Thread by @drmusanordin

US FDA issued 1st Emergency Use Authorization (EUA) for an antigen-based diagnostic test for SARS-CoV-2
Previous tests used PCR-detects viral RNA.
New tests detect fragments of proteins ANTIGENS (Ag) found on or within the virus
Results within minutes
Cheaper
Nasal swabs used

Rapid Ag Diagnostic Kits can be done at Point Of Care (POC)
Specificity-High.
If Positive Very Likely #COVID19
Sensitivity-Not as High
Negative results do NOT rule out infections
ie High False Negatives
May need to confirm with PCR.
fda.gov/news-events/pr…

Other Rapid Diagnostic Kits are serological tests that look for ANTIBODIES to the virus
It identifies individuals who have developed an immune response to the virus, either due to active infection or a prior infection
NOT used to diagnose active infection
fda.gov/media/137599/d…

The most likely ANTIBODY test in Msia is:
VAZYME Serology IgG/IgM RTK (Venous blood)
Not WHO approved!
Approvals :
China FDA
HSA SG
IMR/MKAK/KKM
Philippines FDA
CE Marking

Blood specimen from finger prick
After blood placed in test kit results read at 10 minutes
Can be done at POC at GP/Clinic/Hospital

Tests must b interpreted within the context of the clinical presentation
COSTS:
1. My best guess the cost price for ANTIBODY Rapid Diagnostic Test is RM50 per test (excluding labor/PPE etc)
2. PCR only at major hospitals/labs-at least RM350 inclusive
3. ANTIGEN-NA in M’sia yet

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Ramp up testing to achieve and maintain #COVID19 positives at <3%
Identify the infected people ASAP 
Fast Turn Around Time, preferably <24 hours to reduce the opportunity for transmission of infection
Immediately isolate the infected & reduce spread. This is only half the battle

Other 1/2 is testing all the contacts
This will identify who else are infected but are either pre-symptomatic or asymptomatic
Neither of then showing any symptoms but the pre-symptomatic will eventually manifest with symptoms namely fever, cough, difficulty breathing

The pre-symptomatic COVID-19 positives is particularly of concern because they are drivers of transmissibility (45%) like the symptomatic cases
Asymptomatic COVID-19 are not drivers of infectiousness (5%). They however are a considerable portion of COVID-19 positive cases (40%)

Since we can’t distinguish them in the first few days, fast contact tracing will identify both groups & quarantine will reduce the period of pre-symptomatic infectiousness.
In terms of priority we first test people with symptoms, followed by all their contacts.

With enough testing, we can EASE MCO further.
This is a smart strategy of protecting the community without locking down the entire population
This will allow the business community to resume their activities which will help to reboot the economy

Besides testing those with symptoms & contacts of COVID-19 case we need to target high-risk groups who r potential nidus for outbreaks:
 1. Tabligh cluster – ever recurring due to wide presence at all levels of society
2.  Migrant workers – 2 million legal+4 million undocumented

3. Refugees-175,000 most in Klang Valley (150,000) & clusters in Johor/Kedah/ Penang
4.  Importation-70% from Indonesia
5.  HCW-they care for high-risk patients/ensure their status is rapidly diagnosed once symptomatic or in contact with index cases. NHS regularly test their HCW.

6. Sentinel testing – All ILI & SARI must be screened
Due to limitations of rt-PCR-cost, longer TAT, available only at major hospitals & laboratories, we may need to begin to incorporate rapid diagnostics kits in our testing program.
Check this out: threadreaderapp.com/thread/1259984…

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