| distribution and prevalence of spotted fever group rickettsiae in ticks from south carolina, with an epidemiological survey of persons bitten by infected ticks. | live ticks removed from human hosts were tested for the presence of spotted fever group rickettsiae from 1974 through 1976. spotted fever group rickettsiae were detected in dermacentor variabilis, amblyomma americanum, amblyomma maculatum, and ixodes scapularis. persons from whom positive ticks were removed in 1974 and 1975 were questioned about ensuing illness. eleven of 51 persons from whom rickettsia-positive d. variabilis were removed reported some unexplained combination of symptoms compati ... | 1978 | 103448 |
| rocky mountain spotted fever (tick-borne typhus) in south carolina: an educational program and tick/rickettsial survey in 1973 and 1974. | because the incidence of spotted fever is increasing in south carolina, campaigns were carried out in 1973 and 1974 to provide the public and medical practitioners, through pamphlets and news media, with information about spotted fever and the ticks which transmit the causative agent, rickettsia rickettsii. people were also invited to save and submit live ticks removed from vegetation, animals and humans, for examination by the hemolymph test. a total of 1,186 ticks consisting of 987 dermacentor ... | 1975 | 811127 |
| rickettsia-like organisms in ticks and antibodies to spotted fever-group rickettsiae in mammals from northern mississippi. | studies were conducted from april through august during 1974 and 1975 on 30 randomly selected trapping sites in wall doxey state park, holly springs national forest, and 1.6 km south of the park in marshall county, mississippi to provide information on the occurrence of ticks involved in the maintenance and transmission of spotted fever-group rickettsiae in nature. of 365 animals (14 species) collected, 186 (51%) were parasitized by 4,169 ticks. species of ticks collected included: dermacentor v ... | 1985 | 3923212 |
| erythema migrans-like rash illness at a camp in north carolina: a new tick-borne disease? | borrelia burgdorferi, the causative agent of lyme disease, has never been isolated from a patient thought to have acquired lyme disease in any southeastern state. | 1997 | 9531233 |
| phylogenetic placement of rickettsiae from the ticks amblyomma americanum and ixodes scapularis. | a rickettsial isolate (isolate moaa) belonging to the spotted fever group (sfg) was obtained from the lone star tick amblyomma americanum. we used pcr to characterize the genes for the rickettsial outer membrane proteins rompa and rompb. we sequenced the pcr products (domains i of both the rompa gene and the rompb gene) of moaa and wb-8-2, another rickettsial isolate from a. americanum. to place moaa and wb-8-2 and two other nonpathogenic isolates (rickettsia rickettsii hip2 and rickettsia monta ... | 1998 | 9574696 |
| risk of lyme disease: perceptions of residents of a lone star tick-infested community. | lone star ticks (amblyomma americanum) have been suggested as a vector of the agent of lyme disease (borrelia burgdorferi sensu lato) in the usa, based on associations with an infection manifesting mainly as erythema migrans. in laboratory experiments, however, they failed to transmit b. burgdorferi sensu stricto. | 2001 | 11693973 |
| absence of rickettsia rickettsii and occurrence of other spotted fever group rickettsiae in ticks from tennessee. | rocky mountain spotted fever (rmsf) is the most common tick-borne illness in tennessee. little is known about the occurrence of r. rickettsii, the causative agent, in ticks in tennessee. to better understand the prevalence and distribution of rickettsial agents in ticks, we tested 1,265 amblyomma, dermacentor, and ixodes adult and nymphal ticks. additionally, we tested 231 amblyomma americanum larvae. ticks were collected from 49 counties from humans, wild animals, domestic canines, and flannel ... | 2010 | 20810834 |
| 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 |
| rickettsia rickettsii transmission by a lone star tick, north carolina. | only indirect or circumstantial evidence has been published to support transmission of rickettsia rickettsii by amblyomma americanum (lone star) ticks in north america. this study provides molecular evidence that a. americanum ticks can function, although most likely infrequently, as vectors of rocky mountain spotted fever for humans. | 2011 | 21529399 |
| expanding range of amblyomma americanum and simultaneous changes in the epidemiology of spotted fever group rickettsiosis in the united states. | spotted fever group (sfg) rickettsia species are etiologic agents of a wide range of human infections from asymptomatic or mild infections to severe, life-threatening disease. in the united states, recent passive surveillance for sfg rickettsiosis shows an increased incidence and decreased severity of reported cases. the reasons for this are not well understood; however, we hypothesize that less pathogenic rickettsiae are causing more human infections, while the incidence of disease caused by mo ... | 2015 | 26503270 |
| prevalence of antibodies to spotted fever group rickettsia spp. and ehrlichia spp. in coyotes (canis latrans) in oklahoma and texas, usa. | coyotes (canis latrans) are commonly infested with ticks, including amblyomma americanum, the predominant vector of ehrlichia chaffeensis and ehrlichia ewingii; dermacentor variabilis, an important vector of rickettsia rickettsii; and amblyomma maculatum, a major vector of rickettsia parkeri, a spotted fever group (sfg) rickettsia. to determine the degree to which coyotes are infected with or exposed to tick-borne bacterial disease agents, serum samples collected from coyotes in oklahoma and tex ... | 2013 | 23778619 |
| molecular detection of rickettsia species within ticks (acari: ixodidae) collected from arkansas united states. | rocky mountain spotted fever (rmsf), caused by the etiological agent rickettsia rickettsii, is the most severe and frequently reported rickettsial illness in the united states, and is commonly diagnosed throughout the southeast. with the discoveries of rickettsia parkeri and other spotted fever group rickettsiae (sfgr) in ticks, it remains inconclusive if the cases reported as rmsf are truly caused by r. rickettsii or other sfgr. arkansas reports one of the highest incidence rates of rmsf in the ... | 2015 | 26334827 |
| vector competence of amblyomma americanum (acari: ixodidae) for rickettsia rickettsii. | rickettsia rickettsii - the etiologic agent of rocky mountain spotted fever (rmsf) - is widely spread across the americas. in the us, dermacentor spp. ticks are identified as primary vectors of r. rickettsii and rhipicephalus sanguineus s.l. has been implicated in transmission of this pathogen in several locations in the southwest. conversely, ticks of the genus amblyomma are recognized vectors of rmsf in central and south america, but not in the us. a. americanum is one of the most aggressive h ... | 2017 | 28433728 |
| "rickettsia amblyommii" and r. montanensis infection in dogs following natural exposure to ticks. | to determine the risk of canine infection with spotted fever group (sfg) rickettsia spp. following natural tick exposure, 10 dogs determined to be free of evidence of exposure to or infection with tick-borne disease agents were exposed to ticks via weekly walks in a wooded area in north-central oklahoma. after each walk, dogs were examined and the number and species of ticks present were recorded. the dogs were then returned to outdoor kennels to allow the infestations and subsequent transmissio ... | 2014 | 24359419 |
| the prevalence of rickettsial and ehrlichial organisms in amblyomma americanum ticks collected from ohio and surrounding areas between 2000 and 2010. | the lone star tick, amblyomma americanum, feeds upon a variety of hosts and is a known vector of several human pathogens. in ohio, populations of a. americanum have been expanding their range and increasing in abundance and distribution, thereby elevating the public health concerns regarding bites from this species. we used a set of pcr assays to detect the presence of ehrlichial and rickettsial species in a. americanum ticks submitted to the ohio department of health zoonotic disease program ov ... | 2014 | 25108789 |
| rickettsia rickettsii (rickettsiales: rickettsiaceae) in amblyomma americanum (acari: ixodidae) from kansas. | the role of lone star ticks as vectors for rocky mountain spotted fever (rmsf) remains poorly described. we compared the entomological inoculation rates (eirs) for rickettsia spp. for representative sites in missouri and kansas, states that frequently report rmsf each year. host-seeking ticks were collected during 2006 and pooled tick homogenates analyzed by polymerase chain reaction to detect probable r. rickettsii, with confirmation for multiple gene targets performed on individual ticks from ... | 2011 | 21485390 |
| tick-borne diseases in north carolina: is "rickettsia amblyommii" a possible cause of rickettsiosis reported as rocky mountain spotted fever? | cases of rocky mountain spotted fever (rmsf) in north carolina have escalated markedly since 2000. in 2005, we identified a county in the piedmont region with high case numbers of rmsf. we collected ticks and examined them for bacterial pathogens using molecular methods to determine if a novel tick vector or spotted fever group rickettsiae (sfgr) might be emerging. amblyomma americanum, the lone star tick, comprised 99.6% of 6,502 specimens collected in suburban landscapes. in contrast, dermacen ... | 2008 | 18447622 |
| 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 |
| antibodies to spotted fever-group rickettsiae in dogs and prevalence of infected ticks in southern connecticut. | blood samples and ticks were obtained from dogs to assess canine exposure to spotted fever-group (sfg) rickettsiae during 1978-1980 in southern connecticut. of the 1,576 dog sera screened by microimmunofluorescence. 174 (11.0%) contained specific antibodies at titers greater than or equal to 1:64 against rickettsia montana (n = 34), r rickettsii (n = 31), r rhipicephali (n = 19), or the unclassified 369-c rickettsia (n = 90). end points greater than or equal to 1:8,192 to r rickettsii and to r r ... | 1982 | 6803626 |