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PubMed2000

The relapsing fever spirochaete, Borrelia crocidurae, activates human endothelial cells and promotes the transendothelial migration of neutrophils.

The blood-borne, erythrocyte-aggregating Borrelia crocidurae, the causative agent of African relapsing fever, have been shown to induce severe cellular lesions in mice. In this paper, we present the first report of how the endothelium is stimulated during an African relapsing fever B. crocidurae infection. B. crocidurae co-incubated with cultured human umbilical vein endothelial cells (HUVECs) activated endothelium in such way that E-selectin and intercellular adhesion molecule 1 (ICAM-1) became upregulated in a dose- and time-dependent fashion, as determined by a whole-cell enzyme-linked immunosorbent assay (ELISA). The upregulation was reduced by treatment that killed the bacteria, suggesting that viability is important for the stimulation of HUVECs by B. crocidurae. Furthermore, conditioned medium from HUVECs stimulated with B. crocidurae contained interleukin (IL)-8, which is a chemotactic agent for neutrophils. Activation of HUVECs by B. crocidurae resulted in migration of subsequently added neutrophils across the endothelial monolayers, and this migration was inhibited by antibodies to IL-8. The activation of endothelium by B. crocidurae may constitute a key pathophysiological mechanism in B. crocidurae-induced vascular damage.

Animals↗
PubMed1988

Clinical presentation of louse-borne relapsing fever among Ethiopian refugees in northern Somalia.

Louse-borne relapsing fever (LBRF) is still endemic among Ethiopian populations. In order to assess the clinical presentation of LBRF in an Ethiopian refugee camp in northern Somalia, a referral system was organized for all pyrexias of unknown origin. Among the 134 patients referred, 37 showed Borrelia in fresh and stained blood smears. Common clinical features were: high fever (above 39 degrees C in 73% of the cases), headache and general body pain (88%), liver tenderness (62%), petechia (54%), nausea and vomiting (46%), chills and rigors (30%) and epistaxis (11%). Jaundice was absent. No fatalities were observed. The clinical picture was less severe than in previous studies on LBRF. This difference might be due to the fact that the present study was community-based as opposed to the previous studies which were hospital-based.

Adolescent↗
PubMedDate not supplied

Spraying tick-infested houses with lambda-cyhalothrin reduces the incidence of tick-borne relapsing fever in children under five years old.

Tick-borne relapsing fever (TBRF) is a major cause of morbidity and mortality of children in central Tanzania. This study assessed the effect of house interior residual spraying with lambda-cyhalothrin on domestic tick infestation and the incidence of TBRF in children under 5 years old. Two neighbouring villages were studied: one was sprayed with insecticide, the other left untreated. Samples of earth from the floors of 50 houses before and after spraying, and 50 houses in the control village, were sieved and ticks counted. The incidence of TBRF was estimated by microscopy of thick blood films taken from all children under 5 years old presenting with fever to the village dispensary or health workers. After 2 cycles of spraying, no tick was found in the treated houses; in the controls, tick numbers remained high. In the treated village there were 29 cases of TBRF among the 960 children under 5 years old in the 4 months before spraying, and one in the 4 months after spraying. In the control village there were 10 and 4 cases in the same periods among the 510 children. There was a significant reduction of 0.09 in the odds ratio of infection after spraying (95% confidence interval 0.01-0.87).

Child, Preschool↗
PubMed1979

Tick-borne relapsing fever in Colorado. Historical review and report of cases.

Since 1915 the front range of the Colorado Rocky Mountains has been postulated as a focus of endemic tick-borne relapsing fever. However, the disease has rarely been identified: only two cases have been reported in Colorado since 1944. Three sporadic cases in 1977--tightly grouped geographically and temporally--prompted an epidemiologic review. Tick-borne relapsing fever should be considered in the differential diagnosis of recurrent paroxysmal fever--with or without known presence of ticks--whenever exposure in an endemic area is part of a patient's history.

Adult↗
PubMed1983

Meptazinol diminishes the Jarisch-Herxheimer reaction of relapsing fever.

Naloxone, an opioid antagonist, and meptazinol, an opioid antagonist with agonist properties, were tested in a double-blind placebo-controlled trial in 24 Ethiopian patients with louse-borne relapsing fever. The potentially fatal Jarisch-Herxheimer reaction (J-HR), which invariably follows tetracycline treatment of the disease, was unaffected by naloxone, 30-40 mg intravenously, but was diminished by meptazinol, 300-500 mg intravenously. Compared with naloxone and placebo, meptazinol reduced the clinical severity of the reaction, significantly delayed and shortened its chill phase, delayed the rise in temperature, and reduced peak temperature and changes in pulse and respiratory rates and leucocyte count. High-dose corticosteroids given before or at the time of tetracycline treatment failed to alter the reaction, which is thought to result from release of endotoxin-like substances. Meptazinol is the first effective treatment for the J-HR of louse-borne relapsing fever. This finding suggests a role for endogenous opioids in the pathogenesis of the J-HR.

Adolescent↗
PubMed1975

Tropical thrombophlebitis. The role of relapsing fever in its causation.

In tropical thrombophlebitis the leg veins are most often involved, but in some patients thrombosis of the visceral veins may be fatal. As its cause is unknown, attention is called to outbreaks of relapsing fever in the Transvaal which effects labourers on citrus and maize farms and which often develops into thrombophlebitis. Appropriate tests for relapsing fever should be done in patients who develop this complication. Passengers on long overnight journeys by air are liable to deep vein thrombosis and should exercise to avoid it.

Aerospace Medicine↗
PubMedDate not supplied

[The activity of cyfluthrin and cypermethrin-based preparations against the vector of the causative agent of tick-borne relapsing fever].

Laboratory tests have established a high activity and long-term persistence of some cipermethrin isomers (fendone, fastac) and cifluthrin (zolfac) against the tick Ornithodoros papillipes, a carrier of tick-borne relapsing fever. These indices are considerably superior to those of an isomer mixture of cipermethrin (cimbush, ripkord). This can be applied to deltamethrin and cigalothrin. The findings suggest that these agents are highly promising in controlling the carrier of tick-borne relapsing fever along with a significant reduction in the ecological pesticidal load in the focus.

Animals↗
PubMed1995

Treatment of louse-borne relapsing fever with low dose penicillin or tetracycline: a clinical trial.

A clinical trial was conducted in order to evaluate the efficacy of procaine penicillin and tetracycline, respectively, in the treatment of louse-borne relapsing fever. 184 patients (160 men, 24 women) admitted to the Gondar hospital during the rainy season 1992 were assigned to 1 of 4 treatment groups: procaine penicillin 100,000 (PP100), 200,000 (PP200) or 400,000 (PP400) international units (IU) intramuscularly (i.m.), or tetracycline 250 mg per os (TTC, p.o.). All drugs were given as single doses. The overall case fatality rate was 3.3%. Frequency of relapses, Jarisch-Herxheimer-like reactions (JHR) and deaths were significantly different between patients treated with TTC and those treated with PP100. Relapses occurred most often in the group receiving the lowest dose of penicillin (46%), and decreased with increasing dosage of penicillin; none of the patients treated with TTC had a relapse. Occurrence of JHR showed the opposite pattern: whilst 2 (5%) patients treated with PP100 developed a JHR, 16 (29%) in the PP200 group, 10 (31%) in the PP400 group, and 27 (47%) in the TTC group developed a JHR. As mortality is linked to severe JHR, and most relapses are clinically mild and easily treated, these results speak in favour of using low-dose penicillin to initiate the treatment of relapsing fever.

Adolescent↗
PubMed1993

Evaluation of agents for use in medium for selective isolation of Lyme disease and relapsing fever Borrelia species.

Barbour-Stoenner-Kelly (BSK) II medium containing fosfomycin, 5-fluorouracil, trimethoprim and sulfamethoxazole was evaluated for the selective isolation of the Borrelia species responsible for Lyme disease and relapsing fever. The maximum non-inhibitory concentrations of fosfomycin, 5-fluorouracil, trimethoprim and sulfamethoxazole for six strains of borreliae were 500 to > 1000 micrograms/ml, 250 to > 500 micrograms/ml, 125 to 500 micrograms/ml and 125 to 500 micrograms/ml, respectively. The combination of four agents (fosfomycin 400 micrograms/ml, 5-fluorouracil 100 micrograms/ml, trimethoprim 10 micrograms/ml, sulfamethoxazole 50 micrograms/ml) did not inhibit the growth of borreliae, allowing growth in cultures inoculated with a few organisms (theoretically a single organism). In contrast, the four-agent combination completely inhibited the growth of 12 of 13 other bacterial strains tested as possible contaminants. This combination also allowed the selective growth of borreliae in experimentally contaminated specimens. The four-agent combination in BSK II medium may be useful for selective isolation of Borrelia species responsible for Lyme disease and relapsing fever from clinical and environmental samples.

Bacteriological Techniques↗
PubMed1998

[Joseph Désiré Tholozan and the Persian relapsing fever].

In the year 1879, Tholozan seems to have been convinced of the danger caused by the bites of ornithodores in Persia, as a result of very careful observations of sick persons suffering from iranian relapsing fever due to Borrelia persica. Among the ticks collected by him and sent to entomologists in France was the true vector, named Argas (presently Ornithodoros) tholozani by Laboulbene and Megnin. Tholozan's contribution to our knowledge on persian relapsing fever is really important. He was one of the first to provide a good clinical description of the disease and to involve an argasid tick in its transmission. He discovered the real vector species which is now called after him.

Animals↗
PubMed1992

Relapsing fever in children--demographic, social and clinical features.

Louse-borne relapsing fever (LBRF) is an acute febrile illness endemic Ethiopia. To date reports of childhood LBRF are few. The demographic, social and clinical features of eighty children with LBRF admitted to Ethio-Swedish Children's Hospital, Addis Abeba between 1989 and 1991 is presented. The mean age of patients was 8.8 years (range 4 months to 15 years). The male to female ratio was 1.2:1. Seventy-seven (97%) patients came from Addis Abeba. They came from poor families living in overcrowded homes. Fever, headache, right upper quadrant pain, chills and rigors were common symptoms. Fever and hepatosplenomegaly were common signs. Three drug regimens were used in the treatment of patients. A combination of penicillin and tetracycline, chloramphenicol alone and erythromycin alone, all given for 3 days. There was only one death. The literature on LBRF in adults is reviewed and the results are compared (1).

Adolescent↗
PubMed1989

[Tick-borne relapsing fever in Madagascar: an eradicated disease?].

Since about thirty years, no relapsing fever due to Borrelia duttoni is recorded from Madagascar. A survey was conducted in the formerly endemic area, between Soalala and Majunga, in order to collect data on possible cases and to look if the vector, Ornithodoros moubata is still present. No mention of the disease was recorded; all Ornithodoros seem to have completely disappeared in the area, without any clear reason. However, a few O. moubata specimens were recorded from piggeries in Mahasolo, 150 km west of Tananarive, outside the endemic area.

Animals↗
PubMed1977

Tick-borne relapsing fever: an interstate outbreak originating at Grand Canyon National Park.

During the 1973 summer season, 27 employees and 35 overnight guests at the North Rim, Grand Canyon National Park, Arizona, acquired febrile illnesses compatibel with relapsing fever. Sixteen cases were confirmed by finding Borrelia spirochetes in peripheral blood smears or inoculated Swiss mice. Retrospective surveys of 278 employees and 7247 guests at the park revealed that acquisition of illness was significantly associated with the persons sleeping in rustic log cabins and acquiring bites of "unknown" insects. From rodent nesting materials found in the walls and attics of cabins where cases had occurred, infective Ornithodoros hermsi ticks were recovered. Exceptional activity of ticks in human populations appeared to have resulted from a decreased population of the ticks' usual rodent hosts. Vector control activities consisted of spraying the cabins with residual insecticide, removing nesting materials, and "rodent proofing." This outbreak, the largest yet identified in North America, extends the known range of a principal vector and establishes the North Rim as an endemic source of tick-borne relapsing fever.

Adult↗
PubMed2005

Phylogenetic analysis of the spirochetes Borrelia parkeri and Borrelia turicatae and the potential for tick-borne relapsing fever in Florida.

Isolates of Borrelia turicatae, Borrelia parkeri, and the Florida canine borrelia (FCB) were examined to further phylogenetically characterize the identities of these spirochetes in the United States. DNA sequences of four chromosomal loci (the 16S rRNA gene, flaB, gyrB, and glpQ) were determined for eight isolates of B. turicatae and six isolates of B. parkeri, which grouped the spirochetes into two distinct but closely related taxa (>98% sequence identity) separate from Borrelia hermsii. The FCB was clearly separated with the group identified as B. turicatae, confirming this bacterium as a relapsing fever spirochete. Therefore, the potential for tick-borne relapsing fever in humans and other animals exists in Florida and future efforts are needed to determine the enzootic hosts and distribution of this spirochete in the southeastern United States. Analysis of plasmids demonstrated both linear and circular forms in B. turicatae but only linear plasmids in B. parkeri, which should be of interest to investigators concerned with plasmid diversity and evolution within this group of spirochetes.

Bacterial Proteins↗
PubMed2006

Residual brain infection in relapsing-fever borreliosis.

BACKGROUND: Neurological involvement is common in the spirochetal infection relapsing fever (RF) in both humans and experimental animals. RF is best known for antigenic variation caused by the sequential expression of variable outer membrane lipoproteins of 2 sizes, variable small (Vsp) and variable large (Vlp) proteins. Less understood is the persistence of RF borreliae in the brain after they are cleared from the blood, referred to as residual brain infection (RBI). Our goal was to investigate the phenomenon of RBI in RF. METHODS: We studied RBI in immunocompetent mice by culturing blood and perfused brain samples 1 month after intraperitoneal inoculation with Borrelia turicatae serotype 1 (Bt1). Mice deficient in Toll-like receptor 2 (TLR2-/-) or in B and T cells (scid) were included for comparison. RESULTS: All scid mice had persistent infection in blood and brain. RBI was found in 3 (19%) of 16 immunocompetent and TLR2-/- mice. RBI was caused by either persistence of the original serotype (Bt1) or newly emerged Vsp (n=1, renamed Bt3) or Vlp serotypes. The Vsp of Bt1 (Vsp1) and Bt3 (Vsp3) were 75% identical. CONCLUSIONS: RBI in RF is relatively frequent and can occur by persistence of the original or newly emerged serotypes.

Animals↗
PubMed2003

Analysis of the ability of spirochete species associated with relapsing fever, avian borreliosis, and epizootic bovine abortion to bind factor H and cleave c3b.

Some Borrelia species associated with Lyme disease bind the complement-regulatory protein factor H (fH), a process that may aid in immune evasion. In this report we demonstrate that some Borrelia species associated with relapsing fever bind fH, but not those associated with avian borreliosis and epizootic bovine abortion. Cell-bound fH was also found to mediate cleavage of exogenously supplied human C3b, demonstrating the biological relevance of fH binding and its possible importance in the pathogenesis of the relapsing-fever spirochetes.

Abortion, Veterinary↗
PubMed2006

In situ immune response in brain and kidney during early relapsing fever borreliosis.

Characterization of the host immune response during initial pathogenesis of relapsing fever neuroborreliosis would be a key to understanding Borrelia persistence and factors driving the inflammatory process. We analyzed immune cells in brain and kidney with the highly invasive B. crocidurae during the first two weeks of murine infection. In both organs, microglia and/or macrophages predominated while T-cell changes were minimal. Compared to kidney, brain neutrophils infiltrated more rapidly and B-cells were essentially absent. Our results indicate that during early neuroborreliosis, brain defense is comprised primarily of innate immune cells while adaptive immunity plays a minor role.

Animals↗