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 THE DISTRIBUTION OF RICKETTSIA IN THE TISSUES OF INSECTS AND ARACHNIDS

1923 ◽  
Vol 37 (4) ◽  
pp. 431-456 ◽  
Author(s):  
E. V. Cowdry
Keyword(s):  
Rhipicephalus Sanguineus ◽  
Dermacentor Variabilis ◽  
Animal Products ◽  
Gram Negative ◽  
Pediculus Humanus ◽  
Larval Stages ◽  
Pulex Irritans ◽  
Boophilus Decoloratus ◽  
Occasional Occurrence ◽  
Definition Of

In the absence of a satisfactory definition of Rickettsia the observations herein recorded were arbitrarily limited to bacterium-like organisms which are intracellular and Gram-negative. Rickettsia of this type were found in the following species: Amblyomma americana, Amblyomma hebræum, Boophilus decoloratus, Atomus sp., Casinaria infesta, Chrysopa oculata, Ctenocephalus canis, Dermacentor variabilis, Lepisma saccharina, Lucoppia curviseta, Margaropus annulatus, Margaropus annulatus australis, Ornithodoros turicata, Pulex irritans, Rhipicephalus sanguineus, Rhipicephalus evertsi, and Salticus scenicus. Since intracellular, Gram-negative Rickettsia have been recorded in the literature as existing in Cimex lectularius, Dermacentor venustus, Melophagus ovinus, and Pediculus humanus, the occasional occurrence of such bodies must be conceded in the following groups not closely related phylogenetically: Attidæ, Trombidiidæ, Argasidæ, lxodidæ, Cinura, Acanthiidæ, Pediculidæ, Hippoboscidæ, Chrysopidæ, Pulicidæ, and Ichneumonidæ. The species which harbor Rickettsia differ widely in diet and habitat. One such species is insectivorous throughout life, two are insectivorous in larval stages, becoming vegetarian in the adult condition, one is chiefly vegetarian but partakes of some animal products, and two are usually entirely vegetarian; while the remainder subsist wholly upon a diet of mammalian blood. Rickettsia are associated, in only a few cases, with diseases in mammals. The evidence at hand does not lead beyond the conclusion that the Rickettsia mentioned above are true Gram-negative microorganisms, easily distinguishable from mitochondria and all other cytoplasmic and nuclear granulations, rather completely adapted to an intracellular existence, exhibiting in some cases a remarkable degree of host specificity, and often inherited through the eggs.

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.

Bayesian jackknife empirical likelihood

Biometrika ◽  
2019 ◽  
Vol 106 (4) ◽  
pp. 981-988
Author(s):  
Y Cheng ◽  
Y Zhao
Keyword(s):  
Bayesian Inference ◽  
Empirical Likelihood ◽  
Small Sample ◽  
New Approach ◽  
U Statistics ◽  
Posterior Inference ◽  
Jackknife Empirical Likelihood ◽  
General Tool ◽  
Control Study ◽  
Better Than

Summary Empirical likelihood is a very powerful nonparametric tool that does not require any distributional assumptions. Lazar (2003) showed that in Bayesian inference, if one replaces the usual likelihood with the empirical likelihood, then posterior inference is still valid when the functional of interest is a smooth function of the posterior mean. However, it is not clear whether similar conclusions can be obtained for parameters defined in terms of $U$-statistics. We propose the so-called Bayesian jackknife empirical likelihood, which replaces the likelihood component with the jackknife empirical likelihood. We show, both theoretically and empirically, the validity of the proposed method as a general tool for Bayesian inference. Empirical analysis shows that the small-sample performance of the proposed method is better than its frequentist counterpart. Analysis of a case-control study for pancreatic cancer is used to illustrate the new approach.

scholarly journals Effects of multiple transmission pathways on Zika dynamics

2018 ◽  
Vol 3 ◽  
pp. 331-344 ◽  
Author(s):  
Omomayowa Olawoyin ◽  
Christopher Kribs
Keyword(s):  
Transmission Pathways ◽  
Multiple Transmission

A highly invasive chimeric ranavirus can decimate tadpole populations rapidly through multiple transmission pathways

2019 ◽  
Vol 410 ◽  
pp. 108777 ◽  
Author(s):  
Angela Peace ◽  
Suzanne M. O’Regan ◽  
Jennifer A. Spatz ◽  
Patrick N. Reilly ◽  
Rachel D. Hill ◽  
...  
Keyword(s):  
Transmission Pathways ◽  
Multiple Transmission

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.

scholarly journals The under-investigated wild side of Escherichia coli : genetic diversity, pathogenicity and antimicrobial resistance in wild animals

2021 ◽  
Vol 288 (1948) ◽  
Author(s):  
Katherine M. Lagerstrom ◽  
Elizabeth A. Hadly
Keyword(s):  
Escherichia Coli ◽  
Genetic Diversity ◽  
Agricultural Production ◽  
Small Body ◽  
Source Tracking ◽  
Human Populations ◽  
Wild Animals ◽  
Global Public Health ◽  
E Coli ◽  
Transmission Pathways

A striking paucity of information exists on Escherichia coli in wild animals despite evidence that they harbour pathogenic and antimicrobial-resistant E. coli in their gut microbiomes and may even serve as melting pots for novel genetic combinations potentially harmful to human health. Wild animals have been implicated as the source of pathogenic E. coli outbreaks in agricultural production, but a lack of knowledge surrounding the genetics of E. coli in wild animals complicates source tracking and thus contamination curtailment efforts. As human populations continue to expand and invade wild areas, the potential for harmful microorganisms to transfer between humans and wildlife increases. Here, we conducted a literature review of the small body of work on E. coli in wild animals. We highlight the geographic and host taxonomic coverage to date, and in each, identify significant gaps. We summarize the current understanding of E. coli in wild animals, including its genetic diversity, host and geographic distribution, and transmission pathways within and between wild animal and human populations. The knowledge gaps we identify call for greater research efforts to understand the existence of E. coli in wild animals, especially in light of the potentially strong implications for global public health.

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