Early-phase transmission (EPT) is a recently described model of plague transmission that explains the rapid spread of disease from flea to mammal host during an epizootic. Unlike the traditional blockage-dependent model of plague transmission, EPT can occur when a flea takes its first blood meal after initially becoming infected by feeding on a bacteraemic host. Blockage of the flea gut results...

INTRODUCTION The wildlife plague system in the Pre-Balkhash desert of Kazakhstan has been a subject of study for many years. Much progress has been made in generating a method of predicting outbreaks of the disease (infection by the gram negative bacterium Yersinia pestis) but existing methods are not yet accurate enough to inform public health planning. The present study aimed to identify char...

Rickettsia species are obligate intracellular bacteria with both conserved and lineage-specific strategies for invading and surviving within eukaryotic cells. One variable component of Rickettsia biology involves arthropod vectors: for instance, typhus group rickettsiae are principally vectored by insects (i.e., lice and fleas), whereas spotted fever group rickettsiae are exclusively vectored b...

Temporal variation in body condition and immunological variables of animals that harbor parasites may explain patterns of variation in infestation, as well as parasite impact on the host. We emulated such variability in Sundevall's jirds by manipulating food availability and flea infestation in juveniles and adults and examining how these changes affect survival of fleas on their hosts. Body co...

Major introductions of roof rats (Rattus rattus) likely occurred in the ports of East Africa during the Third Plague Pandemic in the late 1800’s. Transport via trains, boats, and trucking likely introduced this species to inland areas of East Africa, ultimately including Northwest Uganda. Historic plague outbreaks occurred during the early part of the 20th century and continue to cause a human ...

Crucial factors influencing the epidemiology of Rickettsia felis rickettsiosis include pathogenesis and transmission. Detection of R. felis DNA in a number of arthropod species has been reported, with characterized isolates, R. felis strain LSU and strain LSU-Lb, generated from the cat flea, Ctenocephalides felis, and the non-hematophagous booklouse, Liposcelis bostrychophila, respectively. Whi...

The San Joaquin kit fox (Vulpes macrotis mutica Merriam (Carnivora, Canidae)) is an endangered small carnivore endemic to the San Joaquin Valley of California. Commercial and agricultural land expansion has contributed to the species' decline and invasion of more cosmopolitan species, providing means for potential ecological shifts in disease vector and host species. Fleas are common ectoparasi...

The flea beetle Phyllotreta nemorum L. (Coleoptera: Chrysomelidae) is genetically polymorphic for resistance against the defences of one of its host plants, Barbarea vulgaris R.Br. (Brassicales: Brassicaceae). Whereas resistant flea beetles are able to use B. vulgaris as well as other cruciferous plants as food, non-resistant beetles cannot survive on B. vulgaris. This limitation to host plant ...

T he gram-negative bacterium Yersinia pestis, which undergoes an obligate flea-rodent-flea life cycle, causes bubonic plague, a rapid and highly fatal zoonotic disease that was responsible for at least three pandemics (in the 5–6th centuries, the 8–14th centuries, and the 19–21st centuries). During the mid-1940s, researchers began studying a series of Y. pestis virulence determinants to learn h...

Transmission by fleabite is a relatively recent evolutionary adaptation of Yersinia pestis, the bacterial agent of bubonic plague. To produce a transmissible infection, Y. pestis grows as an attached biofilm in the foregut of the flea vector. Biofilm formation both in the flea foregut and in vitro is dependent on an extracellular matrix (ECM) synthesized by the Yersinia hms gene products. The h...