Eating out, poor hand hygiene and erratic weather may be among causes, say medics
Gauff, who only entered the field as a lucky loser after failing to qualify, completed a dream week in Linz in front of a supportive crowd to become the youngest player to win a WTA event since Czech Nicole Vaidisova, who triumphed in Vancouver and Tashkent two months apart in 2004.
"I'll remember this day for the rest of my life," the delighted Gauff said after receiving a minutes-long standing ovation from 3,000 spectators.
"I had an amazing week and I hope to be back in the future."
"I'm still overwhelmed, it's shocking and crazy to say I've won my first WTA title," she added.
"This tournament was definitely not even on the calendar for me at the start of the season.
"I didn't think I'd have a chance to get in - now I'm the champion."
Gauff will shoot up from 110 in the rankings into the 80s, according to WTA calculations, after becoming the youngest American to earn a WTA trophy since Jennifer Capriati at Toronto in 1991.
The hype surrounding the youngster has grown this year after solid performances this summer at both Wimbledon and the US Open, where she was defeated in the third round by defending champion Naomi Osaka, and her displays in Linz have enthralled tennis fans.
Gauff had to make a recovery in the final after sweeping the opening set but losing serve three times in the second as 2017 Roland Garros winner Ostapenko levelled.
"She started hitting the ball fast and coming up with winners," Gauff said. "There was not much I could do."
But the American came alive in the third set, going up two breaks before her opponent managed to save a pair of match points while trailing 5-1.
Ostapenko asserted herself with a break to make the score 5-2 in the third but was unable to extend her fightback, Gauff closing out victory a game later after Ostapenko hit a return long on the third match point.
"Well done today to Coco," Ostapenko said. "You have a bright future, it was a pleasure to share the court with you today.
"This has been a tough week for me, but I'm so glad to have made it to the final, even if the result was not what I wanted."
With her debut week on the European indoor circuit a roaring success, Gauff is now scheduled to compete next week in Luxembourg to wrap up her WTA season.
Eating out, poor hand hygiene and erratic weather may be among causes, say medics
The goal-scoring striker is suffering from a muscle injury sustained during the Champions League quarter-final loss to Real Madrid
Lieutenant General Abdullah Khalifa Al Marri, Commander-in-Chief of Dubai Police, made the announcement on Wednesday
6G will further elevate capabilities of robots, AI, autonomous transport and remote surgery/diagnostics among others
The Nobel laureate has been condemned for partnering with Hillary Clinton, an outspoken supporter of Israel's war against Hamas
Net profit (after tax) up 32% per cent y-o-y to Dh1.45 billion
Goalkeeper Eisa delivered a fantastic performance against Al Hilal to help Al Ain reach the final
Volunteers of the Samantha Kerala Sunni Student Federation used the machine to navigate challenging terrain