It has killed millions in its march through the human population, including the famous—Chopin, Emily and Anne Brontë, Eleanor Roosevelt—and more abundantly, the not-so-famous. It currently infects about one-third of the world’s population, able to linger without symptoms in people who may never be aware that they’re carrying it. What is it?
It’s tuberculosis (TB), caused by the bacterium Mycobacterium tuberculosis. TB can lurk in a latent form, causing no symptoms at all, or it can cause active disease. People with latent TB usually don’t even know they have it unless they’ve had a skin test. Luckily, they also are not infectious to others. But people with active disease—and latent infections often turn active—are infectious. Highly so.
But not so infectious that a single contact will give another person TB. TB typically transmits in close quarters—prisons can be hotbeds of infection—requiring a person to cough up or sneeze the infectious bacteria into the air close to another person. You can’t get TB by shaking hands with someone or even by kissing them, but you can get it simply by living with them.
Latent or active infections both require treatment because even latent infections carry a risk of becoming active. While medical science has successfully attacked TB with antibiotics, misuse and abuse of these antimicrobial agents has led to a rise in multi–drug-resistant TB.
People with these highly resistant infections must often be quarantined for weeks and weeks while health professionals throw the kitchen sink of antibiotic treatments at the disease. Up to two years of chemotherapy may even be necessary.
What does an active TB infection look like? While it can infect tissues other than the lungs, including the brain or spine, in the lungs, it looks like this:
- a bad cough that persists three weeks or more that can include coughing up blood or mucus
- weight loss
- fever, chills, night sweats
Twenty years ago, health experts thought TB had been defeated, at least in areas of the world where antibiotics seemed to have wiped it out. But today, the resistant strains of TB have made an alarming comeback, sometimes traveling the world in the form of unwitting—or in at least one instance, witting (PDF)—infected people.
Particularly alarming is the combination of TB together with HIV. The two infections often occur together, as HIV-infected people may be less able to fight a TB infection. In addition to being especially lethal, this combination also interferes with efforts to prevent the spread of resistant TB to other populations.
How can you avoid acquiring a TB infection? A vaccine is available, but is not completely effective and not widely used in the United States. Your best bet is to take precautions when traveling to parts of the world where TB is common—which includes Latin America, the Caribbean, Africa, Asia, and Eastern Europe—staying away from crowded populations at particular risk.
TB is most common in prisons, drug-treatment centers, homeless shelters, and healthcare clinics. If you are going to be in a place where TB rates are high, consult a healthcare professional about steps you might take against acquiring it. If you think you may have been exposed, get a skin test.
Awareness of a latent infection—and treating it—is one step in the successful advance against the renewed uprising of TB.
Image courtesy of mjagbayani