We’re learning more about the COVID-19 coronavirus every day. What one research team recently discovered is that the virus sticks around even after the symptoms have abated. Worse yet, those patients may still be contagious.
A new study revealed that half of the patients treated by one research team for mild cases of COVID-19 had lingering cases of the coronavirus. Their post-symptomatic positive tests surprised researchers and may throw a wrench into what we think we know about the disease.
In a research letter published online in the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine, the team said the virus lingered in some of the post-symptomatic survivors for up to eight days.
In “Time Kinetics of Viral Clearance and Resolution of Symptoms in Novel Coronavirus Infection,” Lixin Xie, MD, Lokesh Sharma, PhD, and co-authors report on a study of 16 patients with COVID-19, who were treated and released from the Treatment Center of PLA General Hospital in Beijing between January 28 and Feb. 9, 2020. Patients studied had a median age of 35.5 years.
Patients in the study had been discharged after recovering from COVID-19 and testing negative in at least two consecutive polymerase chain reaction (PCR) tests. The researchers then collected throat swabs from the patients on alternate days and analyzed them.
“The most significant finding from our study is that half of the patients kept shedding the virus even after resolution of their symptoms,” said co-lead author Dr. Sharma, instructor of medicine, Section of Pulmonary, Critical Care & Sleep Medicine, Department of Medicine, Yale School of Medicine. “More severe infections may have even longer shedding times.”
The patients’ primary symptoms were typical for most COVID-19 cases. They included a cough, fever, dyspnea (labored or difficult breathing) and pharyngalgia (pain in the pharynx.) The drug therapies used to treat the virus varied by patient.
All but one of the patients had developed symptoms within the median incubation period of 5 days. Two of the patients were diabetic and one had tuberculosis. Neither of these comorbidities impacted the length of time the patients were symptomatic for COVID-19. Symptom duration averaged eight days for the group, with their post-symptomatic contagious periods ranging from one to eight days.
“If you had mild respiratory symptoms from COVID-19 and were staying at home so as not to infect people, extend your quarantine for another two weeks after recovery to ensure that you don’t infect other people,” recommended corresponding author Lixin Xie, MD, professor, College of Pulmonary and Critical Care Medicine, Chinese PLA General Hospital, Beijing.
The authors had a special message for the medical community: “COVID-19 patients can be infectious even after their symptomatic recovery, so treat the asymptomatic/recently recovered patients as carefully as symptomatic patients.”
They also pointed out that the study was small and all of the patients in question had mild symptoms of infection and appeared to fully recover from the virus. They indicated that it’s possible the results would be different in more vulnerable patients. These would include the elderly and patients on immunosuppressive therapies or whose immune systems were otherwise impaired or suppressed.
“Further studies are needed to investigate if the real-time PCR-detected virus is capable of transmission in the later stages of COVID-19 infection,” Dr. Xie added.
So it seems that even after you beat this thing, it doesn’t want to go away. More serious, though, is the potential public health risk associated with this finding. More research is needed, and quickly.
Keep the faith and keep after it!
Journal Reference – De Chang, Guoxin Mo, Xin Yuan, Yi Tao, Xiaohua Peng, Fusheng Wang, Lixin Xie, Lokesh Sharma, Charles S Dela Cruz, Enqiang Qin. Time Kinetics of Viral Clearance and Resolution of Symptoms in Novel Coronavirus Infection. American Journal of Respiratory and Critical Care Medicine, 2020; DOI: 10.1164/rccm.202003-0524LE