A lesson from Hong Kong
The way forward to the near-future in which the world has to live with the new coronavirus is clearly shown by SARS-buster Prof. Malik Peiris, Professor of Virology at the School of Public Health, Hong Kong University.
What is next, he asks, after explaining the strong measures taken in Hong Kong, a combination of social distancing, aggressive diagnosis, contact tracing and quarantining/isolation to bring the outbreak under control.
“The case numbers are very low but we cannot maintain this extent of social distancing because even though we are not in lockdown it is still hurting the economy quite dramatically. From next week
Hong Kong will gradually begin to relax some of these measures. But, I think we all fully understand that this is a disease, this is a problem that will not go away,” he says.
Reiterating that it is not a ‘sprint’ but a ‘marathon’, Prof. Peiris points out that the only way this outbreak will come under complete control is when the population has sufficient immunity to the virus, which means about 50% or more of the population. The only way you will get immunity is either through natural infection which will be terrible or vaccination and we know that a vaccine is still well over one year away.
“We have to make a long-term effort to keep this outbreak under control. So there is ‘no back to normal’ that we can think about, but we have to try to relax,” is his message.
Comparing the situation to being at the top of a steep hill, Prof. Peiris says that if you imagine that there is calm at the top, you still have to get to the bottom of the hill. The only way to do so is applying the brakes and releasing the brakes in a graded process so that the car doesn't go out of control…….essentially brake hard or brake less and do this in a very informed way.
“The way forward as we see it, is that Hong Kong will do some relaxation of these measures in a very gradual process but will maintain very high surveillance, very high testing and if we notice the outbreak re-emerging, then social distancing measures will be reintroduced,” he says.
He too underscored the importance of contact tracing. “We now know through studies done by my colleagues at the School of Public Health that about 45% of infections are acquired before the index case develops symptoms. If a lot of transmission is taking place before the person even knows that he/she is ill, diagnosing and isolation is important but is not sufficient. You really have to get ahead of that curve and that is where the very aggressive contact tracing becomes so important.”
The Hong Kong experience – the early wave starting in mid-January to end February with mainly people coming from mainland China and some local transmission. In addition to the other measures, PCR testing for diagnostics was rapidly ramped up initially, of course, focused on identifying suspected patients and their contacts and then extended to accident and emergency units and also to private practitioners. More recently, Hong Kong has also begun testing all incoming travellers at the airport, so nobody is allowed to leave the airport until they are tested and found to be negative.
The second big peak (through March and early April) had come not due to people arriving from mainland China, but Hong Kong students in Europe mainly in the United Kingdom, returning home.
Once again with the combination of interventions, we have been able to bring the outbreak under control, Prof. Peiris says, adding that for the last five days there has not been a single case.