A security staff member checks a passenger's temperature at Chongqing Jiangbei International Airport in southwest China's Chongqing, Jan. 26, 2020. File photo: Xinhua

China has reported at least 18 newly confirmed COVID-19 cases imported from India or involving Indian citizens as of Wednesday, and a source from the Chinese Center for Disease Control and Prevention (CDC) said that China may continue to see new cases imported from India, but they are unlikely to result in further domestic infections due to China's effective and strict entry rules. 

China CDC Weekly, which publishes public health event investigation reports, revealed three recently confirmed COVID-19 patients tested positive in Chongqing after returning from India via Nepal.  

An epidemiological investigation revealed the three patients, who are coworkers at a cellphone company based in Noida, India, went to New Delhi in a chartered car on April 19 before flying to Kathmandu with protective clothes, N95 respirators, goggles, and gloves later that day. 

They stayed in a hotel in Nepal for two days and then flew to Southwest China's Chongqing on April 21 and immediately tested positive for COVID-19 after landing in Chongqing, according to the China CDC Weekly. 

The B.1.617 COVID-19 variant that was discovered in October 2020 in India was found in the three patients and the China CDC Weekly said that the three patients were probably infected in India. 

As well as these three cases, South China's Zhejiang Province and Shanghai have also reported imported cases and asymptomatic cases from India. One asymptomatic case involved an Indian man who landed in Shanghai from Niger via Paris, and he then went to Zhejiang's Yiwu on April 30 after quarantine and tested positive on Saturday. 

Neighboring countries including Nepal and Southeast Asian countries such as Laos, Vietnam and Thailand have seen significant surges in COVID-19 cases amid India's COVID-19 crisis. A source from the Chinese Center for Disease Control and Prevention who requested anonymity, told the Global Times on Wednesday that India's spike in coronavirus cases has increased the pressure on China to prevent imported cases, and China will continue to see imported cases from India. 

"But due to strict entry measures including quarantine and multiple tests, the possibility of these sporadic imported cases sparking domestic infections is very low," the source said. 

Wu Zunyou, chief epidemiologist at the China CDC, said on April 29 that the rapid surge of COVID-19 cases in India has pushed the global COVID-19 pandemic to a new peak and made Asia a worst-hit area for the disease. He said that the virus has been mutating constantly since the epidemic, and that it is crucial to put epidemic control measures into practice, which will not only stop the mutated strains but also stop new mutations from emerging.