if I were starting this blog today, I’d be tempted to name it the Department of Unintended Consequences. So much of what I write about seems to belong in that zone: Send U.N. troops to Haiti, start a cholera epidemic. Aim to eradicate wild polio, clear the way for the vaccine-derived kind. Drive down the price of producing animal protein, ramp up antibiotic resistance.
Now add to the list: Develop cheap rapid tests for detecting sexually transmitted diseases, and lose the ability to track that those diseases are becoming resistant to the last antibiotics that work reliably against them.
In my latest column at Scientific American, I take a look at the recent rapid increase in antibiotic resistance in gonorrhea. I’ve explored this problem in two earlier posts here: Resistance to cephalosporins, the last class of antibiotics that are reliable, cheap, and effective enough to not require a follow-up visit, first emerged in Japan in 1999 and began spreading around the globe from there, arriving in California in 2008 and moving across to the East Coast by last year.
That’s bad enough, because while we may think of gonorrhea as a minor illness long ago eclipsed in seriousness by HIV/AIDS, it remains one of the most-reported diseases in the country, with more than 600,000 known cases per year. Gonorrhea that goes untreated is personally and socially costly, causing pelvic inflammatory disease, infertility and widespread organ damage. And when resistance is not detected, it is possible for gonorrhea to go, effectively, untreated, because the drugs that are given to cure the infection will not work against the resistant form.
But what turns out to be worse — and here is where the unintended consequences come in — is that public health’s attempts to track STDs, as an important public health priority, may have enabled the spread of resistant gonorrhea. That’s because the cheap rapid tests that allow the disease to be diagnosed quickly don’t detect resistance. From my column:
For years standard practice has been to quickly identify an infection, dole out the appropriate treatment and then move on to the next patient. If symptoms return, the assumption has been that the patient was reinfected. Experts now say that such patients may in fact have harbored resistant bacteria that were never killed in the first place — bacteria that the patients possibly spread to others.
Physicians would not have recognized that they were dealing with increasingly resistant bacteria, because the rapid tests most commonly used to diagnose sexual infections cannot identify resistant organisms. Instead the tests look for a DNA segment that is unique to gonorrhea, destroying the bacteria in the process. Identifying resistance requires intact living bacteria that researchers can grow in a lab dish and expose to antibiotics to see which drugs work or do not.
STD control — for many decades, one of the most effective of all public health’s accomplishments — was built on quick outpatient treatment. Public health could afford to fund the apparatus of STD control because the drugs were inexpensive and the clinical encounters were uncomplicated. But identifying and tracking resistant gonorrhea could change STD control from something relatively affordable to something that isn’t even close. From my column:
Routinely testing patients for resistant strains with the culture tests instead of rapid tests would be costly and time-consuming. But in [a] February New England Journal editorial, lead author Gail Bolan, director of the CDC’s division of STD prevention, argues that it is necessary. She also recommends retesting patients after treatment to make sure the infection is gone.
Doctors who treat sexually transmitted infections say that although such changes are sensible, they are not easy. Collecting bacterial samples for analysis requires supplies that most offices do not keep on hand, says Melanie Thompson, executive director of the AIDS Research Consortium of Atlanta, which also does STD testing. “A health care provider who suspected a resistant case would have to recognize it,” she explains, “contact the CDC or state health department to report it, go about getting the materials and then get the patient back in to give a sample.”
The need to invest in new testing regimens and new treatment arrangements — in which patients must return for multiple visits and be retested to see whether their infections have persisted — comes at a particularly bad time for STD control. Over the past few years, according to the National Coalition of STD Directors, 69 percent of state STD programs suffered budget cuts.
The situation is considered sufficiently alarming that the CDC will hold a Grand Rounds on resistant gonorrhea on May 15 (accessible to the public by webcast as far as I can tell; details are here.) As the agency’s STD director, Bolan, and two academics said in that February NEJM editorial referenced above: “There is much to do, and the threat of untreatable gonorrhea is emerging rapidly.”
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