WARSAW, Poland (AP) — Medical and genetics experts in Poland say that a heart infection caused by a common skin bacteria could have caused the 1817 death of Tadeusz Kosciuszko, a Polish and U.S. military leader and national hero.

The experts said last month they found the genome of the Cutibacterium acne in the wax, wood and linen that had long-term contact with the tissues of Kosciuszko’s heart, which has been preserved. They said it could have led to endocarditis, or inflammation inside the heart, and to his death, aged 71, in Switzerland.

The team was led by Prof. Michał Witt, head of the human genetics institute at the Polish Academy of Sciences in Poznan and Dr. Tadeusz Dobosz of the Wroclaw Medical University. They took the samples for their molecular tests from a vessel where the heart is being kept, at the Royal Castle in Warsaw.

Under some conditions, skin bacteria can attack the internal organs, including the heart, leading to very serious problems, Witt told Polish Radio Zet24.

He stressed that it’s hard to say for sure what caused Kosciuszko’s death but that their findings have led them to the “rationally based hypothesis” that it was the acne bacteria that caused the documented rapid deterioration of his health and death.

Previously, typhoid fever or pneumonia were believed to have ended Kosciuszko’s life. He was said to have developed a high fever and chills after he had fallen off his horse into a cold stream.

Born in 1746 in the then-Polish-Lithuanian Commonwealth, Kosciuszko fought as colonel of the Continental Army in the 1776 American Revolutionary War. A military engineer and architect, he designed and oversaw the construction of America’s fortifications, including West Point.

Back to restless Poland, in 1794 he commanded an ill-fated uprising against the Russian Empire that was annexing some of Poland’s lands. He spent his last years in Switzerland.