Stardate 20040306.1046

(Captain's log): I'm worried about politics, so as is my wont I'll start by writing about something which is apparently totally unrelated.

Tuberculosis is one of the great killer diseases of all time. Historically it didn't tend to create massive outbreak plagues the way celebrity diseases like cholera did, but it's taken a steady toll on the human race for centuries. Right now it kills about two million people a year, worldwide.

I grew up in the 1950's, and my generation of children were the first to be protected against polio by the newly-developed Sabin and Salk vaccines. I was vaccinated against tetanus, diphtheria, polio, and smallpox. I was not vaccinated against any of the four strains of measles, or against mumps or chickenpox, because those vaccines had not yet been developed. When I was a kid, it was pretty much assumed that all kids would eventually catch them all; it was considered "normal", even though still worrisome and still a risk of death or damage.

In the case of rubella and mumps, it was seen as desirable to get them over with in childhood, since they could have very serious consequences in adults. Even though all of those diseases can be very dangerous, I was not harmed by any of them. (But I nearly died from influenza when I was about 3.)

There was also no vaccine for tuberculosis. We got shots to protect us against tetanus, and we got a skin test for tuberculosis. A lot of people my age have a peculiar circular scar high on one arm from that skin test. But all it did was to determine if you'd been exposed to tuberculosis; it didn't protect you against it.

There still isn't really a good vaccine for tuberculosis, though there's a lot of work being done to find one. (The Gates Foundation has been pouring money into this area.)

As massively fatal diseases go, tuberculosis is quite unusual. It's bacterial (as is cholera), but it's slow. One might almost say pokey. Where most bacteria will divide about every half hour in favorable conditions – such as inside you and me – the tuberculosis bacterium divides about every 12 hours. That means that after you've been infected it takes a long time for the population to build up to the point where it will make you feel ill. It also makes research difficult. And it has another pernicious consequence.

For a very long time, tuberculosis was on the long list of terribly dangerous diseases we don't know how to treat. People infected by tuberculosis in America and Europe often ended up in special sanatoriums, in part to care for them but mostly to get them out of circulation so they didn't infect other people. As with any other untreatable infectious disease, the best public health measure available was quarantine. A lot of patients ended up dying in those sanatoriums.

I have long been an admirer of Richard Feynman. In one of his books he included a section describing his early life as a child and young adult, including the time he spent on the Manhattan Project. He was newly married then, and to hear him describe his wife, she was sweet and loving and utterly gorgeous, the girl everyone else wanted. (As is how any young man in love feels.)

Unfortunately, she also had tuberculosis. She was sick with it before he married her. When he moved to Los Alamos, his wife moved to a sanatorium in that same area, and he visited her there when he was able to get away from work. She died of the disease in 1945. Feynman didn't write much about how it affected him, but it was clear that even decades later, it still hurt him a lot.

Drugs were eventually developed to treat tuberculosis. But if tuberculosis grows slowly, it also dies slowly. Antibiotics generally target and severely impede specific biochemical processes essential to bacterial life, and if the bug lives fast the drug works fast. If the targeted process happens slowly, the drug takes a long time to be effective.

Most bacterial diseases can be licked with a ten-day treatment with antibiotics (as was the case with my walking pneumonia last year). But it takes months of continuous treatment to be cured of tuberculosis.

The standard treatment protocol includes six months of isoniazid and rifampin. Isoniazid inhibits synthesis of mycoloic acids, which are an essential part of the bacterial cell wall. Rifampin targets RNA synthesis. (If you want to know more, the guy to ask is Derek Lowe.)

Most Americans now are not at risk of tuberculosis because they'll never be exposed to it. But among the poorest of the poor, it's always been a lot more common. It was particularly common among the homeless back in the day, and homeless shelters which provided beds out of the weather for them in winter also provided large rooms full of people in poor health, some of whom had tuberculosis and spent the entire night coughing. As you might imagine, pretty soon a lot more of them were infected.

It was one of many diseases which afflicted the homeless, and agencies trying to aid the hom