| a cluster of tick-borne infections: association with military training and asymptomatic infections due to rickettsia rickettsii. | during the spring of 1989, 86 members of a military unit from the state of maryland, usa, participated in two-week-long training manoeuvres in the states of arkansas (location fc) and virginia (location faph). acute febrile illnesses due to infections with two tick-borne pathogens, rickettsia rickettsii and ehrlichia sp., were confirmed serologically in 2 initial cases who were admitted to the hospital. a seroepidemiological investigation among unit members found an additional 17 of 109 individu ... | 1992 | 1412666 |
| serologic evidence of rickettsialpox (rickettsia akari) infection among intravenous drug users in inner-city baltimore, maryland. | we tested single serum samples from 631 intravenous (i.v.) drug users from inner-city baltimore, maryland for serologic evidence of exposure to spotted fever group rickettsiae. a total of 102 (16%) individuals had titers > or = 64 to rickettsia rickettsii by an indirect immunofluorescence assay. confirmation that infection was caused by r. akari was obtained by cross-adsorption studies on a subset of serum samples that consistently resulted in higher titers to r. akari than to r. rickettsii. cur ... | 1999 | 10403316 |
| spotted-fever group rickettsia in dermacentor variabilis, maryland. | three-hundred ninety-two adult dermacentor variabilis were collected from six maryland counties during the spring, summer, and fall of 2002. infection prevalence for spotted fever group rickettsia was 3.8%, as determined by polymerase chain reaction. single strand conformational polymorphism (sscp) analysis followed by sequencing indicated that all infections represented a single rickettsial taxon, rickettsia montanensis. | 2004 | 15496254 |
| co-circulating microorganisms in questing ixodes scapularis nymphs in maryland. | ixodes scapularis can be infected with borrelia burgdorferi, anaplasma phagocytophilum, bartonella spp., babesia microti, and rickettsia spp., including spotted-fever group rickettsia. as all of these microorganisms have been reported in maryland, the potential for these ticks to have concurrent infections exists in this region. to assess the frequency of these complex infections, 348 i. scapularis nymphs collected in 2003 were screened for these microorganisms by pcr with positives being confir ... | 2007 | 18260514 |
| infrequency of rickettsia rickettsii in dermacentor variabilis removed from humans, with comments on the role of other human-biting ticks associated with spotted fever group rickettsiae in the united states. | abstract from 1997 to 2009, the tick-borne disease laboratory of the u.s. army public health command (usaphc) (formerly the u.s. army center for health promotion and preventive medicine) screened 5286 dermacentor variabilis ticks removed from department of defense (dod) personnel, their dependents, and dod civilian personnel for spotted fever group rickettsiae using polymerase chain reaction and restriction fragment length polymorphism analysis. rickettsia montanensis (171/5286 = 3.2%) and ricke ... | 2010 | 21142953 |