of any of the four study specimen collection processes. Manufacturing of the NP Wash and the Oral Capsule devices is handled by the UNMC Department of Emergency Medicine fabrication lab. The NP wash study device is manufactured using fused deposition modeling (FDM) 3D printing technology with polylactic acid (PLA) printing material. The Oral Capsule device is manufactured using FDM 3D printing technology with polypropylene printing material. All study device will be sterilized via a cidex rinse, allowed to dry, then stored in a specimen bag. The NP wash device is designed to irrigate the user's nasopharyngeal cavity with 3 ml of sterile saline and recapture the irrigation solution into a specimen chamber as it drains back from their nose. The Oral Capsule device is designed to collect saliva via intermittent suction force generated within the device as the patient repeatedly bite on the device. With the implementation of our study devices we anticipate the following potential paradigm shifts in testing procedures: 1) minimizing the invasive nature of the procedure as a swab applicator is not utilized and 2) the procedure can be performed by a healthcare professional or solely by the patient, minimizing the risk of cross-infection to the healthcare professional. Nasopharyngeal irrigation is a common home remedy (neti-pots/bottles) for cold symptoms and is generally well tolerated by the user.