Infectious Disease Physician
Dr Leong Hoe Nam is an infectious disease specialist practising at Mount Elizabeth Novena Hospital, Singapore. He had first-hand experience managing infectious diseases such as the Severe Acute Respiratory Syndrome (SARS) coronavirus and the Influenza A (H1N1) virus. Here’s what he says about the novel coronavirus in his Facebook Live interview with ONE FM 91.3.
The COVID-19, also known as SARS-CoV-2, is a coronavirus like the Middle East Respiratory Syndrome (MERS) and SARS coronaviruses. However, it is distinct from SARS – this means that even if you have been exposed to SARS previously, you can still get the novel coronavirus.
The SARS-CoV-2 is highly pathogenic (causes illness), virulent (has harmful effects) and spreads very quickly. Originating from Wuhan city, China, infections have now been reported around the world. There is reason to believe that the novel coronavirus may have its origins in bats or pangolins, before spreading between humans. The exact source is still unclear.
Symptoms of the virus include:
Transmission of the COVID-19 virus happens via droplets and contact. There is a possibility of airborne transmission, however there is limited consensus on how infectious this mode of transmission may be.
Airbone: Evidence shows that small, fine droplets can remain suspended in the air up to 3 hours. The risk of transmission would be greatest within 2m of an infected person, where the concentration is greatest, and diminishes with distance. Airborne exposure would also be affected by factors such as airflow and environmental factors such as temperature, humidity and exposure to sunlight.
Droplets: A person can get infected through the spit of an infected person landing on them (within 2m)
Contact: A person can get infected through touching a surface (eg. a door handle or table) with infectious secretions. In both cases, one can be infected by the virus coming in contact with his eyes, nose or mouth.
It is still uncertain how quickly the coronavirus spreads between humans. The chances of the virus spreading through transient contact with an infected person are low (eg. walking past someone, touching someone briefly and washing hands afterwards). However, prolonged close contact with an infected person may increase the chances of the virus spreading. For instance, being in close proximity with an infected person who is an exuberant speaker for an extended amount of time in an air-conditioned room.
Significantly, recent scientific data suggests that transmission may occur prior to the onset of symptoms. We call these pre-symptomatic or asymptomatic transmission.
There is currently no cure for COVID-19 but there are safe and effective vaccines available. The Pfizer BioNTech and Moderna COVID-19 vaccines are both approved by the HSA for use in Singapore under the Pandemic Special Access Route (PSAR).
The Pfizer BioNTech vaccine is approved for children aged 12 years and above while the Moderna vaccine is approved for individuals 18 and above.
The Sinovac vaccine is also approved for use under the Special Access Route, hence it is not subsidised and may only be administered by private healthcare providers to individuals who wish to have it.
Learn more about the COVID-19 vaccine here.
Currently, the treatment for infected individuals is supportive care. This means that the virus symptoms are managed by providing good nutrition and hospital care to let the patient recover. This is likely to work for a vast majority of patients. While more information needs to be gathered, Dr Leong surmises that the recovery period for patients can take at least 10 – 14 days.
Scientists are working on developing a cure for the virus. While there are ongoing studies on using HIV treatment to treat the virus, these are still undergoing trials and deemed experimental. Drugs like remedesivir and favipiravir are currently on trial to demonstrate effectiveness. The drug hydroxychloroquine has been proven ineffective in patients with COVID-19.
Here are some other questions about the virus that you may have, as answered by Dr Leong:
Dr Leong: You should wear the blue and white surgical masks. The plain white masks are very thin compared to the blue and white surgical masks, which have 3 layers. The first outer layer is for general protection against spills. The second layer acts as a filter, and the inner layer is for your comfort when you wear the mask.
While the N95 mask works as a protection measure as well, I would discourage people from wearing it. This is because wearing the N95 mask can cause a lot of discomfort, and you may end up touching your face a lot as you adjust the mask, which should be avoided.
Face masks should be used in public and community settings while surgical or medical masks should be used in clinical settings where you may be exposed to an infected or potentially infected individual, including visits to clinics and hospitals.
Dr Leong: When wearing a mask, the blue side of the mask should be facing the outside, and the white side facing inside. There is no reason to wear it the other way round – doing so may trap things within the folds on the blue side.
Strap the sides over your ears first. Next, pull the top of the mask up to cover your nose, and ensure that the bottom of the mask covers below your chin. Thereafter, pinch the metal piece on your nose bridge to ensure the mask doesn’t slip from your face.
However, if your mask is relatively clean and dry after use, you can take it off and put it into a sealable bag, to be reused again.
At the end of the day, I would encourage you to discard it once it has been used. When disposing of your mask, make sure to wrap it up with a tissue paper or bag, to ensure that germs on the mask do not spread to other surfaces.
Dr Leong: If you have to visit a clinic, make sure you wear a mask and wash your hands with soap and water. Avoid touching your face.
Dr Leong: If you look at the fecal matter of bats, there are thousands of coronavirus. No one knows which strain will go pandemic. Even if vaccines are prepared for all the coronavirus strains, the viruses can mutate easily and turn into a completely new virus, rendering the vaccines useless. It is also nearly impossible to predict how these viruses will mutate.
Watch Dr Leong’s interview with ONE FM 91.3 in full.