Assassin bugs (or kissing bugs) in the genera Triatoma and Rhodnius transmit a protozoan pathogen (Trypanosoma cruzi) that causes Chagas disease in South and Central America.
Human lice (Pediculus humanus and P. capitus) spread Borellia recurrentis, a spirochaete pathogen that causes epidemic relapsing fever. They also carry the rickettsial pathogens that cause epidemic typhus (Rickettsia prowazeki) and trench fever (R. quintana).
Black flies spread Onchocerca volvulus, a parasitic roundworm. Onchocerciasis, the disease caused by infestion of these worms, may cause blindness in peoples of Africa, Mexico, and Central and South America.
Sand flies in the genus Phlebotomus are vectors of a bacterium (Bartonella bacilliformis) that causes Carrion’s disease (oroyo fever) in South America. In parts of Asia and North Africa, they spread a viral agent that causes sand fly fever (pappataci fever) as well as protozoan pathogens (Leishmania spp.) that cause Leishmaniasis.
Mosquitoes in the genus Anopheles are the principle vectors of malaria, a disease caused by protozoa in the genus Plasmodium. Aedes aegypti is the main vector of the viruses that cause yellow fever and dengue. Other viruses, the causal agents of various types of encephalitis, are also carried by Aedes spp. mosquitoes. Wuchereria bancrofti and Brugia malayi, parasitic roundworms that cause filariasis, are usually spread by mosquitoes in the genera Culex, Mansonia, and Anopheles.
Horse flies and deer flies may transmit the bacterial pathogens of tularemia (Pasteurella tularensis) and anthrax (Bacillus anthracis), as well as a parasitic roundworm (Loa loa) that causes loiasis in tropical Africa.
Muscoid flies (families Muscidae, Calliphoridae, and Sarcophagidae)
House flies (family Muscidae), blow flies (family Calliphoridae), and flesh flies (family Sarcophagidae) often live among filth and garbage. They can carry the pathogens for dysentary (Shigella dysentariae), typhoid fever (Eberthella typhosa), and cholera (Vibrio comma) on their feet and mouthparts. They have also been suspected as vectors of the viral agent that causes poliomyelitis.
Tsetse flies in the genus Glossina transmit the protozoan pathogens that cause African sleeping sickness (Trypanosoma gambiense and T. rhodesiense).
Rat fleas, especially Xenopsylla cheopis (the Oriental rat flea), are the principle vectors of Pasturella pestis, the bacterial pathogen of bubonic plague. Fleas can also transmit murine typhus caused by Rickettsia mooseri.