Fatigue and shortness of breath still afflict many patients a year after their hospitalisation for Covid-19, according to a new Chinese study calling for a better understanding of the pandemic's long-term health effects.

Around half of patients discharged from hospital for Covid still suffer from at least one persistent symptom -- most often fatigue or muscle weakness -- after 12 months, said the study published in British medical journal The Lancet Friday.

The research, the largest yet on the condition known as "long Covid", added that one in three patients still have shortness of breath a year after their diagnosis.

Graphic on ongoing problems experienced by some people who initially showed mild symptoms of the noval coronavirus
Graphic on ongoing problems experienced by some people who initially showed mild symptoms of the noval coronavirus AFP / John SAEKI

That number is even higher in patients hit more severely by the illness.

"With no proven treatments or even rehabilitation guidance, long Covid affects people's ability to resume normal life and their capacity to work," The Lancet said in an editorial published with the study.

"The study shows that for many patients, full recovery from Covid-19 will take more than 1 year."

The study followed nearly 1,300 people hospitalised for Covid between January and May 2020 in the central Chinese city of Wuhan, the first city affected by the pandemic
Representational image of a man in hospital after contracting COVID-19. AFP / Yasuyoshi CHIBA

The study followed nearly 1,300 people hospitalised for Covid between January and May 2020 in the central Chinese city of Wuhan -- the first place affected by a pandemic that has since infected 214 million people worldwide, killing more than 4 million.

The share of observed patients with at least one symptom decreased from 68 percent after six months to 49 percent after 12 months.

Respiratory discomfort increased from 26 percent of patients after six months to 30 percent after 12 months, it said.

It found affected women were 43 percent more likely than affected men to suffer from fatigue or persistent muscle weakness, and twice as likely to be diagnosed with anxiety or depression.

But it said 88 percent of patients who worked before their diagnosis had returned to their jobs a year later.

The study adds to previous research that warned authorities in different countries they must be prepared to provide long-term support to health workers and patients affected by Covid.

"Long Covid is a modern medical challenge of the first order," the editorial said, calling for more research to understand the condition and better care for patients who suffer from it.

Coronavirus