Entangled Pathogens - Interview with Dr. Lina Moses

Dr. Lina Moses is an epidemiologist and disease ecologist. Her primary interest is the control of viral zoonoses transmitted from small mammals. Moses utilises methods from both epidemiology and ecology to understand the interface of human, animal and pathogen. In addition to observational and quasi-experimental field studies, she is interested in implementing human and animal surveillance for zoonoses at the community level. The ultimate goal of her research is to develop interventions to respond quickly to and reduce primary animal-to-human transmission of pathogens. 

Dr. Moses teaches TRMD 6420 Tropical Virology in Tulane University, New Orleans.

The following are transcribed excerpts from a conversation I had with Dr. Moses in her office at Tulane University on May 14th 2019, notably prior to the global Covid19 pandemic. Dr. Moses kindly agreed to talk with me after I attended a public lecture she delivered alongside a screening of the film Panic In The Streets as part of the Science on Screen series.

Panic in the Streets in a 1950 film noir thriller set in New Orleans. The film’s premise is that a passenger (patient zero) arrives in New Orleans by ship infected with the pneumonic plague. The same day he is murdered. The plot is a nail-biting race against time to solve the case and locate the murderers (patients 1 and 2) before a full-scale epidemic breaks out.

During Dr. Moses’ presentation she continually referenced aspects of epidemiology which were beyond the classic bounds of science. Throughout her talk she referenced ecological, socio-political and economic factors which influence both how diseases spread and at what point we consider a pathogen a serious threat.

KR: During your talk what really spoke to me is how you connected conceptions of disease and epidemics with political questions, about who is the other, how and why borders exist and whom they allow in.

LM: The diseases that I study are emerging diseases and they are often high consequence, high-threat pathogens, like Ebola, or Lassa fever. But they actually occur very regularly in endemic areas. This disease Lassa Fever is transmitted by rodents and lots of people get it every year.

There’s this global health security agenda that is placing a lot of… I don’t want to say sensationalism but there is a lot of focus on things that are ‘over there’ that can come ‘over here’ and really defining health and health strategy from a biosecurity perspective. A lot of the diseases I study are approached in that way, just because they are high consequence, high-mortality pathogens.

I think that it’s a huge problem because when you frame it like that, then you are creating ‘the other’, you are creating the idea that things are coming from the ‘dark continent of Africa’ more often than other places and being imported here. So we can put up walls if we want to, to stop people (I think that that’s even questionable how effective that is) but definitely pathogens don’t see those walls and those barriers. So there is this movement, this fluid movement, of pathogens. Ultimately the artificial, or the man-made barriers that we create are really somewhat superficial and probably ineffective.

KR: I remember you mentioning these moments where the optics of epidemics are politically instrumentalized. Did you have experience of this working on Ebola or Lassa Fever?

LM: Yes, I remember during Ebola in the U.S there were only five ports of entry through which we could come in by air, five designated airports. So if you were travelling from West Africa you could only fly through those. They had a health official working in each of these, an epidemiologist who would basically give you a series of questions and assess your risk exposure, give you some guidelines. You were supposed to check your temperature every day and call in if there were any issues.

One time I flew through Chicago O’Hare and there was a person, as I got off the plane, waiting for me. They had a list of people who had come from West Africa, they were waiting for me and handed me a face mask and basically kind of marched me past all the people who had just spent 8 hours on a plane with me! I was made to put a face mask on even though Ebola is not airborne and so that wouldn’t have prevented anything and then I was marched through this whole area. How terrifying for the person who just sat next to me for eight hours, right? There was just a lot of hysteria building up with no evidence base.

I had been in Sierra Leone for about nine months the first time I came back and a few weeks after I returned, the U.S started to get their own cases. Their first case from Liberia was the only person who came in who was not a health worker and being closely monitored. He had been exposed in Liberia and came in to see his family, got sick and I remember after he died and his body was incinerated there were issues about where his ashes should be kept… so things really had reached that level of hysteria.

Ebola was definitely politicized in ways that I didn’t expect, that I thought you would only see in films. Or, in West Africa, where there is a lot of distrust of governments, but to see that happen here… The governor of Louisiana was intending to run for president and he wanted to be seen as someone who was aggressive and could be tough and so he instigated a ridiculous home-quarantine policy that was not based on any evidence. The CDC came out with guidelines on how hospitals and borders should be protected and then that was politicized because people criticized it for not being sufficient, even though, based on the observations as well as the scientific evidence, what they were proposing was absolutely appropriate and adequate. But the CDC succumbed to political pressure and ramped things up as a result. It was a very strange, weird time, very surreal.

Steven Soderbergh’s film Contagion; I saw that before this Ebola outbreak and I thought it was a bit ridiculous and exaggerated, and of course it is, in many ways, but then I saw it afterwards and I was like wow, maybe not as exaggerated as I thought.

KR: I have to watch that.

LM: It’s really interesting. All the little things that you don’t anticipate happening, happen.

KR: You said at the screening of Panic in the Streets that it was oddly scientifically accurate, is Contagion also?

LM: It is a bit more far fetched. Panic In The Streets is based on a real pathogen; the Pneumonic Plague, and they actually talked about this: They talked about the right kinds of antibiotics that you use for it and then immunoglobulins, which are basically antibodies that are harvested from someone or an animal that has been exposed to the pathogen in the past and so they have mounted an immune response that will protect them from future exposure. So, they’ll harvest those antibodies and they can give them to someone else. That’s something you would do with the Pneumonic Plague, it’s all really accurate. I thought that the drama of the crime and the murder and things like that were a great play on how an outbreak normally happens: Usually when someone comes in with a pathogen and spreads it into a community that person will go undetected and unnoticed. This is actually a rare occasion where someone was murdered and as a result the disease was recognised really early on, in the first individual. That happens very, very rarely. So, I thought the whole story was really contrived, but exciting and dramatic. But then there was an episode of this podcast called Hidden Brain I think it was in 2016 and it was the re-telling of a stabbing that had happened in Monrovia in Liberia during the Ebola outbreak and that’s how they discovered this cluster of Ebola cases. A very similar real-life example.

KR: How do colonial histories play into epidemiology and ways that we understand disease?

LM: Often people who are recognised as having a strange epidemic-causing disease come from some level of privilege. I just saw a film called 93 days which was about Ebola being introduced into Nigeria and how Nigeria handled the outbreak. The person who brought Ebola into Nigeria was a Liberian-American diplomat. So, of course when he gets sick people notice. But what often happens with epidemics is that when you have forest borders with people moving across them very easily. We don’t – most countries don’t – build walls everywhere and so many of the countries that have a colonial legacy are divided not according to ethnic group or cultural identity but based on arbitrary parameters – whatever Colonial powers decided at the time, so people still move across those borders very, very easily. And often those people are unrecognized by even a formal health system that can identify an epidemic. So usually epidemics move very quietly across borders among people who are often ignored themselves. Most viral diseases that have been identified in the last 100 years emerged in, say, a white missionary or something like that, rather than being recognized in the community where it has been endemic and circulating for millennia but just no one ever decided to give it a name and identify a pathogen for it. That’s a really common occurrence when you’re studying emerging diseases.

KR: That totally makes sense but it’s so… unjust that epidemiology reinforces these hierarchies between bodies and who even seeks treatment or believes they can seek treatment.

LM: Absolutely. Yeah. And you’re starting to see this with Ebola so much because Ebola is not a disease that is transmitted easily. You do have to get into quite close contact with infected people. Ebola kind of flourishes in areas where you have clinical care that’s really informal, where you have a health sector that’s commonly disrupted by conflict. One of the big things, when you have conflict is you have this total disruption of education, disruption of agriculture, but you have disruption of the health sector as well that is quite profound. People stop trusting the health sector because you don’t have workers who are properly trained because also their education system has suffered. You don’t have supply chains, you don’t have evidence, you don’t have a lot of things that a functioning health system should have and so people aren’t going to trust the health system when something really bad happens and an epidemic unfolds in their communities. Yeah, it’s a problem.

KR:You showed some images from Sierra Leone where people were educating within their communities by creating public health messages in the form of painted graffiti on public walls.

LM: Sierra Leone has about 30% literacy so everything that you do needs to be visual. You can’t rely on words and people to be able to understand them so everything has to be pictorial. So just contrasting the effectiveness and the effort that goes into something like putting up a billboard, trying to give education to a population that has low literacy. There’s always this compromise and it’s a spectrum from this to radio where you can have more quality and in-depth information. With visual messaging you can reach a huge amount of people but the nuance is missing. You get that with these megaphone campaigns, there’s some level of interaction there. Once again, it’s more labour-intensive but you can probably get a little bit of interaction. And then there’s going door-to-door explaining what the situation is.

I think the really important thing with getting people to understand what you’re doing, in terms of epidemic response, and trying to get them to adopt certain behaviours is it has to be bi-directional; it has to be a conversation. Because it doesn’t work if you’re just shooting information at them without understanding their perspective, and how they’re conceptualising that information, or any kind of barriers to adopting the things or any conflict in terms of priorities, all of that stuff. It has to be more of a dialogue than a delivery of a message and we’re really not very good at that in public health. We have this idea that we know what health is and how to keep people healthy. The people who are not doing those things are the ones that need our knowledge to be bestowed on them, rather than really understanding and accepting that people are the experts of their own context and their world and understanding that if we want people to do things to protect a larger population, we have to meet them at least half-way. It’s more figuring out what they need and why they would want to adopt these measures.

KR: One example that you gave in your talk is when you are going door-to-door it is extremely rude not to shake someone’s hand as the first thing that you do but that’s exactly what you don’t want to do if you’re in a really high-risk area. So, how do you navigate that?

LM: I think it’s pretty easy, I think I just treat people the way that I would want to be treated. So I think sometimes we forget that in public health, we put on a public health hat and then we forget that we’re actually human, we have a human perspective as well, and common sense. So, what I would do is I would say “I’m sorry I can’t shake your hand because of precautions, these are the things that we’re doing.” And use it as an education experience to demonstrate on the job the things that they can do to protect themselves as well. Spending five minutes talking to someone and explaining why you’re doing what you’re doing is something that people don’t think about, which I think is rude and just not okay. But I remember in the movie [Panic In The Streets] when the police officer was going with the doctor to do the investigations. One of the things I talked about was criminalisation of the investigation. I see a lot of people in real life who are doing these investigations; going into people’s houses and it’s almost like an interrogation. And you saw in the movie, when the doctor went by himself, went and talked to people and he wasn’t concerned about criminal activity he managed to earn their trust; people were much more forthcoming and so that’s something I have always tried to teach case-investigators. When I am doing a case-investigation I explain to people that information is confidential that what we’re interested in is who is sick and who could be exposed; anything that they have done to cause them to be exposed is not my business and it’s not something I would tell other people.

So, these are things that I think are really important; to move from an interrogation kind of criminalisation-type procedure in outbreak response to more one of health advocacy. You’re really trying to identify people to protect the community, get it contained and get people in for treatment. If you approach it from that perspective I think people have a lot more trust.

KR: That seems logical, makes sense.

LM: Yes, so explaining that and explaining the process to people. I think people are very rational. Everything that I have seen in any kind of epidemic where we consider communities that are resistant or non-compliant, or crazy or acting completely irrationally, given the context, are actually really rational. So explaining why you’re doing what you’re doing I think is just respectful of the person that you’re trying to engage with.

KR: One of the things I’ve been looking at is attitudes to disease. I am particularly interested in the theory of miasma, which was thrown out when germ theory became the dominant one. I’ve been looking into examples of where somehow the concept of miasma comes back into play in contemporary contexts. 

We have had an almost fascistic obsession with cleanliness in hospitals and homes etc where everything has to be disinfected and they become these sealed spaces. Western hospitals are air conditioned and the windows don’t open. And in the UK now you have superbugs developing because patients are inhaling only human particles, there is no microbes from the outside, which is extremely unhealthy. So there is now a trend of revisiting old ideas about opening the windows, letting the air circulate, letting microbes from plants and animals in and getting rid of air conditioning.

LM: Right, letting the exchange happen. When we try to seal up those barriers it can end up being more dangerous. This is one thing with wild animals – a lot of emerging diseases come from wildlife. And so there’s this whole idea about bush meat, which is one way that the spillover of new pathogens occurs and enters the human population. There’s this big narrative about that and it’s interesting because the alternative that people talk about is ‘oh why don’t you just raise those animals and rear them’. What they don’t understand is that it’s the same thing with humans; if you pen them up in a very small space, it will cause infectious diseases to proliferate, communicable diseases are communities, so it’s actually that many of those pathogens we’ve already been exposed to or we deal with them. But just sticking a bunch of animals together in close quarters so they aren’t able to move around is definitely a recipe for all the pathogens we associate with livestock these days.

KR: Yes, and those animals are, of course, pumped full of antibiotics.

LM: Yes, exactly. Especially in the U.S. and that’s creating all sorts of superbugs now so it’s not just in the hospitals. It’s in our food system as well, in how we’re closing things off and keeping them contained. Not necessarily for the protection of the population or to keep a hospital maintained but really it is for economic convenience and benefit to keep all these animals in a small space.

KR: When you talked before about the missionary or the white nurse or doctor getting sick and that being the moment when a pathogen is… pathologised… Prior to that how do closed communities conceptualise and deal with these pathogens without the use or approach of western medicines?

LM: Culturally people have quarantined and isolated sick people, and they do it with their animals as well. With livestock you’ll see that a lot where people will recognise a disease in one animal and they’ll isolate that animal. The same is done with humans too. To be honest with you, this is not something that I study that much so I don’t know a whole lot other than my own personal experience and what I’ve seen. In Sierra Leone they do have access to a more Western medicine kind of system. Most people in Sierra Leone actually turn to traditional healers anyway, for various reasons. Sometimes they’re just better. For example, there’s no specialist orthopaedic surgeon in Sierra Leone and so the doctors don’t really have good enough training to set complicated fractures and things like that. They have traditional healers that even though they don’t have X-ray machines, they have been doing it, they are trained.So honestly if I had a break I would probably go to a traditional healer rather than a doctor in Sierra Leone. I mean local people know which healer to go to for specific things and they say they get better care, although maybe not better outcomes. The traditional healers in Sierra Leone are not cheaper than Western doctors but there’s this idea in Western medicine that the person isn’t a person anymore: It’s a disease or it’s a health issue that needs to be fixed. And the bedside manner and the care that people get it’s culturally not there in the formal medical system. So, many people say they prefer to go to traditional healers even if they’re less effective, just because they’re nicer.

You do hear a lot of rumours, during the Ebola outbreak and for Lassa and other diseases. There was one that if you bathe in salt water at three o’clock in the morning on this day your Ebola will go away. There’s this belief in that and it’s grounded in something it didn’t just come out of thin air and so I think that there’s a lot out there that might not be so effective and then some of it is.

KR: I wanted to ask a question about how we move through the world. In the past, before we had this proliferation of global travel options, I’m guessing that epidemics would stay fairly localised and would kill a percentage of people, other people would develop antibodies and gradually it wouldn’t be such a problem for people who lived in that area. But how is that changed by the way we move and navigate these days?

LM: Globalisation has been going on for centuries, of course, but with technology it has accelerated. It’s not just transportation, but transportation is the biggest thing. We think someone can be sick and get on a plane or, not be sick but be incubating and when they land they’re completely sick and they’re spreading a pathogen everywhere. We also import food from all over the world and pathogens can hitch a ride on different food products, and there are animals that we import for the pet trade, there are many aspects of globalisation. We have a much smaller world these days, not just because of travel. It’s interesting because I think people who live in capital cities in low-income developing countries, they are often the more educated elite, they’re the ones who have professional jobs, they often have a framework and a world view that is similar to someone, say, here in New Orleans. And someone in the very poor areas of Appalachia might have a very similar world-view to someone in rural Sierra Leone. And a lot of this is information exchange, we have access to so much information these days, globally, and so pathogens, although they can’t be transmitted through Twitter, WhatsApp and Instagram, there’s definitely a lot of the messaging and the rhetoric and sometimes a lot of misinformation that gets moved across those technologies.

It’s a matter of population density. In the past you would have people in your community who are susceptible because they’ve never been exposed to the pathogen before so their immune system doesn’t identify that pathogen. A pathogen can sweep through a community and will stay there as long as there continues to be more susceptibles that can transmit and infect another susceptible. So, that’s a matter of population dynamics and community size.

KR: Almost like a monster that gets as big as what it can consume?

LM: Yes, exactly. And then if you have someone who is infected and moves to a different community through trade or through a plane there’s a possibility of that pathogen being introduced there. One of the diseases that I’m interested in is this disease called Lassa fever. Lassa is transmitted by rodents; a really common rodent that is found in villages all over sub-saharan Africa. It looks like this rodent doesn’t necessarily move from village to village very effectively on it’s own (in West Africa at least). It piggy-backs off of humans who transport a box or a big basket of things, it might catch a ride in there when people are going to market or something like that. It could be infected with Lassa and then it moves into the rodent population in that new community so then those dynamics of who’s susceptible, who’s resistant because of past exposure occurs in animals as well, not just humans, where you have what they call source and sink populations. Sources are these reservoirs of pathogens, sink is where the pathogens can move and fill in a community. But it’s not just humans who are the hosts, it’s often animals who are the hosts and humans just happen to get infected.

With Lassa we’re still trying to figure how to predict this but you’ll have a community, a small village where you’ll have a lot of cases for two or three years and then it simply goes away and if you look at the rodents in those communities you’ll see the virus sweep through the rodent population and then if enough rodents are infected then that transmission can’t occur in the rodents you’ll see the virus die out and then you won’t see human cases any more.

KR: Does the rodent get sick? Or is it just a carrier?

LM: For Lassa it doesn’t look like the rodent has any sort of disease. This virus has probably been in the rodent for a really long time and so they’ve done the dance of evolution of being pathogenic and killing your host too, several generations later not very pathogenic and the host lives and the pathogen can persist in that host for a really long time.

KR: So, how does it transmit are people getting bitten?

LM: We aren’t entirely sure how people are getting infected, the only risk factor we know of is communities that consume rodents have more antibodies to Lassa so it looks like they’re getting exposed more. So we think maybe butchering and being exposed to body fluids whether it’s blood, urine, faeces, saliva. We’re not entirely sure. Butchering is a messy process.

KR: The kind of bush-meat hysteria, my familiarity with that is through the alleged origin story of HIV – that it was transmitted to humans through bush meat (chimpanzee) and then proliferated globally through an air steward who travelled around a lot spreading the virus.

LM: The interesting thing about bush meat is people who hunt in the U.K. or the U.S., we never call that bush meat. So when we select ‘bush meat’ as a term rather than ‘game’. It’s often very racially and geographically focused. So I think calling something bush meat exoticizes that process and creates ‘the other’ when it’s really people going out and shooting game. It’s interesting because when Donald Trump Jr. goes over to Africa and shoots and goes hunting, it’s still called game hunting. But if a villager is going out to do hunting to sell it commercially, not even for subsistence it’s called bush meat hunting. So, yeah, the term is very loaded I think!