A roof rat escalates diseases such as salmonellosis through foods in the pantry that get contaminated by their droppings. The rats also can transmit rat bite fever via bacteria inside their oral cavity. Trichinosis might be spread through the consumption of undercooked meat of animal species which have fed on rats. Rats that contaminate food preparation surfaces or food may pass on food poisoning.
A roof rat is the main reservoir of plague all throughout the world. Infected fleas historically have transmitted severe plagues from rats to human beings. Bubonic plague scourged Europe multiple times all throughout history. There still are plague outbreaks inside the U.S. and worldwide today.