Relapsing fevers

2020 ◽  
pp. 1188-1197
Author(s):  
David A. Warrell
Keyword(s):  
Blood Transfusion ◽  
High Fever ◽  
Relapsing Fever ◽  
Pediculus Humanus ◽  
Tick Vectors ◽  
Body Lice

Louse-borne relapsing fever and tick-borne relapsing fever are characterized by repeated episodes of high fever separated by afebrile periods. They are caused by Borrelia spirochaetes distinct from those responsible for Lyme borrelioses. Untreated patients may suffer as many as five (louse-borne relapsing fever) or ten (tick-borne relapsing fever) febrile relapses of decreasing severity. B. myamotoi is much less likely to relapse. Humans are the sole reservoir of epidemic louse-borne relapsing fever caused by B. recurrentis and transmitted by body lice (Pediculus humanus corporis). Endemic tick-borne relapsing fevers are caused by at least 17 different Borrelia species and have their own particular species of soft Ornithodoros, or, in the case of B. myamotoi and B. lonestari, hard Ixodes or Ablyomma tick vectors that also act as reservoirs. Transmission transplacentally, or by needlestick, blood transfusion, or laboratory accident is also possible.

The influence of nutrition on egg-production and longevity in unmated female body-lice (Pediculus humanus corporis: Anoplura)

Parasitology ◽  
1941 ◽  
Vol 33 (1) ◽  
pp. 40-46 ◽  
Author(s):  
A. J. Haddow
Keyword(s):  
Female Body ◽  
Egg Production ◽  
Egg Laying ◽  
The Body ◽  
Unmated Female ◽  
Pediculus Humanus ◽  
The Third ◽  
Significant Difference ◽  
The Mean ◽  
Body Lice

1. Isolated unmated female body-lice were worn in pillboxes between the skin and the clothes. They were kept constantly on the body but, by a simple device, groups of ten were permitted feeding periods of different length. These groups were fed for 4, 8, 12, 16, 20 and 24 hr. per day respectively. Another group of ten were never allowed to feed after the last moult.2. Some of the figures for egg yield were high. Lice in the 24 hr. group were able to maintain a rate of ten eggs per day for 4−5 days at a time.3. No significant difference in longevity or rate of egg-laying was found to exist between the 12, 16, 20 and 24 hr. groups nor between the 4 and 8 hr. groups but a pronounced and significant difference exists between the 8 and 12 hr. groups. Below 12 hr. there is a sharp fall in longevity and rate of egg production. The unfed group all died, without laying, on the third day.4. The rate of laying as shown by the mode increases progressively with increase in time allowed daily for feeding.5. With regard to the mean eggs per louse the position is less clear. It is felt that the 24 hr. group may differ significantly from the 12, 16 and 20 hr. groups but this is uncertain.

scholarly journals Borreliae Part 2: Borrelia Relapsing Fever Group and Unclassified Borrelia

Biology ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1117
Author(s):  
Giusto Trevisan ◽  
Marina Cinco ◽  
Sara Trevisini ◽  
Nicola di Meo ◽  
Maurizio Ruscio ◽  
...  
Keyword(s):  
Geographical Distribution ◽  
New World ◽  
Common Ancestor ◽  
Etiological Agent ◽  
Hard Tick ◽  
Soft Tick ◽  
Relapsing Fever ◽  
Old World ◽  
Pediculus Humanus ◽  
Candidate Species

Borreliae of the relapsing fever group (RFG) are heterogenous and can be divided mainly into three groups according to vectors, namely the soft-tick-borne relapsing fever (STBRF) Borreliae, the hard-tick-borne relapsing fever (HTBRF) Borreliae, the louse-borne relapsing fever (LBRF) Borreliae, and the avian relapsing fever ones. With respect to the geographical distribution, the STBRF Borreliae are further subdivided into Old World and New World strains. Except for the Avian relapsing fever group Borreliae, which cause avian spirochetosis, all the others share infectivity in humans. They are indeed the etiological agent of both endemic and epidemic forms of relapsing fever, causing high spirochaetemia and fever. Vectors are primarily soft ticks of Ornithodoros spp. in the STBRF group; hard ticks, notably Ixodes sp., Amblyomma sp., Dermacentor sp., and Rhipicephalus sp., in the HTBRF group; and the louse pediculus humanus humanus in the TBRF one. A recent hypothesis was supported for a common ancestor of RFG Borreliae, transmitted at the beginning by hard-body ticks. Accordingly, STBRF Borreliae switched to use soft-bodied ticks as a vector, which was followed by the use of lice by Borrelia recurrentis. There are also new candidate species of Borreliae, at present unclassified, which are also described in this review.

scholarly journals Human ectoparasites and the spread of plague in Europe during the Second Pandemic

2018 ◽  
Vol 115 (6) ◽  
pp. 1304-1309 ◽  
Author(s):  
Katharine R. Dean ◽  
Fabienne Krauer ◽  
Lars Walløe ◽  
Ole Christian Lingjærde ◽  
Barbara Bramanti ◽  
...  
Keyword(s):  
Bayesian Inference ◽  
Compartmental Model ◽  
Human Populations ◽  
Black Death ◽  
Pediculus Humanus ◽  
Pulex Irritans ◽  
Transmission Pathways ◽  
Multiple Transmission ◽  
Better Than ◽  
Body Lice

Plague, caused by the bacterium Yersinia pestis, can spread through human populations by multiple transmission pathways. Today, most human plague cases are bubonic, caused by spillover of infected fleas from rodent epizootics, or pneumonic, caused by inhalation of infectious droplets. However, little is known about the historical spread of plague in Europe during the Second Pandemic (14–19th centuries), including the Black Death, which led to high mortality and recurrent epidemics for hundreds of years. Several studies have suggested that human ectoparasite vectors, such as human fleas (Pulex irritans) or body lice (Pediculus humanus humanus), caused the rapidly spreading epidemics. Here, we describe a compartmental model for plague transmission by a human ectoparasite vector. Using Bayesian inference, we found that this model fits mortality curves from nine outbreaks in Europe better than models for pneumonic or rodent transmission. Our results support that human ectoparasites were primary vectors for plague during the Second Pandemic, including the Black Death (1346–1353), ultimately challenging the assumption that plague in Europe was predominantly spread by rats.

scholarly journals Whole genome sequencing of Borrelia miyamotoi isolate Izh-4: reference for a complex bacterial genome

BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Konstantin V. Kuleshov ◽  
Gabriele Margos ◽  
Volker Fingerle ◽  
Joris Koetsveld ◽  
Irina A. Goptar ◽  
...  
Keyword(s):  
Single Molecule ◽  
Bacterial Genome ◽  
Borrelia Miyamotoi ◽  
Whole Genome ◽  
Relapsing Fever ◽  
Linear Chromosome ◽  
The North ◽  
Long Read ◽  
Variable Major Proteins ◽  
Tick Vectors

Abstract Background The genus Borrelia comprises spirochaetal bacteria maintained in natural transmission cycles by tick vectors and vertebrate reservoir hosts. The main groups are represented by a species complex including the causative agents of Lyme borreliosis and relapsing fever group Borrelia. Borrelia miyamotoi belongs to the relapsing fever group of spirochetes and forms distinct populations in North America, Asia, and Europe. As all Borrelia species B. miyamotoi possess an unusual and complex genome consisting of a linear chromosome and a number of linear and circular plasmids. The species is considered an emerging human pathogen and an increasing number of human cases are being described in the Northern hemisphere. The aim of this study was to produce a high quality reference genome that will facilitate future studies into genetic differences between different populations and the genome plasticity of B. miyamotoi. Results We used multiple available sequencing methods, including Pacific Bioscience single-molecule real-time technology (SMRT) and Oxford Nanopore technology (ONT) supplemented with highly accurate Illumina sequences, to explore the suitability for whole genome assembly of the Russian B. miyamotoi isolate, Izh-4. Plasmids were typed according to their potential plasmid partitioning genes (PF32, 49, 50, 57/62). Comparing and combining results of both long-read (SMRT and ONT) and short-read methods (Illumina), we determined that the genome of the isolate Izh-4 consisted of one linear chromosome, 12 linear and two circular plasmids. Whilst the majority of plasmids had corresponding contigs in the Asian B. miyamotoi isolate FR64b, there were only four that matched plasmids of the North American isolate CT13–2396, indicating differences between B. miyamotoi populations. Several plasmids, e.g. lp41, lp29, lp23, and lp24, were found to carry variable major proteins. Amongst those were variable large proteins (Vlp) subtype Vlp-α, Vlp-γ, Vlp-δ and also Vlp-β. Phylogenetic analysis of common plasmids types showed the uniqueness in Russian/Asian isolates of B. miyamotoi compared to other isolates. Conclusions We here describe the genome of a Russian B. miyamotoi clinical isolate, providing a solid basis for future comparative genomics of B. miyamotoi isolates. This will be a great impetus for further basic, molecular and epidemiological research on this emerging tick-borne pathogen.

Quantitative Analysis of Proliferation and Excretion of Bartonella quintana in Body Lice, Pediculus humanus L.

2007 ◽  
Vol 77 (3) ◽  
pp. 562-566 ◽  
Author(s):  
Naomi Seki ◽  
Mutsuo Kobayashi ◽  
Tsuguo Sasaki ◽  
Noriko Saito ◽  
Minoru Mihara ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Bartonella Quintana ◽  
Pediculus Humanus ◽  
Body Lice

scholarly journals THE EXPERIMENTAL INFECTION OF THE HUMAN BODY LOUSE, PEDICULUS HUMANUS CORPORIS, WITH MURINE AND EPIDEMIC LOUSE-BORNE TYPHUS STRAINS

1945 ◽  
Vol 82 (1) ◽  
pp. 1-20 ◽  
Author(s):  
J. C. Snyder ◽  
C. M. Wheeler
Keyword(s):  
Human Body ◽  
Experimental Infection ◽  
Body Louse ◽  
Pediculus Humanus ◽  
Typhus Fever ◽  
Human Body Louse ◽  
Body Lice

Experiments are described which demonstrate that human body lice (Pediculus humanus corporis), were infected experimentally with murine and epidemic louse-borne strains of typhus fever by feeding on suitably prepared rabbits. Details of the two methods of infection, the "bleb technique" and the "I.V. technique," are presented. It is concluded that the experimental infection of human lice with typhus can be accomplished very easily and rapidly with these methods. The possible applications of the method are discussed.

Blood transfusion transmission of the tick-borne relapsing fever spirocheteBorrelia miyamotoiin mice

Transfusion ◽  
2014 ◽  
Vol 55 (3) ◽  
pp. 593-597 ◽  
Author(s):  
Peter J. Krause ◽  
Jeanne E. Hendrickson ◽  
Tanner K. Steeves ◽  
Durland Fish
Keyword(s):  
Blood Transfusion ◽  
Relapsing Fever

scholarly journals Whole genome sequencing of Borrelia miyamotoi isolate Izh-4: reference for a complex bacterial genome

2019 ◽  
Author(s):  
Konstantin V. Kuleshov ◽  
Gabriele Margos ◽  
Volker Fingerle ◽  
Joris Koetsveld ◽  
Irina A. Goptar ◽  
...  
Keyword(s):  
Single Molecule ◽  
Bacterial Genome ◽  
Borrelia Miyamotoi ◽  
Whole Genome ◽  
Relapsing Fever ◽  
Linear Chromosome ◽  
The North ◽  
Long Read ◽  
Variable Major Proteins ◽  
Tick Vectors

Abstract Background: The genus Borrelia comprises spirochaetal bacteria maintained in natural transmission cycles by tick vectors and vertebrate reservoir hosts. The main groups are represented by a species complex including the causative agents of Lyme borreliosis and relapsing fever group Borrelia. Borrelia miyamotoi belongs to the relapsing-fever group of spirochetes and forms distinct populations in North America, Asia, and Europe. As all Borrelia species B. miyamotoi possess an unusual and complex genome consisting of a linear chromosome and a number of linear and circular plasmids. The species is considered an emerging human pathogen and an increasing number of human cases are being described in the Northern hemisphere. The aim of this study was to produce a high quality reference genome that will facilitate future studies into genetic differences between different populations and the genome plasticity of B. miyamotoi. Results: We used multiple available sequencing methods, including Pacific Bioscience single-molecule real-time technology (SMRT) and Oxford Nanopore technology (ONT) supplemented with highly accurate Illumina sequences, to explore the suitability for whole genome assembly of the Russian B. miyamotoi isolate, Izh-4. Plasmids were typed according to their potential plasmid partitioning genes (PF32, 49, 50, 57/62). Comparing and combining results of both long-read (SMRT and ONT) and short-read methods (Illumina), we determined that the genome of the isolate Izh-4 consisted of one linear chromosome, 12 linear and two circular plasmids. Whilst the majority of plasmids had corresponding contigs in the Asian B. miyamotoi isolate FR64b, there were only four that matched plasmids of the North American isolate CT13-2396, indicating differences between B. miyamotoi populations. Several plasmids, e.g. lp41, lp29, lp23, and lp24, were found to carry variable major proteins. Amongst those were variable large proteins (Vlp) subtype Vlp-α, Vlp-γ, Vlp-δ and also Vlp-β. Phylogenetic analysis of common plasmids types showed the uniqueness in Russian/Asian isolates of B. miyamotoi compared to other isolates. Conclusions: We here describe the genome of a Russian B. miyamotoi clinical isolate, providing a solid basis for future comparative genomics of B. miyamotoi isolates. This will be a great impetus for further basic, molecular and epidemiological research on this emerging tick-borne pathogen.

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