From the United States to Europe, the Middle East, Africa and Latin America, hospitals are facing acute shortages of the ventilators they need to treat seriously ill Covid-19 patients when they develop breathing difficulties.

And governments and hospitals are turning to China, the world’s factory, for the mechanical breathing aids. But while Chinese ventilator makers say they have ramped up production, there are fears that the global shortage is unlikely to be resolved fast enough.

Analysts say a big challenge is the disruption of global supply chains amid the pandemic. Chinese ventilator makers depend on key components they can only get from Europe and the US, where many places have been locked down, and international flights are limited.

In Wuhan, where the first cases of the virus were reported in December, Chinese companies provided more than 27,000 ventilators to hospitals, according to Xu Kemin, an official with the Ministry of Industry and Information Technology.

The number of infections has been steadily falling in the central Chinese city – it had dropped below 1,800 by Monday from a peak of more than 46,000 in February.

So far, Chinese manufacturers have shipped more than 1,700 invasive ventilators to the global market – half the number they usually send in a year. But there are nearly 20,000 orders pending – including 2,000 ordered by Spain – and manufacturers say they are receiving inquiries every day.

“Our companies are working around the clock and overtime to help control the global pandemic,” Xu told reporters in Beijing on Monday, adding that employees had even been reassigned from R&D departments to production lines. “Pushing for [early] resumption of medical equipment production has always been our top priority.”

Finding the parts to make ventilators is a challenge. Each one has more than 1,000 components, and some parts – like the turbines and sensors – are mainly made in Europe. Suspended production and transport restrictions there and elsewhere are making it hard for Chinese firms to get what they need.

In Beijing, the municipal government has made it a little easier for local manufacturers by reducing the time needed to secure import permits for key components from a week to one day, according to The Beijing News.

Xu said it was unrealistic to believe China could meet global demand. The country’s 21 ventilator makers that had export permits could only meet one-fifth of the demand at present, he said.

The US alone could have 960,000 Covid-19 patients in need of ventilators – far more than the 200,000 units available in the country, according to an estimate by the Society of Critical Care Medicine.

Wu Chuanpu, director of Vendeng.cn, an e-commerce platform for medical supplies based in Jiangsu, told 21st Century Business Herald that almost all ventilator makers in China were stretched to capacity trying to meet orders from overseas.

Some manufacturers may stay at full production until May, he said, adding his company was receiving over 60 orders a day, many from foreign governments, seeking hundreds or thousands of ventilators.