COVID-19 Roundup: CDC Updates Isolation Guidelines; Lingering Heart Issues; and FDA Approves New Antibodies Test

CDC: Most No Longer Infectious With COVID-19 Ten Days After Symptom Onset

Mounting evidence is indicating that most people remain infectious with COVID-19 for no longer than 10 days after they started having symptoms, public health officials say.

Now, the U.S. Centers for Disease Control and Prevention (CDC) has revised its guidelines: People confirmed with with mild to moderate COVID-19 symptoms, which is “most persons with COVID-19 illness,” can leave their isolation after 10 days — without receiving a negative test.

“For most persons with COVID-19 illness, isolation and precautions can generally be discontinued 10 days after symptom onset and resolution of fever for at least 24 hours, without the use of fever-reducing medications, and with improvement of other symptoms,” the CDC states.

The CDC adds that “persons with more severe to critical illness, or severe immunocompromise, likely remain infectious no longer than 20 days after symptom onset.”

Within the revised guidance, the CDC is discouraging people from getting tested a second time after they recover.

For people who have tested positive but don’t have symptoms, “isolation and other precautions can be discontinued 10 days after the date of their first positive RT-PCR test for SARS-CoV-2 RNA,” the CDC says.

The CDC states that small virus particles have been found in patients up to three months after the onset of symptoms. But those particles have not been shown to be capable of transmitting the disease.

Heart Muscle Inflammation Seen Two Months After Recovery From COVID-19, Study Finds

People who recover from COVID-19 may have lingering inflammation of the heart muscle, or other heart issues, at least two months after being diagnosed, even if their condition did not require hospitalization, a new study out of Germany indicates.

The study, published in the journal JAMA Cardiology, involved 100 adults, ages 45 to 53, who had recently recovered from COVID-19 in Germany. About one-third of participants required hospitalization, while the rest were able to recover at home. MRI scans were taken more than two months after tested positive. About three-quarters of these patients showed signs of heart abnormalities, including inflammation of the heart muscle, or myocarditis.

Many patients also were diagnosed with some levels of troponin, a protein in their blood. Troponins are proteins in the cardiac and skeletal muscles. When the heart is damaged, it releases troponin into the bloodstream. Doctors measure your troponin levels to detect whether a patient is suffering a heart attack.

The researchers, however, are not certain what their findings mean for patients’ heart health in the long term after recovering from COVID-19. The heart issues observed in the study occasionally occur with respiratory diseases, such as influenza, and could be temporary. Mild cases of heart inflammation may not show symptoms and often improve on their own, says the National Heart, Lung and Blood Institute.

“These findings indicate the need for ongoing investigation of the long-term cardiovascular consequences of COVID-19,” the German researchers concluded.

FDA Authorizes First Tests That Estimate Quantity of Antibodies in Person with COVID-19

The U.S. Food and Drug Administration (FDA) has authorized the first two COVID-19 blood tests that produce an estimate of the quantity of antibodies in the blood of a person who has been infected with the coronavirus.

The two “semi-quantitative” tests, developed by Siemens Healthineers — the ADVIA Centaur COV2G and Atellica IM COV2G — provide only estimates, not precise measurements of the number of antibodies produced by COVID-19, the FDA emphasizes in its news release.

“There are still many unknowns about what the presence of SARS-CoV-2 antibodies may tell us about potential immunity, but today’s authorizations give us additional tools to evaluate those antibodies as we continue to research and study this virus,” stated Tim Stenzel, M.D., Ph.D., director of the Office of In Vitro Diagnostics and Radiological Health in the FDA’s Center for Devices and Radiological Health. “Patients should not interpret results as telling them they are immune, or have any level of immunity, from the virus.”

Because of these unknowns, the FDA cautions patients against using the results from these tests “as an indication that they can stop taking steps to protect themselves and others, such as stopping social distancing, discontinuing wearing masks or returning to work.”