Intended for healthcare professionals


Covid-19: China installs fences and alarms in Shanghai in effort to curb cases

BMJ 2022; 377 doi: (Published 27 April 2022) Cite this as: BMJ 2022;377:o1076
  1. Luke Taylor
  1. Bogotá

The Chinese government has introduced unprecedented public health measures in the city of Shanghai in an effort to curb an outbreak of covid-19 and is reportedly considering locking down Beijing if infections continue to climb in the capital.

Residents of Shanghai have been locked down for a month but woke up to unexpected restrictions late last week. Local authorities erected two metre high fences outside the residences of some communities with a confirmed covid-19 infection to prevent residents from going outside.1

Electronic alarms have also been installed on the doors of residences with a confirmed covid-19 infection. Some residents have been evacuated so that their homes can be disinfected.

The measures come amid signs that China’s strict covid-19 strategy, which has been largely successful in keeping infections close to zero during the pandemic, may not work against the more infectious omicron variant.

Shortages of food and medicine in Shanghai have caused an unusual wave of public criticism of the restrictions in Chinese social media, which has been met with government censorship.2 There have also been reports of people dying from non-covid causes because they cannot access their usual medicines.3

Shanghai reported 21 000 new infections of SARS-CoV-2 on 24 April and a record 39 deaths from covid-19.1 Infections dropped to 17 000 on 26 April, but deaths increased to 52.

Authorities in Beijing are rolling out mass testing in the hope of catching a localised outbreak before the city follows Shanghai’s fate and requires stricter measures. The capital reported 33 new cases on 25 April, up from 19 a day earlier.

Global equity markets fell on 25 April after reports that the Chinese government was considering implementing lockdown measures in the capital that would disrupt global supply chains.4

Covid-19 infections began rising throughout China in March, when they exceeded numbers not seen since the initial Wuhan outbreak. Daily infections have continued growing throughout April, which some experts say show that China’s zero covid strategy is not effective against omicron.5

Less effective vaccines

The country’s homegrown inactivated vaccines are also less effective than western produced mRNA vaccines at preventing severe illness from omicron and preventing its onward transmission.6

The head of China’s Centre for Disease Prevention and Control previously expressed concern that locally produced jabs would not reduce case numbers sufficiently.7 China began boosting the immunity of citizens vaccinated with Sinopharm or Sinovac jabs with domestically produced mRNA vaccines in February 2022.8

Stay-at-home orders in Shanghai were first rolled out in targeted areas before being applied in a staggered fashion, and they then became blanket restrictions for the city’s 26 million residents when the measures failed to reduce infection rates. Thousands of military personnel have been dispatched to help manage the lockdown and send symptomatic patients with covid-19 to field hospitals, sometimes hundreds of kilometres away.

The aim of the strict public health measures is not to eliminate all individual infections but to contain clusters before they can spread exponentially, the head of China’s covid-19 response panel told state run media.9 Authorities will remove the restrictions only if vaccines can better protect vulnerable people, more effective drugs are available, or infection sources can be detected more quickly and accurately, he added.

Although covid infections in Shanghai have dropped each day in the past week, public health restrictions will not be relaxed until all new infections are detected within isolation facilities, government officials said on 22 April.10

The number of cases in Beijing is expected to increase in the coming days, the deputy director of the Beijing Centre for Disease Prevention and Control, Pang Xinghuo, told the state run newspaper China Daily on 25 April.11

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