And by mid-January, China, the world's leading maker and exporter of reagents and coronavirus test kits, was itself scrambling for diagnostic kits to screen for COVID-19 as the outbreak spread in Hubei Province and beyond.
Chinese demand and an export ban dried up global supplies and exacerbated a test-kit shortage that affected responses around the world to the mounting pandemic.
There was a knock-on effect in Europe, the coronavirus's second "epicenter" by March, which quickly fell behind on demand for test kits. It still has not recovered, according to the head of the European Center for Disease Prevention and Control (ECDC), Andrea Ammon.
In the United States, the Centers for Disease Control and Prevention (CDC) blamed "one reagent that isn’t performing as it should consistently" when it hit a major snag rolling out test kits to states in February.
A month later, the head of the CDC warned that reagents essential to test kits "now are in short supply."