Diagnosing the Disease
COVID-19’s manifestation in patients is now well-known, such as the loss of smell and the fact it is infectious before symptoms appear. HKUMed scholars have contributed to that understanding and are working to identify potential targets for treatment and vaccine.
- To detect COVID-19 virus in patients, we developed rapid nucleic acid amplification tests that were quickly circulated and, by mid-March, had been used by public healthcare laboratories in more than 70 countries and territories.
- We showed that deep throat saliva samples, especially if taken early in the morning, were highly sensitive and effective for diagnosis.
- Temporal profiles of the viral load in posterior oropharyngeal saliva samples and serum antibody responses in infected patients suggested that the load was highest near presentation and the serological assay could complement RT-qPCR for diagnosis.
- Viral load was also identified as a potential marker for assessing disease severity and prognosis, after a study of samples showed the viral load to be much higher in severe cases.
- The loss of the sense of smell was explored and a mechanism discovered that may explain this temporary symptom in patients. It was also shown that loss of smell is a common symptom and may, in some cases, be the only symptom. We also demonstrated that SARS-CoV-2 could infect and damage the olfactory sensory neuron of hamsters.
- The gastrointestinal effects of COVID-19 were found to be slightly more prevalent in children than adults, especially children aged under two years. This study provided further evidence that this may be a route of
infection. In addition, the enteric involvement of COVID-19 was verified in human intestinal organoids, an ex vivo human intestinal organ tissue culture model, and our golden Syrian hamster model.
- Based on evidence from Wuhan, the overall fatality rate of patients with symptoms was estimated to be about 1.4 per cent in a study published in March — well above the rate for seasonal flu. HKUMed scholars also
identified groups at greater risk of dying after developing symptoms, and of being infected.
- Auto-antibodies that attack the immune system were detected in more than one in 10 people who developed severe COVID-19, regardless of age and pre-existing medical conditions. The international study, which includes HKUMed scientists, found another 3.5 per cent of patients had genetic diseases called inborn errors of immunity. The findings explain why some patients suffer a more severe disease than others of the same age.