By Huizhong Wu and Andrew Galbraith
BEIJING/SHANGHAI (Reuters) - China, where the coronavirus outbreak first erupted in December, logged fewer new infections on Thursday, but measures restricting movement have been tightened in some parts of the country due to a fear of more imported cases.
China had 35 new cases of the disease on April 1, all of which were imported, the National Health Commission (NHC) said on Thursday.
The central province of Hunan, which had recently downgraded its emergency response to the lowest level, reported its first imported infection on Wednesday, state media reported on Thursday, citing the provincial health commission.
Authorities remain concerned about the risks posed by imported cases of COVID-19, and have in recent days banned foreign passport holders from entering and ordered a sharp reduction in the number of international flights.
China currently allows no more than 134 international flights per week to enter the country to meet demand from citizens and students abroad wishing to return home, and just 108 flights have been granted permission this week, Lu Erxue, the deputy director-general of China's civil aviation administration said at a briefing on Thursday.
A total of 1.6 million Chinese students study overseas, of which 36 have tested positive, said Ma Zhaoxu, vice-minister of foreign affairs, at the same briefing.
The civil aviation administration arranged nine flights between March 4 and 26 to bring Chinese citizens back from overseas, and dispatched another plane on Thursday to ferry about 180 students back to China from the UK, Ma said.
China has also seen a gradual reintroduction of restrictions, including closures of cinemas that had been permitted to reopen, amid worries that early relaxation of lockdowns could spark another wave of infections just as the world's second-largest economy is struggling back to its feet.
On Wednesday, a county in the central province of Henan said it had banned people from leaving without proper authorisation, and prevented residents from leaving their homes for work without clearance following several coronavirus infections in the area.
On Thursday, Henan reported one new imported asymptomatic case, according to the provincial health authority. A total of 10 asymptomatic cases remained under medical observation, six of which involved travellers arriving from abroad. The remaining four were locally transmitted.
Meanwhile, in Hubei province, the epicentre of the outbreak, 37 new asymptomatic cases were logged as at the end of Wednesday, according to the official Xinhua news agency.
NO SYMPTOMS
The number of new asymptomatic cases fell sharply to 55 on April 1, from 130 the day before.
China said it is treating such cases like confirmed ones and plans to publish information in a timely and transparent way, according to comments made by NHC official Wang Bin at a news briefing.
Asymptomatic carriers are less infectious than confirmed cases, said China CDC Chief Epidemiologist Zunyou Wu, citing a Ningbo CDC research paper.
But around 2 out of 3 such carriers will develop symptoms, said Wu.
One asymptomatic patient can only pass the virus to, on average, less than one person while confirmed cases can pass it to three, Wu added.
Users of Chinese social media have expressed fear that carriers with no symptoms could be spreading the virus unknowingly, especially as authorities ease curbs on travel for previous hotspots now that infections have subsided.
Last week, WHO epidemiologist Maria van Kerkhove said symptomatic patients were the main drivers of transmission, while most of those classified as asymptomatic developed symptoms a few days after diagnosis.