September 2 coronavirus news

It's been almost five months since Shelby Hedgecock tested positive for Covid-19, and the former personal trainer said her symptoms are still debilitating.

Hedgecock is among patients who call themselves "long-haul survivors" -- those who experience symptoms long after testing positive. And long-term effects like theirs need to be taken seriously, a doctor researching these symptoms told CNN on Monday night.

Covid-19 can be a prolonged illness, even among young adults without underlying chronic medical conditions, the US Centers for Disease Control and Prevention reported in July. Some 35% of patients surveyed by the agency said they still weren't back to their usual good health even two to three weeks after testing positive for the disease. The rest said they'd returned to their usual state of health five to 12 days after a positive test.

Hedgecock first tested positive in April. And though she tested negative in May, she is still having neurological issues, cognitive issues, shortness of breath, chest pain, loss of smell and body aches and pains that send her to her bed for days if she participates in even gentle yoga, she told CNN.

Hedgecock's experience is not unique, Li said. His team is looking to connect the symptoms, with data pointing to the virus not just affecting the lungs but the blood vessels that connect the whole body, the doctor said.

"We think that this long-term damage may in part be due to vascular damage, kind of a footprint that the virus leaves even when it's gone from the body," Li said.

Read more:

RELATED

The US needs to talk about long-term coronavirus symptoms, a doctor and a patient say

Covid-19 patients may need to wait over a month before being retested to know whether they have cleared the virus, and one in five negative test results could be false, according to research published Tuesday in the British Medical Journal.

Dr. Francesco Venturelli of the University of Modena and Reggio Emilia and colleagues studied 1,162 patients in the Reggio Emilia Province of Italy who tested positive for Covid-19 using a polymerase chain reaction (PCR) test.

Patients were retested around 15 days after their first test, 14 days after their second and nine days after their third. The researchers set these time intervals in accordance with European Centre for Disease Control and Prevention recommendations.

About 60.6% of the patients who recovered tested negative for Covid-19 by their first follow-up test. Another test confirmed that negative result in just 78.7% of these patients, which the team says suggests about one in five negative tests are false negatives. They say this could mean that many are still shedding the virus after testing negative and unknowingly passing it on to others. 

The researchers determined a patient had cleared the virus once they tested negative on two consecutive PCR tests. Overall, it took about 30 days from diagnosis and 36 days from the onset of symptoms for patients to clear the virus.

It took slightly longer for older patients and those with more severe disease to clear the virus. The length of time increased from 35 days for those under 50 years old to 38 days for those over 80. Non-hospitalized patients took about 33 days, while hospitalized patients took about 38 days.

By 34 days after patients first noticed symptoms, nearly 87% of them tested negative. This suggests patients may need to wait a month or longer to determine whether they have truly cleared the virus, the researchers said.

The team notes that understanding the timing of viral clearance is key to determining testing strategies and ensuring people don’t have to spend unnecessary time in isolation. The say that postponing the follow-up testing of those who are no longer experiencing illness or symptoms could increase the efficiency and performance of testing strategies.