Exclusive: China Traces Covid-19 Cluster to Contaminated Trucks

China traced the now-contained Covid-19 outbreak last month in the northwestern Xinjiang autonomous region to contaminated freight trucks that transported export goods to neighboring countries.

The virus was discovered on the inside surface of multiple trucks in Kashgar, and the first case was traced to a loading worker who might have been infected through a contaminated truck, according to Wu Zunyou, chief epidemiologist at the China Center for Disease Control and Prevention.

Object-to-person transmission of Covid-19 has gained attention after a recent outbreak in Shanghai was tracked to an air cargo container at Shanghai’s Pudong International Airport. The outbreak was linked to two cargo handlers who cleaned a container that arrived from North America.

The Kashgar worker, an asymptomatic patient, first passed the coronavirus to his wife and other family members, which eventually led to a cluster of cases in a garment factory, Wu said. Kashgar tested all of its 4.75 million residents over three days in late October and found 183 Covid-19 cases after the outbreak at the garment factory, which employs 252.

Wu said it’s not clear whether the first worker became infected through direct contact with a contaminated surface or through breathing virus-laden air inside the truck. Possibly foreign workers contaminated the trucks while unloading goods, and then the Kashgar worker was infected, a person close to the investigation told Caixin.

It is worth noting that the local infections in Kashgar and Shanghai were traced to shipments that weren’t chilled or frozen, unlike many other cases that were linked to cold supply chains, said Zhang Wenhong, director of the infectious diseases department at Huashan Hospital in Shanghai.

With the onset of winter, viruses survive for notably longer periods of time on surfaces outside the human body, Zhang said. If goods are stored in a cold and wet container, the virus can remain infectious for a while, posing a great risk to anyone who comes into physical contact with it, Zhang said.

Zhang suggested measures to strengthen the sterilization and disinfection of non-cold chain logistics in winter and ensure proper handling of goods and containers in environments with lots of light and good ventilation.

China is still tracing the original source of the Kashgar outbreak. The Kashgar Prefecture borders Kyrgyzstan, Tajikistan, Uzbekistan, Afghanistan and India. As these countries don’t provide data to an international Covid-19 database, it’s unknown which country the Kashgar worker was infected from, the person close to the investigation said.

The Kashgar outbreak was first reported Oct. 24, but a patient went to a private clinic as early as Oct. 13, Wu said.

“If we had discovered the first patient, the whole outbreak could have been only five or six cases,” Wu said. “The most important thing in pandemic prevention is to make better use of the community and small clinics.”

Contact reporter Denise Jia (huijuanjia@caixin.com) and editor Bob Simison (bobsimison@caixin.com).

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