CDC Update: Estimate of Asymptomatic COVID-19 Carriers Increased to 40%
Asymptomatic coronavirus carriers, or those who do not experience any symptoms, unknowingly contribute to the spread of COVID-19, infectious disease experts say. Now the U.S. Centers for Disease Control and Prevention (CDC) has issued new guidance  that raises the estimate of asymptomatic carriers to 40 percent of people who have COVID-19.
Previously, the CDC estimated asymptomatic carriers at 35 percent, a figure reported in late May. The agency concedes that “asymptomatic cases are difficult to identify and transmission is difficult to observe and quantify.”
The CDC had estimated that the chance of transmission of COVID-19 from asymptomatic people was 100 percent. But that figure has been revised downward this month to 75 percent. That means that the CDC now says asymptomatic individuals are less likely to transmit infection, compared to symptomatic individuals who have a 100 percent chance of transmission.
Children have been identified as having a lower risk of suffering serious illness and death from COVID-19, the CDC says. But they can function as asymptomatic carriers of the virus and can pose risks to vulnerable, older adults, the agency says.
Jerome Adams, the U.S. Surgeon General, said that the U.S. could rebound from the current spikes in COVID-19 positive cases in two to three weeks if “everyone does their part” by following official orders or guidance that include social distancing and the regular use of faces masks or face coverings.
U.S. Mask Usage Varies Widely, Different Surveys Find
A majority of U.S. adults used cloth face-coverings after the federal government recommended them as a primary way of slowing the community spread of COVID-19, said the U.S. Centers for Disease Control and Prevention (CDC) in survey results  released this week.
The CDC looked at data taken from more than 800 adults in two Internet surveys in April and May. The survey participants reported going outdoors in the past week. The results showd that 62 percent of people reported using cloth face-coverings when they left home. And that figure jumped to 76 percent a month later.
The use of face coverings increased in May across socio-demographic groups. The largest increases were among non-Hispanic Whites (54 perent to 75 percent), people older than 65 years (37 percent to 79 percent), and those living in the Midwest (44 percent to 74 percent).
High rates of use were reported during both time periods among African-Americans (74 percent to 82 percent), people aged 18–29 years (70 percent to 76 percent) and aged 30–39 years (74 percent to 84 percent), and residents of the Northeast (77 percemt to 87 percent).
The CDC concluded that: “Research among persons who report not wearing a cloth face covering while in public is needed to understand potential barriers and to shape services or messages that would facilitate and encourage adoption of this recommendation.”
A separate recent survey by U.S. analytics firm Gallup, taken June 22-28, also found that 54 percent of Americans say they are worried about the lack of social distancing in their community. Gallup also found that 86 percent of U.S. adults said they have worn a mask in public in the past week.
However, the Gallup survey also found that only 44 percent of respondents reported they “always” wore a mask or face covering. Three in 10 reported wearing a face covering less often: 11 percent “sometimes;” 4 percent “rarely;” and 14 percent “never.”
Fatigue, Shortness of Breath Lead List of Lingering Symptoms, Researchers Say
There are increasing reports of long-lasting effects, or lingering symptoms, in some recovered COVID-19 patients who have been discharged from acute care, a new study indicates.
In a research paper published in the Journal of the American Medical Association , Angelo Carfi, M.D., and colleagues in Rome, Italy found that 87 percent of 143 previously hospitalized patients had at least one lingering symptom — particularly fatigue and shortness of breath — after more than a month following discharge from a hospital.
Post-discharge testing was conducted from April 21 to May 29. Among the results:
- Just 12.6 percent of the 143 patients were completely free of any COVID-19 symptoms
- 32 percent of patients had one or two symptoms and 55% had three or more
- None had fever or other signs and symptoms of acute illness
- 53 percent of patients still had fatigue, 43 percent had dyspnea (shortness of breath), 27 percent had joint pain, and 22 percent suffered chest pain
- 44 percent reported a worse quality of life following discharge, compared to life before COVID-19.
The researchers concluded: “Clinicians and researchers have focused on the acute phase of COVID-19, but continued monitoring after discharge for long-lasting effects is needed.”