The spillover of the Delta variant worsened the pandemic in many countries near India in South and Southeast Asia. Even after strengthening border controls and restricting passenger flows, it is hard for any country to keep the virus completely out.
China faces similar challenges, and there have been previous smallscale outbreaks in many of the country’s border and port cities, including Ruili, on the border of Myanmar and Southwest China’s Yunnan Province, and the eastern seaports of Qingdao and Dalian.
On July 7, a new outbreak in Ruili prompted a new round of citywide testing and a lockdown, with more than 100 positive cases detected, including imported cases and community infections.
But Guangzhou, the biggest entry-exit port for passengers returning to the Chinese mainland, bears the brunt of the threat. On May 20, Duan Yufei, director of the Guangdong Provincial Health Commission, said that Guangdong receives 90 percent of all inbound travelers entering the country every day. There are over 300 designated quarantine venues in the province, and nearly 30,000 people are in some stage of quarantine every day with nearly 20,000 staff working at quarantine sites.
In late June, Guangzhou announced it would construct a 5,000-person temporary quarantine center for international arrivals to cope with more infectious variants like Delta. It is expected to open in September.
In 2020, Guangzhou Baiyun International Airport surpassed Hartsfield-Jackson Atlanta International Airport in the US to become the world’s busiest airport with the largest passenger capacity. Since October 2020, three asymptomatic infected people or patients that had recovered from Covid-19 subsequently tested positive in Huadu, Nansha and Haizhu districts of Guangzhou, two workers in quarantine hotels and a Chinese national that had traveled from the UK.
Wei Sheng, a professor at the Department of Epidemiology and Health Statistics of the School of Public Health, Tongji Medical School of Huazhong University of Science and Technology, told NewsChina that Guangdong is unique in its prevention and control of import-related infections because it receives 90 percent of inbound arrivals. The city’s closed-loop management efforts for inbound passengers involves many departments and stages, so managing it and controlling the risks is complex.
Addressing the pressure of rising imported infection cases, the already strict border policy was tightened even more. It already includes restrictions on flights, bans on direct flights to some countries, while it has been hard for most non-Chinese nationals to enter the country for well over a year, including overseas students.
The China CDC announced on May 14 that in addition to the required 14-days quarantine for entry for people from outside the Chinese mainland, people coming from overseas must also provide two nasopharyngeal swab samples with two different nucleic acid testing reagents and obtain two testing reports from different agencies before they can be released from quarantine.
After release from quarantine, people must undergo two nucleic acid tests on the second and seventh day. Requirements are even stricter in some parts of China, including Beijing, with extended periods of monitoring and quarantine lasting 21 or even 28 days.
On June 5, nine new infections were reported in Guangzhou, six in the same family, the Zhangs, who live in Guangzhou’s Nansha District. The husband and wife had dined in a restaurant in Liwan District where a confirmed case had been.
Nansha District started testing all residents on June 4, which revealed a few new cases. When the couple returned to their home in Nansha from Liwan, the area had not yet imposed any lockdown restrictions. The Zhangs were busy, visiting many places including restaurants, a kindergarten and a chess club. The family’s infection meant a new outbreak had started unnoticed within the wider community.
The Zhang family case triggered a sudden escalation of prevention and control measures. From the afternoon of June 5, urban buses, subways, ferries and long-distance buses were stopped, residents were encouraged to not leave the district and expressways and high-speed railways and docks were temporarily shut down. The lockdown measures in Nansha were much stricter than in Liwan.
On May 29, Huang Guanglie, director of the Guangzhou Municipal Health Commission, described the situation during a press conference: “We must run a little earlier and faster to stop the transmission of the virus and cut the chain of infection, otherwise, there is a high chance of more local infections.”
An epidemiologist from the China CDC told NewsChina that implementing prevention and control measures within a limited scale while controlling an outbreak is a challenge that will test the ability of local officials. He said that a megacity like Guangzhou, with more than 18 million permanent residents, is so densely populated and economically active that it is difficult for the local government to decide to what degree to enforce prevention and control measures, since there is a consequent economic impact. In Guangzhou, as the outbreak continued, there was a continued ramping up of testing and lockdown measures.
Tightened control measures at transportation hubs since the end of May resulted in a drop of more than 60 percent in daily passenger trips in Guangzhou. Starting June 7, people in areas deemed medium or high risk were not allowed to leave their homes.
In early June, other city districts also conducted nucleic acid testing for all residents.
“We emphasized targeted prevention measures, but as we are countered by such a rapid transmission of the Delta variant, we must set up in advance prevention and control measures. So largescale nucleic acid screening is very effective and very necessary,” said Zhang Zhoubin during an interview with Central China Television. According to Zhang, since the start of mass nucleic acid screening on May 26, as of June 5, more than 16 million test samples were collected in Guangzhou, with 33 positive results.
On May 30, the R number decreased to 4.19. Yang Zhicong, director of the Guangzhou CDC, said the effect of the mass testing in Guangzhou was significant. “We calculated through mathematical models that without effective prevention and control measures, there would be nearly 300 cases.”
Unlike the SARS epidemic in 2003, which spread and was contained within months, the fight against Covid-19 is a prolonged battle. “We must have zero tolerance towards sporadic outbreaks and the spread of mild infections,” Zhang Wenhong, professor and head of the Center for Infectious Disease, Huashan Hospital of Fudan University in Shanghai, told media on June 3 during the Boao Forum for Global Health for Asia.
Zhang pointed out that only when the vaccination rate in China is high enough can the country get sufficient data, including the duration of the vaccine protection rate and the resistance of the vaccine against imported infections. When China’s existing medical network can resist sporadic cases and can control the Covid-19 mortality rate and morbidity to a very low level, then the country can talk about relaxation of current intervention measures, Zhang said.
Feng Zijian, a researcher at the China CDC, said at the same forum that the only goal at the moment is to have all people vaccinated as quickly as possible. “It’s the safest way, and then we can have the conditions to consider adjusting our strategy,” Feng said.
Given a jolt by the recent outbreak, vaccination in Guangdong Province, with a population of more than 180 million, has accelerated. Data on June 2 indicated that 60 million doses had been administered in Guangdong. It took Guangdong 108 days to fulfill the first 10 million doses, and 26 days for the second 10 million doses, 13 days for the third 10 million doses, and a mere six days for the sixth batch of 10 million doses. As of June 2, vaccination coverage of the target population between ages 18 to 59 in major cities in Guangdong, including Guangzhou, Shenzhen, Foshan and Dongguan, had exceeded 70 percent for the first dose.
While the vaccine campaign was slow to start in China, efforts to vaccinate the population have ramped up, particularly after the recent outbreaks, with many previously hesitant people flocking to vaccination centers. As of July 13, across China, over 1.4 billion doses of Covid-19 vaccine have been administered.