- A woman in China passed COVID-19 to an estimated 71 people through a single elevator journey, a report published by the U.S. Centers for Disease Control and Prevention has said.
The woman had no direct contact with any of the other people and the only shared space was an elevator in the apartment block where she lived. Researchers say this superspreader case shows how a single case of the disease can result in “widespread community transmission” and the challenges of containment via self isolation.
The 25-year-old woman returned to Heilongjiang Province, China, from the U.S. on March 19. Prior to her arrival, there had been no cases of COVID-19 in the region since March 11. She had no symptoms and was asked to quarantine at home. The only indirect contact she had with anyone else in her building was through a shared elevator. Tests for antibodies for SARS-CoV-2, the virus that causes COVID-19, came back negative on March 31 and April 3.
On March 26, the woman’s downstairs neighbor had his mother and her partner stay overnight. Three days later, the mother and her boyfriend went to a party. On April 2, one of the people at the party had a stroke and was admitted to hospitals, accompanied by his sons. On April 7, the mother’s boyfriend started showing COVID-19 symptoms.
“He tested positive for SARS-CoV-2 on April 9, the first confirmed case in this cluster,” the research letter published in the journal Emerging Infectious Diseases said. Several of his contacts also then tested positive, including the neighbor of the woman who had been traveling in the U.S..
While the stroke patient was in hospital, 28 other people were infected with coronavirus on the ward. Five nurses, one doctor and one member of staff at the hospital were also infected. In the second hospital he was treated, another 20 people became infected.