A new study shows that the spread of COVID-19 in American households is greater than previously thought.
The research was published in the journal on Friday (October 30) Morbidity and mortality weekly report, Involving 191 people in Tennessee and Wisconsin who lived with someone who was recently diagnosed with COVID-19. Among these people, 102 were infected within 7 days after being included in the study, and the “secondary infection rate” was 53%. (The secondary infection rate is the percentage of the exposed population who contracted COVID-19 from the first case.)
About 75% of these secondary infections occurred within five days after the first family member became ill.
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The first author of the study, Dr. Carlos Grijalva (Dr. Carlos Grijalva), associate professor of health policy at the Vanderbilt University Medical Center in Nashville, said: “We observed that after the first family member fell ill, the family quickly found Several infections.”
Other research Spread COVID-19 In families-mostly in Europe and Asia-the secondary infection rate was found to be 30% or lower. However, this new study was conducted from April to September and is the first study to study the spread of COVID-19 in American households in a systematic way. Participants receive a daily COVID-19 test.
The authors say that compared with previous reports, part of the reason for the higher rate of secondary infections in the new study may be due to the study’s rigorous methods and follow-up testing of household contacts.In addition, studies in other countries/regions may have lower secondary infection rates because people in these countries/regions wear it faster Mask Another family member was in his house when he was sick. (Traditionally, masks are not used when sick) American culture, And in some other countries).
The study also found that “mass transmission” occurs regardless of whether the first family case (called an index case) is a child or an adult.
Indeed, in families with index cases younger than 12 years old, the secondary infection rate is 53%. The report found that in families with index patients aged 18 to 49, the secondary infection rate was 55%.
Grijalva said: “Whether the first family member to get sick is a child or an adult, the infection happens very quickly.”
Moreover, less than half of family members showed symptoms when they tested positive for COVID-19, while the remaining 18% Asymptomatic In the seven-day study. According to the authors, this finding emphasizes that if people stay in close contact with someone who has tested positive for COVID-19, they need to be isolated.
Overall, the report says: “People who suspect that they may have COVID-19 should be isolated, stay at home, and use separate bedrooms and bathrooms if feasible.” This isolation should even be done before testing or obtaining results Just start.In addition, all family members should start wearing masks at home, especially Social isolation The author said that this is impossible.
The authors point out that their study was conducted in two cities in the United States-Nashville, Tennessee and Marshfield, Wisconsin-and the households in the study may not represent the overall population of the United States.
Originally published in “Life Science”.