Assessment of dysuria

Presence of nitrites and either RBCs or leukocytes is highly suggestive of UTI and warrants urine microscopy and culture, with a positive predictive value of 92%.[56]Little P, Turner S, Rumsby K, et al. Dipsticks and diagnostic algorithms in urinary tract infection: development and validation, randomised trial, economic analysis, observational cohort and qualitative study. Health Technol Assess. 2009 Mar;13(19):iii-iv, ix-xi, 1-73. https://www.journalslibrary.nihr.ac.uk/hta/hta13190/#/full-report http://www.ncbi.nlm.nih.gov/pubmed/19364448?tool=bestpractice.com Absence of both leukocytes and nitrites makes diagnosis extremely unlikely.

Lower counts of 10² to 10³ CFU/mL in symptomatic patients may be an early indication of a UTI.[51]Kass EH, Finland M. Asymptomatic infections of the urinary tract. J Urol. 2002;168:420-4. http://www.ncbi.nlm.nih.gov/pubmed/12131280?tool=bestpractice.com [52]Giesen LG, Cousins G, Dimitrov BD, et al. Predicting acute uncomplicated urinary tract infection in women: a systematic review of the diagnostic accuracy of symptoms and signs. BMC Fam Pract. 2010;11:78. https://bmcfampract.biomedcentral.com/articles/10.1186/1471-2296-11-78 http://www.ncbi.nlm.nih.gov/pubmed/20969801?tool=bestpractice.com

An untreated UTI can lead to low birthweight and premature labour.

Indicated only if upper urinary tract pathology suspected, or in patients with complicated or recurrent UTI.

Leukocytes are commonly present, although they are non-specific for the diagnosis.

Non-invasive test (urine or vaginal swab), which is suitable for both sexes.[57]Savolainen E, Kettunen A, Narvanen A, et al. Prevalence of antibodies against Chlamydia trachomatis and incidence of C. trachomatis-induced reactive arthritis in an early arthritis series in Finland in 2000. Scand J Rheumatol. 2009;38:353-6. http://www.ncbi.nlm.nih.gov/pubmed/19296404?tool=bestpractice.com [58]Berry J, Crowley T, Horner P, et al. Screening for asymptomatic Chlamydia trachomatis infection in male students by examination of first catch urine. Genitourin Med. 1995;71:329-31. https://sti.bmj.com/content/sextrans/71/5/329.full.pdf http://www.ncbi.nlm.nih.gov/pubmed/7490057?tool=bestpractice.com [59]Hopkins M, Ashton L, Alloba F, et al. Validation of a laboratory-developed real-time PCR protocol for detection of Chlamydia trachomatis and Neisseria gonorrhoeae in urine. Sex Transm Infect. 2010;86:207-11. http://www.ncbi.nlm.nih.gov/pubmed/20522633?tool=bestpractice.com [60]Jensen JS, Cusini M, Gomberg M, et al. 2021 European guideline on the management of Mycoplasma genitalium infections. J Eur Acad Dermatol Venereol. 2022 May;36(5):641-50. https://onlinelibrary.wiley.com/doi/10.1111/jdv.17972 http://www.ncbi.nlm.nih.gov/pubmed/35182080?tool=bestpractice.com

Microscopy of urethral or meatal swab from patients with penile urethral discharge has a sensitivity of 90% to 95% for N gonorrhoeae infection and allows immediate diagnosis in these individuals.[61]Fifer H, Saunders J, Soni S, et al. 2018 UK national guideline for the management of infection with Neisseria gonorrhoeae. Int J STD AIDS. 2020 Jan;31(1):4-15. https://journals.sagepub.com/doi/10.1177/0956462419886775

Historical diagnostic standard. Invasive and uncomfortable. Has been superseded by less invasive tests, but helpful for determining antimicrobial susceptibility in patients with confirmed gonorrhoea infection.[61]Fifer H, Saunders J, Soni S, et al. 2018 UK national guideline for the management of infection with Neisseria gonorrhoeae. Int J STD AIDS. 2020 Jan;31(1):4-15. https://journals.sagepub.com/doi/10.1177/0956462419886775

Presence of nitrites and leukocytes is highly suggestive of urinary tract infection (UTI) and warrants urine microscopy and culture, with a positive predictive value of 92%.[56]Little P, Turner S, Rumsby K, et al. Dipsticks and diagnostic algorithms in urinary tract infection: development and validation, randomised trial, economic analysis, observational cohort and qualitative study. Health Technol Assess. 2009 Mar;13(19):iii-iv, ix-xi, 1-73. https://www.journalslibrary.nihr.ac.uk/hta/hta13190/#/full-report http://www.ncbi.nlm.nih.gov/pubmed/19364448?tool=bestpractice.com Absence of both leukocytes and nitrites makes diagnosis extremely unlikely.

Indicated only if upper urinary tract pathology suspected, or in patients with complicated or recurrent UTI.

Generally performed only if ultrasound raises the possibility of abnormality in the renal tract. If urolithiasis is suspected, CT can identify calculi within renal tract.

Non-specific.

Bacterial infections (including trichomoniasis) or atrophic vaginitis. Candidal infections usually associated with normal pH.

Vaginal samples added to two different slides, one with saline solution and one with potassium hydroxide (KOH) solution.

Bacterial vaginosis: clue cells (vaginal epithelial cells with distinctive stippled appearance by being covered with bacteria) are present and are seen as vaginal epithelial cells covered with many rods and cocci, with a granular appearance. The numbers of lactobacilli are decreased, and WBCs are absent.

Important to also exclude sexually transmitted disease, if appropriate.

Non-specific.

Bacteria are frequently isolated in acute bacterial prostatitis, but rarely in chronic prostatitis. Therefore, absence of bacteria in the urine does not rule out prostatitis.

Bacteria are frequently isolated in acute bacterial prostatitis, but rarely in chronic prostatitis. Therefore, absence of bacteria in the urine does not rule out prostatitis.

Flow rate is non-invasive and can provide all the necessary information in uncomplicated cases.

May help to exclude prostate cancer. May be falsely elevated in the setting of infection or recent urinary tract manipulation.

More sensitive than MRI, ultrasound, and plain abdominal radiograph for detecting renal and ureteric stones in adults.[69]National Institute for Health and Care Excellence. Renal and ureteric stones: assessment and management. Jan 2019 [internet publication]. https://www.nice.org.uk/guidance/ng118 [70]American College of Radiology. ACR Appropriateness Criteria: acute onset flank pain - suspicion of stone disease (urolithiasis)​. 2023 [internet publication]. https://acsearch.acr.org/docs/69362/Narrative ​ Allows degree of obstruction to be assessed. Provides important information about other abdominal organs and renal stone burden. Non-contrast CT should be performed first to detect stones; contrast can then be given if appropriate. 

CT is the standard test for diagnosis of urolithiasis anywhere along the urinary tract. However, in patients unable to undergo these tests (e.g., pregnant women, children), depending on the size of the stone, ultrasound can help identify stones.[70]American College of Radiology. ACR Appropriateness Criteria: acute onset flank pain - suspicion of stone disease (urolithiasis)​. 2023 [internet publication]. https://acsearch.acr.org/docs/69362/Narrative

Tissue culture success is operator dependent, but this modality can yield positive results within 48 hours of inoculation.

Sample can be obtained from blood, tissue, or spinal fluid.

Involves smearing cells taken from a fresh blister or ulcer onto a microscope slide and staining them. Quick, reproducible, and inexpensive diagnostic test.

Can be negative for leukocytes or nitrites and is therefore not very reliable for diagnosis.

Not routinely required in all cases, particularly if not complicated.

Non-invasive test (urine or vaginal swab).[57]Savolainen E, Kettunen A, Narvanen A, et al. Prevalence of antibodies against Chlamydia trachomatis and incidence of C. trachomatis-induced reactive arthritis in an early arthritis series in Finland in 2000. Scand J Rheumatol. 2009;38:353-6. http://www.ncbi.nlm.nih.gov/pubmed/19296404?tool=bestpractice.com [58]Berry J, Crowley T, Horner P, et al. Screening for asymptomatic Chlamydia trachomatis infection in male students by examination of first catch urine. Genitourin Med. 1995;71:329-31. https://sti.bmj.com/content/sextrans/71/5/329.full.pdf http://www.ncbi.nlm.nih.gov/pubmed/7490057?tool=bestpractice.com [59]Hopkins M, Ashton L, Alloba F, et al. Validation of a laboratory-developed real-time PCR protocol for detection of Chlamydia trachomatis and Neisseria gonorrhoeae in urine. Sex Transm Infect. 2010;86:207-11. http://www.ncbi.nlm.nih.gov/pubmed/20522633?tool=bestpractice.com [60]Jensen JS, Cusini M, Gomberg M, et al. 2021 European guideline on the management of Mycoplasma genitalium infections. J Eur Acad Dermatol Venereol. 2022 May;36(5):641-50. https://onlinelibrary.wiley.com/doi/10.1111/jdv.17972 http://www.ncbi.nlm.nih.gov/pubmed/35182080?tool=bestpractice.com

Cannot differentiate between active and past exposure.

Eosinophilia present in over 90% of acute infections.[62]de Jesus AR, Silva A, Santana LB, et al. Clinical and immunologic evaluation of 31 patients with acute schistosomiasis mansoni. J Infect Dis. 2002 Jan 1;185(1):98-105. https://www.doi.org/10.1086/324668 http://www.ncbi.nlm.nih.gov/pubmed/11756987?tool=bestpractice.com

Evidence of unrecognised pulmonary TB or evidence of old healed TB (e.g., upper lobe fibrosis) may be present; such abnormalities should prompt sputum collection for smear, culture, and nucleic acid amplification testing.

Testing of 3 specimens (minimum 8 hours apart, including an early morning specimen) is recommended in many countries; consult local guidance.[63]Lewinsohn DM, Leonard MK, LoBue PA, et al. Official American Thoracic Society/Infectious Diseases Society of America/Centers for Disease Control and Prevention clinical practice guidelines: diagnosis of tuberculosis in adults and children. Clin Infect Dis. 2017 Jan 15;64(2):111-5. https://www.doi.org/10.1093/cid/ciw778 http://www.ncbi.nlm.nih.gov/pubmed/28052967?tool=bestpractice.com

Sputum specimen should be tested in patients with suspected extrapulmonary TB, as active pulmonary TB is seen in 15% to 20% of patients with extrapulmonary TB.[64]Geldmacher H, Taube C, Kroeger C, et al. Assessment of lymph node tuberculosis in northern Germany: a clinical review. Chest. 2002 Apr;121(4):1177-82. http://www.ncbi.nlm.nih.gov/pubmed/11948050?tool=bestpractice.com [65]Weir MR, Thornton GF. Extrapulmonary tuberculosis. Experience of a community hospital and review of the literature. Am J Med. 1985 Oct;79(4):467-78. http://www.ncbi.nlm.nih.gov/pubmed/4050833?tool=bestpractice.com [66]Baydur A. The spectrum of extrapulmonary tuberculosis. West J Med. 1977 Apr;126(4):253-62. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1237539/pdf/westjmed00272-0024.pdf http://www.ncbi.nlm.nih.gov/pubmed/855317?tool=bestpractice.com

Culture of Mycobacterium tuberculosis typically takes several weeks (up to 8), decisions on treatment are usually made before culture results are known.​​​​

Although NAATs were originally designed and approved for respiratory specimens, they may also be requested on specimens from other sites where involvement of TB is suspected (e.g., cerebrospinal fluid, lymph node aspirate, lymph node biopsy, pleural fluid, peritoneal fluid, pericardial fluid, synovial fluid or urine).[63]Lewinsohn DM, Leonard MK, LoBue PA, et al. Official American Thoracic Society/Infectious Diseases Society of America/Centers for Disease Control and Prevention clinical practice guidelines: diagnosis of tuberculosis in adults and children. Clin Infect Dis. 2017 Jan 15;64(2):111-5. https://www.doi.org/10.1093/cid/ciw778 http://www.ncbi.nlm.nih.gov/pubmed/28052967?tool=bestpractice.com [67]World Health Organization. WHO consolidated guidelines on tuberculosis. Module 3: diagnosis - rapid diagnostics for tuberculosis detection. Mar 2024 [internet publication]. https://www.who.int/publications/i/item/9789240089488 ​​​

In the US, use of NAATs for extrapulmonary specimens is not approved by the US Food and Drug Administration, and use would be off-label.

Several rapid NAATs are available for the diagnosis of TB and some are also able to detect genes encoding resistance to TB drugs.[67]World Health Organization. WHO consolidated guidelines on tuberculosis. Module 3: diagnosis - rapid diagnostics for tuberculosis detection. Mar 2024 [internet publication]. https://www.who.int/publications/i/item/9789240089488 ​​

One Cochrane review found the lateral flow urine lipoarabinomannan (LF-LAM) assay to have a sensitivity of 42% in diagnosing TB in HIV-positive individuals with TB symptoms, and 35% in HIV-positive individuals not assessed for TB symptoms.[68]Bjerrum S, Schiller I, Dendukuri N, et al. Lateral flow urine lipoarabinomannan assay for detecting active tuberculosis in people living with HIV. Cochrane Database Syst Rev. 2019 Oct 21;10(10):CD011420. https://www.doi.org/10.1002/14651858.CD011420.pub3 http://www.ncbi.nlm.nih.gov/pubmed/31633805?tool=bestpractice.com [ ] What is the accuracy of lateral flow urine lipoarabinomannan (LF‐LAM) for detecting tuberculosis (TB) in symptomatic HIV‐positive adults?/cca.html?targetUrl=https://www.cochranelibrary.com/cca/doi/10.1002/cca.2824/fullShow me the answer [ ] What is the accuracy of lateral flow urine lipoarabinomannan (LF‐LAM) for detecting tuberculosis (TB) in unselected HIV‐positive adults (symptomatic or asymptomatic)?/cca.html?targetUrl=https://www.cochranelibrary.com/cca/doi/10.1002/cca.2825/fullShow me the answer​​​​ WHO recommends that LF-LAM can be used to assist in the diagnosis of active TB in HIV-positive adults, adolescents, and children with signs and symptoms of TB, or in those with advanced HIV or who are seriously ill.[67]World Health Organization. WHO consolidated guidelines on tuberculosis. Module 3: diagnosis - rapid diagnostics for tuberculosis detection. Mar 2024 [internet publication]. https://www.who.int/publications/i/item/9789240089488 ​​​

Culture would still be required for drug susceptibility testing (DST).

Flow rate is non-invasive and can provide all the necessary information in uncomplicated cases.

Involves inserting a catheter in the distal part of the urethra and instilling contrast.

Can be difficult to assess the exact length of the stricture.

Most protocols recommend that forensic evidence should be collected if less than 72 hours have passed since the assault, but some are as late as 168 hours.

Most protocols recommend that forensic evidence should be collected if less than 72 hours have passed since the assault, but some are as late as 168 hours.

Test becomes positive 1-2 weeks after chancre formation. Titres can be used to monitor response to treatment.

Most protocols recommend that forensic evidence should be collected if less than 72 hours have passed since the assault, but some are as late as 168 hours.

Test becomes positive 1-2 weeks after chancre formation. Titres can be used to monitor response to treatment.

Most protocols recommend that forensic evidence should be collected if less than 72 hours have passed since the assault, but some are as late as 168 hours.

Tissue culture success is operator dependent, but this modality can yield positive results within 48 hours of inoculation.

Most protocols recommend that forensic evidence should be collected if less than 72 hours have passed since the assault, but some are as late as 168 hours.

Sample can be obtained from blood or tissue.

Most protocols recommend that forensic evidence should be collected if less than 72 hours have passed since the assault, but some are as late as 168 hours.

In the presence of leukocytes or nitrites, an alternative diagnosis should be sought. Generally a diagnosis of exclusion.

Comparative microbiological analysis of urine from urethra, bladder, and expressed prostatic secretion. Must not be performed in acute prostatitis.

Comparative microbiological analysis of urine from urethra, bladder, and expressed prostatic secretion. Must not be performed in acute prostatitis.

investigations are used to exclude other causes of pain and to aid phenotyping.

Performed if colovesical fistula is suspected.

Elevation can also be noted in benign prostatic hyperplasia (BPH), in urinary tract infection, and after instrumentation.

Multiparametric MRI integrates functional and anatomical information, and can identify lesions to target for biopsy.[71]National Institute for Health and Care Excellence. Prostate cancer: diagnosis and management. Dec 2021 [internet publication]. https://www.nice.org.uk/guidance/ng131

Invasive procedure, but is often performed under local anaesthetic and is well tolerated by most patients. May be performed as trans-rectal or trans-perineal procedure.

No radiation involved but operator dependent. Can sometimes fail to fully characterise the lesion.

Easy to perform and provides information about the nature of the tumour and any involvement of adjacent organs. Good visualisation in obese patients.[Figure caption and citation for the preceding image starts]: CT scan showing transitional cell carcinoma of the bladder blocking the right ureteric orificeFrom the personal collection of Dr Kasra Saeb-Parsy [Citation ends].

Invasive, but allows biopsies to be taken to help with the diagnosis.

Part of haematuria screen. Positive results are helpful, but negative results do not rule out malignancy.

No radiation involved but operator dependent. Can sometimes fail to fully characterise the lesion.

Easy to perform and provides information about the nature of the tumour and any involvement of adjacent organs. Good visualisation in obese patients.

Key diagnostic criteria include: abnormal vascularity, white change with acetic acid, or obvious exophytic lesions.