Fifty per cent of the new cases were reported from Chennai, which reported 589 new cases on Friday compared to 397 new cases on Thursday. Along with Chennai, cases in Chengalpet also increased. The adjacent district reported 136 new cases compared to 103 on Thursday. While the average test positivity rate for the infection in Chennai and Chengalpet is around 1.4%, Kancheepuram and Tiruvallur are reporting 1% test positivity rate. Other districts with high positivity rates include Ranipet (1.4%) and Coimbatore (0.9%). While 1, 144 cases were from within the state, seven from UAE, one each from Qatar, Sri Lanka and Oman and another from West Bengal tested positive.
Increase in number of Omicron cases
In the last 24 hours, the number of confirmed Omicron cases rose to 120 from 46. “We are seeing new clusters every day,” health minister Ma Subramanian. “The S-gene dropout, which is considered a proxy indicator for Omicron, is no longer seen in patients with international travel history or their contacts.”
On Friday, Pune-based National Institute of Virology confirmed that 74 more Covid-19 patients in Tamil Nadu carried the Omicron variant, taking the tally to 120. Of this, 63 patients did not travel or have direct contact with international passengers. So far, 232 passengers have been tested positive for Covid-19 and among them, 152 had S-gene dropout. So far, 57 patients have been confirmed with the Omicron variant. “We now have more patients within the city testing positive with S-gene dropout,” the minister said.
New cluster among students
On Friday, the health department announced a cluster of 34 Covid-19 cases from a NEET coaching centre in Saidapet. On December 29, a 17-year-old boy, who complained of fever and cold, tested positive for Covid-19. The Greater Chennai Corporation tested 90 close contacts of the patient of which 34 returned positive. Lab authorities confirmed S-gene dropout in almost all patients. “All students have mild or no symptoms,” he said. While one patient with severe anaemia was admitted to the Government Corona Hospital in King Institute campus, another student was admitted to a private hospital. The 32 others are in two well-ventilated wards in the Guindy hospital. “Some of them are studying there. We have told them we will also fix a TV in their wards,” he added.
High secondary attack rate
Doctors said the secondary attack rate of patients with S-gene drop is very high. The test positivity rate among close or primary contacts is close to 50%. Nearly 3% of the secondary contacts are also infected. “That explains why the disease is spreading so fast,” said health secretary J Radhakrishnan. While the state does not have an estimate on the number of cases they will see over the next few weeks, the state continues to see patients with both Omicron and Delta variants, he said. Besides covid appropriate behaviour, vaccination will be the only way to keep the infection under control, he said. Nearly 86% of adults in the state have taken the first dose and 58% of them have taken the second. At least 94 lakh people are due for the second dose, Radhakrishnan said.
Patients negative in four-five days
Doctors have told the government that patients with the new variant were having a mild infection without the requirement of oxygen or ICU admission. “Unlike in Delta, where most patients tested negative only after 10 days, patients carrying Omicron test negative in four to five days,” Subramanian said. According to hospital records of the 120 patients carrying the Omicron variant, 66 have been discharged. Meanwhile, Coimbatore reported 70 cases, compared to 73 on Thursday. All other districts reported fewer than 50 cases each. Ariyalur and Mayiladuthurai reported no new cases and 33 districts reported zero deaths.