Covid spreads faster within households than previously estimated

Study revealed that 51 per cent of others living with someone who was positive for COVID-19 also became infected

Washington: Transmission of the novel coronavirus within households is high, occurs quickly, and can originate from both children and adults, according to a new study which assessed 101 houses in the US.

The preliminary findings from the ongoing research, published in the journal Morbidity and Mortality Weekly Report, revealed that 51 per cent of others living with someone who was positive for COVID-19 also became infected.

“We observed that, after a first household member became sick, several infections were rapidly detected in the household,” said Carlos G. Grijalva, study co-author and associate professor of Health Policy at Vanderbilt University Medical Center in the US.

“Those infections occurred fast, whether the first sick household member was a child or an adult,” Grijalva said.

According to the research, at least 75 per cent of the secondary household infections occurred within five days of the first person in the household experiencing symptoms. It also found that less than half of household members experienced symptoms when they first tested positive, and many reported no symptoms throughout the seven-day daily follow-up period.

“In the absence of an efficient approach for identification of infections without regard to symptoms, these findings suggest that prompt adoption of isolation measures as soon as a person feels ill might reduce the probability of household transmission,” the scientists wrote in the study.

Citing the limitations of the study, the scientists said the initial household member who experienced symptoms was considered the index patient in the research, while other household members may have been infected concurrently but developed symptoms at different times or remained asymptomatic.

However, the researchers believe the findings still underscore the potential for transmission from symptomatic or asymptomatic contact with household members and the importance of quarantine.

“Because prompt isolation of persons with COVID-19 can reduce household transmission, persons who suspect that they might have COVID-19 should isolate, stay at home, and use a separate bedroom and bathroom if feasible,” the scientists said.

“Isolation should begin before seeking testing, and before test results become available because delaying isolation until confirmation of infection could miss an opportunity to reduce transmission to others,” they wrote in the study.