The COVID-19 outbreak has disrupted the lives of many all over the world. Cities have been locked down with healthcare workers working round the clock to care for patients. While there are those who unfortunately succumbed to the disease, there are also many others who recovered, thanks to the dedicated care and support of frontline healthcare workers.
Three months on, how have things changed? We speak to Infectious Diseases Specialists, Dr. Lam Mun San and Dr. Wong Sin Yew to find out more about the disease that still weighs heavily on our minds today.
Understanding the Virus
According to Dr. Lam, the genomic sequence of COVID-19 is 75% to 80% identical to the 2003 Severe Acute Respiratory Syndrome virus (SARS-nCOV) as well as several bat coronaviruses. The virus enters the lungs via a human enzyme called ACE2 and is spread through the respiratory tract. It is the same receptor as seen in SARS-nCOV, partially explaining why both conditions cause pneumonia-like symptoms.
When the condition first surfaced in late December 2019 to early January 2020, Dr. Lam mentioned that it is likely for COVID-19 to “behave like SARS-nCoV” since reports then showed that infected patients with mild or minimal symptoms contributed to ongoing transmission. True enough, clinical symptoms for COVID-19 patients later proved to include fever, cough and shortness of breath.
“The reports from the Ministry of Health1 said most infected patients in Singapore are stable and some have fully recovered from the illness,” added Dr. Wong. As of March 23 2020, 144 patients have been discharged.1 The elderly and people with underlying medical conditions are more prone to infection and severe outcomes.
Sustained Human-to-Human Transmission
There is evidence that shows a sustained human-to-human transmission, given the many exported cases across the globe. Early in the epidemic, human-to-human transmission of the COVID-19 virus was primarily occurring within families in China.
By mid-January 2020, data suggests that there was a substantial human-to-human transmission. Numerous reports from Vietnam, Germany, Taiwan, Korea and Japan have identified infected persons who had not travelled to China but had had contact with persons from China. Outbreaks were also reported in closed settings such as cruises, prisons, conferences, hospitals and aged care facilities with growing epidemics in other countries.
Transmission Through Droplets and Contaminated Hands
Similar to the common cold and influenza, COVID-19 primarily spreads through droplets such as from an infected person’s sneeze or cough. Infection may also occur if the person touches a contaminated surface such as a doorknob or lift button, and subsequently touches his or her eyes, nose or mouth with contaminated hands.
“Although anti-coronaviral therapies are still in development, public health measures such as strict isolation of infected cases, social distancing, quarantine of contacts, strict infection prevention and control measures will be critical in controlling the spread,” said Dr. Wong.
According to reports2 by the Imperial College researchers group at the World Health Organisation (WHO) Collaborating Centre for Infectious Diseases Modelling, the basic reproduction number for COVID-19 is 2.6; which means that each infectious case will “on average” transmit to 2.6 persons.
“Whether the transmission rate of 2.6 will continue, would depend on the intensive control efforts underway; and the epidemic will slowly end when the reproduction rate falls below 1,” shared Dr. Wong.
According to both Dr. Lam and Dr. Wong, there are still many unknowns about COVID-19 such as:
- Incubation period: The current working period has been “up to 14 days”, but more studies will need to be done to confirm a more accurate range.
- Infectivity: It is still uncertain if patients are “infectious” during the incubation period. There have also been reports that patients with mild symptoms may be infectious, but these would need to be further examined.
- The animal reservoir: Due to its close similarity to several bats-associated coronaviruses, bats are postulated to be the likely primary reservoir. Whether there is another animal reservoir before it jumped species to human infection, is still under investigation.
Now, we can channel our concerns into actions to protect ourselves, our loved ones and our communities. More importantly, spare a thought for those who have been infected. With infections, people always face discrimination. The pandemic is still evolving, and the situation is fluid. Around the world, many have to deal with travel restrictions because of the “lockdown”.
“We hope that this pandemic will end soon and normalcy will return,” said Dr. Lam.
1 Ministry of Health. 2020. Updates on COVID-19 local situation.
Retrieved from: https://www.moh.gov.sg/covid-19
2 Imperial College London. 2020. Report 3: Transmisibility of nCOV-2019. MRC Centre for Global Infectious Disease Analysis.
Retrieved from: https://www.imperial.ac.uk/mrc-global-infectious-disease-analysis/covid-19/report-3-transmissibility-of-covid-19/