More than half of people with COVID-19 have no idea how or where they got infected – underscoring the need for social distancing, more widespread use of masks and better contact tracing, especially at work.
That is the conclusion of a new survey by the Centers for Disease Control, released Tuesday, of 350 patients in nine states treated at 11 academic medical centers, including Stanford University and UC Los Angeles.
It found that 54% of patients were unaware of recent close contact with a COVID-19 patient.
Of patients who knew the source of their illness, 45% said they were likely infected by close contact with a sick family member, 34% by a work colleague and 10% by a friend. Others said they were exposed in a health care setting, assisted living facility, correctional facility, or by a neighbor or client at work.
Until now, reports about sources of exposure to the COVID-19 virus have been focused on so-called congregate settings, such as meat and poultry processing plants and long-term care facilities. And these reports focused primarily on patients who were so sick that they required hospitalization.
This new survey, conducted by phone, is seen as a much more representative snapshot of the individual behaviors and demographic characteristics of a patients in the general population, both inpatient and outpatient.
Approximately two-thirds — 64% — of these patients were employed. Of these, only 17% worked remotely, through “telework.”
“The need for enhanced measures to ensure workplace safety, including ensuring social distancing and more widespread use of cloth face coverings, are warranted,” the CDC report concluded.
The new findings come at a time of surging infections in many states, including California, as counties begin reopening and testing is expanded.
While a bump in cases was expected, ”few expected it to be so fast and widespread,” said Dr. Robert Wachter, chairman of UC San Francisco’s Department of Medicine.
The CDC report is based on telephone surveys of a sample of patients with positive COVID-19 test results between April 15 and May 24 who were either hospitalized or received outpatient care. They were asked about exposure — defined as being within six feet of someone with a COVID-19 diagnosis — during the two weeks before their positive test result or illness.
The average age of outpatients was 42, while the average age of inpatients was 54. Inpatients were less likely to be white and more likely to have an annual household income of less than $25,000. Inpatients also had more underlying chronic conditions, such as cardiovascular disease, chronic respiratory disease or diabetes.
About one-third of sick people seen as outpatients reported that their health had still not returned to normal two to three weeks after testing positive.
Patients described a broader range of symptoms than previously described, including not just shortness of breath, fever and cough — but also chest pain, abdominal pain, nausea, vomiting, diarrhea, confusion, fatigue and loss of smell or taste.
“The wide range of symptoms reported, and the lack of known COVID-19 contact in 54% of patients,” according to the report, “underscores the need for isolation of infected persons, contact tracing and testing during ongoing community transmission, and prevention measures including social distancing and use of cloth face coverings.”