HYDERABAD - Former winner Taufik Hidayat and second seed Chen Jin made a rousing start to their campaigns on Tuesday when the world championships also suffered a swine flu scare.
Fourth-seeded Indonesian Hidayat brushed aside Switzerland's Christian Boesiger 21-14 21-14 while Chinese Chen eased past Dutchman Eric Pang 21-14 21-19.
However, Danish seventh seed Joachim Persson was beaten 16-21 21-14 21-13 by unseeded Japanese Kenichi Tago.
Tago fought back from a game down to win in 57 minutes on the same day a Malaysian coach was quarantined with swine flu symptoms and a doubles pair from Thailand pulled out of a match after one of them complained of a fever.
Eight people have died of swine flu in India, with hundreds infected. The southern state of Andhra Pradesh, of which Hyderabad is the capital, has recorded 76 positive cases.
"We don't see any reason for any major concerns but we have assured the players we will manage the situation over the rest of the tournament and make sure none of the players are in danger," Badminton World Federation chief operating officer Thomas Lund told a news conference.
Ninth-seeded Hsieh Yu Hsing of Taiwan scraped past India's Arvind Bhat 21-14 19-21 24-22 in another first-round match.
In the women's singles, seventh seed Lu Lan of China beat Larisa Griga of Ukraine 21-16 21-5.
The championships are being played under tight security after England pulled out citing a "specific terrorist threat", following media reports the event could be targeted by Lashkar-e-Taiba The Pakistan-based militant group was blamed for November's attacks on Mumbai in which 166 people were killed.