It is a document that comes alive, with intriguing energy and vitality. I knew sooner or later that we would meet to talk about his long professional career and that he would tell me some of the many stories that marked his life and that of the Faculty and the Hospital.
If find him at the Infectious Diseases Library, where he spreads out his many articles, printed emails and research projects. As I discreetly peer at the countless documents lying on the table, I realize that he continues to write much of the information by hand. The detail of his beautiful handwriting easily explains the lucid and wise spirit of this retired Professor who was once Director of the Infectious Diseases Service at the CHULN-HSM and Director of the University Clinic of Infectious Diseases at FMUL for 20 years.
![senhor careca a dar entrevista](/sites/default/files/inline-images/televisao.jpg)
Almost resident commentator, in recent times, on television channels about the new strain of the Coronavirus, SARS-CoV-2, we know that in 2002 and 2004 there was already talk of a Coronavirus, responsible for SARS (Severe Acute Respiratory Syndrome), in which severe disease was the most frequent clinical picture, with isolation in almost all cases, thus reducing the risk of transmissibility. The perversion now with SARS-CoV-2 is that only the most serious cases, which occur in 20% of those infected, 5% of whom are in need of intensive care, are clearly detectable. Of the remaining 80%, many can go unnoticed and there are people out there who don't even know they are infected, as in these cases COVID-19 evolves slightly or is even asymptomatic. Not feeling sick and doing their daily routine, people go out and use public transport, go to restaurants and shops or cinemas and work, participating in various meetings. Thus, they trigger, without knowing it, a chain of transmission of the infectious agent, which can reach a host at risk of becoming seriously ill if more debilitated. The great danger of this virus is that it has no face, because the number of transmitting carriers is unknown, making invisibility its most powerful weapon. Given this scenario, it would be unthinkable not to take advantage of Professor Francisco Antunes' daily presence at the Faculty of Medicine and learn a lot about COVID-19 (the disease associated with those viruses) and about SARS-CoV-2.
This strain of virus was already known to us...
Francisco Antunes: This is a large family of viruses that circulate in animals and in humans. In humans, it commonly cause mild respiratory disease, such as the commonplace cold, which is frequent in the winter. It also affects animals and what is rare and has happened three times in the last 20 years, is that a virus that was transmitted only amidst animals, suddenly adapted and passed on to humans. This seems to be rare, in particular its capacity for sustained transmission from person to person. What happens is that this new coronavirus, responsible for a serious respiratory disease, and the coronavirus that circulated a few years ago and responsible for Severe Acute Respiratory Syndrome (SARS) were both episodes with the characteristic of being a rare, but predictable phenomenon. Both are of the Beta Coronavirus type, with ancestral origin in bats. Then they may have circulated in intermediate animal environments, and it is not yet known which animal (turtle, snake, pangolin?) has acted as the bat's passage to humans. Cats and dogs are carriers of coronavirus, which do not cause disease in humans. But it is also important to say that other viral agents pass from animals to humans, such as swine flu in 2009 (with a mortality rate of 0.02% -0.4%) due to H1N1 or bird flu in 2013 ( with a mortality of 39%) due to H7N9. In fact, several zoonoses have occurred in the last 40 years as emerging infectious diseases.
Flu itself is also evolving from year to year.
Francisco Antunes: They are transmissions from human to human and, in the case of seasonal flu, have a mortality rate of around 0.1%, which, even so, is high, taking into account the high number of people infected. Those who die from the seasonal flu virus are the same ones who are now dying from COVID-19, that is, the elderly and those with chronic, particularly cardiovascular, diseases. In addition to the latter, children are also at risk of severe illness and death from seasonal flu.
But does it belongs to this family of viruses?
Francisco Antunes: No. Bird flu had an extraordinarily high mortality rate because it went from an animal environment to humans, very aggressively. These passages that we call the crossing of the species barrier (when it is transmitted from animals to humans) are, generally, situations of extreme gravity and mortality because they are considered new organisms, which have never had contact with the new host and, therefore, they do not yet have immunity to defend themselves. The flu viruses that have been circulating for many years in humans, in which there is the so-called memory immunity, go unnoticed in most infected people, which means that, in most cases, they are asymptomatic cases.
Does this mean that the human being belongs to the species that adapts to the environment?
Francisco Antunes: Most people have some residual immunity and respond strongly to the infectious agent. But the influenza virus (flu virus) is totally different from this coronavirus.
I am intrigued by the fact that a virus that apparently should remain in an animal, or in some animals, suddenly manages to pass on to humans and has this very harmful effect. Where has this virus been so far that hasn't affected humans before?
Francisco Antunes: It has been asleep, contained in its original environment, but humankind, in his evolution (population growth, globalization, greenhouse effect, deforestation, need to use food sources on an unprecedented scale), created open doors regarding the transmissibility barriers of these infectious agents. Some infectious agents, such as the Coronavirus, are adapted to animal hosts, as there is already a secular relationship between agent and host. Thus, these animals have a peaceful coexistence with these viruses and do not get sick. But, if for any reason, conditions are created that facilitate their contact with humans and if they have mechanisms that allow their adaptation and multiplication, they reveal an aggressiveness that they did not show in the animal environment.
How do these loopholes that allow these phenomena occur?
Francisco Antunes: Many epidemics like these happened in the past, reaching the extent of decimating ⅓ of the world population, like the black plague, in the 14th century. However, from the 19th century, at the beginning of the industrial era, with the improvement of sanitary conditions and in the 20th century with antibiotics and vaccines, it was believed that infectious diseases would no longer be a threat to humanity. AIDS was the first sign that it would not be so. The exponential increase in population, globalization, with very easy circulation from region to region and continent to continent and people's behaviours and habits are some of the causes of the emergence of infectious diseases. As the population grows, so does the rush to consume wild animals (in China they are a food preferences), which act as an environment for these infectious agents and, as such, the contact between humans and these animals is increasing. This is how these outbreaks come about, which are more and more frequent (Ebola, SARS, MERS and COVID-19). It must be said that SARS-CoV-2 is very contagious, as is the Coronavirus responsible for SARS or MERS. Being different infectious agents, the severity (pathogenicity) is related to multiple factors, one of them with the entrance door. If the infection occurs at the level of the upper respiratory tree, the infection may be milder than for those cases in which the virus enters the deep lung. in the first case, there may be a greater risk of transmission and in the second greater risk of severity. SARS-CoV-2 has a lower severity rate than that associated with SARS. SARS recorded very high mortality with a rate between 9-12%. In the case of SARS-CoV-2, the rate is 2-3%, which approximates the mortality of viruses associated with seasonal influenza viruses. (Important note: this interview was conducted in early March, so the data available is not the same as the current data)
Let me reinforce this idea, that this is a virus with a great impact, because, as I was told, it does not manifest itself in all of its human carriers, and, as such, it is more uncontrollable because it "runs wild".
Francisco Antunes: The initial idea of “checking” body temperature at airports was good, "if you have a fever, you are a suspect". But this virus does not work like that, because the fever may be absent, at the beginning of the clinical picture, or there may be no symptoms at all. As it is a relatively benign disease, for the general population, it is more severe if the infected person has a chronic disease, or if, due to ageing, he has underlying diseases, such as heart, kidney, lung disease or diabetes. But for the elderly population (over 65 years old), with chronic underlying diseases, it can be a tragedy, because it implies greater severity of COVID-19, requiring hospitalization in an intensive care unit.
Curiously, children don't seem to be at risk.
Francisco Antunes: In relation to influenza, they are an important risk group, but in this particular case, apparently they are not. What has been noted is that children are little affected or are not diagnosed, taking into account the benignity of the clinical picture. According to China's epidemiological data, in general, people over 20 are affected, with the severity increasing from the age of 60.
From your vast experience, both in hospital and in lecturing and research, can you tell what is the estimated time to discover the first treatment solutions to fight this virus?
Francisco Antunes: One drug that was used in the AIDS virus, lopinavir/ritonavir and other antivirals has been used in patients with COVID-19. In the meantime, no drug, so far used "as a last resource " is supported by scientific evidence of its efficacy for SARS-CoV-2. However, it must be said that it is easier to find something (an antiviral) effective for treatment than for prevention (a vaccine). In prevention there are several vaccines under study, but some time is needed to verify their effectiveness (towards the end of the year?). The evolution of this outbreak, on a global scale, is unknown, but it can follow one of two paths, that is, what happened with SARS in the past, when the outbreak was extinguished in less than a year or as in the seasonal flu, in which the virus is installed in humans and can circulate under the same conditions as other respiratory viruses. With the available data, I think more about the second hypothesis. As for flu, for most infected people the disease is mild, which means that many cases go unnoticed and it is not possible to isolate them, thus perpetuating the risk of transmission, with outbreaks perpetuating themselves over time. With regard to the future, we do not know how to predict what will happen when winter gives way to warmer seasons, mitigating its transmissibility, as SARS-CoV-2 is very sensitive to heat.
Is there a difference in the first symptoms between a common flu and COVID-19?
Francisco Antunes: No. None.
The clinical picture of seasonal influenza (which we are still experiencing) includes body pain, cough and, sometimes, fever, similar to that of COVID-19. What should people do?
Francisco Antunes: The first thing is to stay at home and cut any kind of socialization, including with one’s own family. Then, take paracetamol, to relieve body pain and fever and contact the Saúde 24 line. Check body temperature 3-4 times a day and only take paracetamol if the fever is above 37.5ºC (do not take antipyretic medication before checking the temperature). Another sign of suspicion is the worsening of the cough (more and more frequent and of longer duration). In this contact with the health services, people will be asked a series of questions to enable identifying some links to risk situations. These structured surveys try to identify the source of the infection and the contacts. If there is no suspicion, there is no cause for alarm. In case of suspicion, the patient will be contacted by a health team to carry out a confirmatory test and then guided to follow-up. If a person tests positive for COVID-19, follow-up can be done at home (for less severe cases), following strict family and social isolation until clinical improvement and two negative tests for SARS-CoV-2 have been taken. In the most serious cases, people will be hospitalized. People must not forget something that is always very important, hand hygiene, since they are one of the main vehicles that transmit infection. People shouldn't bring their hands to their faces, let alone sneeze and cough into their hands. And they should wash their hands often!
Can someone who catches this virus catch it again, or becomes immune?
Francisco Antunes: We still don't know for sure. But the experience of other diseases with the same characteristics and in very similar viruses tells us that immunity is created and that it can be maintained until three years later. But this may not be the case, depending on the host's immune status and the virus's ability to escape his defence mechanisms. In influenza there are always mutations in the agent, to which the host loses the immunity acquired previously.
It may be a completely basic question and perhaps I shouldn't be asking it. But for someone without a background in science, like me, I think is that viruses are highly "intelligent" organisms. Is it possible to say so?
Francisco Antunes: (remains silent for a long time). We know that this infectious agent has a high capacity to adapt to the host, preventing him from recognizing it immediately and eventually eliminating it, before causing any damage. However, this ability to escape the host's defence mechanisms is much greater than expected. The capacity for mutation through its genetic machinery for survival is practically unlimited. See what happens with the problem of resistance to antibiotics, antivirals and antifungals, which are also a threat on a global scale.
Because the virus learned to defend itself?
Francisco Antunes: Yes. In order to defend itself against death caused by the host's various defence mechanisms, it unleashes means that prevent its recognition. This ability to defend oneself is much more reduced in humans.
And couldn't we decode how the virus self-builds and turn it against itself?
Francisco Antunes: It is a relatively new science that investigates the genetic and molecular characteristics of infectious agents, but despite advances in knoledge about the agent, its complexity does not allow immediate means of prevention and treatment to be available. It has a lot to do with the interrelation that is established between the infectious agent and the host and this is very complex and a lot is unknown. However, in the specific case of COVID-19, I must recognize that advances have been very rapid, opening up horizons for the discovery of effective therapy and a vaccine.
I ask you one last question in a provocative way. Is Nature giving us messages?
Francisco Antunes: I think that what is happening is not just a natural phenomenon, man has made his contribution. At the moment, the world’s population is 7 billion people, with the probability that it will exceed 10 billion this century - it is an overpopulated world and the planet may not be able to withstand this accelerated growth. This population growth is concentrated in large cities that are not prepared from the point of view of health and access to drinking water, which represents an increased risk for communicable diseases. On the other hand, globalization is not only the mobility of people, but also the circulation of microorganisms and genes of these microorganisms, environments and vectors of infectious agents. In addition, human interaction with wildlife is increasingly frequent, particularly in terms of deforestation to gain arable land to cover food needs. Do you want a good example? Smallpox was eradicated almost 50 years ago and earlier this century, in remote regions of Africa, cases similar to those of “smallpox”, originating in African monkeys, appeared. These cases were confined to these remote regions of Africa, now imagine if it was in Europe? The contact that is established with the environments and vectors of infectious diseases is more and more frequent. And what about feeding this entire population? There are tons of foods that circulate around the world and these foods themselves can be a vehicle for infectious agents. Finally, there is one factor that can have a major impact on the emergence of infectious diseases, which is global warming, especially regarding vector-borne diseases, such as mosquitoes and ticks. As their survival is very dependent on climatic conditions, the hotter the world becomes, the greater the risk of expansion for those vectors that survive better in higher temperatures. These vectors multiply more and more and feed each time more. And what do they feed on? On the blood of the hosts and, at the same time, inoculate, during the meal, the agents that they carry.
Joana Sousa
Editorial Team
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