Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Relapsing Fever”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 451 records · Page 25Linked to original sources
PubMed1994

Differential association of Borrelia species with cultured neural cells.

Studies of the interactions of relapsing fever Borrelia species with cultured neural cells have not been reported. In the present work, the interaction of the relapsing fever agents Borrelia hermsii and Borrelia turicatae with cultured neural and endothelial cells was studied and compared with Borrelia burgdorferi, the agent of Lyme disease. All Borrelia species bound each cell type tested. Host cell association was time-dependent and saturable. With the exception of human neuron cells, B. hermsii and B. turicatae associated to a greater degree with neural-derived cell types than did B. burgdorferi. In contrast, B. burgdorferi associated better with endothelial cells than did the relapsing fever borreliae. B. burgdorferi were found in human neuron cells to compete for association sites with B. hermsii and B. turicatae, suggesting the existence of some identity between the ligands or receptors used. Data indicate that the study of in vitro association of Borrelia species with neural-derived cells may provide valuable information for a better understanding of pathogenic mechanisms in neuroborreliosis.

Borrelia↗
PubMed1996

Prevention of Jarisch-Herxheimer reactions by treatment with antibodies against tumor necrosis factor alpha.

BACKGROUND: In patients with louse-borne relapsing fever (Borrelia recurrentis infection), antimicrobial treatment is often followed by sudden fever, rigors, and persistent hypotension (Jarisch-Herxheimer reactions) that are associated with increases in plasma concentrations of tumor necrosis factor alpha (TNF-alpha), interleukin-6, and interleukin-8. We attempted to determine whether sheep polyclonal Fab antibody fragments against TNF-alpha (anti-TNF-alpha Fab) could suppress the Jarisch-Herxheimer reaction. METHODS: We conducted a randomized, double-blind, placebo-controlled trial in 49 patients with proven louse-borne relapsing fever. Immediately before the intramuscular injection of penicillin, the patients received an intravenous infusion of either anti-TNF-alpha Fab or a control solution. RESULTS: Ten of the 20 patients given anti-TNF-alpha Fab had Jarisch-Herxheimer reactions with rigors, as compared with 26 of the 29 control patients (P = 0.006). The controls had significantly greater mean maximal increases in temperature (1.5 vs. 0.8 degrees C, P < 0.001), pulse rate (31 vs. 13 per minute, P < 0.001), and systolic blood pressure (25 vs. 15 mm Hg, P < 0.003), as well as higher mean peak plasma concentrations of interleukin-6 (50 vs. 17 micrograms per liter) and interleukin-8 (2000 vs 205 ng per liter) (P < 0.001 for both comparisons). Levels of TNF-alpha were undetectable after treatment with anti-TNF-alpha Fab. CONCLUSIONS: Pretreatment with sheep anti-TNF-alpha Fab suppresses Jarisch-Herxheimer reactions that occur after penicillin treatment for louse-borne relapsing fever, reduces the associated increases in plasma concentrations of interleukin-6 and interleukin-8, and may be useful in other forms of sepsis.

Adolescent↗
PubMed1993

Analysis of intra-specific variation in the fatty acid profiles of Borrelia burgdorferi.

Analysis of the fatty acid methyl esters (FAMEs) of bacteria is a commonly used chemotaxonomic technique. Application of this methodology to spirochaetes associated with Lyme borreliosis revealed distinct clusters corresponding to three genetically distinguished groups: Borrelia burgdorferi sensu stricto, B. garinii, and the VS461 group. However, B. garinii formed a common group with B. hermsii, a relapsing fever spirochaete, and VS461 grouped with B. turicatae and B. parkeri, two other relapsing fever spirochaetes. The diversity in fatty acid profiles of Lyme disease spirochaetes has implications for the protean clinical manifestations of the disease.

Animals↗
PubMed2006

Antigenic variation with a twist--the Borrelia story.

A common mechanism of immune evasion in pathogenic bacteria and protozoa is antigenic variation, in which genetic or epigenetic changes result in rapid, sequential shifts in a surface-exposed antigen. In this issue of Molecular Microbiology, Dai et al. provide the most complete description to date of the vlp/vsp antigenic variation system of the relapsing fever spirochaete, Borrelia hermsii. This elaborate, plasmid-encoded system involves an expression site that can acquire either variable large protein (vlp) or variable small protein (vsp) surface lipoprotein genes from 59 different archival copies. The archival vlp and vsp genes are arranged in clusters on at least five different plasmids. Gene conversion occurs through recombination events at upstream homology sequences (UHS) found in each gene copy, and at downstream homology sequences (DHS) found periodically among the vlp/vsp archival genes. Previous studies have shown that antigenic variation in relapsing fever Borrelia not only permits the evasion of host antibody responses, but can also result in changes in neurotropism and other pathogenic properties. The vlsE antigenic variation locus of Lyme disease spirochaetes, although similar in sequence to the relapsing fever vlp genes, has evolved a completely different antigenic variation mechanism involving segmental recombination from a contiguous array of vls silent cassettes. These two systems thus appear to represent divergence from a common precursor followed by functional convergence to create two distinct antigenic variation processes.

Antigenic Variation↗
PubMed2006

[A case of HIV-1 and HHV-8-associated Castleman disease with a relapsing high fever and lymphoadenopathy].

A 48-year-old man infected with an HIV-1 experienced intermittent bouts of fever, lymphadenopathy, elevated CRP level, and thrombocytopenia, each lasting about 2 weeks, and recurring at 2-3 month intervals. His CD4 count was about 500/microL, and he had never received antiretroviral therapy (ART). In March 2005, he experienced the same symptoms, accompanied by liver damage, splenomegaly, pleural fluid, and a high serum soluble IL-2 receptor level. Examination of a cervical lymph node specimen resulted in a diagnosis of Castleman disease, plasma cell type. Immunohistochemical studies confirmed the presence of HHV-8 and Ebstein-Barr virus (EBV). Since the plasma HHV-8 DNA and serum IL-6 were elevated during the flare-up, were negative between episodes, he was treated with ART to control the Castleman disease. He remained asymptomatic for 3 months, but, similar symptoms recurred with a high level of HHV-8 DNA in his PBMCs. Oral valganciclovir was them started at 1,800 mg twice daily, and his symptoms immediately improved. The HHV-8 DNA level in the PBMCs decreased markedly over the course of 4 weeks, and valganciclovir was discontinued. One week later, he experienced another flare-up, and was successfully treated with 10 days of valganciclovir 1,800 mg, followed by maintenance with valganciclovir 900 mg. ART was discontinued, because the valganciclovir plus ART caused severe fatigue. No subsequent flare-ups have been observed, and, no HHV-8 DNA has been detected in his PBMCs. Castleman disease is an unusual complication in patients with HIV-1 and HHV-8 infection, but it should be included in the differential diagnosis of patients who exhibit a relapsing systemic inflammatory syndrome and lymphoadenopathy. Further study is needed to determine the appropriate usage and timing of the anti-HHV-8 and HIV-1 medication.

Castleman Disease↗
PubMed1991

Tick-borne borreliosis in west Africa.

Reported cases of tick-borne relapsing fever due to the spirochaete Borrelia crocidurae are rare in West Africa, and few epidemiological data are available. To see how common relapsing fever is in Senegal thick blood smears from cases of fever of unknown origin and from randomly selected clinic outpatients from a rural dispensary were examined for Borrelia. The prevalence of Borrelia infections in small mammals was also assessed. Borrelia was seen in smears of 12 (0.9%) of 1340 children. All children who tested positive had complained of acute fever. Prevalence was 0% (0/496), 0.5% (2/417), 1.6% (5/308), and 4.2% (5/119) at ages 0-1, 2-4, 5-9, and 10-14, respectively. 26 other instances of borreliosis were seen in patients from different regions of Senegal. Blood samples from 7 of these patients were inoculated intraperitoneally into white mice; serious infection developed in all mice. Borrelia was seen in thick smears from 65 of 461 wild rodents or insectivores. Six rodents species were infected. From a sample of 93 rodents, 33.3% were infected, as judged by intraperitoneal inoculation of white mice, compared with 14.1% by direct smear examination. The findings suggest that borreliosis has a wide distribution and a high incidence in Senegal. This disease may be a major cause of morbidity in rural areas throughout much of West Africa.

Acute Disease↗
PubMedDate not supplied

Pathophysiology of the Lyme disease spirochete, Borrelia burgdorferi, in ixodid ticks.

The pathophysiology of Borrelia burgdorferi, the Lyme disease spirochete, is unique in tick/vector relationships, differing substantially from that of other spirochetes, e.g., Borrelia duttonii, the agent of tick-borne relapsing fever, and Borrelia recurrentis, the agent of louse-borne relapsing fever, in their respective vectors. Following ingestion by a tick, B. burgdorferi lodges in the midgut diverticula, in some instances penetrating the gut wall and invading various tissues. Certain investigators suggest that transmission of the spirochete occurs via infectious saliva, although, in light of the fact that only 5% of adult ticks are systemically infected, this mechanism is open to question. Alternatively, transmission may occur via periodic regurgitation of gut fluids during the feeding process. While ticks of the genus Ixodes were once thought to be the only vectors, it now appears that other genera, and possibly other hematophagous arthropods, may also be involved.

Animals↗
PubMedDate not supplied

[Climate change in spain and risk of infectious and parasitic diseases transmitted by arthropods and rodents].

Due to Spain's being located near Africa, being a stopping-off point for migrating birds and individuals and due to its climate conditions, nearing those of areas where there are vector-borne diseases, this is a country where this type of diseases could taken on greater importance due to the climate change. The possible risk would result from the geographical spread of already established vectors or due to subtropical vectors adapted to surviving in cooler, dried climates being imported and taking up residence. Hypothetically, the vector-borne diseases subject to be influenced by the climate change in Spain would be those transmitted by dipterans, such as dengue fever, West Nile encephalitis, Rift Valley fever, malaria and leishmaniasis; tick-transmitted diseases, such as Crimean-Congo hemorrhagic fever, tick-borne encephalitis, Lyme disease, spotted fever and endemic relapsing fever; and rodent-transmitted diseases. But the greatest, most viable threat would be the Aedes albopictus mosquito, which would be capable of transmitting viral diseases such as West Nile encephalitis or dengue fever, taking up residence. But, for actual areas of endemia being established, a combination of other factors, such as the massive, simultaneous influx of animal or human reservoirs and the deterioration of the social healthcare conditions and of the Public Health services.

Animals↗
PubMed1996

[Back again: the clothes louse (Pediculus humanus var. corporis)].

In two homeless men aged 38 and 32 years, who suffered from itching, infestation with body lice (Pediculus humanus var. corporis, a.k.a. clothes lice) was diagnosed. This infestation is rare in the Netherlands. In 1993 and 1994 and infection with body lice was registered 41 times in 31 patients at the clinic for homeless of the Community Health Service of Utrecht. The body louse can be seen by the naked eye. Treatment is by hygienic measures, pediculicides if necessary, and by prevention. Important to recognize is that P. humanus can be the vector of trench fever (Bartonella quintana), relapsing fever and typhus.

Adult↗
PubMed1986

Relapsing fever/Lyme disease. Multiple sclerosis.

Lyme Disease and Relapsing Fever caused by Borrelia burdorferi and Borrelia hermsii, respectively, have been generally considered curable if diagnosed early. However, it is becoming apparent that when these diseases are left undiagnosed and untreated they may cause severe problems for some people. They, in fact, may be one of the major causes of Multiple Sclerosis. These two Borrelia infections, when left untreated, are now known to be capable of causing neurological problems, cardiac problems, relapses as much as ten years later, increased IgG/albumin ratio and increased lymphocytes. These same things hold true for Multiple Sclerosis patients. This paper discusses the Borrelia spirochetes which cause Lyme Disease and Relapsing Fever and what correlation that may have with Multiple Sclerosis.

Dietary Fats↗
PubMed2001

Lone star tick-infecting borreliae are most closely related to the agent of bovine borreliosis.

Although Borrelia theileri, the agent of bovine borreliosis, was described at the turn of the century (in 1903), its relationship with borreliae causing Lyme disease or relapsing fever remains undescribed. We tested the previously published hypothesis that spirochetes infecting Lone Star ticks (Amblyomma americanum) may comprise B. theileri by analyzing the 16S ribosomal DNAs (rDNAs) and flagellin genes of these spirochetes. B. theileri, the Amblyomma agent, and B. miyamotoi formed a natural group or clade distinct from but most closely related to that of the relapsing fever spirochetes. B. theileri and the Amblyomma agent were 97 and 98% similar at the nucleotide level within the analyzed portions of the 16S rDNA and the flagellin gene respectively, suggesting a recent divergence. The agent of bovine borreliosis might be explored as a surrogate antigen for the as-yet-uncultivatable Amblyomma agent in studies designed to explore the etiology of a Lyme disease-like infection associated with Lone Star ticks.

Animals↗
PubMed1986

Spirochetal diseases of the CNS.

The neurotropism of the spirochete is evident from the above discussions of syphilis, Lyme disease, leptospirosis, and relapsing fever. In all of these diseases, the organism very likely enters the CNS very early in the course of the disease. The fate of the organism then depends on the virulence of the spirochete, the host defenses, and any antibiotic treatment administered. Why Treponema pallidum lays dormant in the CNS and then somehow reactivates is a mystery; the same mystery occurs in Lyme disease. Leptospirosis and relapsing fever seem to be infections much more limited in time, and are not reported to cause these long-term sequelae. The treatment of these last two infections seems to be fairly straightforward. However, the appropriate treatment for the various stages of the disease in both syphilis and Lyme disease in order to prevent long-term sequelae is not universally accepted. At this time, it seems that high-dose intravenous penicillin is the treatment of choice for each of these infections shown to be active in the nervous system.

Central Nervous System Diseases↗
PubMed1988

Antigenic variability of Borrelia burgdorferi.

Borrelia burgdorferi strains (six isolates from North America and 28 isolates from Europe) were analyzed by physicochemical and immunological methods. By SDS-PAGE, all Borrelia burgdorferi strains tested had two major proteins with constant molecular weights of 60 and 41 kDa and one, two, or three variable low molecular weight proteins (OspA = 30-32 kDa, OspB = 34-36 kDa, pC = 21-22 kDa). All combinations--except OspB alone or OspB/pC--were observed. Borrelia burgdorferi strains were different from relapsing fever borreliae by strong reactivity with OspA- and/or pC-specific polyclonal antibodies, whereas relapsing fever borreliae were only weakly reactive. Among 25 Borrelia burgdorferi isolates, seven different serotypes of Borrelia burgdorferi were defined according to their reactivity in the Western blot with three monoclonal OspA-specific antibodies (H5332, H3TS, and LA5), four OspA- or OspB-specific polyclonal antibodies, and 12 polyclonal antibodies against whole borreliae. Antigenic differences between European CSF and skin isolates were observed, all skin isolates (n = 11) belonging to serotype 2 in contrast to only two out of seven CSF isolates. CSF isolates were antigenically heterogenous (serotypes 1, 2, 3, 4, and 5). Serotypes 6 and 7 were represented by two tick isolates, and the other European tick isolates are not yet fully characterized. Antigenic differences between European and North American strains may play a role in differences in the clinical picture of Lyme borreliosis.

Antigens↗
PubMed2006

Crystal structure of neurotropism-associated variable surface protein 1 (Vsp1) of Borrelia turicatae.

Vsp surface lipoproteins are serotype-defining antigens of relapsing fever spirochetes that undergo multiphasic antigenic variation to allow bacterial persistence in spite of an immune response. Two isogenic serotypes of Borrelia turicatae strain Oz1 differ in their Vsp sequences and in disease manifestations in infected mice: Vsp1 is associated with the selection of a neurological niche, while Vsp2 is associated with blood and skin infection. We report here crystal structures of the Vsp1 dimer at 2.7 and 2.2 A. The structures confirm that relapsing fever Vsp proteins share a common helical fold with OspCs of Lyme disease-causing Borrelia. The fold features an inner stem formed by highly conserved N and C termini and an outer "dome" formed by the variable central residues. Both Vsp1 and OspC structures possess small water-filled cavities, or pockets, that are lined largely by variable residues and are thus highly variable in shape. These features appear to signify tolerance of the Vsp-OspC fold for imperfect packing of residues at its antigenic surface. Structural comparison of Vsp1 with a homology model for Vsp2 suggests that observed differences in disease manifestation may arise in part from distinct differences in electrostatic surface properties; additional predicted positively charged surface patches on Vsp2 compared to Vsp1 may be sufficient to explain the relative propensity of Vsp2 to bind to acidic glycosaminoglycans.

Antigens, Bacterial↗
PubMed1996

Analysis of the genetic polymorphism of Borrelia burgdorferi sensu lato by multilocus enzyme electrophoresis.

In recent years, Borrelia burgdorferi sensu lato has been subdivided into three species, Borrelia burgdorferi sensu stricto, Borrelia garinii, and Borrelia afzelii, and a new species restricted to Japan, Borrelia japonica, has been isolated from Ixodes ovatus. In addition, members of several new genomic groups have been found in America and in Europe, suggesting that there are additional genospecies. In order to study the diversity of B. burgdorferi sensu lato, we analyzed 54 isolates, cultured from humans and from different tick species and obtained from diverse geographic areas, including Europe, the United States, Japan, and the People's Republic of China. In order to investigate the genetic relationship between microorganisms that are transmitted by soft ticks and microorganisms that cause Lyme disease, we also included three strains of relapsing fever spirochetes. The method which we used was multilocus enzyme electrophoresis; 12 genetic loci were characterized on the basis of the electrophoretic mobilities of their products, and 50 distinct allele profiles (electrophoretic types) were distinguished. The mean genetic diversity per locus was 0.747. a cluster analysis of a matrix of genetic distances for pairs of electrophoretic types revealed 11 divisions that were separated at genetic distances greater than 0.65. Five of these divisions corresponded to B. burgdorferi sensu stricto, B. garinii, B. afzelii, B. japonica, and the newly proposed species "Borrelia andersonii." Our results also confirmed that there are two additional genomic groups in Europe and at least one additional group in the United States. The relapsing fever spirochetes were were not clearly separated from the spirochetes associated with Lyme disease. In conclusion, we believe that the previously proposed subdivision of B. burgdorferi sensu lato into only four species should be reconsidered.

Alleles↗
PubMed2005

'Candidatus Borrelia texasensis', from the American dog tick Dermacentor variabilis.

TXW-1, a Borrelia strain isolated in March 1998 from an adult male Dermacentor variabilis tick feeding on a coyote from Webb county, Texas, USA, was characterized by using randomly amplified polymorphic DNA (RAPD) analysis, RFLP and sequence analysis of flaB and rrs (16S rRNA gene), DNA-DNA hybridization analysis, SDS-PAGE and Western blotting with mAbs. It shows different banding patterns in RFLP analysis of flaB and forms distinct branches in phylogenetic analysis derived from flaB and rrs genes. It differs from other borreliae based on the banding patterns obtained by RAPD analysis. This strain contains a small, 38-kDa endoflagellar protein. DNA-DNA hybridization experiments revealed that the levels of DNA reassociation between TXW-1 and previously described relapsing fever borreliae were 38.64 % (Borrelia turicatae), 38.40 % (Borrelia parkeri), 7.39 % (Borrelia hermsii) and 18.30 % (Borrelia coriaceae). However, the level of DNA relatedness between B. parkeri and B. turicatae was 78.78 %. Sequence analyses of flaB and rrs genes indicate that the similarities of nucleotide sequences among TXW-1 and B. turicatae or B. parkeri are less than that between B. turicatae and B. parkeri, and that the genetic distances among TXW-1 and B. turicatae or B. parkeri are greater than that between B. turicatae and B. parkeri. TXW-1 lacks an ospC gene. Electron microscope observations showed that this spirochaete had different morphological structures compared to previously described relapsing fever borreliae. All the results obtained from the above-mentioned analyses indicate that TXW-1 is different from other described Borrelia species and that it represents a novel species of Borrelia. We have been unable to revive frozen cultures and so can not meet the requirements of the Bacteriological Code to deposit viable type material at two different culture collections. Therefore we use the Candidatus designation; based on these results, the species 'Candidatus Borrelia texasensis' is proposed.

Animals↗
PubMed2005

Columbian black-tailed deer (Odocoileus hemionus columbianus) as hosts for Borrelia spp. in northern California.

The prevalence of infection of Columbian black-tailed deer (Odocoileus hemionus columbianus) with Borrelia spp. was evaluated in an area of northwestern California (USA) where Lyme disease is endemic and the relapsing-fever group spirochete Borrelia coriaceae is enzootic, and in a far-removed comparison area having a disparate climate and lower density of vector ticks. Blood samples collected from both deer herds in 1987, 1988, and from 2000-02 were assayed for borrelial infection with microscopic and molecular methods. Serum specimens from two (5%) of 39 deer from the Dye Creek Preserve in Tehama County versus 13 (20%) of 64 animals from the Hopland Research and Extension Center (HREC) in Mendocino County, California were polymerase chain reaction (PCR) test positive for B. burgdorferi sensu lato. DNA sequencing analyses revealed that eight animals were infected with B. bissettii, six with three unclassified genotypes, and one with B. burgdorferi sensu stricto. One serum sample (2%) from HREC was positive for a relapsing-fever group spirochete that had a 16S rRNA sequence homology of 99% with the C053 type strain of B. coriaceae. Spirochetes undetermined to geno-species were detected in thick-blood drops prepared from three (8%) of 36 deer from the HREC by direct immunofluorescence. Adults of the hippoboscid flies Lipoptena depressa (n=73) and Neolipoptena ferrisi (n=24), the Pacific Coast tick (Dermacentor occidentalis) (n=22), and the western black-legged tick (Ixodes pacificus) (n=1) that had been removed from deer from both study areas in 2002 were PCR test negative for borreliae. The occurrence of diverse borreliae in deer from northern California confounds and, consequently, reduces the utility of borrelial serosurveys for detecting specific genospecies, unless they are complemented by more specific assays (e.g., immunoblotting, PCR/sequencing analysis).

Animals↗
PubMed1987

Susceptibility of the hispid cotton rat (Sigmodon hispidus) to the Lyme disease spirochete (Borrelia burgdorferi).

The susceptibility of the hispid cotton rat, Sigmodon hispidus, to the Lyme disease spirochete, Borrelia burgdorferi, was investigated by inoculating rats with infected tick suspensions or by allowing infected Ixodes scapularis nymphs to feed on them. Culture of blood samples in BSK II medium demonstrated that cotton rats developed spirochetemias that lasted for a minimum of 3 to 4 weeks and were of sufficient concentration to infect simultaneously feeding normal I. scapularis nymphs. The spirochetemias were characterized by alternating spirochete-positive and spirochete-negative phases similar to patterns caused by relapsing fever borreliae. The possibility that B. burgdorferi is subject to antigenic variations, as reported for the relapsing fever spirochete, B. hermsii, is suggested.

Animals↗