[Borrelia miyamotoi: a recently identified human pathogenic tick-borne relapsing fever spirochete]. / Borrelia miyamotoi: egy újabb, humán patogén, kullancs által terjesztett, visszatéro lázat okozó baktérium.

Borrelia miyamotoi is a recently described relapsing fever spirochete transmitted by ticks of the Ixodes ricinus complex. This pathogen is different from Borrelia burgdorferi sensu lato (the Lyme borreliosis spirochetes) in its epidemiology, ecology and also genetics. Over 50 patients have been described worldwide with Borrelia miyamotoi disease, and three immunocompromised patients were reported with neurological symptoms. Our knowledge about Borrelia miyamotoi infection in ticks and its distribution in different habitats and also the mechanism of the infection is limited. The most common symptom is fever; thus it can be easily confused with other tick-borne diseases. Due to the intensive research in recent years, Borrelia miyamotoi infection in ticks and hosts has been reported from different regions and also the number of patients is increasing, thus this bacterium is considered as an emerging pathogen. In this literature review we would like to summarize the available knowledge about this spirochete. Orv Hetil. 2017, 158(29): 1124-1130.

Epidemiological study of relapsing fever borreliae detected in Haemaphysalis ticks and wild animals in the western part of Japan.

The genus Borrelia comprises arthropod-borne bacteria, which are infectious agents in vertebrates. They are mainly transmitted by ixodid or argasid ticks. In Hokkaido, Japan, Borrelia spp. were found in deer and Haemaphysalis ticks between 2011 and 2013; however, the study was limited to a particular area. Therefore, in the present study, we conducted large-scale surveillance of ticks and wild animals in the western part of the main island of Japan. We collected 6,407 host-seeking ticks from two regions and 1,598 larvae obtained from 32 engorged female ticks and examined them to elucidate transovarial transmission. In addition, we examined whole blood samples from 190 wild boars and 276 sika deer, as well as sera from 120 wild raccoons. We detected Borrelia spp. in Haemaphysalis flava, Haemaphysalis megaspinosa, Haemaphysalis kitaokai, Haemaphysalis longicornis, and Haemaphysalis formosensis. In addition, we isolated a strain from H. megaspinosa using Barbour-Stoenner-Kelly medium. The minimum infection rate of ticks was less than 5%. Transovarial transmission was observed in H. kitaokai. Phylogenetic analysis of the isolated strain and DNA fragments amplified from ticks identified at least four bacterial genotypes, which corresponded to the tick species detected. Bacteria were detected in 8.4%, 15%, and 0.8% of wild boars, sika deer, and raccoons, respectively. In this study, we found seasonal differences in the prevalence of bacterial genotypes in sika deer during the winter and summer. The tick activity season corresponds to the season with a high prevalence of animals. The present study suggests that a particular bacterial genotype detected in this study are defined by a particular tick species in which they are present.

Where Are the Ticks? Solving the Mystery of a Tickborne Relapsing Fever Outbreak at a Youth Camp.

During the summer of 2014 an outbreak of tickborne relapsing fever (TBRF) occurred in a group of high school students and staff at a youth camp, which was reported to Coconino County Public Health Services District. Six confirmed and five probable cases of TBRF occurred. During the environmental investigation two rodents tested positive for TBRF, but the vector, soft ticks, could not be found in their "normal" habitat. Ticks were finally located in areas not typical for soft ticks.

Borrelia miyamotoi: A human tick-borne relapsing fever spirochete in Europe and its potential impact on public health.

Borrelia miyamotoi is a tick-borne bacterium which has only recently been identified in Europe as a human pathogen causing relapsing fever and little is known about its local impact on human health. There are three types of B. miyamotoi: Asian (Siberian), European, and American. B. miyamotoi is transmitted by the same Ixodes ricinus-persulcatus species complex, which also transmits B. burgdorferi s.l., the Lyme borreliosis group. Both Borrelia groups are mostly maintained in natural rodent populations. The aim of this review is to summarize the available literature on B. miyamotoi, with the focus of attention falling on Europe, as well as to describe its presence in ticks, reservoir hosts, and humans and discuss its potential impact on public health.

Prevalence and risk factors of louse-borne relapsing fever in high risk populations in Bahir Dar city Northwest, Ethiopia.

BACKGROUND: Louse- borne relapsing fever (LBRF) is a vector borne acute febrile illness caused by Borrelia recurrentis and the disease is more prevalent in the high risk groups like prisoners, yekoloremaries and street children. However, prevalence and risk factors of LBRF in these populations about the disease are not known. Therefore, the aim of this study was to determine the prevalence and risk factors of LBRF in high risk populations. METHODS: A cross- sectional survey on prevalence and risk factors of LBRF in high risk populations in Bahir Dar city was conducted in December, 2012. For the study, blood was taken from the tip of the left ring finger of the participants by laboratory technicians and thick blood film was prepared from each participant and stained with 3% Giemsa for 30 min. The slides were examined and the result was reported as positive or negative using light microscopy and finally, data was also collected using a pre- tested questionnaire by face to face interviews. RESULTS: Of the 407 study participants, 383 (94.1%) were males with the mean age of 31 years and 243 (59.7%) had no formal education. The prevalence of LBRF was 2.5% and the positivity rate of LBRF was highest in yekolotemaries (6.1%) followed by street children (4.9%). However, prisoners had nil and statistically significance association was observed between high risk populations and LBRF prevalence (p < 0.001). Those study participants who lived in mud houses had the highest positivity rate (2.2%), followed by those in wood houses (0.3%). However, those who lived in brick houses had nil. Study participants who had low levels of knowledge had the highest prevalence rate of LBRF. CONCLUSION: The overall prevalence of LBRF was 2.5% and the rate of positivity was highest in yekolotemaries, followed by street children. Therefore, health education should be given for these high risk populations.

Jarisch-Herxheimer reaction associated with ciprofloxacin administration for tick-borne relapsing fever.

A 14-year-old girl was seen at a community clinic with a chief complaint of abdominal pain and fevers and was treated with oral ciprofloxacin for presumed pyelonephritis. She became tachycardic and hypotensive after her first dose of antibiotic, and she developed disseminated intravascular coagulation. She was admitted to our hospital for presumed sepsis. Her outpatient peripheral blood smear was reviewed, revealing spirochetes consistent with Borrelia sp. To our knowledge this is the first reported case of the Jarisch-Herxheimer reaction to ciprofloxacin.

Ticks and Borrelia: model systems for investigating pathogen-arthropod interactions.

Blood-feeding arthropods transmit numerous types of infectious agent and parasite that have a tremendous impact on human health and mortality throughout the world. These vector-borne pathogens display a wide array of evolutionary patterns that allow them to infect and to be successfully transmitted by ticks, mites, and hematophagous insects. The vector's method of feeding, type of development, and host preference are also critical factors for the transfer of zoonotic agents from wild animal reservoirs to susceptible humans. Ticks are obligate blood-feeders in all life stages and biologically transmit many infectious agents. In North America, two ticks that are involved in the maintenance and transmission of pathogenic spirochetes include Ixodes scapularis (family Ixodidae) and Ornithodoros hermsi (family Argasidae). These ticks are the respective vectors of the Lyme disease spirochete Borrelia burgdorferi and a relapsing fever spirochete, Borrelia hermsii. Little is known concerning how these and related species of Borrelia adapt to successfully alternate between warm-blooded vertebrates and ticks; however, the possibility that borrelial surface proteins are differentially expressed in their different hosts is an exciting area of current research.

[Tick-borne relapsing fever morbidity in Namangan]. / Zabolevaemost' kleshchevym vozvratnym tifom v Namangane.

The authors discuss the incidence of tick-borne relapsing fever in the town of Namangan (Uzbekistan) in 1976-1991 and the possible sites of human infection; the agent, Ornithodoros papillipes, has never been detected over this period. Analysis of many-year and seasonal time course of the disease incidence, of the age of the patients and their residence, characterization of the possible habitats of the agents, and comparison of the situation in the town with that in the adjacent rural territories permit a suggestion that the majority of the patients were infected at home.

Mortality in high risk patients with tick-borne relapsing fever analysed by the Borrelia-index.

Clinical findings on 25 patients with a high spirochaetemia are presented. The diagnosis was established by demonstration of Borrelia spirochaetes in the thick blood smear and a Borrelia-index was estimated to calculate the density of the spirochaetemia. Causes of death were septicaemia (3x), severe spirochaetemia in a neonate (1x), and successive relapses in complicated cases without adequate treatment (2x). The results show a positive correlation between the degree of spirochaetemia and severity of complications and the Borrelia-index shows to have a prognostic value.

[Changes in the village foci of tick-borne relapsing fever in Uzbekistan over a 10-year period]. / Ob izmeneniiakh poselkovykh ochagov kleshchevogo vozvratnogo tifa v Uzbekistane za desiatiletnii period.

The paper presents the results of repeated investigations in the tick relapsing fever nidus (TRF) conducted after a ten-year interval in Gava settlement situated in the foothill area of the Namangan Province of Uzbekistan. A considerable deterioration in the habitat conditions of the vector, Ornithodoros papillipes Bir., due to the intensified anthropogenic effect, and decrease in its number have been noted. The distribution range of the tick (percent of infested farmsteads) in this case did not reduce. The infection rate of the vector's population with the tick relapsing fever agent decreased that points indirectly to a higher mortality of infected ticks under unfavourable conditions. Wavy course of morbidity with TRF during the period between investigations shows that changes that took place in the nidus were not uniform in their character and may have resulted to some extent from natural cycles. A similar character of anthropogenic effect on the populations of ticks in the settlement natural nidi suggests that the above changes are common to the nidi of this infection.