Index Case
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《新英格兰医药杂志》
Because of my extensive training — four years of medical school, three years of pediatric residency, a two-year fellowship in pediatric infectious diseases — and because of my years of experience in practice, I had no trouble at all diagnosing my illness. I knew what was wrong with me, and I knew the technical term for it: I had the pediatric crud. It was winter, and I was seeing sick kids all day long, and now, after a couple of days of congestion and rhinorrhea, a bad cough was developing. It happens every winter, like clockwork.
Now here comes my big confession. I am ashamed to admit that on day 1 of my bad cough, I started treating myself with antibiotics. Yes, of course, I knew that in all probability I had a viral upper respiratory infection (URI), and I could probably even have named the most likely viruses. And yes, of course, I knew that antibiotics were completely useless in the setting of a viral URI, and I knew that the overuse of antibiotics is a terrible problem in our society and that the demands of patients with viral illnesses and URIs to be treated with antibiotics need to be met with careful education and explanations — certainly not with unnecessary prescriptions. I knew all that, really I did.
On the other hand, I also knew that in winters past, when my annual pediatric crud dragged into its third or fourth week, I usually ended up taking antibiotics. I would wait until my symptoms qualified to be considered bronchitis or until a colleague listened to my lungs and heard some crackles, but in the end, my annual illness would always lead to antibiotics. So since this cough seemed to have gotten so bad so quickly, I reasoned, why not just take the antibiotics right away and see if I could shorten the course? Well, maybe "reasoned" isn't quite the right verb. Let's just say that, more than a little shamefacedly, I treated myself with a five-day course of azithromycin.
It didn't help at all. My cough got worse and worse. I didn't feel too sick otherwise, but I was carrying around a jar of maximum-strength over-the-counter cough medicine, dosing myself whenever I had to see patients, teach, or do anything else that called for conversation. I viewed it as my right and proper punishment for taking unnecessary antibiotics. It never occurred to me to stop seeing patients, of course, nor did it occur to any of my coworkers, I would guess, that perhaps I shouldn't be working. I wasn't really sick, I just had the crud, and we're all wedded to that die-with-your-boots-on ethos whereby you keep on working unless you are sicker than your sickest patients. One day when I was responsible for hospital rounds, I did ask a colleague whether she thought it might be better to have someone else run over to the hospital and see a couple of newborns — I have this pretty dramatic cough, I said, and I feel a little guilty about coughing in the newborn nursery. My colleague, supremely unimpressed, and much too tight for time herself to fit in an unexpected hospital stop, sensibly suggested that I try a gown, a mask, and gloves.
So, well swathed, I rounded on the babies, and then I went on to work the evening session at the health center, seeing patients. I took the maximum-strength cough medicine and washed my hands scrupulously, and whenever I felt a coughing fit coming on in the presence of a patient, I would make some excuse to leave the room and go cough my head off in the doctors' work area. Then, the colleague who had suggested the gown and mask heard me coughing that very night and remarked that I sounded paroxysmal.
Now, "paroxysmal" is one of those coded medical words. It's like saying a baby seems a little "lethargic," rather than simply tired and clingy and cranky. You say it one way, you mean the baby has a little bug; you say it the other way, you mean do a lumbar puncture. So when she said paroxysmal, I thought, for the very first time, of pertussis. And once I had started thinking about it, I couldn't get it out of my mind — after all, I had my cough to remind me. So I went to my internist, who thought my lungs sounded fine and that my cough probably just represented a lingering viral illness — and these coughs, she warned me, can last for some time — and that pertussis was highly unlikely. But to allay my anxieties, she sent off a titer (I was more than two weeks into the cough by this point, so it was too late for a culture). And then I went back to seeing patients, and the laboratory misplaced the sample (by filing it under my first name instead of my last, it turned out), and I had to call a friend in infection control, who got someone at the lab to take another look, and eventually the sample was found — and guess what? I had pertussis.
(Figure)
Bordetella pertussis.
I had suddenly become a public health emergency. A pediatrician, seeing children all day, rounding on newborns, the mother of three children at three different schools, the close colleague of who knows how many doctors and nurses and clerical staff. I was phoned or paged by someone from Public Health every day, sometimes several times a day. I sat at my desk making a list of every friend or acquaintance with whom I had been in close contact during my infectious period.
I felt deeply, deeply ashamed. Calling these people, one after another, I felt alternately like Typhoid Mary and the person at the end of the STD partner-notification line. I had exposed them, contaminated them, put them at risk. I urged everyone to take prophylactic antibiotics, to call the doctor immediately if a cough developed. Most of all, though, I felt ashamed before my colleagues and my patients at the health center. I couldn't stand to look at the letter that was going out to the families I had seen during my period of maximal infectiousness: "Your child may have been exposed to a staff member who has pertussis." I did not want to be the doctor who saw any of those families when they came in to get their antibiotics or, if they were coughing, their nasal swabs and their antibiotics. I did not want any of them to know that I was the staff member with pertussis. And to make matters worse, I was still coughing — now not infectious but still coughing pretty dramatically, just in case the local public health emergency had slipped anyone's mind for even a minute.
Some of my anxieties were relatively well grounded in reality. Pertussis, after all, is most dangerous to infants, who account for almost all the hospitalizations and the deaths associated with the disease. And the surveillance data show a steady increase in the rate of disease among infants in the United States between 1980 and 1999 — an increase that may be attributable in part to increased transmission from adults.1 And here I was, one of those adults. We do know that much pertussis disease in adolescents and adults may present as nonspecific or persistent cough and may therefore go unrecognized.2 We do not know why the rate of disease in adults should be on the increase, if in fact it is. The confluence of various factors may be to blame: the waning immunity of the vaccinated adolescent and adult population, for instance, and the decreased likelihood that immunity will be boosted by exposure to natural disease.
I was an adult, vaccinated as a child, presumably with waning immunity, which had probably been boosted by exposure to some natural disease during my childhood, 40 years ago, and perhaps by the occasional occupational exposure (I can remember at least two occasions during my residency when prophylaxis was prescribed, though I have to confess that back in those days when two weeks of erythromycin were required, my compliance was dubious and I probably did not finish either course). Maybe my own waning vaccine-induced immunity finally intersected with a sufficiently infectious exposure — but epidemiologic speculation feels different when you yourself are the index case. What I kept picturing were sick babies — individual tiny bodies wracked with coughing fits. There were all the infants I had examined in the clinic, there were the babies in the nursery . . . there was even a friend who had shared a cab with me who had a newborn grandchild, and I imagined the chain of risk and exposure stretching far enough to threaten that baby as well.
Of course, I had seen pertussis. I saw a very dramatic case during my residency, in an infant who had deliberately not been vaccinated ("crunchy granola parents," we residents whispered to one another), who was brought into the emergency room looking terrific, but his parents had tape-recorded his coughing spells, telling us they had never heard anything like this. And indeed, the spells were terrifying; you listened to the tape, and you could swear the baby was dying of strangulation before your very ears. And at the end of each spell came that terrifying unearthly whoop, as if the baby were possessed by some evil-intentioned spirit of respiratory compromise. Every resident and medical student in the hospital was brought to that baby's room during his hospitalization, and the word was passed: once you hear a real whoop, you'll never forget it (an audio clip is available with the full text of this article at www.nejm.org). Well, I had never forgotten it, but adults, by and large, don't whoop, so it had never occurred to me that I might have the same disease as that baby. Some pediatric infectious-diseases specialist, some diagnostic whiz kid!
I'm not sure now exactly why I was so ashamed. Presumably, after all, I had contracted pertussis in the line of duty — pediatric infections are an occupational risk, and for all our careful hand washing, if you see sick kids all day long, sometimes some enterprising microorganism makes the jump, through direct contact, through fomite, or through respiratory droplet. It is a professional responsibility, and even a professional point of pride, not to run from the sick but to move toward them and touch them. But there was something about the idea that instead of helping, I might have gone from day to day and from exam room to exam room doing harm that left me deeply embarrassed. In addition, I was embarrassed that despite all that training, the word "pertussis" never crossed my mind until someone else listened to my cough with interest and characterized it for me.
There was only one really bright element in these bleak few days, as I huddled over my list of exposed friends, calling them up one after another with the bad news, as I went slinking through the health center imagining resentful looks from nurses and doctors and patients alike: at least I had taken antibiotics, and taken them early. The public health nurse who was assigned to my messy case kept saying it to me on the phone: "Thank God you took those pills!" Because I had started taking azithromycin (which, in Massachusetts, is now a recommended treatment for pertussis) on day 1 of my cough, I was considered to be noninfectious by day 5, so instead of contacting and prophylactically treating about two weeks' worth of patients, we ended up with a relatively short list of children who might have been exposed — and the consolation that even when I saw many of those children, I had been at least partially treated, which might have reduced the risk of transmission. Those babies in the newborn nursery, for example, were not considered to be at risk. And I found myself saying it to my friends, when I called to notify them: "Now, I did take antibiotics right away, but since we spent some time together before I was fully treated, I just wanted to let you know. . . ." And as time went on and we failed to uncover any secondary cases that could be traced to me, I kept reminding everyone about that early antibiotic treatment, as if it let me cling to some shreds of doctorly dignity: I had done the right thing, I had used my special knowledge, I had protected those I could protect. In other words, I consoled myself for my irrational sense of shame about having possibly exposed patients to infection with an irrational sense of self-satisfaction about having taken antibiotics for no good reason.
Pertussis may be on the increase in this country, but in many ways it still seems like a disease that does not quite belong to our era. When I had to call people and announce, "I have whooping cough," I felt like a medical curiosity or the punch line of someone's ironic anecdote: the pediatrician with the rare, vaccine-preventable disease. When the public health officials were calling me, I felt like some other kind of epidemiologic specimen: patient zero, the walking disease-control headache. And through the whole experience, every so often, all my various emotions would disappear into a true and impressive paroxysm of coughing, coughing, and more coughing, as the microbiology and the respiratory pathology took over and left me doubled over, momentarily speechless, and gasping for breath.
Source Information
From the Boston University School of Medicine and Boston Medical Center, Boston.
References
Tanaka M, Vitek CR, Pascual FB, Bisgard KM, Tate JE, Murphy TV. Trends in pertussis among infants in the United States, 1980-1999. JAMA 2003;290:2968-2975.
Pertussis -- United States, 1997-2000. MMWR Morb Mortal Wkly Rep 2002;51:73-76.(Perri Klass, M.D.)
Now here comes my big confession. I am ashamed to admit that on day 1 of my bad cough, I started treating myself with antibiotics. Yes, of course, I knew that in all probability I had a viral upper respiratory infection (URI), and I could probably even have named the most likely viruses. And yes, of course, I knew that antibiotics were completely useless in the setting of a viral URI, and I knew that the overuse of antibiotics is a terrible problem in our society and that the demands of patients with viral illnesses and URIs to be treated with antibiotics need to be met with careful education and explanations — certainly not with unnecessary prescriptions. I knew all that, really I did.
On the other hand, I also knew that in winters past, when my annual pediatric crud dragged into its third or fourth week, I usually ended up taking antibiotics. I would wait until my symptoms qualified to be considered bronchitis or until a colleague listened to my lungs and heard some crackles, but in the end, my annual illness would always lead to antibiotics. So since this cough seemed to have gotten so bad so quickly, I reasoned, why not just take the antibiotics right away and see if I could shorten the course? Well, maybe "reasoned" isn't quite the right verb. Let's just say that, more than a little shamefacedly, I treated myself with a five-day course of azithromycin.
It didn't help at all. My cough got worse and worse. I didn't feel too sick otherwise, but I was carrying around a jar of maximum-strength over-the-counter cough medicine, dosing myself whenever I had to see patients, teach, or do anything else that called for conversation. I viewed it as my right and proper punishment for taking unnecessary antibiotics. It never occurred to me to stop seeing patients, of course, nor did it occur to any of my coworkers, I would guess, that perhaps I shouldn't be working. I wasn't really sick, I just had the crud, and we're all wedded to that die-with-your-boots-on ethos whereby you keep on working unless you are sicker than your sickest patients. One day when I was responsible for hospital rounds, I did ask a colleague whether she thought it might be better to have someone else run over to the hospital and see a couple of newborns — I have this pretty dramatic cough, I said, and I feel a little guilty about coughing in the newborn nursery. My colleague, supremely unimpressed, and much too tight for time herself to fit in an unexpected hospital stop, sensibly suggested that I try a gown, a mask, and gloves.
So, well swathed, I rounded on the babies, and then I went on to work the evening session at the health center, seeing patients. I took the maximum-strength cough medicine and washed my hands scrupulously, and whenever I felt a coughing fit coming on in the presence of a patient, I would make some excuse to leave the room and go cough my head off in the doctors' work area. Then, the colleague who had suggested the gown and mask heard me coughing that very night and remarked that I sounded paroxysmal.
Now, "paroxysmal" is one of those coded medical words. It's like saying a baby seems a little "lethargic," rather than simply tired and clingy and cranky. You say it one way, you mean the baby has a little bug; you say it the other way, you mean do a lumbar puncture. So when she said paroxysmal, I thought, for the very first time, of pertussis. And once I had started thinking about it, I couldn't get it out of my mind — after all, I had my cough to remind me. So I went to my internist, who thought my lungs sounded fine and that my cough probably just represented a lingering viral illness — and these coughs, she warned me, can last for some time — and that pertussis was highly unlikely. But to allay my anxieties, she sent off a titer (I was more than two weeks into the cough by this point, so it was too late for a culture). And then I went back to seeing patients, and the laboratory misplaced the sample (by filing it under my first name instead of my last, it turned out), and I had to call a friend in infection control, who got someone at the lab to take another look, and eventually the sample was found — and guess what? I had pertussis.
(Figure)
Bordetella pertussis.
I had suddenly become a public health emergency. A pediatrician, seeing children all day, rounding on newborns, the mother of three children at three different schools, the close colleague of who knows how many doctors and nurses and clerical staff. I was phoned or paged by someone from Public Health every day, sometimes several times a day. I sat at my desk making a list of every friend or acquaintance with whom I had been in close contact during my infectious period.
I felt deeply, deeply ashamed. Calling these people, one after another, I felt alternately like Typhoid Mary and the person at the end of the STD partner-notification line. I had exposed them, contaminated them, put them at risk. I urged everyone to take prophylactic antibiotics, to call the doctor immediately if a cough developed. Most of all, though, I felt ashamed before my colleagues and my patients at the health center. I couldn't stand to look at the letter that was going out to the families I had seen during my period of maximal infectiousness: "Your child may have been exposed to a staff member who has pertussis." I did not want to be the doctor who saw any of those families when they came in to get their antibiotics or, if they were coughing, their nasal swabs and their antibiotics. I did not want any of them to know that I was the staff member with pertussis. And to make matters worse, I was still coughing — now not infectious but still coughing pretty dramatically, just in case the local public health emergency had slipped anyone's mind for even a minute.
Some of my anxieties were relatively well grounded in reality. Pertussis, after all, is most dangerous to infants, who account for almost all the hospitalizations and the deaths associated with the disease. And the surveillance data show a steady increase in the rate of disease among infants in the United States between 1980 and 1999 — an increase that may be attributable in part to increased transmission from adults.1 And here I was, one of those adults. We do know that much pertussis disease in adolescents and adults may present as nonspecific or persistent cough and may therefore go unrecognized.2 We do not know why the rate of disease in adults should be on the increase, if in fact it is. The confluence of various factors may be to blame: the waning immunity of the vaccinated adolescent and adult population, for instance, and the decreased likelihood that immunity will be boosted by exposure to natural disease.
I was an adult, vaccinated as a child, presumably with waning immunity, which had probably been boosted by exposure to some natural disease during my childhood, 40 years ago, and perhaps by the occasional occupational exposure (I can remember at least two occasions during my residency when prophylaxis was prescribed, though I have to confess that back in those days when two weeks of erythromycin were required, my compliance was dubious and I probably did not finish either course). Maybe my own waning vaccine-induced immunity finally intersected with a sufficiently infectious exposure — but epidemiologic speculation feels different when you yourself are the index case. What I kept picturing were sick babies — individual tiny bodies wracked with coughing fits. There were all the infants I had examined in the clinic, there were the babies in the nursery . . . there was even a friend who had shared a cab with me who had a newborn grandchild, and I imagined the chain of risk and exposure stretching far enough to threaten that baby as well.
Of course, I had seen pertussis. I saw a very dramatic case during my residency, in an infant who had deliberately not been vaccinated ("crunchy granola parents," we residents whispered to one another), who was brought into the emergency room looking terrific, but his parents had tape-recorded his coughing spells, telling us they had never heard anything like this. And indeed, the spells were terrifying; you listened to the tape, and you could swear the baby was dying of strangulation before your very ears. And at the end of each spell came that terrifying unearthly whoop, as if the baby were possessed by some evil-intentioned spirit of respiratory compromise. Every resident and medical student in the hospital was brought to that baby's room during his hospitalization, and the word was passed: once you hear a real whoop, you'll never forget it (an audio clip is available with the full text of this article at www.nejm.org). Well, I had never forgotten it, but adults, by and large, don't whoop, so it had never occurred to me that I might have the same disease as that baby. Some pediatric infectious-diseases specialist, some diagnostic whiz kid!
I'm not sure now exactly why I was so ashamed. Presumably, after all, I had contracted pertussis in the line of duty — pediatric infections are an occupational risk, and for all our careful hand washing, if you see sick kids all day long, sometimes some enterprising microorganism makes the jump, through direct contact, through fomite, or through respiratory droplet. It is a professional responsibility, and even a professional point of pride, not to run from the sick but to move toward them and touch them. But there was something about the idea that instead of helping, I might have gone from day to day and from exam room to exam room doing harm that left me deeply embarrassed. In addition, I was embarrassed that despite all that training, the word "pertussis" never crossed my mind until someone else listened to my cough with interest and characterized it for me.
There was only one really bright element in these bleak few days, as I huddled over my list of exposed friends, calling them up one after another with the bad news, as I went slinking through the health center imagining resentful looks from nurses and doctors and patients alike: at least I had taken antibiotics, and taken them early. The public health nurse who was assigned to my messy case kept saying it to me on the phone: "Thank God you took those pills!" Because I had started taking azithromycin (which, in Massachusetts, is now a recommended treatment for pertussis) on day 1 of my cough, I was considered to be noninfectious by day 5, so instead of contacting and prophylactically treating about two weeks' worth of patients, we ended up with a relatively short list of children who might have been exposed — and the consolation that even when I saw many of those children, I had been at least partially treated, which might have reduced the risk of transmission. Those babies in the newborn nursery, for example, were not considered to be at risk. And I found myself saying it to my friends, when I called to notify them: "Now, I did take antibiotics right away, but since we spent some time together before I was fully treated, I just wanted to let you know. . . ." And as time went on and we failed to uncover any secondary cases that could be traced to me, I kept reminding everyone about that early antibiotic treatment, as if it let me cling to some shreds of doctorly dignity: I had done the right thing, I had used my special knowledge, I had protected those I could protect. In other words, I consoled myself for my irrational sense of shame about having possibly exposed patients to infection with an irrational sense of self-satisfaction about having taken antibiotics for no good reason.
Pertussis may be on the increase in this country, but in many ways it still seems like a disease that does not quite belong to our era. When I had to call people and announce, "I have whooping cough," I felt like a medical curiosity or the punch line of someone's ironic anecdote: the pediatrician with the rare, vaccine-preventable disease. When the public health officials were calling me, I felt like some other kind of epidemiologic specimen: patient zero, the walking disease-control headache. And through the whole experience, every so often, all my various emotions would disappear into a true and impressive paroxysm of coughing, coughing, and more coughing, as the microbiology and the respiratory pathology took over and left me doubled over, momentarily speechless, and gasping for breath.
Source Information
From the Boston University School of Medicine and Boston Medical Center, Boston.
References
Tanaka M, Vitek CR, Pascual FB, Bisgard KM, Tate JE, Murphy TV. Trends in pertussis among infants in the United States, 1980-1999. JAMA 2003;290:2968-2975.
Pertussis -- United States, 1997-2000. MMWR Morb Mortal Wkly Rep 2002;51:73-76.(Perri Klass, M.D.)