Sindh Health Minister Dr Azra Pechuho on Tuesday urged the public to strictly adhere to the coronavirus standard operating procedures (SOPs), with 35 cases of the highly contagious Delta variant confirmed in Karachi alone so far.

The 35 cases of the Delta variant, first detected in India, have been confirmed in Karachi since June, the Sindh health department said in a statement.

It said "severe symptoms" of the virus had been observed in people who were confirmed to be suffering from the Delta variant.

Read: What we know so far about the Covid-19 Delta variant and its sub-lineage Delta Plus

Five members of the same family in Karachi's Lyari neighbourhood were found to have the Delta variant, the statement added.

It further said 18 cases of the Delta variant were confirmed this month alone, while all affected patients were undergoing treatment.

Pechuho urged the public to limit their movement and follow precautionary measures, including wearing masks in public places.

"The effects the Delta variant had in India are before us; the public will have to show responsibility," she added.

The 35 Delta variant cases have been detected through genome sequencing performed on confirmed infections of Covid-19, suggesting there could be more undetected cases of the Delta strain within communities.

Sindh health department spokesperson Atif Vighio told Dawn.com that genome sequencing was being conducted in cases where a person arrived in the province from another country where the Delta variant is the pre-dominant strain, and tested positive for Covid-19.

He said from a total of 78,000 people who arrived in the province from abroad in June and July, 214 tested positive for Covid-19; all these cases were sent for genome sequencing which confirmed 35 Delta infections.

The Delta variant is a version of the coronavirus that has been found in more than 80 countries since it was first identified in India. It got its name from the World Health Organisation (WHO), which names notable variants after letters of the Greek alphabet.

Viruses constantly mutate and most changes aren’t concerning. But there is a worry that some variants might evolve enough to be more contagious, cause more severe illness or evade the protection that vaccines provide.

Experts say the Delta variant spreads more easily because of mutations that make it better at latching onto cells in our bodies. In the United Kingdom, the variant was responsible for 90 per cent of all new infections last month.

In the US, it represented 20pc of infections, and health officials said it could become the country’s dominant type as well.

"It’s not clear yet whether the variant makes people sicker since more data needs to be collected," said Dr Jacob John, who studies viruses at the Christian Medical College at Vellore in southern India.

On Monday, the Sindh health department had proposed shutting down primary schools in the province as well as banning indoor dining as the coronavirus positivity rate climbed to 7pc in Sindh and 14pc in Karachi.

It further proposed keeping businesses closed for two days, instead of the one safe day a week currently being enforced.

Last week, Prime Minister Imran Khan had warned of a looming fourth wave of Covid-19 in the country, terming the Delta variant “the biggest concern”.

As many as 15 people were diagnosed with the Delta variant in Rawalpindi last week.