WebMD Health News

COVID-19 & Household Spread: How Likely?

photo of group of people

April 30, 2020 --"It was the one thing I was hoping wouldn't happen, and now it has."

Those were the words of CNN anchor Chris Cuomo, talking on air in mid-April with his brother, New York Gov. Andrew Cuomo, as he was quarantined at home with COVID-19 and hoping he wouldn't spread it to the rest of his family.

But he had — his wife, Cristina, tested positive, and then their son Mario,14, also contracted it. The parents have been cleared and are recovered, and Mario is recuperating. Cuomo's fear of spreading the coronavirus to the rest of the family is shared by legions of patients, especially those whose illness is not serious enough for hospitalization and are isolating themselves at home.

According to a new study, fear of transmission to household members is realistic, says Yang Yang, PhD, associate professor of biostatistics at the University of Florida, who led the research to evaluate how commonly patients transmit COVID-19 to close contacts.

His team estimates that more than 19% of people in the same household as a COVID-19 patient, or nearly 1 in 5, can expect to develop the infection. An estimated 14% of close contacts who aren't in the same household but see the patient regularly will also develop the infection themselves, Yang says.

The researchers calculated the risk by using patient information on 212 ''primary" patients, 137 close contacts who developed COVID-19 and 1,938 uninfected close contacts, all in Guangzhou, China. To arrive at the estimates of risk, they also used a statistical model to account for all the differences in exposure level, Yang says, such as whether a household had one person ill or two. The researchers assumed an average incubation period of 4 days and a maximum infectious period of 13 days.

One of the most surprising findings, Yang says, is that ''the infectivity is pretty high during the incubation period, when the patient didn't show any symptoms. The infectivity rate is as high during the asymptomatic period as during the symptomatic period."

Even before the patients' isolation period, ''there was a lot of transmission,” Yang says.

The researchers conclude that SARS-CoV-2, the official name for the coronavirus that causes COVID-19, is more transmissible in households than either SARS or MERS, and that those age 60 and above are the most vulnerable to contracting COVID-19 from family members or roommates.

The study was published as a pre-print in medRxiv and has not yet been peer-reviewed.

One Family's Story

The fear of passing on COVID-19 to family members can be terrifying, as Heidi Horsley, PsyD, a psychologist in New York City and adjunct professor at Columbia University's School of Social Work, now knows well.

In mid-March, Horsley and her daughter Samantha Jing, 15, flew from New York to their home in Tucson, AZ, on Saturday, March 14, joining her husband Markus Redding, 60, and son Alexander Redding, 21, who were already there.

By Monday, she noticed a ''weird pain in the back of my head, and by Tuesday morning I had classic symptoms, everything but the fever.'' She felt like she had the flu, and then the fever set in. Like others, she reported that her sense of smell and taste went away. She got tested March 20 and found out 2 days later she was positive.

"They said, 'Go to your room for 14 days,''' she recalls."My husband would bring food outside the door." She would eat and then try to wash the utensils in the adjacent bathroom, then leave them outside the door again.

She worked on her computer, talked to her family through the door, and kept hoping no one else would become infected. Her husband ordered food for delivery or neighbors would bring supplies and leave them on the driveway, she says. "We were told our family should not leave the house." They followed those instructions to the letter, she says.

"There is a lot of shame and guilt" worrying about spreading COVID-19, Horsley says. "My biggest fear was that I gave it to people unknowingly and to my family." She worries about the people she was close to at the airport, on the plane and in the terminal before arriving in Tucson, fearing she unknowingly exposed people.

They isolated for 3 weeks instead of the recommended 2, and Horsley says nearly all her symptoms disappeared a few days ago. Her sense of taste and smell is still not normal, however. So far, everyone is healthy, she says, although her husband became extremely fatigued, got lightheaded and had a sore throat, but now feels better.  "Maybe he was just run down," she says, citing the pressure of taking care of her, their son and daughter and handling all the household duties. Mild cases of coronavirus, however, are consistent with what her husband was going through.

Expert Guidance on Patients at Home

According to the CDC, when a COVID-19 patient is recovering at home, the person should stay in one room, away from everyone, as much as possible, wear a face mask if around others and use a separate bathroom if possible.

Personal items such as dishes, towels and bedding should not be shared. Household members who wash the laundry of the patient should wear disposable gloves and avoid contact with the items as much as possible.

WebMD Health News Reviewed by Michael W. Smith, MD on April 30, 2020

Sources

CNN: Cuomo Prime Time, April 15, 2020.

CNN.com: "Cristina Cuomo, wife of CNN anchor Chris Cuomo, is now diagnosed with coronavirus." April 15, 2020.

Yang Yang, PhD, associate professor of biostatistics, University of Florida at Gainesville.

MedRxiv:"Household Secondary Attack Rate of COVID-19 and Associated Determinants," April 11, 2020.

Heidi Horsley, PsyD, psychologist and adjunct professor, Columbia University School of Social Work.

CDC: "Caring for Someone at Home." April 15, 2020.

© 2020 WebMD, LLC. All rights reserved.