A teenager infected 11 relatives from four different states with Covid-19 during a three week family holiday, health officials have revealed.
The 13-year-old girl transmitted the virus to family members during the summer vacation in June and July, despite the youngster only showing very mild symptoms.
Authorities say the girl was exposed to coronavirus during a large outbreak in June, but tested negative four days later while asymptomatic.
She then developed nasal congestion but travelled with her parents and two brothers to the family holiday with 15 other relatives aged between nine and 72.
“Fourteen relatives, including the index patient, stayed in a five-bedroom, two-bathroom house for 8–25 days,” said the Centers for Disease Control and Prevention in a report.
“These relatives did not wear face masks or practice physical distancing.”
Officials say six other relatives, including an aunt, uncle and four cousins, then visited for two days but socially distanced and stayed outside without masks.
The CDC says that of the 14 people who stayed in the same house, 11 contracted Covid-19, while four of the six visitors who stayed outside and were tested were negative.
One person was hospitalised and one was treated in the emergency room but both have since recovered.
The identity of the family and the location of the holiday have not been revealed but the CDC report used information from public health departments in Rhode Island, Massachusetts, Georgia and Illinois.
The CDC says that the case shows how the virus can “spread efficiently” during family gatherings.
“Physical distancing, face mask use, and hand hygiene reduce transmission; gatherings should be avoided when physical distancing and face mask use are not possible,” the report states.