Gonorrhea (Neisseria gonorrhoeae) is the second most frequent reportable condition in the United States after chlamydia. Consequences of untreated gonococcal infections include pelvic inflammatory disease, blindness and infertility. Although it was one of the first diseases to be systematically targeted by the magic bullet of antibiotics, gonorrhea mutates rapidly and has an uncanny ability to acquire drug resistant genes. Resistance has brought it in the limelight as a potential public health crisis: in June, WHO issued an action plan and warned about the global spread of untreatable N. gonorrhoeae from Asia to Europe.

Fluoroquinolones were widely used to treat gonorrhea in the 1990s, after penicillin and sulphonamides gradually lost their effectiveness. It was a relatively short stint: rising resistance levels prompted the CDC to advise against their use in 2007. That happened even earlier (2004) among the high-risk group of men who have sex with men (MSM), where resistant strains emerged and were several times more common. As a result of these guideline revisions, the current gonorrhea control strategy relies almost exclusively on one drug class extended spectrum cephalosporins, including cefixime and ceftriaxone, which make up a over 95% of dispensed treatments.

The interactive bubble chart shows the proportion of fluoroquinolone-resistant N. gonorrhoeae (QRNG) and the share of isolates that came from men who have sex with men (MSM) in each of the 25-30 sites participating in CDC s Gonococcal Isolate Surveillance Project (GISP). The time animation shows high QRNG levels spread from Hawaii to other West coast sites (bubbles in dark blue), where the share of MSM isolates was also highest. In 2010, 48% of isolates in Seattle were resistant, whereas all sites in the South (dark orange), Northeast (green) and most of the Midwest (purple) had levels under 20%.

The spread of QRNG is important because resistance to cephalosporins such as ceftriaxone and cefixime the last available drugs against gonorrhea appears to be going down the same road. While there were no true resistant isolates reported by GISP in 2010, susceptibility decreased in the West (California and Hawaii) and among MSM. This alarming trend could herald the arrival of untreatable gonorrhea in the US, unless measures are taken to strengthen laboratory capacity to identify drug-resistant infections, and to encourage the development of new antibiotics active against gonococci.

Static and interactive versions of the visualization, including a map of the states with the highest gonorrhea burden in 2010, are available for download  in the Tools section of our site.