Why couldn't people stop the spread of the Black Death?

People could not stop the spread of the Black Death due to a lack of understanding of disease transmission and inadequate public health measures. At the time, the prevailing theories about illness were rooted in superstition and humoral imbalances, leading to ineffective responses. Additionally, the movement of trade and people facilitated rapid transmission, while sanitation and medical knowledge were insufficient to contain the outbreak. The social and economic disruptions further hindered collective efforts to combat the epidemic.