By HYONHEE SHIN AND SWATI PANDEY, Reuters Published July 3, 2021 5:41am The variant, first detected in India in December last year, has spread to about 100 countries and the World Health Organisation warned recently that it could soon become the dominant form of the virus. It is also driving a spike in cases in Japan, casting a pall over this month's Olympic Games. SEOUL/SYDNEY - The highly contagious Delta variant of the coronavirus is surging through Asia this week, with record numbers of infections in Australia and South Korea, prompting some countries to tighten curbs and others to hasten vaccination. The variant, first detected in India in December last year, has spread to about 100 countries and the World Health Organisation warned recently that it could soon become the dominant form of the virus. It is also driving a spike in cases in Japan, casting a pall over this month's Olympic Games.