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One of the problems of addressing something so broad and monolithic a problem as infrastructural diagnostic capacity, is galvanising political commitment. Could the Essential Diagnostics List provide stewardship for encouraging governments to undertake crucial lab strengthening?

For years, funders and policy makers have been making the case for the development of point-of-care tests that can work in places without laboratory infrastructure. Access was often prioritised over accuracy in these debates. But one of the most striking common themes to run through the presentations at McGill was the recognition of the continued importance of and need for investment in effective centralised laboratory infrastructure in low and middle income countries. Any focus on rapid diagnostic tests (RDTs) or disease specific solutions were more often seated within discussions surrounding their position within a wider assemblage of socio-technical ecosystems.

It is clear that we have reached a point where we are to some extent ‘tool ready’ to address major diseases such as ‘the big three’ (HIV, TB, and malaria), some Neglected Tropical Diseases (NTDs), and even universal threats of Antimicrobial resistance (AMR) and pandemic diseases. In many cases, we have the technology, but not the systems to deliver them where they are most needed. By now it is evident that “science and technology is not the issue. It's the rest of the ecosystem; the neglect, the under-investment, that countries don’t identify these as a problem worth investing in" (Prof Madhukar Pai).

Beyond the regulatory barriers to bringing devices to market, another challenge is how to negotiate the trade-offs between generalisability and local relevance. At one end of the spectrum products must be broadly applicable enough to have a viable market, while at the other we need to make sure tests and interventions are locally adapted and suited to regional needs and contexts. “Say you want to do a febrile panel” commented one discussant during a Q&A session, “in every country that is something different. Do you make a broad one and not make much money? Or multiple specific ones?” Participants largely agreed that many of the devices needed are already developed and exist, but are not adapted to local contexts and fail to reach the frontline in many LMICs where they are needed. As Dr Cédric Yansouni foregrounded his presentation on the role of centralised reference labs, the dichotomy of “point of care versus point of ‘can’ ” need not be mutually exclusive goals, we can and ought to strive for both.

From the outset of the course and throughout the week, the centrality of diagnosis to the wider system of care was signposted as a point of departure to explore key issues in delivering care across different settings, from public health emergencies where "accurate and expedient diagnosis impacts every aspect of outbreak response" (Dr Jana Broadhurst), to elimination programmes. "Diagnostics are a cornerstone to directing who needs treatments, and seal the deal for elimination" remarked Dr Cédric Yansouni (who chaired the majority of panels throughout the week). Using devices to ‘rule out’ infections creates further uncertainties for clinicians dealing with syndromic fevers, "our interventions are bearing fruits, but now clinicians have to consider a whole constellation of causes that they may not be equipped to deal with". This raises some important questions regarding diagnostics’ role amidst this constellation, and how devices evolve in an ever-changing ecosystem of global health priorities.

In June 2018, McGill University's Global Health Programme hosted its 4th annual Summer Institute in Infectious Diseases and Global Health in Montreal, Canada. Shona Jane Lee, an associated researcher with the DiaDev project, attended this year's 5 day course on Global Health Diagnostics. In this mini-series she reports some of the key themes and conversations emerging from the

Taenia solium is a zoonotic disease shared between humans and pigs. Humans become infected with T. solium, also known as the pork tapeworm, when they consume undercooked pork infected with porcine cysticercosis. Human cysticercosis develops when humans ingest T. solium eggs. If cysterici travel to the human brain this leads to neurocysticercosis, a leading cause of onset epilepsy in endemic areas (Singhi ‎2011). In an effort to control T. solium, the International Livestock Research Institute (ILRI) have collaborated with the University of Edinburgh, Arista Inc., and Astel Diagnostics to develop a prototype, pen-side lateral flow assay (LFA). The assay has been designed to detect porcine cysticercosis using blood or serum.

Routine collection of blood samples from neonates – often using so-called Guthrie cards (pictured) – began in the 1960s when a number of North American and European countries set up screening programmes for phenylketonuria, a rare single-gene disorder which leads to developmental delays and early death if untreated. Such programmes have since been introduced in many other countries around the world. At the same time, refinements in laboratory technology – especially the development of tandem mass spectrometry from the early 1990s, followed by the inception of increasingly powerful new genomic technologies – have made it possible to detect a growing range of disorders from the same blood samples. These proliferating possibilities have been accompanied by often intense discussion about just what diseases should be included in newborn screening programmes.