I know RT-PCR is used mostly, but it has some limitations like "Reverse Transcriptase reaction and Primer design" is too sensitive. As we know it is costly, and it is easy to have contamination in the steps or primer doesn't work sometimes. Some people have developed CT-Scan based diagnosis but the reliability is under question. At last, the antibody-based diagnosis by detecting IgM and IgG needs further confirmation. Is any other method or these existing methods could be made more reliable and as well as cheaper?...
Link to a list of current tests with regulatory status linked to it is at the end. To be honest though 'too sensitive' isnt really a thing, you may be thinking non-specific and increased rate of false positives. However in situations like these you prioritise sensitivity over specificity. It is more important to capture as many Covid cases as possible to quarantine them and a handful of false positives who have to self isolate is no major issue, it isnt like all positive cases are getting or require hospitalisation or would increase their on risk so its very worthwhile. The bigger risk is missing Covid cases and allowing increased potential for it to spread as the person had a negative test and thinks all is well and can interact with society safely
https://www.360dx.com/coronavirus-test-tracker-launched-covid-19-tests
CT scans do show promise in the literature currently which is promising but I think a limiting factor to their use will be how many patients you can process with proper clean downs between each use (do not know this number). For rapid assessment it will defiantly be good but for large scale testing in hospitals or for the public/GP services it wouldnt be as viable.
Lung ultrasound is emerging as the test of choice in the diagnosis of Covid-19.
During the pandemic the pre-test probability of disease in any patient will increase with the prevalence of the disease in the community.
If the pre-test probability is high enough then abnormal imaging suggestive of pneumonitis may be sufficient to 'confirm' the diagnosis of Covid-19. Whilst in reality any other respiratory virus could cause the same symptoms and imaging findings, the risk of Covid-19 becomes so high that even if a PCR test were negative we would not be able to exclude Covid-19.
A protocol using lung US for screening and triage has been suggested (not yet validated) but is being used in areas where healthcare systems have been overwhelmed (e.g. Italy).
It is available at:
https://www.butterflynetwork.com/au/covid-19#publications
This site also contains links to publications from China and Italy on the use of POCUS lung US for the management of Covid-19.
Small hand held US machines are portable, easy to clean and provide substantially more information than a portable chest x-ray. Whilst they can not replace CT, if a suspected or positive Covid-19 patient has a CT it can take up to 90 minutes to clean the CT suite. That is a significant down time.
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