Endemic typhus is primarily transmitted by which vector?

Endemic typhus is primarily transmitted by fleas, specifically the fleas that infest certain rodents, such as rats. The bacteria responsible for endemic typhus, Rickettsia typhi, is typically found in the feces of infected fleas. Humans can become infected when flea feces contaminate open wounds or are inhaled. This transmission route underscores the significance of effective pest control measures in areas where rodents are prevalent, as controlling the flea population can help diminish the risk of endemic typhus outbreaks.

The other options presented do not serve as primary vectors for endemic typhus. Roaches, while they may carry various pathogens, do not play a direct role in transmitting the bacteria responsible for this disease. Mosquitoes are well-known vectors for other diseases, such as malaria and dengue fever, but they are not involved in the transmission of endemic typhus. Ticks are vectors for different types of rickettsial infections, such as Rocky Mountain spotted fever, but they do not transmit Rickettsia typhi. Thus, the correct answer reflects the specific biological transmission pathway associated with endemic typhus.