Taipei, Jan. 14 (CNA) A total of 140 individuals infected with the COVID-19 Omicron variant arrived in Taiwan over the past week, bringing the total number of such cases to 278, the Central Epidemic Command Center (CECC) said Friday.

The weekly record of 140 imported Omicron infections was a sizable increase on the 79 cases recorded from Dec. 31 to Jan. 6, reflecting the growing dominance of the contagious variant abroad. The first cases of imported Omicron infection in Taiwan were reported on Dec. 11.

Of the imported cases between Jan. 1 and Jan. 13, genome sequencing showed that 140 were Omicron infections and seven were Delta infections, said CECC official Lo Yi-chun (羅一鈞) during a daily briefing.

Four of the Delta infections came from Turkey and three from Vietnam, Lo added.

To date, Taiwan has confirmed 317 Omicron cases (39 domestic and 278 imported) and 310 Delta cases (52 domestic and 258 imported), the CECC said. A total of 17,692 local and imported COVID-19 cases have been reported in the country since the pandemic began in early 2020.

Of the latest 140 imported Omicron cases, 81 came from the United States, and 59 were from 30 other countries, according to CECC data.

Among all the 278 imported Omicron infections, five were aged under five, two from 5 to 10, 10 from 10 to 20, 77 from 20 to 30, 63 from 30 to 40, 33 from 40 to 50, 44 from 50-60, 28 from 60 to 70, and 16 over 70.

In addition, 259 of the imported cases were breakthrough cases, while four are still being investigated, CECC data shows.

Moreover, 200 of the 278 were confirmed with the disease after being tested at the airport, which indicates there is a high success rate identifying the Omicron variant when people arrive in Taiwan, Lo said.

The rest were identified while staying in quarantine hotels or collective quarantine facilities, suggesting a low risk of the variant entering local communities, he added.

In addition, 144 of the 278 individuals with Omicron infections showed no symptoms while 134 had mild symptoms, according to CECC data.

However, with the majority of imported Omicron investigations being breakthrough cases, people still need to get fully vaccinated to ensure they do not develop serious complications, Lo said.

CECC head Chen Shih-chung (陳時中) said the number of imported infections is expected to rise over the coming days, so from Saturday some of the mild cases or asymptomatic younger people will be directed to government-run quarantine centers instead of medical facilities to reduce some of the pressure on local hospitals.