Hopes that Hong Kong would reach the critical milestone of one month without any untraceable local Covid-19 cases were dashed on Thursday when a boy who health authorities suspected was mistakenly identified as infected was found to indeed be carrying the virus.
The government has been aggressively pursuing a goal of zero infections as it seeks to ease travel restrictions with mainland China and the confirmation of the case could prove an obstacle in negotiations.
In an interview with the Post, Secretary for Food and Health Professor Sophia Chan Siu-chee played down the prospect of a quick resumption of quarantine-free travel within the nation, saying the matter would be decided according to a prevention and control mechanism jointly operated with Guangdong province and Macau.
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“We have been in constant discussion and will notify the public once there is new information,” Chan said.
Health experts have long pointed to 28 consecutive days without a local untraceable infection – equal to two incubation periods of the virus – as a benchmark of success in bringing the pandemic under control. Hong Kong would have hit that target on Friday if the four-year-old boy had been found free of the coronavirus.
He was admitted to hospital last Friday after testing positive although subsequent screenings came back negative.
Final confirmation of the boy’s status came after microbiologist Professor Yuen Kwok-yung, who advises the government on its handling of the health crisis, inspected the private and public laboratories that handled the testing.
“We couldn’t find any lab contamination or loopholes in their procedures … and two different polymerase chain reaction tests conducted at the University of Hong Kong eventually found the boy is indeed infected,” Yuen said.
“We must be cautious. The boy should be regarded as an acute infection case and his close contacts should still be quarantined.”
Hong Kong recorded a single case on Thursday, involving an arrival from Indonesia, while fewer than five people tested preliminary-positive.
Yuen gave two possible reasons for the contradictory test results. He noted the boy could have been infected in January, when a family of four living in the same residential block at Pak Tin Estate were infected.
“The boy might have been infected in January but did not have symptoms. Around 19 to 20 per cent of Covid-19 patients would not have symptoms and antibodies afterwards,” Yuen said.
Another possibility was the boy was infected with two viruses at the same time, causing a condition called viral interference.
“When there is an infection of another virus, it could suppress the replication of the coronavirus … and thus the viral load turned out to be very low,” he said. “Interference of another virus would also delay or even [prevent] the production of antibodies.”
Earlier in the day when it appeared the boy’s case was a false positive, the leader of the city’s largest pro-establishment party called on officials to make good on their earlier promise and push harder for quarantine-free travel to the mainland and Macau.
Starry Lee Wai-king, chairwoman of the Democratic Alliance for the Betterment and Progress of Hong Kong, suggested setting up a quota-based pilot scheme initially covering Greater Bay Area cities, with priority given to residents who were fully vaccinated against the coronavirus.
“We hope the government will seize the opportunity … and make citizens’ urgent priority its urgent priority,” Lee said.
But her party colleague Ann Chiang Lai-wan, a member of the legislature’s health panel, said the government should continue to negotiate with mainland counterparts on further reopening the border.
“The pandemic has gone on for more than a year and caused much inconvenience to Hong Kong people,” Chiang said. “I hope that Hong Kong people who had two doses of a vaccine can soon go to the mainland without being asked to quarantine, or at least not for so long.”
Dr Leung Chi-chiu, a respiratory medicine specialist, said he believed that given the boy’s infection did not trigger a cluster of infections, the city was still on track to the goal of “zero infections” as long as social-distancing rules remained in place for another two weeks.
“His infection won’t really matter that much because we are on track in terms of ending local transmissions,” he said. “Occasional infections also occur in mainland China, and Hong Kong has not found any signs of community transmission from the boy’s infection, so it’s time to resume talks about cross-border travel.”
Health minister Chan also defended the government’s earlier decision to ban the Tiananmen Square vigil on June 4 for a second time, citing public health concerns.
“We need to be careful in any large-scale gathering. This is viewed from the public health perspective here,” she said. “If any transmission chains remain, [the spreading] could go out of control. We must be very careful.”
Additional reporting Kathleen Magramo, Natalie Wong and Tony Cheung
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