Comparison of Zoonotic Bacterial Agents in Fleas Collected from Small Mammals or Host-Seeking Fleas from a Ugandan Region Where Plague Is Endemic.

Fleas ( = 407) were collected from small mammals trapped inside huts and surroundings of homesteads in five villages within the Arua and Zombo districts of Uganda. The most common flea species were (26%) and (50%). Off-host fleas ( = 225) were collected inside huts by using Kilonzo flea traps. The majority of the off-host fleas were (80%). All fleas were examined for the presence of spp., spp., and spp. DNA was detected in 91 fleas, with an overall prevalence of 14%. prevalence was significantly higher in rodent or shrew fleas than in off-host fleas (22% versus 1%). The majority of -positive fleas were of the species (61%), (20%), and (14%). Sequencing analysis identified 12 genetic variants, 9 of which belonged to the zoonotic pathogen species complex. DNA was detected in 143 fleas, giving an overall prevalence of 23%, with a significantly higher prevalence in off-host fleas than in rodent or shrew fleas (56% versus 4%). The majority (88%) of -positive fleas were and were collected from Kilonzo traps, while a small portion (10%) were collected from rodents. Sequencing analysis identified six genogroups that belonged either to zoonotic or to the closely related " Ricksettia asemboensis" and " Ricksettia sengalensis." DNA was not detected in the fleas tested. These observations suggested that fleas in northwestern Uganda commonly carry the zoonotic agents and and potentially play an important role in transmitting these infections to humans. Fleas play critical roles in transmitting some infections among animals and from animals to humans. Detection of pathogens in fleas is important to determine human risks for flea-borne diseases and can help guide diagnosis and treatment. Our findings of high prevalence rates of and in fleas in the Arua and Zombo districts of Uganda implicate these agents as potential causative agents of undiagnosed febrile illnesses in this area.