Virus hotspots becoming more prevelant
The deaths, lockdowns and school closures that accompanied the global spread of Covid 19 may not seem all that very long ago, but top health officials are already busy preparing for what's going to come next. Many researchers believe that another pandemic could soon be upon us - before the end of this decade, in fact. So what can we expect and what efforts are already being made to tackle the emergence of a deadly new agent? Peter Hotez is professor of paediatrics and molecular virology and microbiology at Baylor College of Medicine. He's also the author of 'Preventing the Next Pandemic. Vaccine Diplomacy in a Time of Anti-Science.' I asked him what the next pandemic might look like...
Peter - This is, I believe, the start of a new normal. Covid-19 is the third major coronavirus epidemic we've had just in the last 20 years; we had SARS that arose out of Southern China in 2002, then we had Middle Eastern respiratory syndrome in 2012. That's why we started working on coronavirus vaccines, because we knew a third one was around the corner. And, sure enough, right on cue came Covid-19. And by that same reasoning, we should expect a fourth major coronavirus epidemic/pandemic before the end of this decade - every six, seven years. That's next. I'm still very concerned about the zoonotic influenzas (avian or other) that's on the radar, and other respiratory viruses. And, very importantly, what we're seeing now in the southern United States and in southern Europe is the rise of insect borne infectious diseases. I think it's quite a constellation of serious respiratory illnesses together with diseases transmitted from animals (in some cases there's overlap) and now insect transmitted infectious agents.
Chris - What do you think is contributing to that intensification? You're making the point that this appears to be happening with greater frequency and you're saying it's the new normal. Why do you think that is?
Peter - From what I can see, it's climate change acting in concert with other key social determinants including political instability as well as aggressive urbanisation, deforestation and poverty. Let's take the Middle East where, because of the violence and political instability there, you first of all see a halting of immunisation programmes, but that's not the only thing that's going on. You have unprecedented temperatures of 50 degrees Celsius or more causing people to flee into larger and larger urban areas such as Aleppo and Damascus, which outstrips the ability of the urban infrastructure to maintain safe and sanitary environments. And so you start seeing diarrheal disease and respiratory disease and then you stop your vector control programme so you're not controlling the Sandfly. So there's massive outbreaks of a disease called cutaneous leishmaniasis. So the Middle East is a good flashpoint area to identify how all of these 21st century forces are combining.
Chris - If we can distil it down to a sort of formula of where the hotspots are likely to be, does that mean we've got some areas we should have our eye on around the world where these new infections could be forged? They are those crucibles that you are talking about?
Peter - I think so. Certainly, those areas where we can identify the confluence of those forces. I think one of the hard parts of this is we don't have a very productive dialogue between the biomedical scientists together with the social scientists and the earth scientists. And we need better cooperation between those groups because, if you're a biomedical scientist, you're not typically talking to urban planners and economists and political scientists and sociologists to understand how those 21st century forces are working, or you're not really talking to climate scientists like we should. So we need to be getting the various academic disciplines to start engaging in an uncomfortable dialogue. And I call it uncomfortable because the way things work in academia too often is we're silent and we're encouraged to write and speak for each other and advance our careers on that basis. We need to have better crosstalk between the disciplines because that's how these infectious pathogens are working.
Chris - Where do most of these emerging infections come from? What's the actual origin because a virus or a bacterium can't just pop into existence from nowhere. So what's the root from wherever they are into people? How do they appear in the first place?
Peter - It's hard to make a general point but one of the observations is that many of these new viruses or other pathogens are what are called zoonosis, meaning that they originate in animals. For instance, Ebola, nepovirus, coronaviruses, they all circulate in bats. And so as humans come into closer contact with bats, either because of altered climate patterns which are causing the bats to undergo new migration patterns or humans are through deforestation, urbanisation coming closer into contact with them, often through a second intermediate animal host whether it's livestock or other animals, that seems to be an important driver.
Chris - So as we see human population increase, we see urbanisation increase, we're going to get more of the sorts of conflicts between us and the natural world that means potentially we're going to see more of these jumps.
Peter - That's right. In the last few years, for the first time, more humans live in urbanised environments than in rural environments. And so I think urbanisation is a huge one, particularly when it's accompanied by political instability in those climate vulnerable areas.
Chris - Based on what you've been saying, we actually clearly do understand quite a lot about what causes pandemics to emerge, the risk factors for making it more likely and where they come from. So does this mean then that, in fact, we are quite well positioned if we implement that knowledge the right way to prevent the next pandemic?
Peter - We understand it in broad strokes as we've been speaking, but when it comes to actually uncovering it at a very granular level, how an epidemic begins, we still stumble. More often than not, we don't really understand that. We know, for instance, that Covid-19 began in wet markets in and around Wuhan, but we don't exactly understand it at a granular level because we've never really done that outbreak investigation to detail it at the level that we really need. That's where the emphasis needs to be to be able to create interdisciplinary teams, which include zoologists, ecologists, virologists and immunologists, to go into areas where we think either outbreaks have occurred or where they're about to occur and do that detailed sampling. That's what we're still missing. And now, with international cooperation challenges, it's getting harder and harder to do that.