Official websites use. Share sensitive information only on official, secure websites. This is an open access article under the terms of the Creative Commons Attribution-Non-Commercial Licence , which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.
Viral load may vary at different anatomical sampling sites and accuracy may be compromised by difficulties obtaining specimens and the expertise of the person taking the sample. It is important to optimise sampling accuracy within cost, safety and accessibility constraints.
We did not apply language restrictions. Within a sample pair, we defined a reference sample and an index sample collected from the same participant within the same clinical encounter within 24 hours. Where the sample comparison was concerned with differences in the sample collection method from the same site, we defined the reference sample as that closest to standard practice for that sample type.
Where the sample pair comparison was concerned with differences in personnel collecting the sample, the more skilled or experienced operator was considered the reference sample. Four evaluations were of the effect of operator expertise on the accuracy of three different sample types.
Age, symptom status and use of transport media do not appear to affect the sensitivity of saliva samples and nasal samples. This may, in turn, improve access to and uptake of testing. Quality assessment of the evidence base underpinning these conclusions was restricted by poor reporting. However, this sample is difficult to obtain correctly, causes discomfort and risks spreading infection if individuals cough or sneeze when the sample is taken.
