The presence of the Omicron subvariant XBB.1.16 or Arcturus could be the reason behind the rise in Covid-19 cases in the Philippines, a health expert said on Friday, April 28. The same trend in cases also happened in the past when the Philippines detected other Covid-19 variants, said infectious disease expert Dr. Rontgene Solante of the San Lazaro Hospital in Manila. “Our experience with BA.2 in 2022 or 2023, iyong BA.4 and BA.5 na bigla na lang tumataas ang mga kaso and nakitaan na lang natin na pumapasok na pala itong mga variants of concern or mga sublineages ng Omicron (as well as the BA.4 and BA.5 wherein cases suddenly increased when we have detected these variants of concern of these Omicron sublineages),” said Solante during a public briefing. “So, I would highly expect that this increase, itong mga bahagyang pagtaas ng mga kaso (these slight increases in cases) are driven by the XBB sublineage of the Omicron. Whether it’s the XBB.1.5 or the XBB.1.16 or the other one is the XBB.1.9.1 – these are all variants of interest that there is always a possibility that they can cause increase in the cases among our population,” he added. Solante noted that the Arcturus subvariant “has a growth advantage” compared to other Omicron subvariants. “Ibig sabihin, mas mabilis siyang dumapo sa katawan natin because of the mutations doon sa spike protein, so ibig sabihin, mas mataas ang hawaan (This means, it sticks faster in our body because of the mutations in the spike protein, so that means, the transmission is higher),” he added. However, the Arcturus subvariant does not appear to cause more severe Covid-19, based on the experiences of other countries, said Solante. “Ang importante lang dito (The only important thing here), I think in those countries na marami ng kasong nakikita (where many cases have been recorded), there were no signals that this virus or this variant of interest ay puwedeng mag-cause ng (can cause) severe Covid. So, most of the cases are only mild,” he said. A total of 130 new cases of Omicron subvariants were detected in the Philippines, based on the latest Covid-19 biosurveillance report of the Department of Health (DOH).  This was the result of the latest genome sequencing covering the period of April 12 to 19. The report includes the lone XBB.1.16 from Iloilo province. The DOH previously said that the case was “asymptomatic and has already recovered.” “From March 2023 onwards, XBB and its sublineages were the most detected variant, comprising 63.06 percent of samples sequenced with assigned lineages, followed by the BA.2.3.20 and its sublineages,” the DOH said. Of the 130 cases, 82 were classified as XBB (including 33 XBB.1.9.1 cases, 24 XBB.1.5 cases, and one XBB.1.16 case), 30 as BA.2.3.20, 12 as BA.5 (including two BQ.1 cases), three as XBC, and another three as other Omicron sublineages, the DOH said.