India recorded its biggest single-day spike in coronavirus cases on Monday as testing in the nation of more than 1.3 billion is gradually being scaled up – aided by almost 1 million rapid testing kits from China . Confirmed virus cases have been surging over the last week, with an additional 1,553 over 24 hours reported on Monday, raising the national total past 17,000 with at least 543 deaths. Virus lockdown becomes hunger games for millions of India’s poorest Infectious diseases experts say the true number of infections is likely much higher, however, given that the Indian Council of Medical Research (ICMR) said on Sunday that the country has tested just 383,985 people – or about 0.03 per cent of the population. The number of tests being carried out each day touched 35,000 for the first time this weekend. But as central and state governments try to ease some of the lockdown restrictions that have been in place since March 24, widespread testing is more important than ever – especially in the 170 districts that are still considered infection “hotspots”, which includes all major cities. India received 650,000 rapid testing kits from China on Thursday, followed by an additional 300,000 for the states of Tamil Nadu and Rajasthan over the weekend. Why rapid virus test kits might not be the quick fix some are hoping for These kits, however, contain antibody tests, which are “not the gold standard for diagnosis” and are only really useful “for surveillance”, according to Rajni Kant Srivastava, director of an ICMR regional medical research centre. If an antibody test comes back positive – indicating the person’s immune system has already fought off the virus – then an additional laboratory test needs to be done to confirm the diagnosis, Srivastava said. Yet rapid testing kits are good at giving “an idea how many people were exposed”, he said, “including the asymptomatic who were excluded from earlier criteria of testing”. This in turn, could help authorities set up containment zones and screen infection hotspots. Dr GSK Velu, founder of Trivitron Healthcare which imports testing kits from Chinese suppliers, said that “in the absence of locally manufactured antibody rapid kits in India, good quality Chinese rapid test kits will help in surveillance of Covid-19 spread”. Some are wary of relying on imported kits from China, though, especially following reports last month of thousands of testing kits and medical masks being rejected as below standard or defective by a number of European governments. “Importing [kits] from China leaves me very uncomfortable, to say the least,” said Dr Jacob John, former chief of the centre of advanced research in virology at the Christian Medical College, Vellore, who added that “India can do a lot more testing” but he would prefer to see “Indian manufacturers do [the] commissioned work” of making kits. Other specialists, such as global health and policy researcher Anant Bhan, said concerns about accuracy meant it was “imperative that these tests [from China] be put through quality checks”. “At this time, we need reliability in the testing approaches we use,” he said. Supplies of the testing kits have been coordinated by Indian diplomatic missions in China, led by Vikram Misri, New Delhi’s ambassador to the country. Local media reports suggest more kits are expected soon, though the exact number remains unclear, and India is also looking to source tests from other countries including South Korea , France and Germany , as well as encouraging domestic manufacturers to ramp up production. Meanwhile in Delhi, plasma therapy trials have begun, with doctors looking to use the antibody-rich blood of the more than 1,600 people in the country who have recovered from Covid-19 to treat those who are still severely ill. Lockdown restrictions also began to be eased on Monday, with limited industry and farming allowed to resume where employers could meet social distancing and hygiene norms. Migrant workers can also now travel within states to factories, farms and other work sites. Additional reporting by Associated Press, Bloomberg