It has now been a little over a month since the World Health Organisation announced that it would begin testing people for coronavirus in Idlib, northwest Syria. Half of the population of the province, the last rebel-held area in the country, has been displaced. Hundreds of thousands of its 3 million civilians live in crowded tents near the border with Turkey. The good news is that, as of last week, there have been zero laboratory-confirmed cases in northwest Syria. The bad news is that samples from only 191 individuals have been tested, which means we have nowhere near a basic understanding of whether the virus has taken hold there, or the measures needed to limit the outbreak. As the pandemic continues to ravage both wealthy and impoverished societies around the world, a lack of testing has posed a major challenge for many countries. But the virus's spread among the most vulnerable populations remains unclear. A new study by the Norwegian Refugee Council released this week found that a record 50.8 million are internally displaced around the world, and the NRC says they will be rendered more vulnerable by the pandemic. Where tests have been conducted in refugee camps in Europe, including in Greece and Germany, dozens of cases are found and the camps are locked down. By the time the first infected person is discovered, the virus has already spread through the camp like wildfire. The WHO has championed the idea of widespread testing as a key element of getting to grips with the spread of the novel coronavirus. Countries like the UAE and Germany have tested broadly, and consequently appear better equipped to quell the virus’s threat. In addition to gathering personal protective equipment (PPE) like face masks and gloves for healthcare workers, countries have scrambled to buy test kits from foreign sellers, some of which ended up being scams, like in a recent case in which the British government bought faulty testing kits from a Chinese company. That’s how crucial testing is to engaging in the fight. Conditions in crowded camps in Idlib, now the epicentre of Syria's humanitarian crisis, are a cause for grave concern and a public health catastrophe in waiting. Of course, the challenges in Idlib are unique and myriad, including the context of the Syrian war itself, the systematic destruction of hospitals and targeting of healthcare workers throughout the war that has left the province with precious few locations to conduct testing or isolate potential cases, and the challenge of procuring PPE and delivering it across the border into a war zone. Even the US and Europe do not have enough tests yet to screen all the people they want to. If and when cases are identified, the prospect of social distancing, quarantine, and widespread use of hand sanitizers and masks amid the destitute conditions of refugee camps is remote. But the challenges of testing in Idlib are also reminiscent of those in other refugee and internally displaced camps all over the world, and the lack of enough testing will leave vulnerable communities exposed to a deadly pandemic without recourse for ensuring their well-being. Simply pretending that they do not exist will not make the problem go away. In Idlib, there is just one testing facility catering to an enormous displaced population of three million, and just three facilities that are equipped to host Covid-19 patients. The WHO has a 40 per cent shortfall in funding for its response plan in the area, which will likely be exacerbated by the incredible decision of US President Donald Trump’s administration to sever funding amid a global pandemic. The lack of testing so far, in Idlib and Syria more broadly, where rumours of cases had been rife even before the first one was officially announced in March, likely means coronavirus has been silently spreading. If it has ravaged the first world, what will it do to a destroyed Syria? Or what will it do to communities in refugee and IDP camps in Lebanon and Iraq, where recently discovered cases of Covid-19 have given life to fears of a major outbreak? It is essential that widespread testing is made available in Idlib as well as other refugee and internally displaced camps around the world. These are among the most vulnerable individuals in society, and they do not have the luxury of self-isolating at home or social distancing and losing access to basic services like food and water distribution. It is essential to make testing available for those communities if we are to get a true handle on the extent of the pandemic, and to plan the interventions that will be needed to protect refugees and IDPs. The lack of testing in these communities is so far a shameful failing in the global fight against Covid-19. But there is no good reason to allow present failures to become permanent legacies. <em>Kareem Shaheen is a former Middle East correspondent in Canada</em>