The family members stayed in the same house for up to three weeks, without social distancing or face masks.
A 13-year-old girl recently sickened 11 family members across four states after exposing them to COVID-19 during a family vacation, according to a new report published by the Centers for Disease Control and Prevention on Thursday.
The CDC report explained that the 13-year-old girl—known as the index patient, or the patient with which the outbreak began—was initially exposed to a large COVID-19 outbreak while away from home in June. Because of that, the girl was tested four days after her exposure to the virus with a rapid antigen test when she returned home. At the time of the test, the girl had no symptoms, and the antigen test was negative for COVID-19.
Two days after that test, however, the girl began experiencing nasal congestion, her only symptom. On that same day, she also traveled with her four immediate family members—her parents and her two brothers—to a family gathering with 15 other relatives. In total, 20 family members from five different households across four states attended the gathering, ranging in ages from 9 to 72.
Fourteen family members—including the index patient—stayed in the same house for eight to 25 days, and did not practice physical distancing or wear face masks. The six additional family members visited on two separate occasions and practiced physical distancing by remaining outside, but did not wear masks.
Among the 14 family members who stayed in the same house, 12 family members, including the index patient, experienced symptoms and were eventually found to have COVID-19. Two of those family members with COVID-19 sought medical attention—one was hospitalized, the other visited the emergency room for respiratory symptoms—but both recovered. The six additional family members who stayed elsewhere and practiced physical distancing did not develop symptoms and either tested negative for COVID-19 or weren’t tested at all.
This isn’t the first time that a large gathering with family or friends has turned into a COVID-19 outbreak. In June, 18 members of a Texas family tested positive for COVID-19 after attending a surprise party for “only a couple of hours.” Similarly, a group of 16 friends tested positive for coronavirus after a night out at a pub in Florida, also in June.
The CDC says the most recent family outbreak brings a few important issues to the forefront: First is that children and adolescents can absolutely pass COVID-19 to other family members in a household, even if their symptoms are mild.
The report also confirms that not all COVID-19 tests are created equal. The 13-year-old girl, for example, underwent a rapid antigen test when she was still asymptomatic. The CDC says an antigen test, however, is meant to be used within the first five days of symptoms. Those rapid antigen tests also have a lower sensitivity, compared to standard reverse transcription-polymerase chain reaction (RT-PCR) testing, and because of that, negative antigen tests should be confirmed with a RT-PCR tests for those with possible infections.
This outbreak underscores how well physical distancing works to help stop the spread of the virus—and conversely, how rapidly COVID-19 can spread in group gatherings held indoors for long periods of time, with close contact, and without mask-wearing. The CDC confirmed that “physical distancing, mask use, and hand hygiene reduce transmission,” and that “gatherings should be avoided when physical distancing and face mask use are not possible.”