June 8, 2007

Today’s TB Lesson: Public Health Demands Public Understanding

By Bruce Underhill, MD and Ross Porter

When it comes to commenting publicly about tuberculosis (TB), an infectious (but not very) disease that’s rare in the United States but widespread in some other parts of the world, government officials are wary. Ring the alarm bell too fiercely, and they’ll create the policy equivalent of a panic response. Say nothing, and the resulting ignorance allows TB to take root more firmly in the USA as elsewhere in the world.

The recent sensational press coverage of a very unusual case involving TB has rung the alarm bell very fiercely indeed. With all the public attention to tuberculosis, now is a good time to review some basic facts about this lethal killer that has stalked humanity from its earliest days. (In fact, TB was determined as the cause of death for frozen cadavers from as recently as the 1840s and as long ago as the last ice age.)

Tuberculosis, caused by Mycobacterium Tuberculosis, usually afflicts the lungs and is transmitted like a cold or the flu: through the air as the TB patient coughs. Fortunately, TB is harder to catch than a cold or flu, meaning that those who are most at risk for catching it are not casual contacts (fellow airline or bus passengers, for example) but rather intimate household or work contacts such as family, caregivers, and co-workers.

Unlike colds or flu, TB is rare in the United States because of concerted efforts over the past 100 years to prevent it through early detection, easily available treatment, and long-term prevention. America’s public health system was shaped by the fight against TB, contributing huge advances in research, applied medicine, and the powerhouse disease prevention institutions we enjoy today such as county health departments, the federal institutes of medicine, and the Centers for Disease Control. Decades of charity and government work have led to nearly complete elimination of active tuberculosis in the United States: fewer than 4.6 cases per 100,000 people (10.3 cases per 100,000 in San Diego County, or a total of 315 actual TB cases in 2006). By comparison, a new diagnosis of lung cancer comes for 62.7 per 100,000 Americans each year; asthma afflicts 7,130 per 100,000.

But TB continues to rage in other parts of the world, where poverty, HIV, and unhealthy prisons all contribute to the life cycle of Mycobacterium Tuberculosis. No stronger proof exists that we live in a “global village” than the ability of TB germs to travel from Russia, Asia, Africa, or Mexico to the United States. In return for the fruits of free commerce and universal travel, it’s necessary to think globally with concern about public health conditions that create TB anywhere humanity lives.

Since the 1950s, tools and treatments for TB have multiplied. Today the typical TB case can be fought into remission through a nine- to twelve-month course of treatment with antibiotics. In many countries a “watch-them-take-the-pills” course of treatment is being used successfully to harness TB and force it into latency. (Latency is where the TB bacillus is dormant within the body. No drug has been found to kill off the bacterium inside the human body. Latency is the end stage of treatment where the TB patient is not infecting others and enjoys good health.)

The majority of TB cases are successfully treated with antibiotics. The problems arise when a patient stops medication too soon – when they feel healthy, but the bacillus is not yet completely latent in their body. The heartiest strains of the bacteria survive their too-brief exposure to antibiotics, enjoy a resurgence when the treatment is prematurely ended, and then revive as a drug-resistant strain. This sad story occurs with other infections in addition to TB (such as MRSA: Methicillin-resistant Staphylococcus aureus).

In the case of tuberculosis, incomplete treatments have led to the development of dangerous new strains including “multi-drug resistant” (MDR) and “extremely drug-resistant” (XDR) strains – the most dangerous. What caused public health officials to raise such loud alarms over the recent honeymoon traveler was the fact that the TB strain he carries is the XDR type – not easier to catch than run-of-the-mill TB, but much harder to treat.

What is the average reader to learn about keeping friends and family safe from TB of any kind?

First, know the facts. Catching TB involves exposure (usually prolonged exposure) to someone with active (not latent) tuberculosis. Most cases of TB in the United States (74 percent of San Diego County’s cases) occur among the foreign-born. More facts about TB symptoms and possible exposure can be found online at www.San DiegoTBcontrol.org or at www.LungSanDiego.org (under the heading Lung Infections).

Second, support good public health policies in the United States. People with TB must receive a full course of treatment regardless of who they are or where they come from. Some TV and radio pundits have taken up TB and other diseases as one more rhetorical weapon against immigrants, but the fact is that open borders are the reality. This leads public health officials to the conclusion that treatment of those who have TB must be provided! Most people with TB don’t need to be quarantined. They will pursue their course of medication once they know why, and have a way to do so. San Diego County has enlightened and advanced programs for TB treatment and control. For those few with TB in the United States who don’t understand or will not comply with treatment requirements, laws exist so that public health officials can isolate and require treatment. Such extreme steps are rarely called for, but in the latest well-publicized case of the honeymoon traveler, the first federally-required quarantine since 1963 was successfully imposed.

The long and heroic struggle for medical victory over tuberculosis offers many lessons of history, science, and sociology. The medical field of epidemiology – how infections are born and nurtured through human interaction – has its roots in the fight against TB. Epidemiology has guided more recent battles against HIV and influenza of all types. Epidemiologists depend on public education and understanding as crucial factors in waging war against disease without sacrificing our humanity in the struggle. When you hear the public health alarm bell, listen and learn – but don’t give in to panic.

Bruce Underhill,, is a volunteer with the San Diego County chapter of RESULTS International (www.results.org). Ross Porter is a Communications Director for the American Lung Association of California (www.CaliforniaLung.org).

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