Could mainstream molecular testing hold the key to unlocking the flu challenge?
As we enter the winter flu season, embracing more innovative diagnostics at the point of care (POC) could play a vital role in helping to address the burden which influenza places on public health services, David Fraser, lateral flow product manager, BBI Solutions writes.
With last year’s flu season one of the worst on record - investment and innovation in how we test for, monitor, and treat flu is key.
Diagnostics are the frontline defence with highly contagious conditions like Influenza, and effective POC testing at clinics or doctors’ surgeries can create a step change in rates of infection and transform the epidemiology of infectious disease.
Lateral flow assays (LFAs) are the mainstay of rapid POC diagnostics, with the potential to enable early case management. However, there are recognised limits in terms of sensitivity and specificity when compared to tests performed in a central laboratory.
This means that conditions can slip through the testing net undetected - leading to enhanced risk of infection spreading and exacerbating the problem. This is a particular problem for conditions like influenza which have multiple strains.
Molecular diagnostics, a collection of techniques used to analyse biological markers in the genome and proteome by applying molecular biology to medical testing, offers a more specific and highly sensitive testing response than traditional lateral flow assays.
Recognising the complex nature of human disease, overlapping symptoms and states of co-infections, there is increasing demand for multiplexed systems that can detect multiple biomarkers simultaneously and for improved sensitivity/specificity at the POC.
Polymerase chain reaction (PCR) is considered one of the gold standard molecular diagnostic tests due to the high accuracy of the technology, which accounts for its use in central and reference laboratories.
It can detect disease with as few as several copies of a gene – so is ideal for fast-mutating conditions like influenza, but due to complicated workflows, complex procedures, a requirement for cold chain storage, and time and economic costs, PCR hasn’t been truly feasible in a POC setting.
Although isothermal platforms have entered the POC market for use in clinicians’ offices and clinics, they tend to require an expensive instrument and cold storage for reagents – creating cost and logistical barriers which limit a wide-spread roll out across public health systems.
That is starting to change, and we could expect to see rapid, point of care PCR tests coming to market over the next 12 months. The development of new PCR amplification methods, microfluidics and the integration with lateral flow assay technology is enabling the development of new diagnostic platforms.
These can offer outstanding sensitivity combined with simplified workflows, room temperature stable reagents, lower costs, and the ease of use associated with current lateral flow technology.
For end users of POC assays this provides the convenience and familiarity of traditional POC lateral flow assays combined with the superior sensitivity and specificity of laboratory-based PCR testing.
These platforms are looking to address some of the key challenges of bringing molecular assays to POC, by minimising the complexity and cost of the platform required to run the assays, removing the requirement for cold storage of the reagents and utilising lateral flow assays as the visualisation method for the assay result.
This game-changing development in diagnostics has the potential to transform how patients presenting with suspected flu symptoms are assessed – improving treatment at the point of care and minimising the risk of infection spreading.
The next step on the horizon for this sector is exploring the potential to create truly disposable molecular diagnostic platforms that are even lower cost and require no power source.