By Jeb Blount

RIO DE JANEIRO (Reuters) - German Olympic sailors, one of whom was infected last year by a flesh-eating bacteria after a test run in Rio de Janeiro's sewage-tainted Guanabara Bay, said this week they are less worried about health risks than racing effectively in shifty winds and wild currents while avoiding floating debris.

Three weeks before the start of racing at the Rio Olympics, three top medal prospects from the highly ranked German sailing team told Reuters on Tuesday that plastic bags and bottles, floating logs, the occasional dead dog and other flotsam will make what is already one of the most challenging Olympic sailing venues even harder.

The sailors said those factors will affect their performance on the "playground," as the Germans call the race course, more than the presence of disease-causing pathogens at Rio water-sports venues, the focus much pre-Olympic concern.

"I think we do not care too much about the health issues," said Erik Heil, skipper of Germany's Olympic entry into the 49er two-man skiff class.

Nearly a year ago, after an Olympic test regatta in Rio, Heil was treated in Germany for an antibiotic-resistant Staphylococcus infection that chewed small craters into his leg.

"We don't know the reason, it could be the water, it could be a mosquito, it could be something else," he said.

Heil said he is more concerned with plastic bags and other debris that could snag boats.

The sailing courses inside Guanabara Bay face daily surging tidal currents that push enormous volumes of water, sewage and debris out of the Bay's narrow mouth, only to be replaced later by cleaner seawater flushing in from the Atlantic Ocean.

Debris tends to concentrate along the lines of currents and entering or departing tides, said Heil's 49er crewmate Thomas Ploessel and Germany's one-man, single sail Laser-class entry Philipp Buhl. Taking advantage of currents can mean putting a boat dangerously close to floating junk, they said.

Those currents are further influenced by underwater rocks and mountains. Hills and buildings surrounding the bay change the often light winds and can redirect gusts unpredictably. Courses outside the bay face high waves and high winds.

These myriad challenges have put health issues on the back burner for athletes, Buhl said.

"This is pretty much the dirtiest place I've ever sailed, but I can't care about that too much. I'm just looking forward to a fair competition," Buhl said. "So far, I've been here five times and I've gone back five times healthy."

(Additional reporting by Thales Carneiro; Editing by David Gregorio)