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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.

A key impetus for the invention of a Rapid Diagnostic Test (RDT) for sleeping sickness (also known as human African trypanosomiasis or HAT) was the persuasive advocacy for better ‘field ready tools’ by medical humanitarian agencies such as Médecins Sans Frontières. They were engaged in fighting outbreaks of this disease, which is fatal if untreated, in contexts of weakened health systems and mass displacements during the Central African wars of the 1990s.

This is a photograph of a publicity for a “street corner” obstetrical ultrasound in Brazil. It proclaims: “ultrasound examinations at low prices.” The advertised “low prices” can be indeed be very low: some clinics charge less than US $10 for an ultrasound examination. The aim such examination is to confirm the existence of a pregnancy, provide reassurance, but above all to tell the pregnant woman what the sex of her future child will be, and produce the “baby’s first photograph.”

Diagnosing sleeping sickness (also known as human African trypanosomiasis (HAT)) is complicated, requiring the alignment of clinical suspicion with serological, parasitological, and molecular confirmation to determine appropriate treatment. Previously, diagnosis was carried out by mobile lab teams which confirmed cases in village screenings and transported patients for treatment. Since cases have declined however, expensive active screening campaigns have been phased out and replaced with passive, symptom-based algorithms.

To certify as having eliminated trachoma, countries submit a dossier to WHO, including showing that the prevalence of TT unknown to the health system is <2 cases per 1000 population aged ≥15 years, and that the prevalence of TF in 1-9 year-olds has fallen below 5%, and that this has been sustained for at least two years, in each formerly endemic district. However, the presence of clinical signs of active trachoma (TF and TI) is poorly correlated with detection of infection, especially after MDA where clinical signs tend to over-estimate prevalence relative to infection. The result is that: 1.) We may be conducting unnecessary rounds of MDA; and 2.) Countries may have eliminated ocular chlamydial infection, but not be able to certify as having eliminated trachoma.

Through my work in African laboratories I am regularly made aware of the challenging equipment shortages faced by research laboratories in many low/middle-income countries (LMICs). This extends far beyond the absence of “state-of-the-art” equipment and shiny, new models regularly produced by commercial companies. These shortages include the availability of what would normally be considered ubiquitous laboratory equipment – PCR machines.