Interview with Dr. David K. Henderson

Harden: Dr. Henderson, would you begin by describing your background and education, and the positions you held before you came to the National Institutes of Health (NIH)?

Henderson: I went to undergraduate school at Hanover College in Hanover, Indiana. It is a small, liberal arts college in southern Indiana. I went from there to the University of Chicago Pritzker School of Medicine, where I got an M.D. degree in 1973. From there I went to Harbor UCLA [University of California Los Angeles] Medical Center, which is one of the UCLA teaching hospitals, where I did an internship and a residency in internal medicine. I then stayed on for a two-year fellowship in infectious diseases and, finally, the last year I was there, joined the UCLA faculty for a year.

Harden: What made you decide to go into medicine, and why did you decide to specialize in infectious diseases?

Henderson: The first question is much harder than the second. I have always been interested in science, and in my four years in undergraduate school I was a biology major and I took a lot of chemistry as well. I always seemed to be interested in the practical applications of basic science knowledge in medicine. But I also liked teaching. So I compromised in my own mind by choosing a career in academic medicine where, hopefully, I would never have to “leave the womb,” so to speak, but would be able to stay in touch with medicine and the practical applications of scientific findings as they came from the basic science laboratories into clinical medicine.

Infectious diseases, as a choice, was something of an accident. I had, for a long time, thought that I would be a hematologist and, in fact, went so far in my next to last year at Harbor [UCLA] as to accept a fellowship in hematology. But the infectious disease team at Harbor were the doctor's doctors. If you needed a “doctor consult,” that is, if you had a particularly problematic patient, the team that was always called was the infectious disease team. They were a cerebral group that was fun, and I was, I think, seduced by that. I am really glad that I was, because infectious diseases is, as it turns out, a very academic subspecialty.

Harden: So the intellectual rewards were a very strong pull for you, as they were for many people?

Henderson: Yes.

Harden: Could you describe your research interests before you became involved with AIDS? For example, talk about some of the papers that you were publishing and what you were interested in.

Henderson: Just to pick up, from my time at Harbor, in the last year of my fellowship, I became interested in fungal infections of man. Clinical mycology is, in some respects, a subspecialty in infectious diseases. The major reason I came to the Clinical Center at NIH was to work with [Dr.] John Bennett in NIAID [National Institute of Allergy and Infectious Diseases], who was at that time, and I suspect still is, the world's greatest living clinical mycologist. The opportunity to come back here to work and train with Dr. Bennett was a terrific one. Dr. Bennett was at that time doing the job of hospital epidemiologist gratis for the Clinical Center. There had never been a formal position for a hospital epidemiologist at the NIH. I actually called Dr. Bennett and said, “I have two job offers. I am looking toward a career in clinical mycology. Would you help me decide which of these two job offers is likely to be the best stepping stone to a career in academic medicine?”

He said, “Before you tell me about those two, let me tell you about a third option.” He said, “Why don't you think about coming back to the NIH and being the hospital epidemiologist?” I said, “That would be terrific, if I had any relevant training.” He said, “No one has any relevant training to be a hospital epidemiologist. Come back here and you can cover hospital epidemiology with a small fraction of your time and have the rest of the time to work in the laboratory.”

So I came to NIH, the first year on an IPA [interagency personnel agreement], maintained my UCLA faculty position, was here for a year or a year and a half, and was working for the Clinical Center. I came down and spoke with Dr. Mortimer Lipsett, who was then the director of the Clinical Center, and told him that I needed to take time off to try to find a permanent position. He told me–actually he did not ask me, he told me–that I would not be leaving, that I would be staying, and that he would offer me a job as the full-time hospital epidemiologist.

Harden: Could you tell us more about Dr. Bennett and the Clinical Mycology Section?

Henderson: Certainly. Dr. Bennett, at the time I came, had active research interests in several fungal diseases. He had active investigations in aspergillosis, some in candidiasis, and some in cryptococcosis. I had been interested in Candida when I came to the NIH, coming from UCLA, but he encouraged me to become interested in cryptococcosis. He has a cohort of patients that he had treated over the years; he probably has more patients who have survived systemic cryptococcal infection than any living investigator. The disease in many people's hands has a very high mortality. Dr. Bennett is quite skilled at taking care of cryptococcosis patients and has a loyal following among them. His patients are willing, almost on a moment's notice, to come back and be studied. So we had several ideas of things we might do. I became interested in the role of the humoral immune system in host defense against cryptococcosis. We worked hard on that cohort of patients immunizing them with cryptococcal polysaccharide and also immunizing normal volunteers here and comparing their responses. We wanted to see if we could determine why patients who get this overwhelming systemic fungal infection, who have literally grams of cryptococcal polysaccharide circulating in their bloodstream, never make an antibody response to the polysaccharide. Interestingly, when we immunized normal volunteers they made a brisk antibody response. That was where my work with Dr. Bennett began.

Harden: This work on both of those infections set you up for work on AIDS?

Henderson: Certainly for learning a lot about both the humoral and cellular immunity. One of the things that Jack Bennett wanted me to do when I first came to NIH was to learn a little more about immunology. So, my old mentor from Harbor, [Dr. John] Jack Edwards, and I took two-and-one-half weeks off and went to Frederick, Maryland, to the American Association of Immunologists' Intensive Course in Immunology. That course was a real baptism by fire for me. It took me two or three days to gain an appreciation for precisely which language the lecturers were speaking. The course was a wonderful experience. Thus, really the combination of all of those experiences, I think, in retrospect–that set me up to be able to think about how we ought to manage this problem [AIDS] when it came to our hospital.

Rodrigues: You have already touched upon the role of the hospital epidemiologist and the fact that you were the first person formally to occupy that position at the NIH. Dr. Bennett, you say, was doing this gratis before you came. But could you tell us more about this concept of the hospital epidemiologist? Was this something new emerging in hospitals?

Henderson: The importance of hospital infections, per se, became apparent in the late 1950s and early 1960s when the staphylococcus became resistant to penicillin. There were epidemics of staphylococcal infections in hospitals around the country, with seemingly no way for physicians or the hospital staff to fight them. People did not understand the epidemiology of these infections, how the organism was being transmitted, or what one might do to prevent transmission. The problem of antibiotic resistance continued to accelerate, and the Centers for Disease Control [CDC] became interested. The first conference on nosocomial infections in the U.S. was held in 1970. It was called “The First International Conference on Nosocomial Infections,” and it was essentially at this conference that the concept of a hospital infection control program was developed and discussed.

Such programs had been in existence in England for years, but in the United States, hospital epidemiology or infection control, as a discipline, really arose out of the CDC's interest in trying to control hospital-associated infections. Following that initial conference in 1970, there have been decennial conferences in 1980, 1990, and there will be another one in 2000, evaluating the progress of hospital epidemiology as a discipline in the U.S.

Initially, in most institutions, infection control was a nursing function, and most hospitals did not have physician hospital epidemiologists. Most hospitals had a nurse or two who did surveillance, collected surveillance information, and tracked down nosocomial infections. The nurse often had the assistance of a physician who volunteered his time to support the program. That is how most programs got by in the early days.

In the 1970s this new discipline of hospital epidemiology really sprang out of the Infectious Disease Society of America. Several individuals in that organization began to see a need for a full-time physician in academic hospitals to deal with the problems of the transmission of bacteria, viruses, and fungi in the hospital, in great measure because so little was known about the epidemiology and risks for transmission of nosocomial or hospital-associated infections. In a way, it redefined hospital epidemiology. As I said earlier, I had no formal training in either hospital epidemiology or in the formal discipline of epidemiology; what I have learned, I have learned on the job. I would point out, however that I have not relinquished that job [of hospital epidemiologist] either, and the last hour before this interview I spent with my staff going over epidemiologic principles and some problems specific to the Clinical Center. Despite my increased responsibilities, I still enjoy working in hospital epidemiology and feel to some extent that the Clinical Center is “my laboratory.”

Rodrigues: Was it Dr. Lipsett's decision then actually to formalize this position?

Henderson: What happened, as I recall–and again this is my best recollection-was that Dr. Bennett, in his own inimitable way, had gone to Dr. Lipsett and said, “You have me running the hospital infection control program, and I am also supervising the infection control nurses. It is getting to be more than I want to do and it is taking too much of my time. I do not want to have to do that all the time,” (knowing all along that he had somebody ready to come and do it for him).

Rodrigues: I see.

Henderson: When Dr. Lipsett said, “What should we do about this?” Dr. Bennett said, “I know this young lad who would be just perfect for the job.” This was a classic NIH maneuver where he got Dr. Lipsett to ante up the salary for the first year and then the FTE [full time equivalent position] for the job. Dr. Bennett got another pair of hands to work in his laboratory and someone to do the hospital epidemiology function as well. It was a win/win situation for him and, I must say, for me as well.

Rodrigues: Let us shift gears now to focus on our project and ask you when you first became aware of AIDS. In a sense the way we have framed our question is not quite correct. You probably first became aware of patients with abnormal immune systems and a collection of bizarre opportunistic infections.

Henderson: The first I learned about the disease in detail must have been at the Infectious Disease Meetings in the fall of 1981. The meetings are scheduled long in advance, and this problem was beginning to surface by then. It had been known since June, when the first report was published, and there were several reports by the fall. There was an impromptu meeting held at night. No one likes to go to evening meetings; the only time you ever have any fun as an academic doctor is to go off to some convention and you have the evenings to go out to dinner with your colleagues. But the hall at this impromptu meeting was jammed, literally, with people fascinated by this new disease.

I remember looking at the first patient at the NIH Clinical Center, not knowing what the patient had. The patient had been admitted to [Dr. Thomas] Tom Waldmann's immunodeficiency service and I went as a consultant and stood around the bed of a man whose name I used to be able to remember. I remember standing around with several of the world's most eminent immunologists looking at this young man.