The Union health ministry has written to eight states and UTs to enhance testing, strengthen hospital preparedness, increase the pace and coverage of COVID-19 vaccination drive and ensure strict enforcement of restrictions to counter the spread of the infection.

In the letter, Union Health Secretary Rajesh Bhushan asked Delhi, Haryana, Tamil Nadu, West Bengal, Maharashtra, Gujarat, Karnataka and Jharkhand to be vigilant in view of the recent increase in domestic travel and various events such as marriages, festive celebrations, and vacations having either recently concluded or underway.

With the onset of winter and increased pollution in some states, prevalence of ILI/SARI and respiratory distress symptoms should be closely monitored, he said in the letter dated December 29.

The letter was issued as the country reported single-day rise of over 13,000 new COVID-19 cases after around 49 days and cases of Omicron variant increased to 961.

Bhushan said it has been seen that there has been an increase in the cases and lessening of doubling time in detection of the cases in few states.

Delhi has reported a sudden and significant surge in cases in the last two weeks.

"This issue needs to be addressed proactively and immediately to ensure that neither the transmission spreads further nor do we reach a situation of increased mortality due to late detection of the cases," the letter stated.

As for Gujarat, the letter highlighted that the districts of Ahmedabad, Rajkot and Surat have reported a sudden and significant surge in cases in the last two weeks.

Jharkhand's Ranchi, Karnataka's Bengaluru Urban, Haryana's Gurgaon, Tamil Nadu's Chennai, Maharashtra's Mumbai, Mumbai Suburban, Pune, Thane and Nagpur, and West Bengal's Kolkata have also reported a sudden and significant surge in cases in last two weeks, it said.

The ministry thus advised these states/UTs to undertake immediate measure like enhanced testing in a focused manner, with the maintenance of the ratio between RT-PCR and RAT and do pro-active contact tracing and isolation/quarantine of contacts of positive cases, their testing and follow up.

It also advised setting up containment zones and buffer zones as per extant SOPS, strengthen hospital-level preparedness, ensure optimal utilisation of financial resources under ECRP2, increased pace and coverage of Covid vaccination drive, adherence to Covid appropriate behaviour and enforcement of strict and appropriate restrictions to counter the spread of infection.