Utilising POCT for Detection of Infectious Diseases

It is a proven fact in laboratory medicine/ pathology diagnostics that timely intervention is critical to a favourable and improved patient outcome. Timely delivery of appropriate care can help reduce mortality and morbidity for chronic conditions. Delayed test result follow-up can have major consequences for the quality of care, including missed diagnoses and suboptimal patient outcomes.

Over the last three decades there has been considerable growth and demand in the number of requests in laboratory medicine for Point of Care testing services (POCT), the driving factor is attributed to changes in healthcare delivery which are aimed at delivering less costly care closer to the patient’s home. Point of care testing, sometimes referred to as near patient, bedside, or extra laboratory testing performed by non-laboratory trained personnel, is not new phenomenon.

A wide variety of people can perform point-of-care tests, including laboratory professionals, paramedics, radiologists, doctors, nurses, or other healthcare professionals. POCT devices come in variety of forms, including basic dipsticks as with urinalysis, handheld devices like glucose meters, or sophisticated benchtop analysers such as those used to assess blood gases in critically ill patients.

The area of POCT that are well established include self-monitoring of blood glucose, which is by far the largest segment of POCT and home pregnancy tests. Other common tests are for haemoglobin, haemoglobin A1c as well as prothrombin time/international normalised ratio (PT/INR) for people on the anticoagulant warfarin. There is also a growing need for rapid screening for infectious diseases such as HIV, dengue fever, malaria, and influenza and more recently Covid-19. POCT for infectious disease have proven useful in community clinics and resource-limited areas where there may not be access to a central laboratory or where infrastructure is limited for sample transportation. POCT for infectious diseases at the point of care has been shown to facilitate prompter treatment, which can prevent infections from spreading. However, POCT for infectious disease is not nearly as well established as laboratory disciplines such as clinical chemistry and haematology.

The advent introduction of POCT has been proven to facilitate earlier and more rapid decision making, which in theory should lead to an improved clinical or economic outcome for patients such as

• earlier discharges,
• starting treatment earlier,
• improved adherence to treatment,
• reduced incidence of complications,
• quicker optimisation of treatment,
• reduced reoperation or readmission rate,
• patient satisfaction, and
• potentially increase the capacity of the emergency services to treat more patients.

Ultimately, our focus has shifted to patient demands and the way in which healthcare is delivered. Progressively, there is a new prominence on an overall patient-centred experience, and this is often conflicting with the realities of delivering healthcare in clinically and financially accountable environments.

POCT is usually seen as more costly when considered strictly in view of cost per test. In many instances, however, it yields cost benefits in reduced deployment of resources (e.g., blood products, antimicrobial consumption, use of staff, costs of follow-up testing for tests with poor sensitivity).

The Benefits of POCT for infectious disease detection

Research have proven that POCT facilitates more rapid clinical decision making in the process of infectious disease diagnosis, management choice and monitoring, and prognosis, as well as operational decision making and effective use of resources. The use of POCT such as lateral flow tests (LFTs) have been astounding in the fight against SARS-CoV-2 (Covid-19). The use of LFTs in outbreak response and community testing saw a massive improvement which has provided relatively faster turnaround time of 2-24 hours. Lateral flow test POCT has the added advantage of detecting infectious cases, can be scaled up rapidly for decentralised testing, are comparatively cheap, do not require laboratories, and provide results rapidly.

As such, they are most appropriate for widespread community testing intended to identify and isolate cases and contacts early in the infection, to reduce transmission or time spent in isolation, and to enable economic and social activities to resume normalcy. Additionally, by proactively testing asymptomatic individuals, they increase the potential to break chains of transmission, and also help to protect and enable our critical businesses, key workers, and institutions to continue operating as effectively as possible. In hindsight, for those opting for a lateral flow test, this test is a non-invasive procedure, and the results back are extremely quickly (around an hour).

The introduction of POCT has been shown to improve the speed of access to further investigational interventions; for example, rapid access to influenza results in a paediatric A&E can lead to a reduction in the number of investigations as well as reduced antibiotic use, increased antiviral use and a reduction in the time to discharge patients. Transporting patient samples and specimens to static lab for processing usually means waiting a long time for results. This can lead to wasted time in critical contexts or patients being treated without their care management team having full information about their care needs.

POC testing makes it far easier for results to be obtained quickly and reliably. With these results available, medical staff can more easily make informed decisions about a patient’s treatment and care regime.