CHENNAI: Tamil Nadu on Wednesday tested 88 samples and 50 random samples for Covid-19 from international air travellers who arrived from ‘at-risk’ countries. All the samples collected tested negative, said a senior Health Department official. The procedures were put in place following the Union Health Ministry issuing guidelines on international arrivals, in the wake of the Omicron variant alert from WHO.
In case if any sample is tested positive, the State will send it for genome sequencing at the State Public Health Laboratory (SPHL) in the DMS campus or the Institute for Stem Cell Science and Regenerative Medicine (InStem) in Bengaluru to confirm the virus variant.
After the emergence of the Omicron variant, the State has also designated 12 government RT-PCR labs to use Thermo Taqpath RT-PCR kits for detecting three target genes in the virus, including the S gene, which would inturn help detect whether its the Omicron variant. It is reported that one of the S gene target is not detected in the Omicron variant due to its mutations.
Speaking to TNIE, Deepak Jacob, MD of Tamil Nadu Medical Services Corporation said the State has over 3.25 lakh Thermo Taqpath kits, and that there is no dearth in its supply. Director of Public Health Dr TS Selvavinayagam, in a video message on Wednesday, said the State has activated a surveillance mechanism after the WHO’s alert. He said nodal officers have been appointed at all international airports, and that passengers from 12 countries including China, Hong Kong, United Kingdom and Singapore will be screened and tested.
The State is also sending samples taken from Covid clusters such as those reported in schools for genome sequencing so that the virulence and transmissibility of any new variant in circulation is known, Selvavinayagam added. Reinfection cases; post-vaccination infections; vaccine breakthrough infections; community cluster; unusual transmission events; family clusters; children positive for Covid-19; young adults with severe lung involvement, unexpected disease presentation, and Covid-19 patients with no comorbidities are also put under scanner for genome sequencing. A Health Department official said it will take a maximum of seven days for genome sequencing the samples, and each test would cost nearly Rs 4,000.
Variant of concern
A look at how the State is preparing to identify cases with the Omicron variant of Covid
Any sample with S gene dropout or S gene target failure from government or private RT-PCR labs should be referred to State Public Health Laboratory (SPHL) for sequencing confirmation of Omicron variant
A sudden increase in S gene target failures may be indicative of circulation of Omicron variant. However, confirmation by sequencing is recommended
Thermo Taqpath kits recommended in government labs for detecting three target genes
Institutes with approval for using Thermo Taqpath kits
State Public Health Laboratory, King Institute of Preventive Medicine, Madras Medical College, Kilpauk Medical College, Stanley Medical College,Coimbatore Medical College, ESI Medical College, Trichy Medical College, Salem Medical College, Madurai Medical College, Tuticorin Medical College and Kanyakumari Medical College
Source: Directorate of Public Health