A second wave? Man infects 36 with coronavirus as Chinese city imposes lockdown again
A cluster of new COVID-19 cases has been identified in China’s northeastern city of Harbin, in the Heilongjiang province. This has led to fears of a second wave of the coronavirus pandemic in China.
According to the South China Morning Post (SCMP), the outbreak was traced to an 87-year old, who was treated for a cerebral stroke in Harbin No 2 Hospital between April 2 and 6. He was then transferred to First Hospital, which is affiliated to Harbin Medical University. The man, identified as Chen, may have infected over 30 people, including his four children, as well as patients, relatives, and medical staff at the two hospitals, says the report.
“The man is believed to have passed on the infection to relatives and hospital staff, some of whom tested positive before they showed any symptoms. The local government in the capital of Heilongjiang appealed to people who had visited the hospitals between April 2 and 9 to get tested for the disease and announced that 36 people had already tested positive. It also announced that some officials had been punished for their lax handling of the outbreak,” reports SCMP.
However, a 22-year-old university student, who returned to Harbin from the US, has been identified by authorities as the original source of the new infections in Harbin. She was quarantined at home for 14 days after her return. She is said to have passed on the virus to others in her neighborhood.
“Harbin’s centres for disease control and police now believe that the infection had been passed on to a neighbour who used the same elevator as the student and three other people linked to that neighbour. One of the three was a 54-year-old man named Guo who had dinner with Chen on March 29,” says SCMP.
According to Financial Times, Huang Yanzhong, a senior fellow for global health at the Council on Foreign Relations, said that the outbreak in Harbin illustrates the present and unpredictable risk of a resurgence. Yanzhong said that a “second wave attack could be coming in a way that authorities don’t expect,” says the report.
According to another report, a new cluster of cases has allegedly broken out among the medical staff at Jia County People's Hospital in China's Henan province. “A fresh cluster of cases has been reported among medical staff at Jia County People's Hospital, where one of them had just spent 14 days in quarantine after returning from Wuhan in neighboring Hubei province, where the disease first emerged at the end of last year. As a result, country authorities have imposed travel restrictions, with non-essential travel banned between villages and communities,” reports Daily Express.
According to an official document allegedly leaked to Radio Free Asia, any person who comes in and out of residential compounds has to wear a facemask, have their temperature taken and produce a certificate to prove they are healthy. The Daily Express article also claims that businesses are shut except for supermarkets and farmers' markets, “with 600,000 people effectively living under curfew.”
The National Health Commission of China has, meanwhile, said that on April 18, there were 16 new cases of confirmed infections. These include 9 imported cases and 7 that were transmitted locally (6 in Heilongjiang province and 1 in Guangdong province), 2 new cases of suspected infections (1 indigenous case in Inner Mongolia autonomous region and 1 imported case), and no deaths, says the April 19 update.
The following day, on April 19, 12 new cases of confirmed infections (8 imported cases and 4 indigenous cases, 3 in Heilongjiang province and 1 in Inner Mongolia autonomous region), 2 new cases of suspected infections (both are imported cases in Shanghai municipality), and no deaths, were reported. As of April 19, the Commission has received 82,747 reports of confirmed cases and 4,632 deaths from across China.
Real-time tracking needed to avert second wave
A recent modeling research suggested that China's aggressive control measures appear to have halted the first wave of COVID-19 in areas outside Hubei province, the epicenter of the pandemic. However, given the substantial risk of the virus being reintroduced from abroad, and with economic activity increasing, real-time monitoring of COVID-19 transmissibility and severity is needed to protect against a possible second wave of infection, researchers warned.
The study, published in The Lancet, estimates that in regions outside Hubei, the instantaneous reproductive number of COVID-19 — the average number of cases generated by a single infected individual during the outbreak — fell substantially after lockdown measures were introduced on January 23, and has remained below 1 since then. This suggests that the pandemic has shifted from one that is expanding rapidly to one that is slowly shrinking, say experts.
However, mathematical modeling to simulate the impact of relaxing current control measures suggests that premature lifting of these interventions will likely lead to transmissibility exceeding 1 again, resulting in a second wave of infection, says the research team.
In the study, researchers analyzed local Health Commission data of confirmed COVID-19 cases between mid-January and 29 February to estimate the transmissibility and severity of COVID-19 in four major cities — Beijing, Shanghai, Shenzhen, Wenzhou — and 10 provinces outside Hubei with the highest number of confirmed COVID-19 cases. According to the study findings, the confirmed case fatality risk (the probability of dying among confirmed cases of COVID-19 as officially reported) outside Hubei was 0.98%, nearly six times lower than in Hubei (5.91%).
This varied substantially among different provinces was based on economic development and availability of healthcare resources. Among the 10 provinces with the largest number of confirmed cases, case fatality ranged from 0% in prosperous regions like Jiangsu to 1.76% in less developed provinces such as Henan.
The researchers caution that even in the most prosperous and well-resourced megacities like Beijing and Shanghai, healthcare resources are finite, and services will struggle with a sudden increase in demand. The team suggests that in regions outside Hubei, control measures should be lifted gradually so that the resulting reproductive number does not exceed 1, or the number of cases will progressively rise over the relaxation period.
“Moreover, the estimates suggest that once elevated, simply tightening control interventions again would not reduce the burden back to its original level, and would require extra effort to drive the reproductive number below 1 to revert to the pre-relaxation level, likely resulting in both higher health and economic loss,” say researchers.