A few countries are now seeing a spike in Covid-19 cases, mostly led by Omicron sub-variants. Though much is not known about whether these sub-variants are more infectious than the original strain, a sudden spike in cases places severe strain on healthcare systems. (Image: News18 Creative) United States recorded 15,20,223 cases in 28 days during April 12-May 9, mainly driven by BA.2, BA.2.12.1. (Image: News18 Creative) Australia reported 11,80,331 cases in 28 days from April 12-May 9, mainly driven by BA.2. (Image: News18 Creative) 6,83,168 COVID cases recorded in China, between April 12-May 9. (Image: News18 Creative) South Africa recorded 1,11,997 cases in 28 days between April 12-May 9. (Image: News18 Creative) 14,95,666 Covid cases recorded in Italy in 28 days during April12-May 9, mainly driven by BA.2. (Image: News18 Creative) Japan recorded 10,53,979 cases in 28 days between April 12-May 9. (Image: News18 Creative) Taiwan recorded 3,69,464 cases in 28 days between April 12-May 9, mainly driven by original Omicron strain. (Image: News18 Creative) A look at the Omicron family. (Image: News18 Creative) A snapshot of the Omicron sub-variants that are driving cases in most of the countries. (Image: News18 Creative) BA.2.12.1 was first detected in the US by New York states health officials in April. (Image: News18 Creative) All of these sub-variants are being closely monitored by the World Health Organisation (WHO) as part of Omicron variant of the coronavirus. (Image: News18 Creative)