By Ian Ransom

SYDNEY (Reuters) - The threat of Zika at the Rio Olympics is on the mind of many athletes but few more so than China's former badminton world champion Wang Yihan, who was attacked mercilessly by insects while competing in Indonesia last week.

The svelte 28-year-old, who won silver in the women's singles at the London Games, was still smarting from red bites up and down her arms as she competed at the Australian Badminton Open in Sydney on Wednesday.

"They're itchy," she told Reuters, lathered in sweat after a tough opening round win over Scotland's Kirsty Gilmour at the Sydney Olympic Park Sports Centre.

"And the sweat makes it worse.

"I'm really not sure what kind of bugs they were. I don't think they were mosquitoes. Maybe it was on the bed that I was sleeping on.

"I bought some cream for them, but they're still itchy."

A number of athletes have already pulled out of the Olympics citing health risks associated with the mosquito-borne virus, which can cause crippling birth defects and development problems in babies.

Others are declining to bring family members and loved ones with them, while Olympic long jump champion Greg Rutherford decided to freeze his sperm to safeguard future plans for extending his young family.

However, the outbreak in Brazil will not stop China from unleashing its full artillery of badminton champions, who will attempt to defend their sweep of five titles at London.

"Yes, I think everyone's been thinking about (Zika)," Wang said. "But obviously we've been told about how to be safe, wearing repellent and staying indoors and so on."

Shanghai-born Wang is determined to go one better at Rio, having been upset in London's gold-medal decider by compatriot Li Xuerui, an unheralded player before her Olympic triumph.

Wang's anguish upon losing the final was written large on her face and she was still gloomy as she mounted the podium next to her beaming team mate.

"I did feel disappointed at the time, even though it was my team mate who won the gold," she said.

"Of course it's great to get any medal but in the end, there's only one champion."

World badminton has changed the Olympic rules so that nations can only enter two shuttlers into the singles events, which will make it harder for China to repeat their London domination.

Wang is currently ranked third in the world, ahead of fourth-ranked Li, with the top two spots occupied by Spain's world number one Carolina Marin and Thai Ratchanok Intanon.

China's women have traditionally dominated the singles rankings, so the variety at the top has been welcomed by badminton fans and raised hope of a more open tournament at Rio.

Wang said any number of players could win her event but felt Chongqing-born Li would be hard to beat and perhaps the biggest threat to her own gold ambitions.

"I think Li's game is really complete overall," she said.

"We've both got our different strengths.

"There are other players like Ratchanok, Marin and (Indian player) Saina Nehwal who all have a chance but I think Li is still at a higher level."

(Editing by John O'Brien)