BUCCAL SWAB AS AN ALTERNATIVE SPECIMEN TO DETECT SARSCOV2 USING REAL-TIME RT-PCR METHOD

Abstract

Confirmative COVID-19 is diagnosed only if the specific RNA of SARSCoV2 is detected  using molecular methods, including real time RT-PCR. Naso- and oropharynx swabs are  currently used as routine specimens to detect the virus. However, the specimen collection is inconvenient for the patients. On the other hand, the procedure requires  special training for the collectors. These issues might contribute to the low coverage of  testing in Indonesia. The aim of this study is to develop buccal swab as an alternative  method to collect the specimen in detecting SARSCoV2. This study consists of two phases. The first phase is optimizing the real time RT-PCR to  detect the lowest viral load in the specimen. The target genes used to detect the virus  are RdRp, N1 and N2 genes. The second phase is to compare the result between buccal  swab and naso- and oropharynx swab in 40 participants. Positive percent agreement  (PPA), negative percent agreement (NPA) and overall agreement (OA) were calculated.  The PCR reaction using buccal swab as specimen could detect RdRp, N1, and N2 genes,  with the detection limits of 1.75; 3.5; and 1.75 copy of RNA per reaction respectively. Until  this abstract was made, there are 24 specimens were collected but the PCR reaction  have not been finished yet. The study cannot be concluded at this time. If the buccal swab has low or moderate  agreement with naso- and oropharynx swab, the PCR result should be interpreted  with caution.