A 13-year-old girl gave coronavirus to 11 people across four states during a three-week family gathering, according to a CDC report.
The gathering, which involved five households, took place after the teenager had been exposed to the virus during a “large outbreak” in June. Four days later she tested negative for COVID-19, and the family traveled to the gathering with 15 other relatives. Two days later she began experiencing nasal congestion—the only symptom she developed.
The gathering involved people aged between nine and 72, with 14 of the relatives staying in a five-bedroom, two-bathroom house for between eight and 25 days. During their stay, none of the party practiced social distancing or wore face masks. Six more relatives visited the house on two occasions but maintained social distancing and stayed outdoors.
Of the 14 people staying at the house, 12 developed symptoms of coronavirus and were found to have been infected with the virus. Of the confirmed cases, one person was hospitalized and another was treated at an emergency department for respiratory symptoms.
The CDC estimated exposure and infectious periods based on symptom onset dates. The review into the outbreak led them to conclude the 13-year-old girl was the index patient. “The index patient’s high-risk exposure and symptom onset three to 19 days before that of any other person at the family gathering support the hypothesis that this adolescent’s infection was the source of the family outbreak,” the report said.
“The adolescent’s initial antigen test result was likely a false negative because it was performed before symptom onset; the only antigen test that had Food and Drug Administration Emergency Use Authorization at the time was intended for use within the first five days of symptoms.”
The CDC said the case provides further evidence that children and adolescents can effectively transmit SARS-CoV-2—the virus that causes COVID-19.
It was initially thought that because children seem less affected by the disease, their viral loads—the amount of the virus in a person’s blood—may be lower than in adult carriers. This, it was thought, may reduce the risk of transmission. However, recent research has suggested otherwise. One study found children appear to carry high levels of the virus in their upper airways, potentially allowing them to spread the disease without being badly affected by it—in adults, serious illness tends to occur when the virus enters the lower airways and lungs.
Trying to establish how coronavirus affects children and their role in transmission has been a key issue in reopening schools safely. “Better understanding of transmission by children and adolescents in different settings is needed to refine public health guidance,” the CDC report said.
The CDC said their latest report highlights several important issues. It said the case shows the benefit of maintaining social distancing, as none of the family members who did this became infected. It also said it shows that “regardless of negative test results, persons should self-quarantine for 14 days after a known exposure.” Concluding, the report, it said that SARS-CoV-2 can spread easily at gatherings, especially where there is “prolonged, close contact.”
“Physical distancing, face mask use, and hand hygiene reduce transmission; gatherings should be avoided when physical distancing and face mask use are not possible.”