Asymptomatic Covid-19 Patients May Develop Clinical Abnormalities: Expert

About 40-50% of Covid-19 patients in Malaysia are asymptomatic upon testing positive; half of these are truly asymptomatic throughout the course of disease, says Dr Lee Heng Gee.

KUALA LUMPUR, March 2 — Approximately half of asymptomatic Covid-19 patients are inclined towards clinical abnormalities, such as in their lungs, according to an infectious disease specialist.

Dr Lee Heng Gee, who is currently working in the Infectious Disease Unit in Queen Elizabeth Hospital, Sabah, stated that about 40 to 50 per cent of Covid-19 patients in Malaysia are asymptomatic upon testing positive.

“About half of these asymptomatic patients are truly asymptomatic, which means they remain truly asymptomatic throughout the course of the disease,” Dr Lee said in a webinar last month organised by the Institute of Clinical Research Malaysia. 

Dr Lee stated that the other half of these asymptomatic patients are pre-symptomatic. This means that they can develop symptoms after the initial diagnosis of the coronavirus by rapid antigen rapid test kits (RTK-Ag) or RT-PCR tests. 

“Usually these types of patients will be identified during contact tracing or travel screening. Later, after two to three days, they can develop symptoms.

“But the most important thing about the asymptomatic infection is people without symptoms can still have clinical abnormalities as evidenced by abnormal CT scans,” Dr Lee added. 

Literature reviews based on few studies stated that half of the asymptomatic Covid-19 patients had ground-glass opacities (GGO) or hazy lung shadow during CT scan. GGO can be a sign for a variety of underlying health conditions, including infection, chronic interstitial disease and acute alveolar disease.

Another study in Shenzhen, China, showed that 67 per cent from 55 asymptomatic Covid-19 patients had pneumonia on admission based on the CT scan, where only two patients developed hypoxia, and the rest recovered.

Besides that, a study conducted in Wanzhou district in China last year showed that three asymptomatic Covid-19 patients had lymphopenia and one had thrombocytopenia from a total of 37 asymptomatic patients.

Lymphopenia is a condition where the blood has low levels of lymphocytes, or white blood cells, whereas thrombocytopenia is a situation with low blood platelet count.

Of the 37 patients, six had an increase in alanine aminotransferase (ALT) levels. Usually the ALT level in blood increases when the liver is damaged. Some even had abnormalities in one or both lungs, the study stated.

According to Dr Lee, older patients, or people of any age with underlying health conditions, have a high tendency to be affected by severe Covid-19 disease. Post ICU Syndrome (PICS) occurs among patients who receive treatment in the intensive care unit (ICU) for critical illness.

According to the National Institute of Health in the United States, PICS is the disability that remains in ICU patients after recovery, which includes neuromuscular weakness, reduced cognitive ability (thinking and judgment), or fragile mental health.

“This impairment persists beyond the ICU hospitalisation for as long as five to 15 years,” Dr Lee said. “Those patients at risk of PICS have sepsis, delirium, prolonged mechanical ventilation and multiorgan failure.” 

Being admitted into ICU comes with potential long term complications, he said. 

Dr Lee emphasised the importance of correlating clinical findings with phases or stages of Covid-19, which is the key to recognise post Covid-19 treatments including collaborative measures with rehabilitation, psychiatry and family medicine. 

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