Serious symptoms after negative test, doctors say it may be swab, viral load

Greater Noida: At least three persons who had tested negative for Covid-19 in RT-PCR test had to be later admitted to Sharda Hospital as they exhibited serious symptoms of the disease.
Two of these patients — who were admitted about 10 days ago and have now recovered — were treated in the ICU of the hospital as they showed serious symptoms.
Doctors studying the three cases see two reasons why the RT PCR tests were negative — low levels of the virus in the swab samples and an error in taking the nose/throat swabs. The symptoms manifested only when there was an infection in the lower respiratory tract.
Dr Shivendra Kasana, a consultant in the department of critical care medicine at Sharda, said the three patients had come to the hospital with symptoms of pneumonia, fever and cough even after testing negative. “They had come to us in a critical condition and with very low oxygen saturation levels. Two of them had to be put in the ICU as they required a non-invasive ventilator. They recovered well,” Dr Kasana said. The doctor added that antibody tests done later on these patients came positive.
“This indicates that the body had an infection earlier,” Dr Kasana said. He pointed out that RT PCR test results could be inaccurate if there was a fault in collecting the nasopharyngeal swab or if the patient had a low viral load.
Dr DK Gupta, the director of Child PGI in Sector 30, agreed with Dr Kasana. “We also had three cases where the test results had come negative but the individuals were treated as Covid patients here because they showed symptoms. Their repeat testing with swabs taken from both the nasal and throat sites showed they had Covid-19,” Dr Gupta said.
Dr RK Gupta, director of Government Institute of Medical Sciences, said, “Results also depend on which stage of incubation a person is getting his test done. If the test is done in an extreme symptomatic condition, it will definitely come positive. Otherwise, the result will turn negative.”