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An interview with Mary Cruz Torrico Rojas

Posted by , on 21 March 2023

MiniBio: Mary Cruz Torrico is the head of the Parasitology lab at Universidad Mayor de San Simón, in Cochabamba, Bolivia. She studied her BSc degree in Pharmaceutical Biochemistry at Universidad Mayor de San Simón. She then did a masters degree at the Free University of Brussels, Belgium. She is currently completing her PhD at the University of Barcelona, while in parallel working as a researcher and heading the parasitology lab. She has dedicated her career to the diagnosis and treatment of infectious diseases including Chagas disease, leishmaniasis, and various other protozoans and helminths, all endemic in Bolivia.  

What inspired you to become a scientist? 

I was aware of infectious diseases being a major health burden in my country. I remember playing as a girl with dolls, pretending to be a doctor, and giving them medicine and so on. I might not have understood all the science behind, but it was something empirical, based on what I saw around me. This is what caught my eye for many years before I chose to study the degree of Pharmaceutical Biochemistry. 

You have a career-long involvement in parasitology and microscopy. Can you tell us a bit about what inspired you to choose this path?  

My interest for these areas arose during the 4th year of my undergraduate degree in Pharmaceutical Biochemistry. At this point, back in 1989, we were covering the topic of Microbiology, which I found extremely fascinating. I started participating in small research projects and presenting my work at scientific conferences – that’s when my interest in this area really started to deepen. An inspiration to me was the hope to do something useful for public health and the Bolivian population, where infectious diseases are a major concern. Already before finishing my undergraduate degree, I started working at the Faculty of Medicine as a researcher, in a Microbiology lab focusing on Leishmania (causative of leishmaniasis) and T. cruzi (causative of Chagas disease)I’ve worked on those two parasites ever since, for my whole career. We worked in the lab, in the field, and we had a mobile lab that enabled us to do diagnosis in endemic areas. Microscopy was the first step in any research project – in addition to molecular tools, parasite isolation and cell culture. The group I was working with was very large and it brought together experts in various areas: medical doctors, biochemists, chemists, biologists, etc. It was not only multi-disciplinary, but for some projects, international. It brought together scientists from Bolivia, Peru, Colombia, Belgium, Brazil and other countries. Currently I’m about to finish my PhD in parasitology, and microscopy continues to be a key tool. I still work on neglected tropical diseases. In 1995, after I had had sufficient work experience as a researcher, I was involved in putting together from scratch the Parasitology Lab, which until now is very active. Microscopy continues to be a standard tool in the lab both for blood and tissue-based research in the field of parasitology. It’s our first line of research, to then go on to use more sophisticated and sensitive techniques to continue the research question. I must also say, that the COVID-19 pandemic has allowed us to implement novel molecular biology tools in many labs, which we can now offer to patients in the context of various diseases. There are many regions in Bolivia which are endemic to many parasites of medical importance – Giardia, Leishmania, Plasmodium, Chagas, etc. Being able to diagnose these diseases promptly and carry out research is of great importance to me. We also have lots of co-morbidities of course, together with infectious diseases: cancer, immunosuppression or transplants to name a few – it’s therefore of great importance to be able to give the best possible diagnosis and care to patients throughout the country. Regarding my scientific path- I studied my BSc in Bolivia, and then did my MSc in Belgium, at the Free University of Brussels. Now I’m doing my PhD at the University of Barcelona, in Spain.  

Can you tell us a bit about what you have found uniquely positive about becoming a researcher in Bolivia, from your education years?

Experimental labs in public schools in Bolivia at the time I was studying my early education, didn’t quite exist yet. In secondary school I had some lab practicals, but they were very basic – to study some simple chemical reactions for example. That was interesting, but I don’t feel it was a huge incentive for me to enter the research field as early as I would have liked to. This incentive came much later.   

 Can you tell us a bit about your day-to-day work at Universidad Mayor de San Simon?

I’m doing my PhD at the University of Barcelona, but it’s a joined project with my current university in Bolivia. In parallel, I’m working at the Faculty of Medicine at Universidad Mayor de San Simon as a researcher, focusing on clinical research. I also teach. We focus on both, diagnostics and research. I feel we’re privileged here – we get to work on diagnostics for patients who request it. Currently we work together with 6 labs specialized in bacteriology, parasitology, virology, molecular biology, and immunology. I think we are privileged because we get to combine diagnostics and research. For us a sample is never just a sample – it allows us to a) understand the disease better and b) help give the best care to the patient. It gives it a more human perspective – we look at the bigger picture. 

Team at Parasitology lab in LABIMED, Faculty of Medicine, Universidad Mayor de San Simon, Cochabamba, Bolivia.

Did you have many opportunities to interact with other Latin American groups, outside of Bolivia?      

Yes, I’ve worked in joined projects with colleagues from Peru, Brazil, Cuba, and Argentina. I’m very interested in networking and opportunities to work together. The COVID-19 pandemic has affected some collaborations, but we are pushing forward now, to be able to complete the projects. 

Who are your scientific role models (both Bolivian and foreign)?

All the scientists who were my mentors of course, and from whom I was able to learn a lot. One of them is Prof. Faustino Torrico – he is well-known in the field of Chagas disease. We have a lot of standardized protocols and techniques thanks to him. Another was Dr. Hernán Bermúdez in the field of Leishmania. Then in USAID, there is Dr. Fanor Balderrama, whom I also met thanks to Dr. Torrico. These are the 3 Bolivian researchers that come to my mind. Other Latin Americans include Alejandro Llanos and Jorge Arevalo from Peru, with whom we collaborated through EuroLeish. 

What is your opinion on gender balance in Bolivia, given current initiatives in the country to address this important issue. How has this impacted your career? 

I think abilities are valuable regardless of gender. Maybe in other careers there’s more of a direct impact. But say, when a call is open for research proposals or for job openings, we evaluate skill, and performance in the lab, regardless of gender. I don’t feel I ever faced gender-based discrimination. My personal opinion, after many years working in labs, is that women are very well organized, and rarely ever leave things for the next day. I see this in myself and in other female colleagues. But that’s just an opinion. 

Are there any historical events in Bolivia that you feel have impacted the research landscape of the country to this day?

After a symposium that took place at the University in December 2022, there has been a new implementation where we (the professionals in labs) are listed as researchers. Before this, the position of researcher didn’t exist. To be considered a researcher you must be registered among the yearly operating projects within the university. If you’re not registered, you cannot hold the position of researcher. We cannot freely choose our holidays because of the service we provide, so we often coordinate to have our holidays in December. This year we were told we could not take holidays, because there was no certainty we would come back to work, because we hadn’t been appointed yet as researchers. I think this is terribly wrong – rest shouldn’t be refused. We are the only ones to whom this was imposed. At least now, with the re-categorization as researchers, our working conditions can improve. Still, we got a letter saying that based on experience, we would be categorized as researcher type A, B, C or D, with D being the “higher rank”, but we were also told that this was merely nominative – it wouldn’t be linked to remuneration or benefits. Yet the requirements we have to fulfill to reach those positions are vast. I think working conditions need to improve. 

Have you faced any challenges as a foreigner if you have worked outside Bolivia?

My main challenge when I went to Belgium is that I left my country without speaking a word of French. I did all I could and got a fellowship, and did very well, but it was a daunting experience. Language now is a challenge as a researcher – I speak French, but not English yet. In Spain it was easier because of the language, but here the challenges were different – my age for starting a PhD is one factor – also, I have a family and many obligations in addition to my work, my position as head of labs, and my doctoral degree. Despite this, thanks to my supervisor’s support, I’ve managed to carry on with the PhD, which I hope to finish by the middle of this year. Still, completing my PhD was a personal challenge, and I’m happy to have done it. Cultural adaptation is never easy, but I think one has to be observant to understand the culture and to be able to integrate. It helped that many of the environments I’ve worked in are very international, with people from all over the world. However, I must say that the process of adaptation was easier because in my mind I always knew these positions were temporary. I was only going abroad to work for a certain amount of time. I never had in mind being permanently uprooted from my own culture. All my tickets were return tickets 🙂 Otherwise it’s a whole different thing. 

What is your favourite type of microscopy and why?

In Bolivia we use light microscopy most often. We use light microscopy for diagnosis, and we will spend hours on end at it, so I firmly believe we should have good equipment. We use dark field microscopy, phase contrast microscopy and conventional bright field microscopy. I’ve never had the chance to work with electron microscopes, and we don’t have confocal microscopes here either. The cost is prohibitive.  

What is the most extraordinary thing you have seen by microscopy? An eureka moment for you?

What is most interesting is the unknown of course. A masters student of mine was working on T. cruzi in a remote region, close to Cochabamba (where I currently am). She collected blood from domestic animals (dogs) and rodents, and used the capillary technique to determine whether or not they were infected and what their cycle was. At some point I saw something extraordinary – like a snake inside a tube – I had never seen something like that before. They were filarial worms, transmitted by mosquitoes, and it was co-habiting with the parasites we were studying. 

Another thing that surprised me because I had only ever read about it, was cerebrospinal fluid in the context of any disease. I had never seen it with my own eyes, and a medical doctor told me that a patient whose sample she took had Chagas disease, and that she would be sending me cerebrospinal fluid. I looked down the microscope and it was swarming with parasites. The patient was in comatose state, and had we not acted quickly, he would have perished. Another experience was a sample from a patient with HIV, completely invaded with Strongyloides larvae. This was completely shocking. I could only feel for the patient, whose immune system was clearly completely overcome. There are many other things I have found surprising when looking down the microscope…

Sample at the microscope. Parasitology lab at LABIMED, Faculty of Medicine, Universidad Mayor de San Simon, Cochabamba, Bolivia.

What is an important piece of advice you would give to future Bolivian scientists? and especially those specializing as microscopists?

I think microscopy is always done by people who really enjoy doing it. I sometimes teach students or interns, and many of them look at a sample down the microscope for 2 seconds and tell me they can’t find anything. I tell them that they have to have very clear organization and be very systematic: define how many fields to quantify and in which order, until you can have an idea of a diagnosis. It’s not just taking a glance. Because of this, I have many colleagues who say they could never do microscopy.To any student coming to learn, I always tell them to sit down comfortably and do things with a clear mind and no worries – there should be no rush, and no thought at the back of the head that “I should leave soon because…”. I always convey the message that the quality of the work they do will inform how a patient is treated and so they should do it very carefully. Always do a high quality job. I also encourage my students to keep slides for microscopy controls whenever other pieces of equipment are used like automatic sorters. Microscopy should back up any result from PCR, FACS or ELISAs, or other compatible techniques. I’ll give you an example: you might be asked to do an ELISA for Giardia, and the result might be negative. Yet, in our country, there are many co-infections, and you can miss out on things you’re not looking for. A microscopy diagnosis will allow you to identify if there is anything else which might be harmful to the patient.

Where do you see the future of science and microscopy heading over the next decade in Bolivia, and how do you hope to be part of this future? 

I’ll answer this question taking as basis a project we’re doing in collaboration with Instituto Carlos III in Madrid, and an NGO called SpotLab, working on artificial intelligence for microscopic diagnosis of infectious diseases. We are aiming to identify in an automated way, any parasite. In the long run, I think we will have robots that allow us to do image acquisition and image analysis. Yet, personnel in labs won’t just be replaced by machines. We- the thinking beings – will still be the ones validating those results. Same goes for delicate procedures, for instance in Leishmania, where the diagnosis depends a lot on accurate sample acquisition, which for now,  a machine cannot do. 

I had the chance to see the robot in action, in my last visit to Spain – the robot takes the blood sample, does the smear, does the staining, searches with the microscope, and gives you the outcome. It’s super advanced. We’re currently writing a paper with our results in the context of Chagas and leishmaniasis. Robotics as a subject is now being introduced as a subject in school in Bolivia. Let’s see how this develops in the coming years. 

Beyond science, what do you think makes Bolivia a special place to visit? 

Bolivia is a very big country- many of us (Bolivians) haven’t seen all the marvels of our entire country. We have 3 main geographical areas in the country: the plateau, the valleys (including Cochambaba, Chuquisaca and Tarija), and the Amazonia – the tropical region. There’s a huge variety of foods, of landscapes – for example if you like the cold, you can go to El Salar de Uyuni (Uyuni Salt Flat). If you like waterfalls and lakes and mountains you can also visit other areas, and in the tropical region you can see completely different views, and even tribes that only live there. I personally don’t like the tropical region because there are many dangerous insects. 

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Categories: Latin American Microscopists, Interviews

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