Intended for healthcare professionals

Letters Uncomplicated lower urinary tract infections

Urinary infections are complex and hard to treat

BMJ 2017; 359 doi: (Published 18 December 2017) Cite this as: BMJ 2017;359:j5766
  1. James Malone-Lee, emeritus professor of medicine
  1. University College London, London N8 8JD, UK
  1. james.malone-lee{at}

Kronenberg and colleagues find that a quinolone beats a non-steroidal anti-inflammatory drug at treating dipstick positive urinary tract infections (UTIs).1 Why are we testing this? We have vastly more serious problems.

Culture of 103-106 colony forming units per µl of a pathogen is insensitive,2 and dipsticks are even worse.3 Dismissing UTI on dipstick or culture data confuses “no evidence of disease” with “evidence of no disease.” Fresh, microscopic pyuria counts are the best option4 and are unused.

The normal and infected bladders evince a complex, polymicrobial soup, including fastidious or unculturable organisms.25 Culturable isolates are not necessarily the culprits, and multiresistance in these is no justification for broad spectrum prescribing. Mixed cultures are unsurprising and not necessarily contaminants. Abundant urinary epithelial cells seem to be expressions of the UTI6 and not grounds for specimen rejection.

Treating acute cystitis is no less problematic. Scrutiny of the tables at the back of the key Cochrane review reveals microbiological and symptomatic failure in 28-37% of patients after 4-14 days of treatment.7

Urine infection represents numerous realignments of a complex microbiome.8 It may involve parasitisation of the uroepithelial cells and the formation of surface and intracellular biofilms. These deter antibiotics and are hard to eradicate.9 No evidence shows that three or 14 days of antibiotics correct the situation. The doses used may not penetrate sufficiently.

This is an extremely worrying situation. The evidence implies that some people fail guidelines, are betrayed by insensitive tests, and have untreated infection. I see such people, and they experience years of suffering. They certainly manifest validated markers of infection.8 They are difficult and controversial to treat.

An honest reappraisal of our assumptions and guidelines could lead to the prevention of such misery at its onset.



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