Interview: Gregory Bisson

In Current Issue, Interviews on October 29, 2009 at 11:52 pm

UPenn’s rising star in infectious disease and epidemiology

Gregory Bisson is an Assistant Professor at the University of Pennsylvania in the Department of Medicine’s Infectious Disease Division and a Senior Scholar at the Center for Clinical Epidemiology and Biostatistics. His work focuses primarily on the study of HIV and its co-infections with an emphasis on its presence in Africa. Dr. Bisson aims to bridge the gap between epidemiological research and clinical medicine to improve healthcare for HIV patients in Africa.

HCGHR: Tell me a little bit about yourself and how you got to where you are now.

Bisson: I originally was a Japanese language and literature major in college and was interested in politics and working for the State Department. I was initially not thinking about being a doctor and then I did a year abroad in an exchange program through the University of Madison Wisconsin with a University in Japan (Nanzan University in Nagoya). It was a transformational experience and I fell in love with Japan and became even more interested in international relations (vaguely defined).

Then when I traveled around South East Asia and I became very impressed with what I felt to be a challenging state of global public health. I had a glimpse of this through traveling in some parts of Asia. At that point I started to question what my mission in life would be about and after seeing people that are suffering in developing countries and that are suffering from things that are often preventable and treatable really was something that motivated me to eventually go into medicine.

When I came back from Japan I was a senior in college. Then I took a year off and applied to medical school and worked at the U.S. Senate and got a close up look at how certain aspects of healthcare legislation were being created. I got into medical school and went back to the state where I am from (University of Minnesota).

Ever since my travel in South East Asia I was always looking at international health as being my career. At the very beginning I wanted to get at the big picture as much as possible and I think I didn’t really know what epidemiology was at the time but I became increasingly interested in doing that for my career over time. At that point during medical school I realized what I wanted to do was something that would be most applicable to global health and that for me was Infectious Disease. So I decided to go into Internal Medicine and later specialized in Infectious Disease. I went to the University of Pennsylvania to do an Internal Medicine Residency and then continued there to do my Infectious Disease Fellowship.

HCGHR: You’ve done a lot of work in Botswana. What inspired you to go there in the first place and what was your first trip like?

Bisson: The Chief of the Infectious Disease Division at Penn was invited to be involved and have the Infectious Disease Dept. at Penn be involved in scaling the HIV therapy in Botswana by some of the stake holders that were concerting that massive treatment in Botswana. This is Dr. Harvey Friedman; he is fundamentally a basic scientist as well as being the Chief of the Division. One of the things that he was always interested in was getting a research aspect to Penn’s involvement in Botswana up and running.

When I applied to the Internal Medicine Residency and Infectious Disease Fellowship all of my statements were ever about were doing global health and doing research. To me, the way I wanted to make a difference was by doing research and that differs I think than primarily being involved and implementing the work. I was a Fellow in Infectious Disease and at the time we were on a clinical rotation together and he said why don’t you think about going to Botswana and I was increasingly interested in focusing on HIV research at the time so it made sense.

The first trip took place several years ago and I went knowing no one except some introductions that were made. I met a lot of people, sat down and tried to listen as much as I could and really had to ask myself what could I do to add value to this situation. The first trip was sort of daunting. You are meeting people trying to work together to address this massive epidemic but people do not necessarily know what you are about. The first trip was a lot of meeting people and trying to think and then explain how I could potentially try to do something worthwhile. It felt like I was not just going there on a mission to help, it was something I always wanted to do and so it was an opportunity of a lifetime for me.

HCGHR: There are a lot of Harvard students interested in the kind of research you do, based on your two major studies. Can you describe your research for those two projects – specifically, some challenges you faced, how you got around them, and what your results revealed?

Bisson: The initial projects that I wanted to focus on, I was interested in the treatment of HIV. That was my primary interest and still is. I wanted to try and figure out what I could do to improve outcomes. One of the things I began to look at was how paying out of pocket for therapy medications influences outcomes on treatment.

It can be an inherently intense situation where you have a place where people have a certain income per year and drugs can take up a substantial amount of that income. I wanted to see if higher out of pocket costs are related to worse outcomes. We went through clinic records trying to characterize patients with respect to their co-morbidities and demographic characteristics also how they did with respect with their antiretroviral treatments and in particular how much they paid for medications and then went forward on treatment.

One of the major challenges was trying to just logistically deal with the situation there in terms of getting valid information from the medical charts. But, my goal was initially to succeed at something that was relatively small. I looked at outcomes among individuals in one of the main public clinics and in a private clinic. What we found was that, of all the people that died in the first year of antiretroviral therapy studying withdrawal therapy, 90% had CD4 counts of <100 and 90% of the deaths occurred within the first 6 months. We called this phenomenon “early death.” Early death was highly concentrated among individuals with advanced HIV and it brought up the question of why do these patients – even despite accessing and initiating potent medications that we know treat HIV – still die?

The fundamental paradigm is if you take your medicines your viral load goes down and your immune system recovers. That may be different in these people if they take their medicines and their viral loads don’t go down because their system cannot absorb the drugs because they are so sick, or their gastrointestinal system doesn’t work the way we think it does, or other reasons. That study led to our hypothesis and that there may be a U shaped relationship between immune recovery and antiretroviral therapy and survival in very late stage disease.

This made me think a lot about monitoring and trying to evaluate from a clinical care perspective and from a health perspective how patients are doing in this global antiretroviral therapy effort. In many of these places the first thing you need to do is get people on antiretroviral therapy and then you want to ensure good follow-up. In our first study, almost 60% of the patients were lost to follow-up after antiretroviral therapy initiation actually died. What we showed on the Plus One paper was that unless you count lost to follow-ups as deaths, you may very well overestimate your survival.

Later we did something larger looking at several countries from Southern Africa that were trying to scale up CD4 counts monitoring. CD4 count changes essentially relate to whether or not you are taking your HIV medications or whether your virus is suppressed. If you take your medication and your viral load goes down then your CD4 count goes up. Many programs were trying to monitor CD4 counts among these patients. We found a more direct measure of monitoring their virus that was not a laboratory test at all.

It was actually looking at how consistently and completely patients were taking their medications. We relied on the cards that the patients carry with information about when they get their drugs refilled to predict virologic failure. We compared adherence as measured by pharmacy refills by CD4 count monitoring and we found that adherence was a more accurate predictor.

We said that you should think about taking away this monitoring test and just monitor adherence because that is the most essential. You want to keep patients on the same drug regimen that they started initially. That is the cheapest and the best regimen. You want to detect lapses in adherence early as possible in order to prevent subsequent resistance. What you are doing with CD4 count monitoring is finding patients too late. When you are seeing their CD4 counts going down, their virus is already out of control.

What we suggested in the article is that monitoring adherence could identify virologic failure earlier than monitoring CD4 count. The big idea was maybe we should think about doing away with CD4 count monitoring for patients on antiretroviral therapy. Pharmacy refill adherence is something that can be automated by computerized approaches or it could be something very simple as in Botswana.

HCGHR: Finally, students interested in global health often encounter obstacles related to their qualifications when trying to pursue learning opportunities outside of the classroom. What kind of advice can you offer such students?

Bisson: Be persistent. In high school one of things my brothers and I did to make money over the summer was sell meat and seafood door to door. The one thing it taught me was that every part of life is sales. You need to have good things that you are trying to accomplish but you really have to believe in your product and you also need to be persistent and go out there and really try to sell your idea. Many of the research projects that I have gotten involved in or even some of the biggest projects that I have done, people have initially said are not good ideas. Knowledge combined with persistence essentially can make many of the people interested in global health highly successful.


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