Tuesday 5 January 2016

Not very Neisseria

It's a while since Uncle Bob was giving you some second hand advice about the Pox Neisseria gonorrhoeae. Two years ago I was asserting that injectable gentamicin given simultaneously with oral azithromycin would knock gonorrhoea out of any orifices in which it might be lurking since your last fling of unprotected sex.  Even Wikipedia now says that gentamicin is not effective for either gonorrhoea or its partner chlamydia.  I don't mean to imply that these two bacteria are particularly closely related, Neisseria are part of the betaproteobacteria which includes Bordatella petussis the cause of whooping cough. alpha- gamma- delta- and epsilon-proteobacteria are the other named sections of this part of the bacterial tree and they include an awful lot of known human pathogens. Chlamydia, OTOH, is off in a distant group about as far as possible from the proteobacteria while still being Gram-negative.

At the moment the blast of choice against Neisseria is a double-whammy of injected ceftriaxone and the same old oral azithromycin. Using outmoded antibiotics like gentamicin and penicillin is foolish because the strain of N.gonorrhoeae which your patient has is almost certain to be resistant those drugs.  They will nevertheless upset your intestinal flora and may lead you to a iatrogenic [doctor-caused] infection by Clostridium difficile which will be really difficult [hence the name difficile] to shake. Giving ceftriaxone without azithromycin or vice-versa will precipitate a similar disaster. In March there was an outbreak of ceftriaxone-resistant gonorrhoea in Leeds, which proceeded to romp through several cities in Northern England. If you're a doctor in rural Ireland you have maybe a couple of years when your young and promiscuous patients will respond well to ceftriaxone, but someone in your parish may already have gone on a stag-party to Bradford or Newcastle and brought the more robust strain home to roost. So please treat all cases with the double-drug combo. Not least because chlamydia is definitely not responsive to ceftriaxone.

The thing about the pox is that it is not very nice, but it's also not very fatal. Indeed 50% of infected women are asymptomatic. We are looking to go back to endemic, more or less untreatable gonorrhoea after two generations where, so long as you got yourself tested and treated, you could get yourself cured.  I guess it's not your fault that penicillin was over-prescribed in humans by doctors who failed to have adequate continuous professional development CPD courses and used as a growth-promoter in chickens under an insane policy of nil-regulation of 'agricultural' antibiotics. BUT you could use a condom! It's safer: getting Neisseria is not nicer.

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