A genetics scientist has dismissed claims that there were new covid19 variants in Trinidad and Tobago and by extension the rest of the Caribbean.
At the ministry’s covid19 media conference on Saturday morning, professor of molecular genetics and virology at the University of the West Indies (UWI) campus in St Augustine, Christine Carrington said the claims of an undetermined strain stemmed from inaccurate reports on social media.
In September, reports coming out of Grenada suggested that there was an undetermined covid19 variant, which was attributable to its rise in cases in mid-August.
The claims said samples from Grenada as well as Barbados sent to the Caribbean Public Health Agency (CARPHA) for testing came back undetermined and further genome sequencing and analysis were needed.
Carrington said, “I can assure that no undetermined variant was discovered among the samples from Grenada or Barbados when sent to Trinidad for home genome sequencing.
“I am absolutely certain about this because it is my lab at UWI that does the sequencing and I report the results, myself, to CARPHA and to the Ministry of Health.”
She described the claims as erroneous and said it came about because of a misinterpretation of the genome sequencing results.
“Genome sequencing is like putting together a jigsaw puzzle, if you are able to extract enough pieces of the virus’ genetic information from a sample and, work out the position of the virus’ genome, then you can work out what lineage you are looking at, and whether it is a variant of concern.
“Sometimes samples are not of sufficient quality to get enough pieces of that puzzle, to build enough of a picture to work out which lineage the virus belongs to. In those cases, to determine if it is a variant of concern, you cannot say yes or no because you do not have enough information,” she explained.
As such, Carrington said, the low quality of the samples taken from Grenada and Barbados, was unable to show the lineage of the virus, which meant the results were undetermined and not that there was an undetermined variant.
She explained that home genome sequencing revealed the detailed structure of the virus and the only way to characterise new variants, while PCR testing was done to determine if the virus was present in a person, and they should not be confused.
When the matter was first detected and reported in September, the Pan-American Health Organization (PAHO) also dismissed the claim.
It said, “Our specialists have confirmed with the laboratory involved that a result from the samples in Grenada could not be determined due to their low quality and not due to an undetermined variant.”
Carrington added that in TT, the covid19 variants of concern were present were alpha, gamma and delta, in which gamma and delta were evidenced to be spread at community level and alpha was not.
The mu and lambda variants, she said were not detected in TT, but detected in other regional countries.