Positive samples of foreign travellers to be tested for Omicron

Positive samples of foreign travellers to be tested for Omicron

Directorate of Public Health designates 12 laboratories to do the test

30/11/2021

Health Minister Ma. Subramanian and Health Secretary J. Radhakrishnan at a genome sequencing lab.B. JOTHI RAMALINGAM

Special CorrespondentCHENNAI

The samples collected from all foreign travellers who test positive for COVID-19 shall be subjected to genomic sequencing, the Directorate of Public Health has said.

The tests will be done at 12 designated government RT-PCR laboratories that are equipped with the World Health Organisation-recommended Thermo TaqPath RT-PCR testing kits to identify the new variant, Omicron, designated as B.1.1.529. According to the Directorate’s notice issued on Monday, most diagnostic tests could detect the variant.

The variant exhibits a deletion of certain spike protein positions, similar to the Alpha variant. The laboratories have been instructed to prioritise such specimens for sequencing to confirm the presence of Omicron. A proxy test for the variant, known as Thermo Fischer TaqPath Assay, could be used, pending genome sequencing confirmation, the notice said.

The government laboratories identified for the assay include the State Public Health laboratory; the King Institute of Preventive Medicine; Madras Medical College; Kilpauk and Stanley Medical Colleges in Chennai; Coimbatore Medical College; and ESI Medical College, Coimbatore; and the Government Medical Colleges in Tiruchi, Salem, Madurai, Thoothukudi and Kanniyakumari. Eight categories of samples have been identified for testing.

The samples of the following segments should be subjected to genome-sequencing, if they have tested positive for COVID-19. They are international travellers since October 15; reinfected persons; those infected after vaccination; those who are part of community clusters or an unusual transmission event; those who are part of family clusters; children testing positive; and young adults with severe lung involvement or an unexpected disease or severe illness.

Under the new guidelines, all positive samples referred from government and private RT-PCR laboratories should be sent to the State Public Health Laboratory in the city for genomic sequencing. The Deputy Director of Health Services in the districts should coordinate the process through their epidemiologists and microbiologists.

The protocol should be followed for all inbound international travellers with symptoms of influenza-like illness.

The samples will be screened for S gene dropout using the Thermo TaqPath kit by the government RT-PCR laboratories, Director of Public Health T.S. Selvavinayagam has said.

The Health Department will appoint assistant project officers at the four international airports in the State to oversee the sample collection, Health Minister Ma. Subramanian has said.

“On Wednesday, senior health officials will accompany me to Madurai where we will inspect the airport. Later, we will travel to Tiruchi and Coimbatore. We will also apprise the officials of the procedures to be followed on arrival of passengers. Along with Health Secretary J. Radhakrishnan, I will be supervising how the instructions are carried out,” the Minister said, after inspecting the genome sequencing unit on the Directorate of Medical Services premises here on Monday.

According to him, 95% of the COVID-19 samples tested at the sequencing unit had returned positive for the Delta variant.

At a review meeting, Chief Secretary V. Irai Anbu asked officials to follow the WHO guidelines for tackling the new variant and directed the Collectors to drive home the point among people that vaccination was the only defence against the severity of the disease.