Quarantined: Planning the Exit while Suppressing the Epidemic

Igor Rudan
20 min readApr 5, 2020


How did we get here, how to cope and how to get out

When the crisis caused by the new coronavirus from Asia began to spread to Europe and the United States, and then the virus managed to penetrate beyond the front lines of defense in highly developed Western countries, the leaders of these countries were faced with two very unattractive options. Actually, both were so bad that they found it difficult to judge which one was worse.

Two bad options.

With the first option, the reaction was to be instinctive — nations would be pulled into strict quarantines to prevent the virus from spreading rapidly, and the move would protect human lives. But it was clear to everyone that such a measure was entirely unsustainable in the long run. It would be enormously damaging to the entire society if enacted without some sort of strategy for getting out of that situation also put into place.

Namely, after a month, many people will be left without means for the further purchase of basic groceries. Many will start to lose their jobs like restaurants, movie theaters, concerts, transportation, various services, many shops, beauty salons, gyms and fitness centers will shut down. Therefore, the “large quarantine” strategy will be undermined by its unacceptability to a large number of people over time, and it will be increasingly difficult for them to expect to adhere to the responsible behavior needed to keep the epidemic under control.

After a few weeks of quarantine, the number of infected people in my homeland, Croatia, should drop from a few thousand back down to just a hundred or even a dozen or so remaining infected people. But, even if it went down to just ten infected people nationwide, if we went back to our pre-COVID-19 lifestyle, it would lead to a hundred infected people within a week of people leaving isolation, and a thousand after two weeks.

Croatia would then need to start a new cycle of isolation at that point because most that our health system can handle is several thousand infected people. It should be borne in mind that quarantine is really needed when the number of infected people in the population of Croatia reaches about one thousand. This is because with its very next step, from one thousand to ten thousand infected people, the virus will be able to make a successful jump to the household members of already infected people while we’re in a new episode of quarantine.

Any more infections than a few thousand could endanger the health system and the capacity to offer intensive care to all those in need. So, if the isolation measures we’re currently implementing in Croatia manage to curb the infection from a few thousand infected back down to just a dozen or so, and then we relax these isolation measures, we would only regain up to two weeks of normal life before a new, longer stay in isolation.

Of course, this is only true if during these weeks of quarantine we don’t come up with some solution to “coexist” with the virus, where the virus would no longer spread exponentially. If we do, then we would still have a much longer time and a relatively normal life in comparison to being quarantined.

Another option for the rulers of Western countries, quite contrary to this one about defending isolation, was to let the virus spread and infect a significant portion of the population. Under such a scenario, many citizens would gain immunity by overcoming the disease. As a result, after a while, the virus would have fewer and fewer people to jump on. So, it would start to spread more and more slowly until we gained “herd immunity”. Since we have neither drugs nor vaccines against the novel coronavirus, this would lead to many deaths, especially among the elderly population and among those people with pre-existing diseases. However, life as we knew it would continue and the economy would be saved.

Yet, such a strategy was also associated with many risks. First, no one has managed to estimate, with sufficient certainty, just how many human lives this virus could endanger in the worst-case scenario, i.e., if allowed to spread freely. This is because this virus kills not only directly, through infecting individuals and causing symptoms that cannot be cured and lead to death. It kills many more through a very high rate of spread, thus suddenly creating far too many severe cases who cannot be offered treatment. Third, it also kills indirectly, because the overloaded health system can no longer care for patients suffering from other life-threatening diseases and conditions.

Since we still don’t fully understand how many people become infected with the virus but do not develop significant symptoms, it’s quite difficult to determine even the direct effects of the virus. However, that number should be around one percent of all those infected.

However, the effects associated with the rate of the virus’ spread and the indirect effects of this virus are significantly more dangerous than the direct ones. This is not something commonly encountered in medicine. The speed of the spread of the virus in the population is managing to create new and severe cases that cannot then be helped due to a health system overload. This characteristic makes the novel coronavirus more dangerous than its inherent ability to endanger lives.

A third related problem is that the consequent overload of the health system indirectly leads to further casualties due to the inadequate treatment of all other diseases. For this reason, it is extremely difficult to estimate the effects of the free spread of the virus on the lives likely to be lost in the population.

The strategy of allowing the free spread of the virus is also very dangerous because no one can really predict the ways in which the virus could mutate after infecting so many human carriers. Some new strains could, in principle, become even more deadly than the current one. A further danger of this strategy is that even those small percentages of risk for young people would translate into very large numbers if millions of people were infected. Many relatively young victims in the short term would surely become a central focus of reporting on the progress of this epidemic in any country and undermine any support that this strategy may have enjoyed beforehand.

Additionally, no one can be entirely sure whether the immunity to the virus acquired by recovering from COVID-19 would be permanent. And lastly, even if the strategy of allowing the viral spread succeeded to some extent, even with considerable casualties, the virus would still continue to mutate regardless. Therefore, next season, in its new circle around the world, coronavirus would likely shorten many human lives again, as the immunity acquired during a previous season may no longer protect the people — as is the case with the flu. In order for any leader to bet that all these unknowns would turn in their favor during the spread of the virus among the population, they would need to be remarkably optimistic.

An important problem in choosing this alternative path, i.e., allowing the virus to spread, is, once again, the human behavior. Namely, even if the plan were carefully explained to the population and it gained support from a large majority, the rapid increase in the death toll, especially in comparison to quarantined countries, would soon become unacceptable to most of the population.

In this scenario, too, it would be increasingly difficult to maintain the responsibility and discipline required to preserve the economy. When people realize that they might end up in intensive care units themselves, many will find excuses to take to their homes and stay there for a long time. Then, many businesses would collapse and the number of unemployed people would increase sharply, despite the fact that this plan initially sought to save jobs.

In conclusion, in both possible approaches to this crisis, the behavior of the population, which will increasingly decline to participate in either plan, will eventually undermine the implementation. In the former case, they will resent the plan for economic reasons; in the latter, for fear of their lives and the lives of their loved ones.

This was quite clear to the leaders of the Western countries, which is why many of them were so keen to seek their own, third approach. But the only thing that would certainly be worse than these two extreme scenarios is to fight the virus with one strategy and then change it after a few weeks and move on to another approach.

Consistent adherence to the first solution would at least save the maximum number of human lives, albeit only temporarily, but it would significantly harm the economy. Conversely, consistent adherence to the alternative solution would preserve the economy and our lifestyle, but with significant sacrifices that are extremely difficult to assess. But, if the leaders pick one, and after a few weeks change their mind and choose the other, then both the economy will suffer and the casualties would be quite large. So, governments were facing two seemingly very bad solutions and a third, middle way, which was even worse.

Picture: Croatian city of Dubrovnik, where the first quarantine was introduced in 1377.

People are always creative and resourceful.

Fortunately, faced with such difficult challenges throughout history, people have always shown creativity and resourcefulness. That’s why we’re probably the only human species, of at least a dozen known to have existed, that have survived to this day. First, China has shown, with its drastic measures, that the epidemic can be suppressed within a few weeks and then kept at a very low intensity. Another heavily affected country was South Korea, which had an unexpected epidemic behind the front line of defense. However, it showed that by mass testing a huge number of people, it could keep up with the virus instead of cowering behind it.

In addition, Japan, Singapore, and Hong Kong have adopted a series of measures, including very active testing and the continuous isolation of those who are infected and their contacts. With reasonable measures of isolation and social distancing, they have all succeeded in achieving some coexistence with the virus without risking it ‘’escaping’’ into free expansion and exponential growth, which would lead to too many seriously ill people in too short a time.

To prevent the virus from spreading from one infected person to two, three or more healthy people, we need to limit its rate of spread so that each infected person can only transmit the virus to only one healthy person at the most. Then, we will need to live like that until a vaccine is developed, or at least until the first effective medication arrives which will reduce the need for intensive care and respirators for the seriously ill.

What does this mean for Croatia?

We’re currently in the phase of “first virus suppression”, which needs to be done decisively in order to complete the task as quickly as possible. The goal is to reduce the number of infected people in our country to less than a hundred, a climbdown from several thousand. No one wants to remain in isolation for a day longer than necessary, but because of the exponential nature of the virus’ growth, it is also important that after isolation, the number of those infected is not too large, because then, it would quickly start growing again.

Croatia will then have to put in place a number of measures that will make it more difficult for the virus to spread to keep the number of newly infected at day counts below 100. The calculation is simple: let’s suppose that the number of severe cases that require a respirator will be about 5 percent of all infected individuals. In addition, let’s assume that everyone will need a respirator for a month until they recover. If 100 newly infected people are identified every day, it will mean 3,000 within a month with some COVID-19 symptoms.

Among them, 5 percent will have such severe symptoms that they will need a respirator, which is 150 people over a period of one month. Croatia’s intensive care capacities are much larger, but it’s important to leave a significant reserve. Namely, if the virus spreads to hospitals or retirement homes, then the proportion of infected people who will need a respirator will no longer be only 5 percent, but perhaps rise up to 20 percent or even 30 percent, so any such incident can overwhelm our health system very, very quickly.

In addition, respirators are needed for patients with other diseases that occur in Croatia. So, for COVID-19, about 500 of them should be sufficient under most assumptions. That’s why it will be important in the “exit strategy” to plan for “coexistence” strategies with the virus, where we will, in every possible way, make it difficult for it to spread, while allowing for a low-intensity epidemic with double-digit numbers of newly infected people every day so that everyone who becomes seriously ill can still receive intensive care.

How do we preserve good initial results in the fight against COVID-19 in Croatia and exit quarantine as quickly as possible?

There are several key tasks to complete in the coming weeks. First of all, it should be well understood that this is an epidemic. All one has to keep in mind during an epidemic is that we need to know who is infected and who isn’t and then actively physically separate the infected from the uninfected. If we’re constantly actively detecting newly infected people with testing and constantly physically separating them from the uninfected people, then we can do no wrong. But if we have the opportunity to separate the infected from the uninfected, and fail to do so, then we will very likely regret it over time.

Protecting hospitals and retirement homes.

We need to keep in mind at all times that not all uninfected people are equally important. The most important group of uninfected people are immunocompromised people — hospital patients in transplant wards, patients with malignant tumors receiving radiation or chemotherapy, patients with diabetes or cardiovascular disease, especially those with high blood pressure, as well as anyone over seventy years of age.

They should be particularly protected from infection if they already have a chronic underlying illness and if they live together in large numbers in retirement homes. These are uninfected persons who should absolutely not be allowed to come into contact with infected persons. In this next phase of the fight against COVID-19, the successes of individual countries will be measured first and foremost by how well they have managed to protect their hospitals and retirement homes from limited COVID-19 epidemics during the isolation period.

Consider the following: A community outbreak can reach figures of as many as a hundred infected people, resulting in only one death among all those infected. However, an epidemic in a retirement home or hospital ward, infecting a hundred people, can cause twenty or thirty deaths. It really is a huge difference and that’s why these groups should be guarded now. How do we secure that? It would be advisable to test every day for the presence of coronavirus on all employees in healthcare institutions and retirement homes.

However, it is very difficult to implement that, for a number of practical reasons. Therefore, a register of people in Croatia who have already acquired coronavirus and acquired immunity may be launched. Those individuals could then be entrusted with the strategically important role of “guardians”. However, while this idea may seem good in principle, the problem is that this virus is an unknown one and we don’t yet know how long immunity against it lasts, or after how long the virus is ejected from the body, so we need to wait for research to be done that can answer these questions for us.

It is also apparent that good organization of hospital care and retirement homes and their protection against the spread of infection will be important in the coming weeks. It is important that most hospitals, as far as possible in individual cities, are strictly separated from those hospitals, or at least their buildings or floors, where COVID-19 infected persons are treated. Other sick and elderly people, as well as healthcare professionals not involved in the fight against COVID-19, would be better off keeping away from those sites until the epidemic is contained.

Inside hospitals, it is quite important for people needing respirators to be exposed to fresh air as much as possible. That would likely enhance the recovery of their airway mucosa. Dry heated air, on the other hand, makes it difficult for the mucous membrane to recover because it dries out, and this benefits the virus. In this new situation, all creative ideas and resources can be of use. As an example, infected physicians with very mild symptoms of the disease, or physicians who, due to contact with infected persons are in self-isolation, may be able to treat individual respiratory patients in tents outside the hospital, which could increase the capacity to provide intensive care in the event of an extreme need.

A “back up” health facility.

It is important, at the national level, to preserve at least one institution as a “reserve” to handle any epidemiological incident, as those incidents are always possible. If an outbreak is detected at another hospital, or in a retirement home, the emergency transport of infected patients, doctors, retirees, and staff would be required. Similarly, if incidents occur in smaller locations where the local health service wouldn’t be able to cope with smaller outbreaks, all those infected should then simply be transported by ambulances or helicopters to such a “backup” facility; then, all the patients with milder symptoms need to be moved to tents outside the hospital, and severely ill patients to that facility.

With such a “back up” well organized in advance, many lives would be saved in the most dangerous situations, namely the spread of contagion in hospitals or retirement homes. In such a ‘’back up’’ facility, the risk of health professionals contracting the virus would be high. Therefore, it would be good for them to stay within the hospital and receive care from their colleagues, rather than spreading the infection to their families. Such a “back up” establishment would be the last line of defense for all cases where the contagion would begin to spread among the most vulnerable members of the population.

In conclusion, hospitals are currently the most dangerous places during this epidemic. Therefore, wherever the infected can be separated from the uninfected in hospitals, this should be done constantly. It would be reasonable for all patients in hospitals, as well as administration staff, and anyone who doesn’t need to be present in the hospitals because their lives are not threatened, to be sent home so that our exposure to hospital outbreaks is kept to an absolute minimum.

How should we behave to reduce the spread of the virus during a quarantine?

I noticed that most of the ambiguities of the past few days in Croatian media were related to whether or not people could leave their homes, sing on windows and balconies, whether they should wear masks, gloves, and how to dispose of shoes; and whether or not we should disinfect packaging from grocery stores.

Here, I will briefly try to answer these questions. First, we’re being confronted with a virus that has shown that it spreads rapidly and very successfully among humans, and it is not yet clear how it does so. Such viruses are usually transmitted by droplets of exhaled air, but also by fingers after someone who is infected touches their eyes or their mouth and nose because we can expect the presence of the virus in tears, and in mucus from the nose, as well as in saliva. Another person may inhale it, but also touch the location or object that an infected person has previously touched.

Leaving home?

What does this mean for the issue of leaving our homes? This, in fact, means that you’re only safe while in your home. As soon as you go out onto the stairs, you can breathe in the air where someone has previously coughed or spoken loudly or you can touch the handrail where someone infected by the virus has touched it. The same is true for door handles. The risk of being infected in this way is, of course, extremely low, but the transmission of the virus in such a way is no longer impossible and it will continue to spread in that way at least somewhere. Because of this, it may be a good idea to avoid going out if it isn’t necessary, especially while the authorities are still trying to control the number of infected people during the first quarantine.

Also, I understand that many people need to move and exercise to maintain good health. For this reason, it’s difficult to make a strict recommendation that would apply in all situations and for everyone. For older people, it is certainly better to stay indoors for now, while for younger people, it is probably better to take a lower risk of going out and maintain better health.

Singing from balconies, shouting from windows?

For the same reason, singing on windows and balconies is probably not a big risk, but it is conceivable that, under certain conditions, some viruses could be transmitted.

Shoes and gloves?

Whenever I go out, I always wear the same shoes and gloves that I keep right next to my door, and I either put a surgical mask over my mouth and nose or cover I cover them with a scarf. I remove my gloves and my shoes and leave them by the door whenever I return home. I believe that wearing gloves while going out is important because touching a handgrip, doorknob or ATM could help the spread of the infection. People unknowingly touch these surfaces during the day and then they touch their mouths, noses or rub their eyes. If they have touched a surface where the virus was present, they will become infected in this way, but gloves will help prevent that.

Face masks?

There were a lot of ambiguities surrounding the issue of masks. There are several sub-questions that should be distinguished. First, do masks primarily serve to protect you or others? If they serve to protect ourselves, then they need to be special, more expensive masks. But in that case, everyone should wear them. As it is difficult for each country to plan for the procurement of special protective masks for all of its citizens, especially since they also have a shelf life, personal protection masks from infection are procured and kept for healthcare professionals. They will certainly be exposed to infected people. Such protective masks should also be distributed to those who are particularly at risk because of their age or their state of health. But for everyone else, if they were just walking down the street, they’d need to meet about a thousand people in Croatia before meeting someone who is infected. Thus, protecting themselves in such situations is not as important as the above examples from an epidemiological point of view. It is much more important, however, that someone who is infected but has no symptoms doesn’t go on to infect others.

Given that we cannot know just who is infected until they present with symptoms of the virus, it is reasonable for everyone to cover up their mouth and nose in some way so as not to inadvertently spread the infection to others. This is significantly more important epidemiologically. So, whatever can be done to make it more difficult for the virus to jump from one person to another, should be done. The reason why in many countries there is no strict recommendation on wearing masks is that medical recommendations need to be made on the basis of solid scientific evidence. However, in the case of mask effectiveness, it’s difficult to obtain a sufficient type of evidence when the required outcome of the study should be whether or not there is more or less contamination. When it comes to such research, no one would be granted ethical approval to conduct it.

Therefore, what we know about the effectiveness of masks is based on studies that were not optimally designed, which is why it is difficult to get a firm recommendation from any official body. Personally, I believe that masks will help to lower the spread of the infection and that everyone should cover their nose and mouth so as not to accidentally infect others. They can also use a scarf, a handkerchief, a surgical mask, or anything that would help towards this aim.

In addition, anyone who wants to, or is particularly at risk can, of course, also wear a more expensive protective mask, even if they are not a healthcare professional. Common sense suggests that any disruption of the viral spread will help combat this pandemic, even where we don’t have the solid scientific evidence we would like in order to make for such a recommendation.

Disinfecting packaging from the supermarket?

Similar to the question of singing on balconies or going out for a walk alone, the risk of such a transfer is probably very small, but until it is better explored, it can’t be completely ruled out. However, those who become infected in this way are likely to have a significantly lower initial dose of the virus enter them than via inhaled air. Therefore, the course of the disease may be milder, although science has yet to confirm that hypothesis. But it would be no surprise to epidemiologists if this was proven, although it should always be reiterated that surprises are always possible with new viruses.

How to cope while quarantined?

Currently, an “epidemic wave” is making its way over the population of Croatia, but the numbers of newly infected people remain in the double-digits day by day, while in many other countries, they are four-digit, indicating how good Croatia’s early response was in the first few steps. Our healthcare system still has plenty of reserves. However, now is really the time for disciplined isolation so that we can see at least a few days of consecutive declines in the numbers of newly infected people. This would convince us all that Croatia is able to curb the spread of this contagion with the use of the available anti-epidemic measures.

But, any failure to adhere to the instructions of the Civil Protection Headquarters will mean more infected persons, then more severely ill persons, and thus more pressure on the health system, as well as a longer stay in isolation. Adhering to the measures will reduce the number of infected and seriously ill people, keep the health system unburdened and shorten the time spent in isolation.

How to get out?

In the next step, however, we will need to get out of isolation as soon as possible and learn to live with the virus. To achieve this as soon as possible, we will need to devise a series of measures that will work together to minimize the rate of spread of the virus to humans. It’s important that each infected person does not infect more than one other person, so that the number of those infected can no longer transition into exponential growth, as this would mean a new quarantine soon. Every day, there are more and more ideas among epidemiologists emerging on how to do this. The exit will most likely involve a combination of several measures that could slow the spread of the virus.

First, we ourselves will adopt the ‘’ maintenance’’ of the gap we need to have between each other, covering our noses and mouths, wearing gloves, and acting with caution and responsibility. This alone will significantly reduce the viral spread. Then, testing capacities will be increased so that we can follow the good examples from South Korea and Singapore and, in addition, actively seek out and isolate those who have become infected.

So, we will need to constantly “cut paths” for the virus in its spread. Then, the hope remains that during the warmer weather, the viral spread would slow down at least somewhat, unless it disappears entirely. Technological solutions are likely to be developed to quickly identify and isolate infected contacts. Innovative solutions could also include “dividing” the population into several completely separate subgroups to “dilute” the population available to the virus to infect.

These are all measures that together, could be sufficient for the relative normalization of life after this initial epidemic shock wave. Personally, I’m pleased to see that Croatian experts have dealt with the phases of the first line of defense so well, as they have with the withdrawal into quarantine, and now they continue to do so with the maintenance of isolation measures.

Obviously, there is already very active thinking going on about measures to get out of isolation as soon as possible, and a recent package of measures has shown that the economy has not been forgotten either. If we recall, for a moment, the grave doubts of the governments of the Western countries from the beginning of this text, it’s hardly possible to go through this unexpected crisis in a more reasonable way. Until we get a coronavirus vaccine or at least medication that could reduce the need for respirators, it will unfortunately not be easy for us to return to the lives we’re used to. But so many people are working on solutions now that we should continue to be persistent and patient and hope for the best.


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English Translation Assistant: Lauren Simmonds

Image credit: personal collection



Igor Rudan

Director, Centre for Global Health at the University of Edinburgh, UK; President, International Society of Global Health; Editor, Journal of Global Health;