CLINICAL MATTERS
One of my favorite places in the world is the French town of Annecy in France. Annecy is also known as the “Venice of the Alps.” It has a large lake, the cleanest in Europe, and has a stunning view of the mountains. I am here as invited faculty at the Advanced Course on Diagnostics (ACDx), a program run by the Fondation Merieux and the London School of Hygiene and Tropical Medicine. This is my fourth time in Annecy. The first time was as an attendee of this course in 2013. Since then, I have been invited back several times as faculty. I always look forward to these trips as this place looks like it came out of fairy tale. The course takes place in the Les Pensieres facility of Fondation Meriuex. Les Pensieres is a converted 16th-century villa on the shores of Lake Annecy. It is one of the most beautiful places I have ever seen.
As wonderful as it is to be in Annecy, the ACDx course has taught me so much about the value of diagnostics. The course director is none other than Professor Rosanna Peeling, a world-renowned expert on diagnostics from the London School of Hygiene and Tropical Medicine. She has been a great mentor to me, especially when it comes to applying diagnostics in government policy.
The training I received from this conference was indispensable during the pandemic. Proper use of diagnostics was needed to manage the limited testing capacity we had, and that included prioritizing those who would benefit the most from testing. As a graduate of this course, I knew immediately that “mass testing” was a terrible idea. This is because there are no perfect tests and all tests have their strengths and weaknesses depending on proper application. With mass testing, many cases would have been missed due to poor sampling, false negatives during the incubation period, and faulty equipment and techniques. Molecular tests like RT-PCR are very difficult to scale up and are prone to contamination if not done by properly trained personnel. Despite the politically charged clamor to do indiscriminate testing, as government advisers we held our ground and focused resources for targeted testing. A modeling study by epidemiologist Adam Kucharski eventually vindicated this choice by showing that random mass testing with RT-PCR would only have a two percent impact on transmission, while incurring an unbelievably large and unsustainable expense. Combining interventions such as masks, face shields, physical distancing, facility-based isolation and quarantine with targeted testing was much more efficient with a 90 percent impact on transmission, at a much lower cost.
The course also equipped me with the tools to recognize that Covid-19 antibody testing was practically useless as a test for acute disease. It takes at least two weeks to begin to develop enough IgM antibodies to be detected by rapid antibody tests. Despite pressure from many sectors of society who thought rapid antibody tests were a valid alternative to RT-PCR, the government advisers again insisted that it had very little utility as a screening test. We did our very best to save the government money by dissuading procurement of these unreliable kits. On our advice, the Department of Health did not procure any rapid antibody tests. Unfortunately, the private sector and some local government units went ahead and ordered and deployed these tests on their own initiative. This did nothing to improve case detection and, in some cases, lulled those who tested negative into a false sense of security. After a few months of struggling to use these tests, most users dropped them and more than a few were stuck with tests they could not use. Understandably, these were the months when any action seemed better than nothing to the general public. The science, however, very clearly did not support the use of rapid antibody tests.
Over the course of the pandemic, the Technical Advisory Group continued to make science-based recommendations, including those pertaining to diagnostics. No less than our “testing czar,” Secretary Vince Dizon sought our advice on the best way to deploy and utilize our procured tests. Sec. Vince was very receptive to our suggestions and incorporated these into the national testing program.
The Covid-19 pandemic placed a spotlight on diagnostics like never before. WHO director general Tedros Ghebreyesus very early on famously stated that countries should, “Test, test, test.” Unfortunately, this exhortation was taken without context, with politicians not understanding that testing needs to be done rationally, and with the correct kind of test. This led to diversion of resources from equally important interventions, such as contact tracing, quarantine, isolation, and vaccination. In countries where resources are limited, the undue emphasis on testing has been detrimental to other aspects of the pandemic response. When used properly, tests are valuable tools for improving health outcomes. Used improperly, they are not just a waste of money but can be potentially dangerous if they mislead healthcare management.
During this iteration of the course, I was asked to sit on a panel of experts to assess the proper use of diagnostics during pandemics. The panel included distinguished scientists from all over the world, including my friend from Senegal, Dr. Amadou Sall. Dr. Sall is a rock star in the diagnostics world. A trained virologist, he leveraged his contacts with different international institutions, including Biomerieux, Insitut Pasteur, and the Global Fund to set up manufacturing facilities in Africa to produce high quality point-of-care tests that his company sells for $1 or less. These tests, including Covid-19 rapid antigen tests, have been gamechangers for African nations which could not afford imported tests or could not procure them due to the global shortage.
Amadou’s innovation could not have come at a better time. The global pandemic pretty much showed that despite pledges of solidarity and equity, in times of stress it is still every nation for itself. The US and Europe ended up hoarding vaccines and RT-PCR kits for themselves. Many resource-poor countries could not procure essential pandemic response tools despite having the money to buy them, because all these were diverted to the highest bidder.
Indeed, self-sufficiency in diagnostics is essential when the world is facing a global emergency. Being able to do this while keeping costs manageable will save the most number of lives and allow poorer countries to invest in many other interventions. The Covid-19 pandemic has brought home the message of the ACDx course, not just to its participants, but to the world.
That message is, “Diagnostics matter and good diagnostics save lives.”
