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Understanding the science behind the COVID 19


The risk of an outbreak of Covid 19 in care homes and old folks home is a terrifying thought for us all. Here are some facts and science behind the policies:


  1. Test for COVID 19 at the moment is with PCR (polymerase chain reaction) which picks up genetic materials in the virus. 

  2. How reliable the test is depends on the sample taken (from nose and throat) and also when it was taken.

  3. A positive test means the virus is present but doesn’t clarify if it is none viable (dead) or viable (alive), if it is infective or not.

  4. PCR test is most accurate if taken within 7 days of symptoms starting. (studies from China) A positive test taken after that may not mean the person is still infectious. 

  5. A Singaporean study (ams.edu.sg/view-pdf.aspx?…) showed that viral RNA detected by PCR doesn’t mean it is infectious. Beyond 2 weeks, no viable viruses were detected, but PCR still test positive

  6. If a person has no symptoms after 2 days and their illness started more than 10 days ago, they are unlikely to be infectious. Also during recovery, protective antibodies will be produced to neutralise the virus.

  7. So, while we can test for Covid 19 in discharged patients from hospitals, care homes and old folks homes, we cannot tell easily if the person is infectious

  8. The most contagious period is also before the symptoms start (incubation period: time between infection and showing symptoms, is approximately 5 days). 

  9. Up to 70% of people with Covid 19 don’t have symptoms.


So as well as mandatory testing of patients coming from hospital to care homes, our New Normal in Angsana Home after CMCO has to be:


  1. Still to wear protective gloves and gowns and social distancing, as we just don’t know who is infectious.

  2. Suspect anyone with symptoms early and isolate (from Old Folks Homes, nursing homes, schools, work places..etc)

  3. Any risk needs to be assessed medically before accepting patients from hospital for admission to care homes, we cannot just depend on a Covid test result.

  4. Allow visits from family, but limited, with precautions and risk assessment (please be patient and cooperate when you are asked to fill in our risk assessment form).

Zero Risk is not Possible, but we can reduce the rate and death cause by having limited visits and protections in place, despite the CMCO lifting.

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