SARS-CoV-2 households have a very high risk of infection

This article, “The risk of infection in SARS-CoV-2 homes is very high,” was originally published in Contagion Live.

The· SARS-CoV-2 According to a new study by a team of researchers in the United States, the risk of infection in individual homes is significantly higher, occurring early in the time when a person spreads the virus.

Survey results presented in IDWeek 2020It provides better properties of home infections, when research focuses primarily on local infections and prevention.

Investigators led by Carlos Grijalva, MD, and MPH, associate professor at Vanderbilt University Medical Center in Nashville, provided up-to-date information on ongoing assessments and shared data from 18 registered families. Home care and quarantine.

The median age of the proband was 37 and the household members were 27. Before symptoms appeared (median 4 days after the first sample was collected for testing), 83% of probands spent at least 4 hours in a room with at least one household member. After the onset of illness, the proportion was halved (44%).

More than half (53%) of non-indexed households were tested positive for the virus during follow-up, with a median of 4.5 days after the onset of index symptoms. Most secondary infections (72%) were detected within the first 3 days of follow-up.

These observations suggest that SARS-CoV-2 transmission is high in the home and that many infections were detected during the first few days of study follow-up.

In an interview with Contagion® During IDWeek, Griharva discussed his team’s findings, their impact on better understanding of SARS-CoV-2 infection risk setting, and what may come next in the study.

Contagion: What was the most imminent result of your team assessing SARS-CoV-2 home infections?

Guriharba: Our study showed that SARS-CoV-2 infection in the home was high, higher than previously reported, and could occur in both children and adults.

The proportion of probands who spend more than four hours in the same room as another household member is essentially halved after the onset of symptoms. How does this inform our understanding of the ability and willingness of self-isolating people following positive cases?

It is encouraging to observe that household members have reported attempts to reduce their exposure to sick household members. We believe that quarantine as soon as you get sick is an important strategy that helps reduce the chance of infection in your home.

What can we do from secondary infections detected early in the follow-up?

Rapid detection of household member infections indicates a high and rapid outbreak of SARS-CoV-2. The estimated secondary infection rate in our study appears to be higher than the rate reported in previous studies. We also observed substantial infections from probands, both children and adults.

What does our understanding of home infections mean in order to achieve an average SARS-CoV-2R0 of less than 1?

Proactive infection studies like ours help us understand how fast infections occur at home. The high infection rates observed in this study suggest that isolation of individuals as soon as they feel sick may help reduce the likelihood of infection at home.

What are your follow-up plans?

We are currently in the process of consolidating data from other US sites that are being evaluated for home infections. This is an ongoing multicenter study with additional households already enrolled and are in the process of testing samples and completing follow-up measures.

We will soon begin investigating the factors involved in the transmission of the infection and their evolution during follow-up. There are several more detailed reports currently under development / review, which will be published in the coming weeks.