What environmental factor is associated with plague transmission?

The association of flea and rodent populations in homes with plague transmission is significant due to the role these animals play as vectors for the disease. Plague is primarily caused by the bacterium Yersinia pestis, which is usually spread to humans through bites from infected fleas that live on rodents. When the rodent population is high, there tend to be more fleas, increasing the risk of transmission to humans. This is particularly evident in areas where rodents such as rats or prairie dogs are prevalent, leading to potential outbreaks. Enhanced understanding of this dynamic aids public health initiatives aimed at controlling rodent and flea populations to mitigate the risk of plague transmission.

While factors like humidity and flooding may influence the habitat of rodents or fleas, they do not directly relate to the transmission mechanisms of the plague as straightforwardly as the presence of these animals themselves does. Pest control can be an effective means to reduce risks, but it does not inherently represent an environmental factor associated with transmission in the way that the presence of flea and rodent populations does.