The growing, global threat of super-gonorrhea
Medical illustration of Neisseria gonorrhoeae, the bacteria that causes gonorrhea. Photo courtesy of the U.S. Centers for Disease Control and Prevention
On Monday, the CDC released its first-ever estimate of superbug infection rates in the United States. And judging from the report, things aren't looking too good.
Superbugs are a huge and growing public health problem – one bad enough to inspire uncharacteristic bursts of hyperbolic language from typically buttoned-up health officials (see: "catastrophic threat," "apocalyptic scenario," and "end to modern medicine as we know it").
Yup, gonorrhea – the CDC currently considers the clap to be one of America's most urgent public health concerns. But this comes as no surprise to infectious disease scientists, especially those who have kept a wary eye on drug-resistant gonorrhea ever since it first emerged in Asia in the 70s.
In the United States, drug-resistant gonorrhea now infects 246,000 people every year – that's equivalent to the entire population of Saskatoon. Further north, the Public Health Agency of Canada found in 2011 that 32 per cent of the 3,360 gonorrhea samples it tested were resistant to at least one antibiotic – that's up from 25 per cent in 2000. Here in Toronto, researchers also recently reported on nine patients with gonorrhea infections that failed to clear, even after taking the strongest commercially-available drugs – an alarming development that has prompted Public Health Ontario to start recommending that doctors use injectable (and stronger) drugs for treating gonorrhea from now on.
But globally, we really don't know the true scale of the problem, says Dr. Teodora Wi, medical officer for sexually-transmitted infections at the World Health Organization.
"We don't have the global figure; we cannot release an accurate number because the surveillance is so patchy," Wi told me on Monday over the phone. "If you look at the current statistics, you'll see that very few countries are monitoring the burden of gonorrhea. Very few countries are even reporting on antimicrobial resistance in gonorrhea."
This is clearly evident in a report recently published by Wi and her WHO colleague, Dr. Lori Newman, which looked at STD surveillance efforts around the world. The Eastern Mediterranean Region only had one laboratory currently participating in an international surveillance network, called GASP, that was set up in 1992 to track resistance in gonorrhea. Africa only has five countries participating and Southeast Asia has six (Europe, by comparison, has 22 participating countries and the Americas have 13).
But the data that is available paints a grim picture. Currently, the most powerful and commercially-available antibiotics for treating gonorrhea belong to a class called cephalosporins: cefixime, which comes in pill form, and ceftriaxone, which is injected. According to Wi's report, the first case of treatment failure to cefixime was reported in Japan in 2002 ("treatment failure" is defined by the WHO as a failure rate of at least 5 per cent). Since then, nine other countries have also seen treatment failures for both cefixime and ceftriaxone, indicated by the black dots on the below map (courtesy of the WHO report):
But in reality, there are probably far more dots on the map that we don't know about due to the lack of good data. The majority of treatment failures reported thus far have mostly been in developed countries – and, as the report notes, we can safely assume "that the treatment failures in these 10 countries represent only the tip of a silent epidemic of antimicrobial resistance."