Featherweight titlist Chris John is in the hospital in his native Indonesia battling a case of dengue fever, adviser Sampson Lewkowicz told ESPN.com on Saturday.
"It is not life or training threatening and [John] will return to training shortly," Lewkowicz said.
Dengue fever is a virus-based disease typically spread by mosquitoes.
Lewkowicz said John has been hospitalized for three days. He said John, 30, is planning to attend to the WBA's annual convention, which begins Nov. 16 in Colombia. After that, John is "looking forward to making his 13th title defense sometime around May 2010," Lewkowicz said.
John (43-0-02, 22 KOs) easily outpointed Rocky Juarez in his last fight on Sept. 19 in Las Vegas on the Floyd Mayweather-Juan Manuel Marquez undercard. It was a rematch of their disputed Feb. 28 draw in Juarez's hometown of Houston.
John, who has held a world title since 2003, suffered a fainting spell in June because of a blood disorder. He was forced to withdraw from the rematch with Juarez.
Dan Rafael is a boxing writer for ESPN.com.