Raphael Koch, a retailer of medical devices in the small Swiss town of Wil, has been busy for the past two weeks fielding a flurry of phone calls. Most are from Indians or India-based companies looking for oxygen concentrators, with some even wanting as many as 500 at once.

But Koch’s Oxymed store barely has any stock left of the little known machines that separate the critical gas from air and assist patients with low blood-oxygen levels. And he isn’t expecting fresh supplies from manufacturers until at least mid-June.

"They’re desperate,” he said, referring to the callers he’s been speaking to lately. "They tell me about relatives dying on the streets, that there’s no space in the hospitals and that the few oxygen concentrators that are still available are being sold for up to 10 times the normal price.”