The Centre is worried over the surge in Covid-19 cases in 6 states as the number of fresh daily infections surged to a 4-month high of 700, taking the total number of patients to 4,623, according to Union Health Ministry data updated on Thursday morning.

Union Health Secretary Rajesh Bhushan on Wednesday wrote to Maharashtra, Gujarat, Telangana, Tamil Nadu, Kerala, and Karnataka asking them to step up testing, treating, tracking, and vaccination to control the spread of Covid-19 cases.

“There are few states which are reporting higher number of cases indicating possible localised spread of infection and there is a need to follow a risk assessment-based approach to prevent and contain the infection, without losing the gains made so far in the fight against the pandemic,” the letter said.

The letter advised states to examine the situation of Covid at micro level (district and sub-districts), and maintain focus on implementation of necessary measures for prompt and effective management of Covid-19, “duly ensuring effective compliance with various advisories issued by this ministry”.

This is the second letter sent to the states after the first on Saturday which had highlighted the gradual increase in Covid test positivity rates in some states.

Scientists are of the view that it is the milder omicron version of coronavirus and its sub-lineages that are currently circulating in India. The fact that most Indians have now been vaccinated is also helping to slow the spread of the disease.

According to the health ministry’s website, 220.65 crore doses of Covid vaccine have been administered so far under the nationwide vaccination drive.