Press Releases

            Washington—Senator Dianne Feinstein (D-Calif.) sent a letter to the Center for Disease Control and Prevention calling on the agency to develop coronavirus testing guidelines that will help identify presymptomatic and asymptomatic cases. These cases present a high risk of spread in congregate settings, and challenges with their detection must be addressed as states reopen.

            “Across the country, outbreaks are becoming more common in workplaces and residences where people interact in close proximity to each other, such as nursing homes, food processing plants, prisons, and homeless shelters.  Given how easily this virus spreads and that otherwise healthy-seeming individuals could be unintentionally infecting others, we must expand our efforts to detect presymptomatic and asymptomatic carriers in these higher risk settings,” wrote Feinstein.

            “As we continue to prepare for a second wave of infections, national guidelines are needed to account for these individuals, especially those living and working in higher risk congregate settings.”

            Full text of the letter is available here and below.

June 5, 2020

Dr. Robert R. Redfield
Director
Centers for Disease Control and Prevention
1600 Clifton Road, Atlanta, Georgia 30329

Dear Dr. Redfield:

            I write to ask that the Centers for Disease Control and Prevention (CDC) publish detailed guidelines on testing individuals working or residing in congregate settings in order to ensure there is a comprehensive national approach to detecting presymptomatic and asymptomatic carriers of coronavirus.

            According to a recent study published in the Proceedings of the National Academy of Sciences, the novel coronavirus is so easy to spread that simply talking can cause airborne transmission of the virus in confined environments.  After exposure, presymptomatic individuals may be unknowingly spreading the virus to others until symptoms show, which is typically five days later.  

            New research is also finding that asymptomatic carriers may be more prevalent than previously estimated.  In fact, a recent study published in The Journal of the American Medical Association found that out of 78 patients tested in Wuhan, China, 42% were asymptomatic.  A separate study published in the medicine journal Thorax found that after an outbreak occurred on a cruise ship, approximately 80% of passengers who tested positive for the virus showed no symptoms.

            Across the country, outbreaks are becoming more common in workplaces and residences where people interact in close proximity to each other, such as nursing homes, food processing plants, prisons, and homeless shelters.  Given how easily this virus spreads and that otherwise healthy-seeming individuals could be unintentionally infecting others, we must expand our efforts to detect presymptomatic and asymptomatic carriers in these higher risk settings.

            We have seen how this policy can be effective at minimizing coronavirus transmission in congregate settings.  Namely, a study published in the CDC Morbidity and Mortality Weekly Reports found that testing residents regardless of symptoms helped contain an outbreak in a long-term care facility for veterans in Los Angeles.  Similarly, in a study published in the New England Journal of Medicine, researchers found that more than half of infected residents of a nursing home in Washington State were asymptomatic at the time they were tested, so focusing only on symptomatic residents was not sufficient to prevent transmission. 

            Presymptomatic and asymptomatic carriers are likely playing a significant role in why the virus is continuing to spread so easily, and continuing to only test individuals after symptoms appear is likely too late to effectively contain outbreaks.  As we continue to prepare for a second wave of infections, national guidelines are needed to account for these individuals, especially those living and working in higher risk congregate settings. 

            Thank you for your consideration, and I look forward to your response.

Sincerely,

Dianne Feinstein
United States Senator

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