Coronavirus: What’s the problem?

Empty Berlin Central Station

After publishing my article comparing the pandemic response of tiny island Mauritius to that of Canada and the United States, I received a few indignant criticisms that this was an “apples to oranges” comparison. After all, Canada and the United States are big countries.

They are right about the apples to oranges, but for the wrong reason. Size has nothing to do with it.

As it turns out, Mauritius is far from alone in its approach to the virus. Other countries of varying sizes in Europe and Asia are using similar tactics with equal success.

What is success anyway?

Business leaders set goals and monitor KPIs (key performance indicators) to inform their decisions. Scientists devise experiments to test their hypotheses. In computer science, we talk about optimization problems, where we want to find the best of all the possible solutions. In any field, we first need to articulate what the problem is and what success means. Only then can we come up with solutions and metrics to evaluate our progress.

So what can success look like for a COVID-19 response? It depends on how the problem is defined!

The government responses to COVID-19 can be broadly classified into three different approaches that reflect three different problem definitions: elimination, reduction, and tolerance.

Depending on which of the three strategies a country adopts, the metrics of success are different, and so are the next steps when conditions change. (Of course, there is the fourth option of “do nothing”, which thankfully is not a popular one.)

Comparison of the three strategies: elimination, reduction, tolerance.

In the elimination strategy, we are aiming for zero community transmission. We want to isolate all cases until community transmission is improbable, or better yet, impossible. Success would be achieving zero or sustained low infection rates with ability to identify and isolate any new cases quickly to prevent new outbreaks. Countries that have chosen this strategy include Mauritius, New Zealand, Australia, Greece, Slovenia, Taiwan, South Korea, Slovakia, Croatia, Hong Kong, and Singapore.

In the reduction strategy, we are optimizing for lower community transmission and lower death rate until a vaccine is found. In other words, we don’t believe zero community transmission is even achievable. We are simply trying to manage our resources efficiently to minimize deaths. We lower community transmission to buy us time to replenish our stocks and study the virus. Success, then, would be a low death rate and a flattening curve with sustained decrease in active and new cases. Countries using the reduction strategy include Germany, Switzerland, Italy, Spain, France, Belgium, Canada, and many more. Most countries fall into this category. (The U.S. is technically in this category, but more on that later.)

In the tolerance strategy, we are optimizing for herd immunity, while also maintaining a low-enough rate of transmission to vulnerable populations so as not to overwhelm the healthcare system. Therefore, success is simply being able to cope with ICU bed demands and avoiding exponential growth in cases. Sweden is the only country using this tolerance strategy as far as I’m aware. The U.K. had also considered it but settled on reduction instead. Please let me know if there are other countries in this category.

As you can imagine, the groundwork required to achieve and maintain success as defined in each of these strategies varies greatly. But when it’s all over, I suspect the only real metric of success will be whether the strategy minimized or prolonged physical, mental and economic suffering.

I am of the opinion that the elimination strategists will have won that race. Unfortunately, we have no choice but to bet our lives on our leaders and hope they know what they are doing, or at least know when it’s time to admit they have no idea what they’re doing. Remember that next time you’re voting.

Elimination vs. Reduction vs. Tolerance

Below, you will see screenshots taken between May 1–2, 2020 on, divided into three columns:

  • Left: the country summary
  • Middle: the graph of active cases
  • Right: the graph of daily new cases

Even if the absolute numbers are not comparable, the trends are undeniable. See the data speak for itself below.

Elimination strategy graphs

Notice that the countries on an elimination strategy saw a sharp decline in both active cases and daily new cases. It is worth pointing out that not all of those elimination strategies involved draconian measures. More on that later.

Reduction strategy graphs

In the reduction strategy category, some countries are showing signs of flattening the curve faster than others.

Tolerance strategy graph

Finally, in the tolerance category, Sweden’s case count is on the rise.

Elimination does not have to be draconian

Mauritius, New Zealand, Taiwan, Australia, Vietnam, Greece, South Korea all adopted an elimination strategy, but that does not mean they used draconian measures like China’s.

South Korea, for example, achieved elimination without a nationwide lockdown of its 51.6 million inhabitants. With strict social distancing and extensive capacity for testing and contact tracing, it was able to flatten the curve with only a few isolated lockdowns. South Korea has a similar policy to Mauritius of isolating patients with mild symptoms into quarantine centers instead of asking them to self-quarantine like in North America.

Hong Kong also adopted an elimination strategy without imposing a complete lockdown. Hong Kong has been successful with strict travel guidelines and quarantines. After several days without new cases, it is slowly easing on social distancing guidelines.

Vietnam is a country about the size of California, but with more than double its population. At 97.3 million people, it is the 15th most populous country. Although it shares a border with China, it was very successful in halting the spread of COVID-19 and has reported no COVID-19 deaths. Vietnam acted decisively to restrict movement into and within the country, quarantining any positive and suspected case in designated quarantine centers, testing and contact tracing extensively. Vietnam was also the first country to emerge from the SARS pandemic in 2003.

New Zealand also ambitiously aimed for elimination and is now in a similar position to Mauritius, with new daily cases in the single digits. Prime Minister Jacinda Ardern has been widely praised for her science-based approach at handling the pandemic, for her leadership and her empathy.

Australia is in the same boat and is starting to lift restrictions as its new daily cases stabilize at low double digits. Australia has also started testing asymptomatic patients in an effort to prevent a resurgence. Australia counts approximately 25 million people and is about 27% smaller than the U.S. in size.

Taiwan’s President Tsai Ing-Wen has taken a preemptive approach. Contact tracing and isolation of positive and suspected cases, anticipatory moves against panic buying, and sanitary measures for disinfecting essential businesses have contributed to its success. Her elimination strategy is very similar to the one used in Mauritius even though Taiwan counts 23.8 million people, somewhere between Texas and Florida’s counts. Taiwan is about four times more densely populated than New York state.

European elimination successes include Greece, Croatia, Slovakia, and Slovenia. Although Greece is still reeling from years of financial trouble, and has one of the oldest populations in Europe, it was able to increase its hospital capacity by 70%, and its fast response prevented the outbreak from crippling its resources.

Slovenia, which borders Italy, imposed a lockdown, mandatory disinfection of buildings, and separate store hours for vulnerable people.

Slovakia was also quick to act and was able to start lifting restrictions at the end of April, with more coming soon.

In Mauritius, contact tracing, testing and quarantining have been key. Not only were all positive and suspected cases quarantined, but so were the medical staff working with COVID-19 patients. In addition to the curfew, strict sanitary guidelines were put in place at supermarkets to minimize risks of contamination. Similar guidelines will be in place at other businesses as the country reopens. After ten days without new cases, Mauritius is now testing all the essential workers, including journalists and police officers, in preparation for the country’s first phase of reopening.

After weeks of aggressively isolating, testing and treating, all of these countries are showing a consistent decrease in active cases and very few new cases. As you can see, not all of these are puny little islands like Mauritius.

The problem with the elimination strategy is that it necessitates decisive action and a lot of groundwork to be put in place really fast. Enforcing strict sanitary guidelines in shops, quarantining and contact tracing are easier said than done in rapidly-changing conditions. It becomes increasingly hard to adopt the elimination strategy as community transmission gets out of control. This is the argument that perhaps some people are trying to make against my article: it was too late.

I disagree. Look at Slovenia. Its proximity to Italy could easily have led to a huge outbreak.

It might have been too late for New York, and maybe a few other hotspots. There are still plenty of measures that could have been taken to eliminate the spread beyond those hotspots. Mandatory quarantines in hotels or convention centers, contact tracing, and testing of both symptomatic and asymptomatic suspected cases were still feasible options in many areas outside of New York City. Some still believe it isn’t too late to try. Again, the measures do not have to be draconian, but they cannot be half-measures.

Singapore: poster child of fleeting success

Early on, Singapore was a good model for a successful elimination strategy without major disruptions to the economy. Singapore’s size is a little over a third of Mauritius’, but it is 4.5 times more populous, and its economy dwarfs that of our paradise island by a factor of 26. Its approach was somewhat similar to that of the U.S. and Canada, except for its extensive contact tracing. It was on track to be among the first countries to have COVID-19 under control until an overlooked hotspot in migrant worker dormitories mushroomed into a national threat. Singapore is now trying really hard to get its daily new cases back down to single digits.

This is the point that many lockdown protesters cannot seem to grasp. What may look like a few isolated cases can very quickly escalate exponentially into an unmanageable crisis. That is why we need extensive testing, quarantining and contact tracing in place to support a re-opening of the economy. South Korea has drive-through testing stations all over the country precisely for that reason. Reopening without systems in place will only lead us down the same path as Singapore, where pockets will go undetected until it’s too late.

Reduction strategy works too.

The first thing to remember is that the goals of this strategy are different from those of elimination strategies. Success is reducing the R factor to an acceptable level such that we have enough PPE, ventilators, healthcare staff, and other resources to cope with severe cases, and reducing likelihood of high-risk patient exposure to the virus. Currently, some experts are recommending we achieve an R of less than 1 as a gauge. Once that is achieved, the goal is to maintain this rate as we try to resume normal activities. This is the most popular approach worldwide.

Reduction strategy seems to be the obvious choice when the initial wave is alarmingly close to, or beyond current hospital capacity, to bring the outbreak under control, as was the case in France, Italy, Spain, and New York. They all saw their healthcare systems get overwhelmed seemingly overnight.

However, after weeks of confinement, there seems to be some light at the end of the tunnel for Italy and France. Although they continue to detect hundreds to thousands of cases daily, the trend is a clear downward one. Both countries have started to relax their lockdown measures. The focus is now on how to maintain their reduction success. The active cases are plateauing while the daily new cases are on a slow but steady drop.

Spain, by contrast, shows a plateau on the number of active cases, but irregular spikes in daily new cases. This could indicate a false plateau in active cases if testing is the bottleneck. Spain is only testing symptomatic patients and is struggling to ramp up its testing capacity. Yet, under their reduction strategy, the changes seem to be enough to phase out their lockdown.

There is a wide range of approaches to the reduction strategy, especially when it comes to determining when success has been achieved, and what to do about it. WHO recommends putting systems in place to detect and isolate positive cases quickly in order to maintain and increase success, but not all countries are willing or able to do so. This is the latest bone of contention in the U.S. as state governors face pressure to reopen the economy even if the public does not yet feel that the situation is under control.

Germany has allowed its curves to show much clearer signs of containment before relaxing its lockdown. Not only has the country shown the most clear sign of a flattening curve, it also has one of the lowest estimated coronavirus death rates in the world. Germany has prioritized testing aggressively, and even tests asymptomatic suspected cases. This has helped them identify and hospitalize high-risk patients before symptoms deteriorate. As the downward trend continues, and with one of the highest number of hospital beds per 1000 patients in the world, Germany is poised to navigate the pandemic without overwhelming its healthcare system.

Switzerland is in a similar situation, with its active cases and daily new cases dropping quite consistently. Switzerland implemented restrictions on gathering sizes gradually, with all non-essential businesses closing on March 20th. It is now easing up on its measures and opening up many of its businesses again. The government plans to ramp up testing and contact tracing as restrictions are lifted.

Canada’s overall strategy is a reduction one, although some provinces such as Newfoundland, Labrador, P.E.I, Manitoba, New Brunswick and British Columbia have been able to use the elimination strategy successfully. Ontario and Alberta also seem to be relatively successful with their reduction strategy and have seen their daily new cases slowly stabilize. Canada is already planning its phrased reopening. With the exception of Quebec, Canada may be on its way down the curve, but shortage of PPE and overworked healthcare workers are still a concern.

The U.S. is still unclear on its strategy, let alone on how to measure its success (or lack thereof). There has been no national plan, no consistency in messaging, no leadership, but plenty of politicizing and blame-shifting from the current administration, leaving the states to scramble and fend for themselves.

Alaska, Hawaii have successfully adopted something closer to an elimination strategy. California, and most blue states adopted a reduction strategy. As did Ohio. New Mexico has been particularly successful given its lack of resources. Some of the red states flirted with “do nothingbefore adopting a short-lived reduction strategy, that is now morphing into a tolerance strategy as patience to restart the economy wears thin.

The current administration contradicted its own guidelines by tweeting in support of lockdown protests and pushing for states to reopen although many of them do not yet meet the White House’s criteria for safe reopening. While most Americans want to continue social distancing, the mixed messages have led to lower adherence to social distancing, with some defying the rules altogether. In other words, the U.S. is a mess.

Tolerance works. But maybe not the way you expected.

Sweden claims its tolerance strategy is working. The rest of the world remains skeptical when looking at the numbers. Both are correct.

Again, if you look at the success criteria for a tolerance strategy, it is to simply not overwhelm the healthcare system with an exponential growth in cases. With this criteria in mind, Sweden has achieved success in solving its problem as it has defined it.

Sweden seems to go back and forth on whether its strategy is aiming for herd immunity or not, although most media outlets claim that it is. Even so, Sweden does recognize the fact that virus mutations could render the herd immunity argument moot. The virus has already mutated several times since its inception in Wuhan, as you can see in the video below. It is unclear how much immunity would be retained, and for how long. Sweden has forbidden visits to senior homes and has some restrictions in place in order to avoid contaminating at-risk patients.

COVID-19 mutations over time, per

Mauritius vs. the U.S. and Canada — apples and oranges.

It’s true. It was an apples to oranges comparison when it comes to the strategies chosen by the leadership.

Not only did Mauritius aim for a loftier goal of elimination, but it succeeded in its execution. It’s still too early to tell whether the pandemic is over for good in Mauritius, but the containing of the outbreak is undeniable.

Canada isn’t doing too bad according to a reduction strategy’s metric of success, though it may seem lackluster in comparison to a successful elimination strategy.

The U.S. still hasn’t shown federal leadership. The New England Journal of Medicine believes that America could succeed with an ambitious elimination strategy in just ten weeks, but the current administration seems content leaving it up to the state governors to navigate their way out of the pandemic.

I therefore maintain my position that, so far, Mauritius has been the most successful of the three in containing the outbreak and protecting its people.

Reduction vs. Elimination: How the problem can complicate the solution

At any point in an outbreak, it will always take less time to achieve success (and start reopening) under reduction compared to elimination. While expediency may be attractive, at the very least, it comes at the cost of reassurance.

In the reduction strategy, as the country reopens with new cases still in the hundreds or thousands, it can be hard to spot the signal from the noise. The question is not if, but when and where next super-spreader event will happen, whether it will be detected fast enough, and whether the hospitals will be able to handle the load. The worst case scenario is that the subsequent waves prove more lethal than the first, as was the case in the 1918 flu pandemic and the country has to go back to more aggressive restrictions multiple times before a vaccine is developed. In that case, the economic impact might be worse than if we had stuck it out until elimination in the first place.

Achieving success under elimination requires herculean coordination efforts from leadership to quickly scale testing, contact tracing, quarantining and other response components. It also requires cooperation and patience from the public in order to reduce the R factor to near zero. However, once these are achieved, it is possible to lift restrictions with more confidence. As new case numbers drop below two-digits, down to zero, calibrating the reopening phases and identifying new clusters become less of a guessing game.


It is inevitable that more deaths will result from successful tolerance or reduction strategies than from successful elimination ones.

However, at the moment, it is unclear how tolerance and reduction strategies would compare. It could be that the death toll is about the same, but the economic downturn is less severe with a successful tolerance approach. Or not.

Countries had a finite amount of time to define the problem as one of elimination, reduction or tolerance. Did they make the right choice for their people? Did the chosen strategy minimize physical, mental, social and economic suffering in the long run?

Tolerance views the death toll as inevitable collateral damage and succeeds as long as its case load doesn’t increase logarithmically and exceed hospital capacity.

Reduction views the death toll as unavoidable damage too. It succeeds if the reproduction factor is reduced to a comfortably low infection rate, and testing capacity is sufficient to mitigate any subsequent outbreaks.

Elimination views the death toll as preventable damage. It succeeds only when the infection rate is completely down and any new cases can be quickly and reliably detected, traced, isolated and treated.

As you can see, success really does come down to the question: what is the problem?

About me
Former data scientist/software engineer, with interest in journalism.
Get in touch with me at or

I also make music:




LA-based writer, artist, producer who used to be a Silicon Valley engineer. Mauritian, Canadian.

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Sherry-Lynn Lee

Sherry-Lynn Lee

LA-based writer, artist, producer who used to be a Silicon Valley engineer. Mauritian, Canadian.

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