Who spread the black death throughout china?

The Black Death is known as one of the deadliest and widespread pandemics in history. It peaked in Europe between 1348 and 1350 and is thought to have been a bubonic plague outbreak caused by Yersinia pestis, a bacterium. It reached the Crimea in 1346 and most likely spread via fleas on black rats that travelled on merchant ships. It soon spread through the Mediterranean and Europe. The Black Death is thought have destroyed 30% to 60% of Europe's population - experts say it took 150 years for Europe to recover its population size. The plague came back several times until the 19th century, when it left Europe for good. Most victims died with two to seven days of becoming infected.