Tuberculosis: the solution?

[part 1, TB: The Problem]

Is there a solution? The short answer is yes, if we give it the time, attention, and money it needs. So the long answer is, “No.”

I’m not really joking. People do have a way of getting their act together when faced with death, but the problem here is that once we’re faced with it, it’ll be too late to do anything effective.

Short term, for instance, we could be doing what the WHO says: prevent global transmission with a SARS-type effort, and make sure everyone with TB is successfully treated. That’s including if it costs actual money and requires actual aid. All I can think is, “What are the chances of that?” (Those of you who have better ideas than me about how we can take our little teaspoons and start digging at the mountain of stupid, help us out in comments.)

What I’m so pessimistic about is people having the sense to take preventive measures. Those are the only kind that will really do us any good long term, because the usual solutions to a disease crisis, drugs, are becoming ineffective as we speak. If we wait for outbreaks, drugs may not save us.

The sinister thing is that bacteria learn a lot faster than bureaucrats. Drug resistant TB is a symptom of broken medical care. Cost-cutting results in anemic anti-TB programs without adequate follow-up to make sure patients take the full course of treatment. Taking only some of the antibiotics, enough to kill the susceptible bacteria but not enough to kill all of them, very quickly leads to populations of drug-resistant TB. MDR TB (multiply drug resistant) began appearing in the early 1990s. By the late 1990s, XDR TB (extremely or extensively drug resistant) had appeared. In 2006, people noticed that XDR TB was appearing everywhere, but they took heart from its low infectivity. Then the South African cluster appeared among AIDS patients. We don’t know whether it would spread as easily among people with healthy immune systems. But now that we’re breeding lots of XDR TB, it’s only a matter of time before one of those is highly infective for everybody. Maybe it’s already here. Maybe it isn’t. But the matter of time is on the order of a year, or three.

The only way to deal with a disease that has no cure is to prevent it. And the only way to do that for TB is to have a vaccine. We have no really good vaccines. If a full-scale effort started now, and was successful, it’ll be a decade or three before it’s ready for use.

There are some good scientific, reality-based reasons why vaccine development takes time. But there are also some regulatory reasons which are nothing but bureaucratic inertia. (For a taste of the complexity, read this Nature commentary.)

For instance, since the early days, the only way to get regulatory approval was to incubate some of the essential components in chicken eggs. Once upon a time, that was the only way to do it, but for the last decade or more, tissue culture and yeast incubation have been the cheaper, better, and much faster method. But regulatory approval stayed stuck in the chicken era until (I believe) the SARS scare. I think at that point they got off their duffs and tried to streamline procedures a bit, but I’d be surprised if there wasn’t still a lot of room for improvement.

The vaccine that we do have right now has issues.

In the US, there’s very little TB, comparatively speaking, so most people haven’t been exposed. That means a very cheap and simple skin test can identify the few people who have been exposed. However, after vaccination, the skin test comes up positive. It can’t tell the difference between people with the disease and people who have fought it off (which is what a vaccine actually does). It takes a more expensive and time-consuming test to make that distinction. Needless to say, the public health authorities would rather keep things simple. For them.

There are also real reasons why it’s not that good an idea to get vaccinated. The effectiveness of the usual BCG vaccine varies. Sometimes in children it gets up to about 85%. However, in a 1966 US government study, it was as low as 14% in adults. Those aren’t very impressive numbers. (Although, maybe, if you’re flying long distances and there are lawyers from Atlanta on the plane, you’d prefer to have some chance of immunity rather than none?) Furthermore, surviving an actual case of TB does not guarantee immunity against new infections, so it’s not surprising that the BCG vaccine can’t either.

Then there’s the fact that unless you’re traveling to a country with serious TB problems, US doctors don’t hand out the BCG immunization. The CDC’s recommendations go so far as to say that if you’re going overseas to spend time in hospitals or prisons, you should get tested before and after to see if you caught TB. No suggestion that immunization might make sense, even if all it does is reduce the chance of catching it. So getting the vaccine probably involves traveling to a country where they do provide it.

Other vaccines besides BCG have an even bigger disadvantage. They’re not available yet. MVA85A is the closest to delivery. It’s a virus engineered to carry important bits of TB and to improve the effectiveness of BCG vaccination. It’s in testing, and although a Nature article makes it seem it’ll be out Real Soon Now, a 2004 BBC report said actual use was expected in 2014.

If effective vaccines aren’t there yet, then what do we do when an outbreak happens? (Note the “when.” It’s intentional.) There is one preventive measure that antibiotics have allowed us to forget about: quarantine.

Forcible quarantine has been mentioned recently only in connection with AIDS (and, of course, the TB lawyer). For a sexually transmitted disease, it makes zero sense. STDs are simple to stop IF you can get people to cooperate. (You see why I’m so pessimistic about anything that depends on cooperation.) But for a lethal disease that’s transmitted like a cold, quarantine makes a lot of sense from an epidemiological standpoint.

Quarantine also makes a whole hornet’s nest of civil liberties and humanitarian issues.

Can you deprive anyone of liberty who has committed no crime? Who’s responsible for the person’s welfare? That’s a non-trivial question when you’re putting a sick person into surroundings with other sick people, who may have different strains of the disease that can cause infections on top of existing infections. Who pays for the enforced hospital stay? If it’s a disease with a high fatality rate (as drug-resistant diseases tend to be), what are the merits of taking someone from her or his family, incarcerating them in a perhaps distant facility, and never allowing direct contact so that the person has to die surrounded by strangers? Who pays for the extra medical personnel and enforcers to look for sick people being hidden by their families?

I’ve put those things as questions because I honestly don’t know the answer. In my healthy, unthreatened state, I want to make sure the sick person is helped to the full extent of modern medicine.

On the other hand, if I’d been on that plane with Mr. “TB Lawyer” Speaker, I’d be livid at him. And at the CDC for not preventing him from flying in the first place.

So, I don’t know how to answer those questions. But what I do know is that all of us, you, me, everyone, have to figure out those answers now. If we wait until people are dying, the answers will be ugly and panicked. Which is the same as saying they’ll be ineffective.

So what would you do?



Filed under 13_quixote

11 responses to “Tuberculosis: the solution?

  1. My concern is with an administration like this one, quarantine could be abused for political purposes. What checks are in place against this?

  2. I think when entering the country, quarantine becomes more of a relevant and useful tool when disease pathogens are found or likely.

  3. Pingback: Tuberculosis: the problem at Shakesville

  4. The sinister thing is that bacteria learn a lot faster than bureaucrats. Isn’t this true of most of the “Lower Life forms” found on this planet?

    As for quarantine, they did that back in my day. Go back and check on the old TB hospitals. Supposedly they were only slightly less horrible than the Insane asylums of the time. This was, of course, back in the good old days before the term “Civil Rights” was coined and N*****s were still N*****s and stepped off the sidewalk into the street when a white man walked by. Hell, they even had “Work houses” where most of the homeless spent their winters. They let them out in the spring to work in the fields though. Which was very generous to my way of thinking. (I had an old uncle that was an epileptic and this is where he sent his winters until he found out where we lived. Grandma’s cooking was loads better according to him.)

  5. Regarding quarantine, we’re talking minimum 6 months, too, aren’t we? Doesn’t it take that long to complete a full drug treatment?

  6. Oddly, it’s possible to deal with the issue without quarantine, but it’s labor intensive. You have a social services person bring the infected person their dosage daily, with penalties for not taking it. The medication is free. I’ve heard of people doing this with other diseases in areas of poverty, like some parts of Africa. So it is possible, even without the likelihood of a vaccine. (And a vaccine seems challenging to me – aren’t all of our current vaccines aimed at viruses, not celled parasites like tb?)

    I have mixed feelings about TB quarantines, because, due to a childhood exposure (after which my mother fed me the full course of antibiotics) I do and always will test positive for TB. I do not have TB. But I do test positive for it. Personally, I don’t like the idea of subjecting my body to years of unnecessary x-rays should testing for TB become standard (the alternative to skin tests).

  7. C. Diane

    Quarantine and isolation are not synonyms. Quarantine regards possible contacts and is difficult to enforce without police. Isolation is the removal of the infectious individual from society until the individual is no longer infectious.

    In the case of TB, that’s until the sputum is cleared, which is normally a few months. Isolation is not necessary once the individual is not infectious, but therapy is required for 6-9 months.

    Latent TB treatment, that is, a person has a positive PPD and a negative CXR and no history of treatment, is 9 months of a single antibiotic. It does not require quarantine or isolation.

  8. oddjob

    TB is quirky in some significant ways, as others have pointed out here. My uncle came down with it while he was a junior officer in the Navy, so he still has it, but will turn 80 shortly. If your infection is weak, your body will encapsulate the infection in your lungs, leaving a calcified nodule that functions as a tomb for the infection and prevents it from spreading.

    However as Rana has pointed out, you will always thereafter test positive for TB even though your infection poses no threat to anyone, including yourself.

  9. kathy a

    rana makes a great point about an effective way to provide treatment [and prevent development of drug-resistant strains], the down side being that it is labor intensive. social services and health care for poor populations seem to always take a hit when budgets aren’t balanced; there does not seem to be much recognition that the impact of inadequate services can go far beyond causing misery to the individuals affected. [infectious diseases are only one aspect of the misery.]

    i’ve heard that in the US, there are relatively high rates of TB among prisoners. one article i glanced at described prisons as “incubators” for the spread of TB, since members of the extremely large prison population rotate in and then back out into the community. this should be a population providing an excellent opportunity for full treatment — prisoners are already isolated in custody, and usually they are on parole [under supervision] for some period of time after release. so the means of ensuring diagnosis and a full course of treatment are already there for a large number of people, if there is the will to take public health seriously.

    i suspect this is another opportunity squandared, though. california, for example, has an enormous prison population, but the provision of health care to inmates is in such desperately bad shape that the entire prison system is currently under supervision of the federal court. after several years of efforts, barely any progress has been made. even something so simple as providing necessary and prescribed medications to a captive audience is something that can’t be managed consistently.

    the TB lawyer raises a lot of questions. i’d sure like to find out where he picked up the drug-resistant strain. but here is the thing — he is someone smart enough to know better, and he could easily manage to live a decent life and get treatment without exposing others unnecessarily to what could be a very deadly disease. his family has the money to allow him to live well. he could arrange to do legal work from home — not as fun and vibrant as getting out, but it’s not like he would have to give up any hope of income and mental stimulation for the duration. he did not *have* to get married overseas — why he placed higher priority on that dream than on other people’s health is a mystery that does not reflect well on his character. [especially since he defied a “no fly” order to come back home illegally, because he “was afraid he was going to die.”] it does not seem mr. TB lawyer was isolated from his family once he got to the hospital, in fact — they just had to take infection control precautions to see him.

    on a larger scale, there needs to be much more awareness that we each have a responsibility to avoid the spread of disease, especially those that can’t be treated easily. i think that people are able to accomodate that in many settings — it takes time and effort, and an ackowlegement that there is a problem.

  10. There’s a pretty wide gulf of civil liberties nuance between preventing a dangerously infected individual to fly and locking said individual away in some infectious diseases warehouse to die alone and miserable. It’s too bad that we can’t actually trust our government to appreciate those nuances, or to put in place a plan to humanely quarantine sick people who are a threat to the population. It would cost money, and in this country we use that to kill people at home and abroad, not save lives. It’s not really all that farfetched – many smaller regional quarantine centers with the capability built in for family wearing appropriate protection to visit, and the option of short-term housing for family nearby who might have to travel to the center to be with a loved one. It can be done humanely and sensibly, but you know it won’t be.

  11. Shakers are the best. You’ve all answered each others questions already.

    When I was painting the dire picture of enforced quarantine I’d just come from reading about the South African situation. Sure, there are ways to prevent the spread of disease that are humane and effective. They also cost significant money.

    One of the big problems to getting the hyper-virulent strain under control in South Africa is simply how to get people to come forward once they know that treatment will likely involve separation from the family. The First World may have the resources to handle it more humanely, but how much do you want to bet that the less white and middle class the patient is, the more treatment will resemble what poor people get everywhere? That’s why I think we need to think about some of those issues, even though we *could* do it better if we wanted to.

    Also, re “home quarantine” (or whatever the right term is), Mr. TB Lawyer provides a pretty clear example of the weak link there. Home treatment works with intelligent, responsible patients who are willing to do what it takes not to spread the disease around. There are other kinds of people. Which is why we need to think about that too.

    Yes, Brynn, you’re right. Treatment for non-drug-resistant TB takes 6 to 9 months. And C. Diane is right that isolation / quarantine is only necessary while the patient is infective, which doesn’t take as long as the full course of treatment.

    Grumpy: As for quarantine, they did that back in my day. I’ve only read about some of that, and it’s hair-raising. People forget so fast. I mean, this is well within living memory, but it’s not on teevee and so we’re headed straight for repeating history.

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