Ticks were collected from ruminants in various areas of Sudan in 1998 and 2000. Primer pairs of rickettsial citrate synthase gene (gltA) and a spotted fever group (SFG) rickettsial 190-kDa surface antigen gene (rompA), respectively, were used for identification. Polymerase chain reaction (PCR)-positive products were used for DNA sequencing. The gltA gene was detected in 55% of the ticks examine...

Because of differences among hosts in reservoir competence for tick-borne diseases, the distribution of larval blacklegged ticks on hosts might determine tick infection prevalence and disease risk to humans. We conducted a three-part study to determine the factors responsible for greater burdens of larval blacklegged ticks on white-footed mice than on eastern chipmunks. A microhabitat study ind...

Ecological interactions underlying the epidemic of Lyme disease involve a spirochete, a tick (with larval, nymph and adult stages), and two (or more) vertebrate hosts. Juvenile ticks ordinarily feed on mice; adult ticks feed on deer. Mice acquire the spirochete from infected nymphs and then pass the infection to larvae of the next tick generation. Lyme disease may result when a human is inadver...

In this study we examined the efficiency of an in vitro feeding technique using glass microcapillaries as a method of establishing rickettsiae-infected lines of ticks. To quantify the volume ingested by ticks during microcapillary feeding, the incorporation of radiolabeled amino acids in tick gut and hemolymph was calculated. Fifteen of 18 ticks consumed between 0.06 and 6.77 microl. However, i...

Lyme disease is caused by infection with the spirochete pathogen Borrelia burgdorferi, which is maintained in nature by a tick-rodent infection cycle. A tick-borne murine model has been developed to study Lyme disease in the laboratory. While naíve ticks can be infected with B. burgdorferi by feeding them on infected mice, the molting process takes several weeks to months to complete. Therefore...

The potential role of ticks as vectors of Bartonella species has recently been suggested. In this study, we investigated the presence of Bartonella species in 271 ticks removed from humans in Belluno Province, Italy. By using primers derived from the 60-kDa heat shock protein gene sequences, Bartonella DNA was amplified and sequenced from four Ixodes ricinus ticks (1.48%). To confirm this findi...

To define the role of birds as reservoirs and disseminators of Borrelia spirochetes, we characterized tick infestation and reservoir competence of migratory passerine birds in Sweden. A total of 1,120 immature Ixodes ricinus ticks were removed from 13,260 birds and assayed by quantitative polymerase chain reaction (PCR) for Borrelia, followed by DNA sequencing for species and genotype identific...

Borrelia miyamotoi, a relapsing fever-related spirochete transmitted by Ixodes ticks, has been recently shown to be a human pathogen. To characterize the prevalence of this organism in questing Ixodes ticks, we tested 2,754 ticks for a variety of tickborne pathogens by PCR and electrospray-ionization mass spectrometry. Ticks were collected from California, New York, Connecticut, Pennsylvania, a...

Control of West Nile virus (WNV) can only be effective if the vectors and reservoirs of the virus are identified and controlled. Although mosquitoes are the primary vectors, WNV has repeatedly been isolated from ticks. Therefore, tick-borne transmission studies were performed with an ixodid (Ixodes ricinus) and an argasid tick species (Ornithodoros moubata). Both species became infected after f...