The CDC found a 53 percent household transmission rate of COVID-19, higher than previously reported, according to the "Morbidity and Mortality Weekly Report" published Oct. 30.
The analysis included 101 households and index patients, or the first person within a household with a confirmed case of COVID-19, and a total of 191 household members who lived with the index patients. Researchers found "substantial transmission occurred whether the index patient was an adult or child."
The secondary infection rate from index patients was 53 percent, of which 75 percent of cases were quickly identified within five days of the index patient's illness. The analysis included households in Nashville, Tenn., and Marshfield, Wis., between April and September. Participants completed daily symptom diaries and self-collected specimens for 14 days.
Less than half of household members with COVID-19 experienced symptoms at the time of diagnosis, with many reporting no symptoms across a seven-day follow-up, "underscoring the potential for transmission from asymptomatic contacts and the importance of quarantine," researchers said.
The CDC concluded those suspecting a case of COVID-19 should isolate before seeking a test, and before results are available in order to reduce the risk of household transmission.
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