HHE Pathology and diagnostics supplement 2018 - Page 22

viruses are prone to mutation and newly emerging strain variants may not be detected by LFA kits. 7 Another situation where POCT might be valuable is in the genitourinary medicine setting. A patient who might not return a week later to be given a test result regarding a sexually transmitted infection might be prepared to wait for an hour. Lateral flow kits are available to screen for viruses such as hepatitis B (HBV), hepatitis C (HCV) and HIV, and some formats use oral fluid instead of blood, which can be more acceptable. 8 However, there are issues with sensitivity and this might lead to a protocol that requires individuals to be screened more regularly than when using the main laboratory assays. Also, any patient who is found to be positive in the POCT test will require further tests to determine the stage of infection, viral load, sequence and type of virus in order to inform treatment and management. 9 Thus it might be more cost effective to do the initial screening test and all the follow up work in the main laboratory. Desk top molecular analysers should be more accurate than LFAs because they are detecting the viral genome directly. The range of viruses which can be detected in molecular POCT is currently quite limited compared to the multiplex main laboratory tests and they are more expensive. Also as mentioned above for the blood borne viruses, positive results might still require follow up sequencing and typing for patient management and epidemiological purposes. However an interesting innovation is the development of a low cost analyser capable of monitoring HIV viral load for use in situations where demand is high, but resources are limited. 10 Another potential application of a respiratory POCT is to identify which patients admitted to hospital with acute respiratory symptoms have virus infections and therefore do not require antibiotics, 11 but could benefit from treatment with an antiviral drug. This could be an important tool in the work to reduce antimicrobial resistance. Conclusions Virology POCT has the potential to supplement the work of the main diagnostic laboratory, but it seems unlikely that they will be a replacement. Although the cost per test is greater at the moment, this could start to reduce if more healthcare organisations use them more widely. Evaluation of POCT in virology involves comparison of the test with the main laboratory EIA or multiplex PCR. These studies tend to include laboratory staff doing the tests, either in the laboratory itself or supervising others in the primary or secondary care setting. More work needs to be carried out to ensure that results are consistent when non-scientists implement the full process of sample collection, testing and reporting. Key areas to consider are training of colleagues and quality assurance of the reagents and equipment. Another issue is how to make sure that any POCT results are recorded accurately in the patient’s notes and are communicated to the laboratory promptly. This is particularly important when follow-up laboratory tests are required. It is clear that POCT devices could be used in more settings and they are being refined using methods such as microfluidic technology (which uses paper instead of cellulose and a smartphone application to analyse the results). However, it is important to note that scientific advances in the main laboratory continue and have recently brought the powerful tool of next generation sequencing. This reveals information about the whole genome of each pathogen in the patient’s sample rather than just detecting a small section. Thus it provides data that will enhance patient care and management in different ways. 22 HHE 2018 | hospitalhealthcare.com References 1 Pitt SJ, Phillips DIM. Diagnostic virology and patient care: from vaguely interesting to vitally important. Br J Biomed Sci 2017; 74:16–23. 2 St John A, Price CP. Existing and emerging technologies for point- of-care testing. Clin Biochem Rev 201 NMMx$͍˂ޝ[HK[HK]\[\^\ˈ\^\[[B M͌LLx$̌ [\H][ H[ BًX\HXܘ]ܞH[[X[ZXܛؚ[K[ZXܛؚ[] M̎N x$ ˂HY\R][ QPՂ[Y[\Y\]܈[ BًX\H[Xܘ]ܞKX\Y\[܈XH\\\X\NHY[[Y][ۈYK[]  MN NNMN $ [\\H][ XYۛXœ\ܛX[Hو[Y[H\\\˜[Ո\Y[Y[]X[ۂ\[[[[\X\H\K[\ MNL$˂0\H][ ][X][ۈق[[][X]ܘ\X\™܈H\Y]X[ۈوB[Y\[RK Mܛݚ\\[[\\[X\H M]\\Z[[K M̌J K][Y^][ X]B\\Y[و\YXYۛX\܈H]X[ۈق[XY\\]]\\\H܈[\ݚ[X\\K[ZXܛؚ[[XŒ M̌ NKLx$MH\][ YX][\›و\]]\\Y\\[YK]X\N\[وB[Z^Y ][X[\YK]\\[\] M̎$KL[][ \ܛX[HقHSPHH[RHULH[ZKTB\܈\[Y[ۚ]ܚ[˜]H[ [ًX\K\Y] M x$ KLH[\][ ][B[X[\[ [ًX\H\[™܈\\]ܞH\\\[Y[œ\[[][]X]B\\]ܞH[\ \NHYX]X[[X[ [Z\Y۝YX[ []\YY M N x$LK