Zero transmission to be achieved when close contacts are the only infections

The lockdown in Xi'an will be lifted only when all COVID-19 patients outside quarantine have been cleared, according to a senior disease control and prevention official from the Shaanxi provincial capital.

Chen Zhijun, deputy director of the Xi'an center for disease control and prevention, said zero transmission in society indicates all newly confirmed cases are detected only among the patients' close contacts and second close contacts who have been placed under quarantine or isolated for medical observation.

The city, which has a population of 13 million, was put under lockdown on Dec 23.

According to statistics revealed by the Shaanxi provincial health commission on Tuesday, the province reported 95 locally transmitted COVID-19 cases on Monday, bringing the province's total to 1,785. All the new cases were detected in Xi'an.

Chen urged more effective measures to prevent and control the spread of the coronavirus in local communities, particularly in the urban villages with high population density.

"It is difficult to ensure that there is not any contact among residents in the urban villages. Therefore, the coronavirus will spread through the public venues, including elevators and lifts in high-rise buildings, if no effective and concrete measures are introduced to block the spread in such villages," Chen said.

"After several rounds of mass nucleic acid testing campaigns and the introduction of effective and concrete measures, the rapid spread of the coronavirus in local communities has been put under control," Ma Guanghui, deputy director of the Shaanxi Provincial Health Commission, said at a news conference on Tuesday.

The province reported 122 confirmed cases on Saturday, 90 on Sunday and 95 on Monday, compared with more than 150 cases several days in a row previously, according to Ma.

"Overall, the number of patients detected has shown a downward trend after great efforts were made and effective measures taken," he said.

Lyu Yongpeng, deputy director of Xi'an health commission, said the new 52 male and 43 female patients detected in Xi'an included three children under the age of 3 and six over 60.

As of Tuesday noon, 18 patients have been discharged from hospitals, Lyu said, adding Xi'an started a new round of mass nucleic acid testing at 9 am on Tuesday.

According to Liu Hongchun, deputy director of the Shaanxi Provincial Bureau of Finance, the central government and governments at all levels in the province have invested more than 2.82 billion yuan ($440 million) to help fight this most recent outbreak.

Liu said the province's finance departments would expand investments to ensure adequate supplies of anti-pandemic materials, food and other daily necessities.

Separately, Henan province reported five confirmed domestic cases in Zhengzhou, Xuchang and Luoyang cities, as well as 19 asymptomatic cases on Monday, the provincial health commission said on Tuesday. Local authorities have been mobilized to contain the new outbreak.

Kang Ruoming contributed to this story.