(CNN) – As coronavirus cases are surging across the United States, a new survey suggests many people who contract the virus have no idea where they caught it.
A survey by the Centers for Disease Control and Prevention shows only 45% of COVID-19 patients studied in nine states knew they had been in contact with someone who had the virus.
Most often when the patient did know, it was a family member or work colleague.
The in-depth survey of 350 patients also showed that those needing hospital treatment – about a quarter of the patients – were more likely to be older, have more underlying chronic health conditions and were less likely to be white than those who did not need hospital care.
In addition, these sicker patients were also more likely to have an annual household income of $25,000 or less and were less likely to be employed.
The CDC says the research highlights the need for increased screening, case investigation, contact tracing and the isolation of those infected.
The agency continues to endorse prevention measures like social distancing and face coverings.