Karachi, Jan 30 : Karachi has witnessed a sharp spike in the Covid-19 positivity rate in the last one week, the Sindh province's Health Ministry said. In a statement on Friday, the Ministry said that three major vicinities of the metropolitan, the positivity rate from the total number of tests conducted surged to 16 per cent, 15 per cent and 9 per cent from the previous 2 per cent, 4 per cent and 2 per cent, respectively, Xinhua news agency reported. Violation of the standard operating procedures (SOPs) during social interactions has caused the sharp rise in positivity rate which is feared to further rise if people fail to follow the SOPs, the statement said. According to the data released by the federal Health Ministry, Pakistan has registered a total of 541,031 coronavirus cases, with Sindh being the worst-hit accounting for 244,340 infections. According to the data, the country's overall death toll stood at 11,560, while 496,745 people have recovered from the diseaser. /IANS