A Plague on All Your Houses



I still remember a seminar I went to years ago in university. It was part of a nebulous course on ‘Health’ that some of us took as a soft route on the way to a bachelor’s degree. It was reputed to consist of essays and a true or false final examination. Also, because the class was small, it was amenable to division into even smaller numbers for several interactive sessions.

There were five of us and a teacher’s aide at the one I remember so well. We were all fresh from high school and, at least in those faraway days, used to being lectured at, rather than actually contributing to the subject matter. The topic that day was Disease, and I remember being mildly interested, but expecting only a list of the usual culprits, complete with causes and treatments -memory fodder for later regurgitation, I suppose.

“What is disease?” the TA started, as soon as we were seated around a rather small wooden table.

One of us -I don’t remember his name now- rolled his eyes and smiled. “Sickness,” he answered, rather smugly.

She smiled in return, as if he’d fallen into her trap rather too easily. “Okay, but haven’t you just used a synonym -defined it in terms of itself?”

He stared at her for a moment, obviously confused. “Well… then, how about saying disease is an abnormality of an organ or a system caused by germs -probably particular germs depending on the disease.”

Her face relaxed and her smile broadened. “Now we’re getting somewhere.” She leaned forward on the table. “Let’s get more specific for a moment. Let’s take tuberculosis… Anybody know the cause for TB?” She glanced around the room, determined to involve us all, apparently.

I looked up at the wrong moment, and she brushed my face with her question and pinned me to my seat with another smile. “Do you know the cause of TB…?” she said, locking eyes with me.

There was no escape. “Uhmm…” I felt embarrassed at being singled out, but the question seemed fairly straightforward. “It’s the tubercle bacterium, isn’t it?”

She sat back in her chair, and shrugged nonchalantly. “Is it?” She said, softly and with just a hint of gentle sarcasm. But her eyes were still sitting on me, and I could tell they meant no harm.

“Tubercle bacillus?” I corrected myself, remembering that people sometimes called it that.

“So…” she glanced around the table again, lifting the weight off my shoulders. “Would you all agree that TB is caused by a bacterium -a bacillus?” she added, looking at me once more. Everybody nodded.

“But don’t some healthy people have a positive skin test for it -the Mantoux test?” she continued.

We all nodded, most of us unwilling to show that we hadn’t known what the test was called.

“So, why is that?” She paused to see if any of us had an explanation, but when nobody said anything, she continued. “If the bacterium Mycobacterium tuberculosis is present…” she slowed down even more for effect. “… if some of us have it… and it causes TB… then why don’t those people have TB?” She straightened in her chair and leaned on the table with her elbows as she searched our faces for the answer.

But she was greeted by blank, albeit confused expressions around the table.

“If disease is caused by the acquisition of a bacterium, then what stops some people from acquiring the disease?”

This was new territory for us, and yet, her eyes stopped at me again. “Our defense mechanisms -the immune system…?” I suppose it wasn’t exactly a scholarly response -even in those days we’d all heard of vaccinations and antibody production.

She started nodding. “Okay, but what makes the immune system strong enough to resist?”

“VSG?” someone said, and immediately blushed because he had obviously taken a leap in the dark with the initials.

She smiled reassuringly. “BCG -Bacille Calmette-Guerin, to give it its full name?” He nodded, presumably relieved. But even in those days, there was some doubt as to its effectiveness, so she merely shrugged again. “But the person may never go for the skin test and so never know she has the bacterium…”

She stared at me again, for some reason. “Well, suppose they’re in good condition -healthy, I mean?” To tell the truth, I didn’t really know what I meant.

“But doesn’t ‘healthy’ mean free of disease? Isn’t that another tautology…?” She walked around the table with her eyes again, but this time more slowly. “So, might there be other causes of disease -apart from the infecting agent, I mean?”

I remember some of us looking at each other, as if we were beginning to understand where she was going with this.

“Where -or maybe under what conditions- do we see a lot of diseases like TB?”

I suppose I remember the seminar so well, because she kept looking at me when nobody else answered. “You mean if somebody’s poor, or living in unfortunate circumstances? Poverty…?” I managed to mumble, hoping that was what she was after.

I still remember her smile.

It was a seminal moment for me, and maybe one of the reasons why I eventually went into Medicine. But it all resurfaced when I happened upon an article in the CMAJ (Canadian Medical Association Journal) from January 22/18 with the rather long and certainly uninviting title, Effect of provincial spending on social services and health care on health outcomes in Canada: an observational longitudinal study: http://www.cmaj.ca/content/190/3/E66

Its thesis, was that spending on health care is escalating so significantly it will soon be unaffordable. The question then, was what to do about it. The study ‘used retrospective data from Canadian provincial expenditure reports, for the period 1981 to 2011, to model the effects of social and health spending (as a ratio, social/health) on potentially avoidable mortality, infant mortality and life expectancy.’ And after using various methods to analyze the figures that I didn’t even try to understand, like ‘linear regressions, accounting for provincial fixed effects and time, and controlling for confounding variables at the provincial level.’ decided that ‘Population-level health outcomes could benefit from a reallocation of government dollars from health to social spending […].’ Or, as they worded it more succinctly in their concluding paragraph: ‘The results of our study suggest that spending on social services can improve health. Social policy changes at the margins, where it is possible to affect population health outcomes by reallocating spending in a way that has no effect on the overall government budget.’

It made me wonder, though, why, if I learned the same thing many years ago, did it still need investigation? Were we so wrong back then? So naïve…?










Ever since I was a little knicker I had a dog, or a cat, or both. It was part of growing up –playing with the dog in the park, avoiding the cat’s claws as it grabbed for the piece of wool dangling temptingly in front of it. And then there were the times sitting curled up in the dog house just to see what it was like to live there, or sharing my ice cream cone with it because it looked hungry. Being licked in the face was also easier than washing before dinner… Memories, no doubt aggrandized with time, but nonetheless part of the mythology of childhood. My childhood; my mythology.

But I had somehow assumed that it was just a part of la Belle Époque for people of my age; something that the younger generations had long since abandoned for fear of contagion or changing perceptions of what a child should be allowed to do -or want to do. We live in a much more heterogeneous, sanitary society than we used to: a cultural melange that often accords animals a different role in our lives. Whether this is an advancement or merely a change in outlook didn’t much concern me: I’ve already had my past, lived my childhood.

But several months ago I happened upon a review article in the Canadian Medical Association Journal http://www.cmaj.ca/content/187/10/736.full on ‘Reducing the risk of pet-associated zoonotic infections’ and it got me thinking about my pregnant patients and their unintended risks. Of course, every health care provider –every woman, it seems- knows about not cleaning out the kitty litter in pregnancy (Toxoplasmosis) –and even avoiding the other end of the cat (Cat-scratch disease: gram-negative bacterial infections)- and yes, or the perils of eating some types of raw fish sushi too frequently (Mercury contamination). These all seem to be part of a societal mythos to which we are so often exposed, that one almost wonders if there is a gene that the placenta activates whose sole job is to send avoidance signals to the pregnant brain.

And yet the article outlined many more diseases that animals can transmit to humans (zoonoses) that are more quietly under the radar –multidrug-resistant bacteria as an increasingly worrisome emerging threat, for example. So, in the interests of patient safety, I thought it incumbent upon me to add animals to my list of questions. There was no spot for them on the prenatal form, so I kind of slipped it in under ‘other’. Along with ‘occasionally’, I find that ‘other’ is one of the more important categories of words that I like to use.

One woman, Lorraine, seemed to find the questions objectionable however. It was almost as if she felt I was accusing her of uncleanliness, or maybe petophilia, or something.

“I’ve never owned a cat, doctor,” she said with a bit of a huff in her voice. “I’ve always thought they were dirty animals,” she added, as if to justify her vehemence. “They eat vermin when you’re not around.”

“Sometimes that’s a good thing,” I said, hoping to calm her down a little.

She pinned me to my seat with needles from her eyes. She obviously resented the inference of suboptimal conditions where she lived. I left it lying fallow.

“We do have a dog, however –my husband insists on having one,” she admitted with a little reluctant shrug, obviously wary of my reaction. “But it is only allowed on the rug in the kitchen –far away from the food preparation area- and it sleeps in the garage.” She stared out the window behind me, this time avoiding my eyes. “And he takes it to the vet all the time for its vaccinations and flea medication. Costs him a fortune, what with the price vets charge nowadays.” Her eyes flitted around the room, obviously tallying the cost of the pictures on the wall, and even the knickknacks on a little oak table that patients had given me. Obstetricians were clearly not immune to price-gouging –although in Canada with our healthcare system, the extortion was presumable aimed at the government.

Then she waxed reflective. “I had a dog when I was young, though. Boots was his name and he used to follow me to school –I lived in a small town with not much traffic,” she was quick to explain, lest I think she was careless about its safety. “We used to share everything, I remember.” She risked a quick, guilty glance at my face to see if she had transgressed, even at that age.

“And then I got parasites –cryptosporidium­. My mother made me memorize the word; she says I got it from being licked in the face by Boots. I remember I had terrible diarrhea and cramps, but I also remember her telling me that there was no treatment for it and that because of what I let the dog do, I was going to have parasites for the rest of my life… She had a drinking problem at the time, though, so she soon forgot about it… I didn’t.” She sighed somewhat theatrically and continued. “After that initial attack of diarrhea I never had the problem again, so like about so many other things, maybe she was wrong about that.”

I nodded reassuringly. “People with intact immune systems seem to be able to restrain it –keep it in check. And besides, how certain were they of the diagnosis back then?”

She shrugged. “It was just something my mother told me…”

A sudden look of panic attacked her face. “The immune system is dampened in pregnancy isn’t it?” But before I could explain what that meant, her eyes opened like she’d seen a ghost. “Am I going to give it to my baby?”

The answer, of course, is probably not –especially if the condition is not active during the pregnancy- but using a ‘probably’ would only inflame her anxiety. I find when there is a heightened level of concern that actually looking it up on the computer as they sit and watch, is very reassuring: I am then au courant. So I Googled the Center for Disease Control website for ‘infections in pregnancy’ (http://www.cdc.gov/ncbddd/disasters/infections.html) and printed it out for her. It wasn’t much, but it seemed to help. It didn’t do anything to foster a more tolerant attitude towards dogs, however…

That night, as I sat reading in the living room in front of a crackling fire and my own dog lay dreaming near the fireplace, I got to thinking about my own life with dogs. Was I at risk? But then, when I stirred in my chair and one of his eyes opened and stared at me curiously, I realized it didn’t really matter. The risk was worth it.

Umm, I did wash my hands this time after he wandered over and licked them, however; but I think he was just telling me not to worry about him


Vehicular Obstetrics

Here I am in New Zealand, land of narrow roads, one lane bridges, and at least for us North Americans, the necessity of switching our cultural allegiance from the right to the left hand side of the road. Personally, my greatest struggle is remembering to get into the car through the correct door. Everything seems mirror-imaged, including the controls on the dashboard –you can tell tourists at a crossroad because their windshield wipers start up before their turning signal.

But of course, that’s what I love about the country; I drive a lot when I come here, so traffic always is in my mind, if not in my heart. The ever-distracting scenery seems to require more attention than back home, despite the smaller population .

It all reminds me of a Canadian study reported in the Canadian Medical Association Journal (CMAJ) of July 8/14  http://www.cmaj.ca/content/186/10/742.full  which  ‘compared the risk of a serious motor vehicle crash during the second trimester to the baseline risk before pregnancy.’  It was a large study which used the women themselves as their own controls before and during pregnancy. Interestingly, the relative risk of motor vehicle accidents rose by 42% in the second trimester of pregnancy. As the authors state: ‘The increased risk extended to diverse populations, varied obstetrical cases and different crash characteristics. The increased risk was largest in the early second trimester and compensated for by the third trimester. No similar increase was observed in crashes as passengers or pedestrians, cases of intentional injury or inadvertent falls, or self-reported risky behaviours.’

In other words, there seems to be something, not so much about pregnancy per se, as about the second trimester. It’s obviously only one study and more research has to be done to substantiate the findings, but there is some corroboration mentioned in a Commentary on the report in the same issue: ‘A population-based study from North Carolina found that the highest risk of a motor vehicle crash during pregnancy occurred at 20–31 weeks’ gestation, with a marked decline in the risk of a crash thereafter,3 which is similar to the current study’s results.’  http://www.cmaj.ca/content/186/10/733.full

Pregnancy has long been coloured by reports of altered memory, concentration, sleep deprivation and fatigue, but why does the second trimester seem to be the time of greatest risk? The authors recognized the difficulties and used an interesting set of criteria to help explain it: ‘with all observational studies, it is difficult to make causal inferences. In this article, we assess the associations shown in the study in light of the criteria proposed by Hill:2 temporality, consistency, biological plausibility and evidence of a dose–response effect.’ In other words, do the study findings satisfy these conditions? By and large, they feel they did, with reservations you can address through the links.

As an obstetrician of many years, I can’t remember being asked about the act of driving while pregnant. About being more careful, yes; about where to position the seatbelt, yes; and even about whether or not to report to the hospital if there is a relatively minor accident –more of a bump than a crash. If asked, I’m sure I would have pointed out the altered anatomy and how it might not fit as comfortably behind a steering wheel as pregnancy advanced, but I don’t think I would have singled out the second trimester as being the time of greatest concern. So I’m intrigued by the findings.

The authors have been diligent in pointing out the limitations of their study –such things as distance travelled, frequency of travel, and that after an accident, a pregnant woman might be more likely to report to a hospital because of worry about her foetus even if she weren’t injured herself. It still doesn’t explain the seeming preponderance of risk in the second trimester, however.

I shall certainly be watching for any further analysis of the data, or any follow-up studies this engenders. And with my now heightened curiosity piqued, I may even include a warning to my pregnant patients to be extra careful behind the wheel. I’ll  certainly be more careful if I see one of them get into a car…