Feasibility of using microbiology diagnostic tests of moderate or high complexity at the point - of - care in a delivery suite

Abstract

Point-of-care testing (POCT) is one of the fastest growing sectors of laboratory diagnostics. Most tests in routine use are haematology or biochemistry tests that are of low complexity. Microbiology POCT has been constrained by a lack of tests that are both accurate and of low complexity. We describe our experience of the practical issues around using more complex POCT for detection of Group B streptococci (GBS) in swabs from labouring women. We evaluated two tests for their feasibility in POCT: an optical immune assay (Biostar OIA Strep B, Inverness Medical, Princetown, NJ) and a PCR (IDI-Strep B, Cepheid, Sunnyvale, CA), which have been categorised as being of moderate and high complexity, respectively. A total of 12 unqualified midwifery assistants (MA) were trained to undertake testing on the delivery suite. A systematic approach to the introduction and management of POC testing was used. Modelling showed that the probability of test results being available within a clinically useful timescale was high. However, in the clinical setting, we found it impossible to maintain reliable availability of trained testers. Implementation of more complex POC testing is technically feasible, but it is expensive, and may be difficult to achieve in a busy delivery suite.

Molecular-based Screening for Perinatal Group B Streptococcal Infection: Implications for Prevention and Therapy

“…It is particularly interesting for obstetrics where the important and relevant pathogens (GBS, Listeria spp.) have predictable antimicrobial susceptibilities and their detection is frequently clinically meaningful [35]. A PCR-based POC test, such as Xpert Ò GBS, can be performed by non-laboratory personnel (i.e., midwives) in the labor suites [36].…”

Point-of-Care Testing for Clostridium Difficile Infection: A Real-World Feasibility Study of a Rapid Molecular Test in Two Hospital Settings

“…However, several manufacturers are developing highly sensitive molecular-based tests that could be implemented at POCT. These tests have been proposed or evaluated in a number of infectious diseases e.g., MRSA [ 10 ], influenza [ 17 ], sexually transmitted infections [ 11 ], group B Streptococcus [ 12 ], tuberculosis [ 13 ] and HIV [ 14 ].…”

Point-of-care (POC) diagnosis of bacterial vaginosis (BV) using VGTest™ ion mobility spectrometry (IMS) in a routine ambulatory care gynecology clinic

“…The accuracy of VGTest for BV diagnostics is 88 %, underscored by 83 % sensitivity and 92 % specificity, is slightly lower than the previous reported accuracy of 94.4 % [10]. The VGTest and prototype IMS devices show similar technical and analytical sensitivity.…”

“…The gram stain with determination of Nugent score is a time-consuming method not always suitable for clinics having high number of patient visits and routine laboratory work flow. Saline wet mount microscopy in combination with Whiff test, apparently simple and quick to perform, distinguishes normal lactobacillus flora from colonization with other bacteria and microbes and remains the preferred method in many ambulatory women's health care clinics for screening of BV [2,5,10,11].…”

“…Additionally, improper grading of lactobacilli in mixed flora, leucocyte infiltrate common in pregnancy and sexual intercourse 24 h prior to testing. Asymptomatic BV without discharge may lead to misseddiagnosis during clinical examination [5,10,12,13]. Social and psychological effects of BV also impact on diagnosis.…”