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 .
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