What are the testing considerations for the next steps in the
pandemic?
A main focus for diagnostics will now be the ongoing monitoring of
emergent strains. As discussed, this will be essential to ensure that
the global rollout of vaccines is successful and to help the
international community emerge from the pandemic.101Currently, as most NAATs detect several SARS-CoV-2 genetic targets, it
is considered unlikely that mutations will lead to false-negative
results; however, the FDA have requested that laboratorians are mindful
that this may occur.103
Standardization of Ct values or fully standardized quantitative NAATs
for SARS-CoV-2 will be extremely useful to assess efficacy of
interventions in COVID-19 patients, to help determine when individuals
are safe to leave quarantine and staff are safe to return to
work.104 Development of reference material to enable
standardization of these assays is recommended.
The data regarding the relationship between diagnostic parameters and
infectivity is currently limited, and research is ongoing in this area
to clarify exactly how these parameters correlate. Recommendations on
the most appropriate diagnostic test for different utilities may change
once more information is available on these points.
The use of alternative sample types to the nasal pharyngeal (NP) swab,
such as saliva, and the use of new technologies, such as CRISPR-based
tests, are under investigation, and these may also provide different
opportunities for testing and additional considerations (e.g. those
concerning school populations or mass testing of large
groups).30,43,105,106 Self-sampling methods that
provide increased sensitivity could broaden the capacity for mass
testing prior to events or entering the workplace.27As it will take time before vaccination will be able to eradicate
COVID-19, testing measures will continue to be important.