China’s official figures for new coronavirus cases suggest transmission has all but ended in many regions, but local experts have warned that official numbers omit important categories of cases.
Hubei, the province where the outbreak originated, has reported no more than one new case a day for more than a week, allowing the government to signal the end of the crisis period. Officials and disease control teams have been able to leave the area, and travel restrictions and quarantines have also been relaxed.
But interviews with local medics and disease specialists reveal that the situation in Hubei’s capital Wuhan could be worse than the official figures make out, suggesting any declaration by Beijing of victory against the pandemic would be premature.
Experts have highlighted the existence of unreported cases, as well as the large number of asymptomatic cases that the government refuses to publicise in its official tally.
Two nurses in Wuhan, who wished to remain anonymous because of the sensitivity of the pandemic, told the Financial Times of “hidden” infections that met the national criteria for confirmed cases but were not being recognised in the city’s official count, helping to keep it at or near zero.
“The medics I know are all telling me that the hospital and the [National] Health Commission are using all their means to control the new case count,” said one of the nurses.
“It is extremely worrying to continue to publicise ‘zero new cases’. It is very risky and it will turn the sacrifices made in Wuhan and the whole of Hubei to nothing.”
Li Keqiang, the Chinese premier, this week warned that “under no circumstances [should] cases be covered up or omitted in order to pursue a zero count” strategy in Hubei.
At its peak in mid-February, more than 50,000 active virus cases were officially reported across China, leading to the lockdown of Hubei that is only now being relaxed. On Thursday fewer than 3,947 cases were recorded.
However, one Beijing-based coronavirus researcher who wished to remain anonymous cast doubt on the official numbers, saying that cases with symptoms were just “the tip of the iceberg”.
“China is counting asymptomatic cases but not making them public,” he said.
The National Health Commission, the government agency that sets guidelines for how cases are reported and disclosed, has always maintained that asymptomatic cases should not be counted in its confirmed case total. Asymptomatic cases are patients who test positive for Sars-Cov-2, the virus that causes the disease Covid-19, but have “no clinical symptoms”.
Coronavirus business update
How is coronavirus taking its toll on markets, business, and our everyday lives and workplaces? Stay briefed with our coronavirus newsletter.
Sign up here
But a member of the Wuhan experts team told the local Caixin newspaper this week that “every day we can still detect a few, or a few tens, of asymptomatic carriers”. The person added: “We cannot conclude yet that Wuhan’s transmission has completely ended.”
Over the past two weeks, Wuhan has gradually allowed some designated virus hospitals to resume normal functions. But a lack of transparency when transferring cases has caused some doctors to question whether their new coronavirus patients are being counted.
“A few nearby hospitals . . . have transferred their coronavirus patients to us,” said Cao Jingchao, a senior staff member of Wuhan Union Hospital West’s inpatient pharmacy division.
“But we were not informed of whether they were newly confirmed cases, or those hospitals’ remaining patients, and if so, how long they had previously been hospitalised for,” added Dr Cao, noting that his staff had not received the medical records of the new patients.
On March 15, Dr Cao’s hospital took in around 100 virus patients, some of whom were confirmed cases transferred from other hospitals, but some of whom Dr Cao suspected were new cases. Four days later, 20 more transferred patients arrived. The local government announced the next day there had been zero new cases that day.
Many experts who point to the dangers of omitting asymptomatic cases from the official count attributed the pandemic’s rapid spread to the carriers without symptoms who take fewer precautions, combined with the virus’s high reproduction rate.
The Chinese government maintains that infections from detected asymptomatic cases are not a problem, as they are held in centralised quarantine for 14 days and observed to see if they become symptomatic, and can be reclassified as confirmed cases if so.
Recent academic work suggests asymptomatic cases are a large number of total infections. A paper by researchers at the Huazhong University of Science and Technology and others, not yet peer reviewed but published in Nature, estimated that at least 59 per cent of infected cases in Wuhan before mid-February were “likely asymptomatic or with mild symptoms, who could mostly recover without seeking medical care”.
A paper published in the International Journal of Infectious Diseases, based on evidence from Japanese evacuees from Wuhan, estimated that almost a third of total infections are asymptomatic.
However, an analysis by the Korea Centers for Disease Control and Prevention of people potentially exposed to a virus cluster at a quasi-Christian sect — which accounted for more than half the country’s nearly 9,000 infections — estimated the proportion of asymptomatic patients at just 8 per cent.
But experts stressed that the results were preliminary and that it was important for information on asymptomatic cases to be reported to encourage social distancing.