Giant panda Ya Ya, who lived 20 years at a United States zoo, is back in China after a controversy over her health played out against the backdrop of a souring relationship between Beijing and Washington.

Ya Ya arrived in Shanghai on Thursday afternoon to a social media storm. Panda lovers who could not make it to the airport launched what they called an online pick-up for Ya Ya.

“We welcome Ya Ya’s return online” had chalked up 340 million reads on the Chinese messaging platform Sina Weibo by the time her 16-hour flight from Memphis, Tennessee, touched down.

The Sina Weibo hashtag “Ya Ya has landed in Shanghai” had been viewed 430 million times as of Thursday evening.

Ya Ya returned to China on a special flight a year after reports began circulating that she and Le Le, the Memphis Zoo’s male panda, were in poor health.

Le Le’s death in February and the emergence of pictures online of Ya Ya looking thin and bony only added to the concerns among panda lovers not only in China but also in the US and elsewhere.

As diplomatic tension grew between the US and China over issues ranging from Taiwan to Xinjiang and human rights, some critics accused the US of not taking proper care of the pandas.

But now that Ya Ya is back home, most are focused simply on seeing her health restored.

“We need to find out the real reason why Ya Ya is sick now,” a Beijing resident who wanted to be identified only as Ms Shi told Al Jazeera. “We need to listen to the experts. We need to be more rational on this incident – if someone made a mistake. Maybe it’s just the American zoo didn’t do a good job. It has nothing to do with the Sino-America relationship. We need to look at it rationally.”

China has long operated a programme of “panda diplomacy“, through which the animals are loaned for a limited time to zoos around the world as a symbol of friendship. Many zoos invest millions of dollars creating panda habitats – in Malaysia’s case, an expansive air-conditioned enclosure – to meet the standards required by Beijing.

Ya Ya, who was born in the Beijing Zoo in 2000, was transferred to the Memphis Zoo under a conservation programme in 2003.

The zoo spent $16m to build a giant panda facility with traditional Chinese cultural elements, set up a breeding management and veterinary team, and planted about 4 hectares (10 acres) of bamboo ahead of Ya Ya’s arrival, according to a report last month in China’s state-run Global Times.

The agreement ended this April.

“Ya Ya is returning to China to live out her golden years,” Memphis Zoo said in a statement on Facebook as the panda left the US. “After 20 years, Ya Ya has become like family, and she will be sorely missed by the Memphis Zoo staff and the local community.”

The Chinese government acknowledged the pandas had been well looked after in the US.

“During the giant pandas’ stay at the Memphis Zoo, they received good care from the zoo and great affection from the American people,” Chinese Ministry of Foreign Affairs spokeswoman Mao Ning said on Wednesday.

Ya Ya began to shed fur in 2006, and her condition worsened in 2014. Experts at the Memphis Zoo and in China tried various treatments for the condition but were unable to solve the problem, according to the Chinese Association of Zoological Gardens.

The organisation said heart disease had been determined as the cause of Le Le’s death. His remains were returned to China on the same flight with Ya Ya.

Beijing-based China analyst Einar Tangen blamed Western media for manufacturing a Chinese furore over Ya Ya’s health.

“She’s become a symbol in the Western narrative. They are saying the Chinese press is whipping up the Chinese public and saying it’s state-owned media. That’s not true,” he told Al Jazeera.

“State media is actually saying she’s fine, and we are just bringing her back. It really does go to show how far the US and Chinese people have drifted apart in perceptions.”

According to the Global Times, China currently has 60 giant pandas on loan to countries around the world.

“The panda is a unique animal from China and a national treasure,” Beijing resident Mr Su said. “I think it’s a good thing that people from other countries have a chance to know more about pandas.”

Ya Ya will be in quarantine for 30 days before she is transferred to Beijing Zoo.

With reporting by Jessica Washington in Beijing