Urinary tract infections in adults

Singapore Med J. 2016 Sep;57(9):485-90. doi: 10.11622/smedj.2016153.


A urinary tract infection (UTI) is a collective term for infections that involve any part of the urinary tract. It is one of the most common infections in local primary care. The incidence of UTIs in adult males aged under 50 years is low, with adult women being 30 times more likely than men to develop a UTI. Appropriate classification of UTI into simple or complicated forms guides its management and the ORENUC classification can be used. Diagnosis of a UTI is based on a focused history, with appropriate investigations depending on individual risk factors. Simple uncomplicated cystitis responds very well to oral antibiotics, but complicated UTIs may require early imaging, and referral to the emergency department or hospitalisation to prevent urosepsis may be warranted. Escherichia coli remains the predominant uropathogen in acute community-acquired uncomplicated UTIs and amoxicillin-clavulanate is useful as a first-line antibiotic. Family physicians are capable of managing most UTIs if guided by appropriate history, investigations and appropriate antibiotics to achieve good outcomes and minimise antibiotic resistance.

Keywords: cystitis; primary care; urinary tract infections.

MeSH terms

  • Adult
  • Aged
  • Amoxicillin / administration & dosage
  • Amoxicillin-Potassium Clavulanate Combination
  • Anti-Bacterial Agents
  • Clavulanic Acid / administration & dosage
  • Cystitis / drug therapy
  • Drug Resistance, Microbial
  • Escherichia coli
  • Escherichia coli Infections / drug therapy
  • Escherichia coli Infections / epidemiology
  • Female
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Primary Health Care
  • Risk Factors
  • Urinary Tract Infections / drug therapy*
  • Urinary Tract Infections / epidemiology*


  • Anti-Bacterial Agents
  • Clavulanic Acid
  • Amoxicillin-Potassium Clavulanate Combination
  • Amoxicillin