Why qPCR & Phenotypic Testing Must Be Displaced ā Part II If you ever want to understand the scale of a problem, look at how much it costs. Tuberculosis alone costs India, Africa, and Brazil 27 trillion INR a year in lost productivity and healthcare expenses. Thatās just one disease. And hereās the thing: we already have tests for TB. The problem isnāt that we canāt detect itāthe problem is how long it takes. Right now, clinicians rely on a combination of qPCR and phenotypic testing to diagnose infectious diseases. qPCR tells you whatās there, and phenotypic testing tells you if itās resistant to drugs. But neither is fast enough. Youāre looking at days or weeks before getting a full resistance profile. That means more suffering, more spread, and more misuse of antibiotics, which fuels antimicrobial resistance (AMR)āone of the biggest health crises weāre facing. The Cost of Delay Every extra day a patient waits for results is another day theyāre: ⢠Getting worse. ⢠Spreading the infection. ⢠Taking the wrong drugs, accelerating drug resistance. This last one is the most dangerous. The WHO estimates that 700,000 people die every year because antibiotics didnāt work for them. If we donāt change how we diagnose infections, that number could hit 10 million per year by 2050. Why Diagnosis is Failing Right now, diagnosing an infection isnāt just slowāitās broken. 1. You run a qPCR test to confirm the presence of a pathogen. 2. If itās positive, you then wait for phenotypic testing to see if itās resistant. 3. Meanwhile, the patient is either untreated, under-treated, or taking broad-spectrum antibiotics that might not even work. This is how AMR spreads. The longer we take to get the right treatment, the more bacteria evolve to resist what we throw at them. What If We Could Fix This? Imagine a single test that could do what qPCR and phenotypic testing do togetherāin one clinic visit. With just one sample, clinicians could get a detailed report that: ⢠Identifies the infection ⢠Maps its entire resistance profile ⢠Provides the right treatment recommendation immediately Thatās not theoretical. Thatās what Targeted Next Generation Sequencing (tNGS) is about to do. How tNGS Works tNGS is a highly efficient sequencing method that hones in on specific regions of a pathogenās genome rather than sequencing the entire thing. This makes it cheaper, faster, and more informative for diagnosing infectious diseases and tracking drug resistance. There are two main ways tNGS is applied: - Hybridisation Capture Sequencing; ideal for highly variable regions, like when weāre hunting for unknown mutations. - Amplicon-Based Sequencing; best for smaller, well-characterised targets. Once sequencing is complete, bioinformatics tools align the reads to a reference database, detecting mutations linked to drug resistance. Unlike qPCR, which only confirms known targets, tNGS can detect novel resistance mutations and co-infectionsāall in a single test. That means faster, more accurate diagnoses and fewer opportunities for AMR to develop unchecked. Why tNGS is Better If you had a way to test for multiple pathogens, identify resistance, and get results in hours instead of weeks, youād take it, right? Thatās what tNGS offers. Hereās how it compares to the current methods: - Broad Diagnostic Capability ā Detects multiple pathogens and all known resistance genes in a single test. - Comprehensive Resistance Profiling ā Instead of waiting for cultures to grow, tNGS detects resistance genes directly. Faster and more accurate. - Speed ā qPCR requires multiple tests. Phenotypic testing takes days or weeks. tNGS delivers results in hours. Why This Matters AMR isnāt theoretical. Itās happening now. Every time an infection isnāt properly diagnosed, and a broad-spectrum antibiotic is thrown at it, resistance builds. Right now, 700,000 people a year die because antibiotics didnāt work for them. That number could hit 10 million per year by 2050. We donāt need more antibiotics. We need better diagnostics. qPCR and phenotypic testing got us this far, but theyāre too slow, too limited, and too reactive. If we want to stay ahead of infectious diseases, we have to move beyond them. tNGS isnāt just faster. Itās more precise, more scalable, and more future-proof. And thatās exactly what we need to fight AMR. Whatās Next The real question isnāt whether we need to replace outdated diagnosticsāitās how fast we can do it. š Want to follow the progress? Iām working on itāstay tuned. š© Letās talk. Reach out and join the movement to make better diagnostics a reality.
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