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Unfortunately, we have a case of a Singaporean who passed away after being cleared of Covid virus

I am just curious, are there different strains of virus, some more infectious and deadly, others less so, in different part of the worlds? Besides the quality of the healthcare systems which might affect mortality, is there a possibility that there are sars-cov2 with different genomes spreading?
Dr. Dinesh G
Space Doctor
24 Streak Score Doctors are able to put a streak together by performing an activity everyday
Good evening @BusinessJing this is not true. Although it may appear that the virus has varied lethality based on differing reports of patients (e.g. those from the west versus those in China/other parts of Asia), this may largely be due to the varying quality of operational responses (like contact tracing/ lockdowns) and healthcare systems (as what you alluded to). There has been no evidence to confirm new strains yet.

The confusion is due to the different terminology for a new "strain" versus a new "isolate" (sample from a person). For a new strain to be confirmed, genetic tests and other laboratory reports of the virus itself are also required (aside from reports of patient outcomes). These will take some time given that it is a new infection. 

Although some reports have emerged that suggest different "strains", these actually refer to different "isolates" that have minor genetic variations with no confirmed change in the nature/properties of the virus. These are expected  variations, that can be seen with different "isolates" of a given virus that are taken from people that are spread across time and space. This can happen with viruses that "reproduce" by a method called RNA synthesis which sometimes makes these errors in their genetic code.

Whether or not these genetic variations confer new biological properties to the virus is what usually determines whether it should be labelled as a new "strain". Examples of these properties include new surface binding proteins that make it more lethal/contagious (which would justify it being termed a new "strain"). This requires more work to be confirmed (e.g. to differentiate phenomena such as "founder effect" from true selective pressure), and there is no conclusive evidence of new "strains" to date.
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