Urinary Tract Infections (UTIs) — NZ Condition Guide | KiwiMeds

What are UTIs?

Urinary tract infections (UTIs) are infections of the urinary system — most commonly the bladder (cystitis) and urethra (urethritis), and less commonly the kidneys (pyelonephritis). UTIs are among the most common infections seen by GPs in New Zealand. They are far more common in women — around 50% of women will have at least one UTI in their lifetime, and many experience recurrent UTIs. Men can also get UTIs, though less frequently.

Symptoms

Lower UTI (cystitis) symptoms include a frequent, urgent need to urinate, a burning or stinging sensation when urinating, passing small amounts of urine frequently, cloudy or strong-smelling urine, blood in the urine (haematuria), and pelvic pain or discomfort in women. Upper UTI (pyelonephritis — kidney infection) causes additional symptoms of fever, chills, back or flank pain, nausea, and vomiting. Pyelonephritis is a more serious infection requiring prompt treatment.

Causes and Risk Factors

UTIs are usually caused by bacteria — most commonly Escherichia coli (E. coli) from the bowel. Risk factors for women include sexual activity, using a diaphragm or spermicide, pregnancy, menopause (reduced oestrogen makes the urethra more vulnerable), and previous UTIs. Risk factors for men include an enlarged prostate and bladder outlet obstruction. Urinary catheters significantly increase infection risk.

Diagnosis

Uncomplicated UTIs in women are often diagnosed based on symptoms alone. A urine dipstick test (checking for nitrites and leucocytes) supports the diagnosis. Urine culture (growing the bacteria to identify it and its antibiotic sensitivities) is important for recurrent UTIs, complicated UTIs, or when antibiotic treatment fails. If kidney infection is suspected, blood tests and imaging may be needed.

Treatment in New Zealand

Most uncomplicated lower UTIs in women are treated with a short course of antibiotics. Trimethoprim (3 days) or nitrofurantoin (5 days) are the preferred first-line antibiotics in NZ — both funded by Pharmac. Cefalexin (an antibiotic) is used for pregnancy. Amoxicillin is no longer recommended due to high E. coli resistance. Increasing fluid intake and urinating frequently helps flush out bacteria. Paracetamol or ibuprofen can help with discomfort. Cranberry products have limited evidence for UTI prevention. For recurrent UTIs (≥2 in 6 months or ≥3 in 12 months), your GP may prescribe low-dose antibiotic prophylaxis or self-start antibiotic therapy.

NZ-Specific Information

Trimethoprim and nitrofurantoin are fully funded on the Pharmac schedule. NZ antibiotic prescribing guidelines (produced by BPAC NZ) provide up-to-date guidance for GPs. Antibiotic resistance is a growing concern in NZ — it is important to take the full course of antibiotics as prescribed and not use left-over antibiotics from previous prescriptions.

Frequently Asked Questions

Can I treat a UTI without antibiotics? Mild lower UTIs sometimes resolve on their own, but antibiotics speed recovery and reduce the risk of kidney infection. Delayed antibiotic prescriptions are sometimes used. Should I see a doctor for every UTI? If you have a straightforward uncomplicated UTI, some GP practices offer a nurse consultation or phone consultation. If symptoms are severe, you have fever, or UTIs are frequent, see a doctor. Why do I keep getting UTIs? Recurrent UTIs need investigation to rule out structural abnormalities. Strategies include post-coital voiding, adequate hydration, and sometimes prophylactic antibiotics.

Supplements That May Support Management

⚠️ Important: The supplements listed below have varying levels of clinical evidence. They are not a substitute for prescribed medications and should only be considered as adjunctive support under the guidance of a qualified healthcare professional. Always inform your GP or pharmacist before commencing any supplement, as interactions with prescribed medicines are possible.

• Cranberry (Proanthocyanidins) — Cranberry proanthocyanidins prevent E. coli from adhering to the urinary tract epithelium. Evidence supports use of standardised cranberry extract (36 mg PAC/day) or concentrated cranberry capsules for prevention of recurrent UTIs in women. Fresh cranberry juice in sufficient quantity (300–400 ml/day) also provides benefit.
• D-Mannose — D-Mannose is a naturally occurring sugar that competitively inhibits bacterial adhesion to bladder wall epithelium. A randomised trial demonstrated its equivalence to low-dose antibiotic prophylaxis (nitrofurantoin) for prevention of recurrent UTIs at 2 g/day, with a good safety profile.
• Probiotics (Lactobacillus reuteri, Lactobacillus rhamnosus) — Restoring healthy vaginal and urogenital Lactobacillus flora through probiotic supplementation may reduce recurrent UTI risk in pre- and post-menopausal women.
• Vitamin C — Vitamin C acidifies urine, creating a less favourable environment for bacterial growth. High-dose supplementation (500–1000 mg/day) is a traditional adjunctive measure with some supportive evidence.

Relevant Vaccinations

Individuals living with urinary tract infections (UTIs) may benefit from the following vaccinations. Please discuss your vaccination status with your GP or practice nurse, as eligibility and funding through the New Zealand National Immunisation Schedule may apply.

• Influenza (annual) — General preventive health recommendation. Illness-related reduced immune function can increase susceptibility to secondary bacterial infections including UTIs.
• UTI vaccine (Uromune, if available) — Uromune is a bacterial lysate sublingual vaccine against the four most common UTI pathogens, with evidence supporting significant reductions in recurrent UTI frequency. Availability varies — discuss with your GP or urologist.

Dietary Guidance

Evidence-based dietary modifications play a meaningful role in the management of urinary tract infections (UTIs). The following foods are generally recommended as part of a balanced, condition-appropriate diet. A referral to a registered dietitian may be beneficial for personalised nutritional planning.

• Abundant water intake (≥2 litres/day) — Increasing urine volume and voiding frequency is the most evidence-based dietary intervention for reducing UTI risk, flushing bacteria from the urinary tract before adhesion can occur.
• Cranberry juice (unsweetened, 300–400 ml/day) — Provides proanthocyanidins that prevent bacterial adherence to urinary epithelium. Unsweetened varieties are preferred. Concentrated capsules may be more practical and cost-effective.
• Vitamin C-rich foods (kiwifruit, citrus, capsicum) — Promotes urinary acidification, which inhibits bacterial growth. Also supports immune function.
• Probiotic-rich fermented foods (yoghurt, kefir) — Supports healthy urogenital microbiome and systemic immune function.
• Limit: sugar-sweetened beverages, refined sugar — Sugar supports bacterial growth and may increase UTI risk. Reducing sugar intake is particularly important in recurrent UTI management.

Related Conditions & Medications

Related medications: Amoxicillin, Trimethoprim. Related conditions: Kidney Health.