| human babesiosis on nantucket island: transmission by nymphal ixodes ticks. | in order to identify potential vectors of human babesiosis (babesia microli) in southern massachusetts, i attempted to transmit the infection via nymphal ticks of that species found to be most abundant on reservoir hosts (peromyscus leucopus) in nature. mice were collected at frequent intervals throughout a year in a known enzootic focus on nantucket island, and ticks were removed by hand. ticks of only two species were present; larvae and nymphs of ixodes scapularis were about 10 times as numer ... | 1976 | 1008124 |
| stability of dermacentor variabilis populations (acari: ixodidae). | | 1990 | 2093615 |
| regulation of dermacentor variabilis by limited dispersion of larvae from the egg mass (acari: ixodidae). | | 1987 | 3322991 |
| adaptions in the life cycle of dermacentor variabilis (say) and ixodes dammini (spielman, clifford, piesman, and corwin) marginal populations (acari: ixodidae). | both the dermacentor variabilis and ixodes dammini adult diapause seasons are followed by a breeding period. at the edge of the ticks' range, where diapause and breeding occur under adverse climatic conditions, the species still conserves its fixed response for the onset of diapause. as a result, most of the following breeding effort is wasted; the population can only be maintained by an aberrant breeding period during the normal diapause season. when the diapause and breeding periods are suitab ... | 1985 | 3916750 |
| spotted fever group rickettsiae in dermacentor variabilis from cape cod, massachusetts. | spotted fever group (sfg) rickettsiae were identified by indirect immunofluorescent antibody tests in 1.1% of 6,956 specimens of dermacentor variabilis collected on cape cod, massachusetts. forty-one of 45 rickettsial isolates were serotyped as rickettsia montana, one as rickettsia rickettsii, and three were unidentified. studies of canines and humans with clinical evidence of spotted fever, and of healthy dogs with antibody to sfg rickettsiae, indicated that exposure of the canine population to ... | 1980 | 6773430 |
| hemocytic rickettsia-like organisms in ticks: serologic reactivity with antisera to ehrlichiae and detection of dna of agent of human granulocytic ehrlichiosis by pcr. | ixodid ticks were collected from connecticut, massachusetts, missouri, pennsylvania, rhode island, and british columbia (canada) during 1991 to 1994 to determine the prevalence of infection with hemocytic (blood cell), rickettsia-like organisms. hemolymph obtained from these ticks was analyzed by direct and indirect fluorescent antibody (fa) staining methods with dog, horse, or human sera containing antibodies to ehrlichia canis, ehrlichia equi, or rickettsia rickettsii. of the 693 nymphal and a ... | 1995 | 8567911 |
| genotypic diversity of francisella tularensis infecting dermacentor variabilis ticks on martha's vineyard, massachusetts. | martha's vineyard, mass., has been the site of two outbreaks of tularemia (1978 and 2000). although most patients from both outbreaks presented with pneumonic disease and although aerosol transmission has been suggested, the bite of a dog tick and exposure to rabbits remain the only proven modes of transmission. the factors that precipitated the tularemia outbreaks or the proximal determinants of human risk remain undescribed. we sought to test the hypothesis that the ongoing outbreak is due to ... | 2004 | 15528681 |
| a new francisella (beggiatiales: francisellaceae) inquiline within dermacentor variabilis say (acari: ixodidae). | while estimating the prevalence of the dermacentor variabilis (say) symbiont (dvs) in dog ticks on martha's vineyard, ma, we identified dna that may represent a heretofore unrecognized francisella sp. polymerase chain reaction targeting a portion of the 16s rdna specific for dvs yielded an amplicon that was only 96.6% similar to that of dvs accessioned in genbank. phylogenetic analysis of the 16s and 23s rdna genes suggests the presence of a distinct bacterium closely related to the other endosy ... | 2005 | 15962806 |
| nonrandom distribution of vector ticks (dermacentor variabilis) infected by francisella tularensis. | the island of martha's vineyard, massachusetts, is the site of a sustained outbreak of tularemia due to francisella tularensis tularensis. dog ticks, dermacentor variabilis, appear to be critical in the perpetuation of the agent there. tularemia has long been characterized as an agent of natural focality, stably persisting in characteristic sites of transmission, but this suggestion has never been rigorously tested. accordingly, we sought to identify a natural focus of transmission of the agent ... | 2009 | 19247435 |
| differential mortality of dog tick vectors due to infection by diverse francisella tularensis tularensis genotypes. | abstract the factors involved in the long-term perpetuation of francisella tularensis tularensis in nature are poorly understood. martha's vineyard, massachusetts, has become a site of sustained transmission of type a tularemia, with nearly 100 human cases reported from 2000 to 2010. we have identified a stable focus of f. tularensis transmission there, where the annual prevalence in host-seeking dermacentor variabilis is about 3%, suggesting that this tick perpetuates the agent. however, labora ... | 2011 | 21612530 |
| the absence of an interaction between a microtus pennsylvanicus density cycle and dermacentor variabilis infestation levels. | | 1986 | 3522382 |