To confirm a diagnosis of acute prostatitis, the recommended laboratory tests primarily include urine analysis and urine culture to identify the causative bacterial pathogen. A mid-stream urine sample should be collected for microscopy, culture, and sensitivity testing to detect bacteriuria and guide antibiotic therapy NICE CKS. Urine dipstick testing for leukocyte esterase and nitrites can support the diagnosis by indicating infection, but culture remains essential for confirmation and antibiotic susceptibility NICE CKS. Blood tests such as full blood count and inflammatory markers may be used to assess systemic involvement but are not diagnostic. Prostate secretion tests (expressed prostatic secretions) and post-prostatic massage urine cultures are generally not recommended in acute prostatitis due to the risk of exacerbating symptoms and are more relevant in chronic prostatitis Rothman & Jaffe 2007. Additionally, if a sexually transmitted infection (STI) is suspected, appropriate STI screening should be performed and urgent referral to genito-urinary medicine (GUM) clinics considered NICE CKS.
In summary, the key laboratory test to confirm acute prostatitis is a urine culture from a properly collected mid-stream urine sample, supported by urine dipstick testing for infection markers. Blood tests may assist in assessing severity but are not diagnostic. Prostate fluid testing is not routinely recommended in acute cases due to potential risks (Rothman and Jaffe, 2007; NICE CKS).