Laboratory diagnosis of urinary tract infections: Towards a BILULU consensus guideline

The BILULU study group consists of seven microbiologists of hospital laboratories located in the region of Flanders (Belgium). A major goal of the group is to standardize diagnostic microbiology procedures based on available evidence and, in the absence of evidence, based on general microbiological principles and expert opinion. Scientific evidence of current urine culture guidelines is incomplete and at some points guidelines don't indicate clear choice. The aim of this project was to develop a clear and unambiguous step-by-step guideline regarding the work-up of urine cultures. Urinary tract infections (UTI) are very common throughout life, both in otherwise healthy as in immunocompromised or debilitated persons. UTI occur more frequent in women, with a lifetime occurrence rate close to 50%. The diagnosis of UTI is based upon clinical signs and symptoms and is supported by laboratory evidence of pyuria and bacteriuria. Laboratory diagnosis consists of urinary WBC count, dipstick analysis and urine culture. Urinary cultures represent a significant part of the workload in microbiology laboratories. Clear instructions for the interpretation of urine cultures by the laboratory technicians are indispensable to obtain standardized, reliable, and clinically useful results. Our search strategy was dual. On the one hand, we consulted reference works and searched the Internet for available guidelines on the subject. The following guidelines were withheld: 'Urine cultures' (Clinical Microbiology Procedures Handbook); 'Laboratory diagnosis of urinary tract infections' (Cummitech); Specimen collection, transport, and processing: bacteriology' (Manual of Clinical Microbiology); Urinary tract infections (Mandell, Douglas and Bennett's principles and practice of infectious diseases). In addition, we consulted reference guidelines of the Infectious Diseases Society of America (IDSA) and the European Association of Urology and performed specific searches on Pubmed (until May 2017) to obtain further evidence on particular items. Discrepancies and unresolved issues were finally discussed by an expert panel of 8 microbiologists.

Journal of microbiological methods. 2018 Feb 07 [Epub ahead of print]

Matthijs Oyaert, Britt Van Meensel, Reinoud Cartuyvels, Johan Frans, Wim Laffut, Patricia Vandecandelaere, Hans De Beenhouwer, BILULU Study Group

Laboratory of Microbiology, OLV Hospital Aalst, Aalst, Belgium. Electronic address: ., Laboratory of Microbiology, Medisch Centrum Huisartsen, Leuven, Belgium., Laboratory of Microbiology, Jessa Hospital, Hasselt, Belgium., Laboratory of Microbiology, Imelda Hospital, Bonheiden, Belgium., Laboratory of Microbiology, Heilig Hart Hospital Lier, Lier, Belgium., Laboratory of Microbiology, Jan Yperman Hospital, Ieper, Belgium., Laboratory of Microbiology, OLV Hospital Aalst, Aalst, Belgium.