1,250 research outputs found
Life histories offer a clue to the future role of infectious disease in coral reefs
No full textIncreased frequency and severity of stressors associated with climate change are drastically altering ecosystems. Caribbean coral reefs differ markedly from just 30 years ago, with much restructuring attributable to infectious disease outbreaks. Using a classic epidemiological approach, we demonstrate how density-dependent demographic rates serve as a mechanism for intrinsic coral resilience to population perturbations arising from disturbances such as disease. We explore the impact of allowing infection status to influence demographic rates and ascertain outbreak thresholds that are corroborated by epizootic patterns observed in the field. We discuss how our threshold calculations may provide metrics of coral epizootic early warning systems. Integrating our infection model with equations describing the interspecific competition for space between coral and macroalgae, we provide new mechanistic understanding of the influence that coral life history dynamism and infectious disease have on the changing face of these threatened ecosystems
Modelling knowlesi malaria transmission in humans: Vector preference and host competence
No full textBackground: Plasmodium knowlesi, a malaria species that normally infects long-tailed macaques, was recently found to be prevalent in humans in Southeast Asia. While human host competency has been demonstrated experimentally, the extent to which the parasite can be transmitted from human back to mosquito vector in nature is unclear. Methods. Using a mathematical model, the influence of human host competency on disease transmission is assessed. Adapting a standard model for vector-borne disease transmission and using an evolutionary invasion analysis, the paper explores how differential host competency between humans and macaques can facilitate the epidemiological processes of P. knowlesi infection between different hosts. Results. Following current understanding of the evolutionary route of other human malaria vectors and parasites, an increasing human population in knowlesi malaria endemic regions will select for a more anthropophilic vector as well as a parasite that preferentially transmits between humans. Applying these adaptations, evolutionary invasion analysis yields threshold conditions under which this macaque disease may become a significant public health issue. Conclusions. These threshold conditions are discussed in the context of malaria vector-parasite co-evolution as a function of anthropogenic effects
Infectious disease and novel ecosystems
No full textThe contributions of habitat destruction, exotic species invasion and climate change on infectious disease ecology are difficult to disentangle. This chapter considers two case studies. The first, African Highland malaria, offers a case study for the multiplicity of anthropogenic changes to natural ecosystems and their effects on infectious disease epidemiology. A natural bias exists in the scientific literature towards human pathogens in linking infectious diseases with novel ecosystems because of the amenability of these subjects to observation. Inaccessibility continues to hamper the study of marine systems. Consequently, marine infectious disease understanding is less developed than it is for terrestrial systems. This issue is addressed in the second case study in the chapter: novel Caribbean coral reef ecosystems. Temporal dynamics of this drastically altered marine system demonstrates not only the effect that infectious disease can have in reshaping ecosystems, but also the recursive nature of the relationship between infectious disease and novel ecosystems
Aerial dissemination of Clostridium difficile spores
No full textYesClostridium difficile-associated diarrhoea (CDAD) is a frequently occurring healthcare-associated infection, which is responsible for significant morbidity and mortality amongst elderly patients in healthcare facilities. Environmental contamination is known to play an important contributory role in the spread of CDAD and it is suspected that contamination might be occurring as a result of aerial dissemination of C. difficile spores. However previous studies have failed to isolate C. difficile from air in hospitals. In an attempt to clarify this issue we undertook a short controlled pilot study in an elderly care ward with the aim of culturing C. difficile from the air.
In a survey undertaken during February (two days) 2006 and March (two days) 2007, air samples were collected using a portable cyclone sampler and surface samples collected using contact plates in a UK hospital. Sampling took place in a six bedded elderly care bay (Study) during February 2006 and in March 2007 both the study bay and a four bedded orthopaedic bay (Control). Particulate material from the air was collected in Ringer's solution, alcohol shocked and plated out in triplicate onto Brazier's CCEY agar without egg yolk, but supplemented with 5 mg/L of lysozyme. After incubation, the identity of isolates was confirmed by standard techniques. Ribotyping and REP-PCR fingerprinting were used to further characterise isolates.
On both days in February 2006, C. difficile was cultured from the air with 23 samples yielding the bacterium (mean counts 53 ¿ 426 cfu/m3 of air). One representative isolate from each of these was characterized further. Of the 23 isolates, 22 were ribotype 001 and were indistinguishable on REP-PCR typing. C. difficile was not cultured from the air or surfaces of either hospital bay during the two days in March 2007.
This pilot study produced clear evidence of sporadic aerial dissemination of spores of a clone of C. difficile, a finding which may help to explain why CDAD is so persistent within hospitals and difficult to eradicate. Although preliminary, the findings reinforce concerns that current C. difficile control measures may be inadequate and suggest that improved ward ventilation may help to reduce the spread of CDAD in healthcare facilities
Emergence and global spread of epidemic healthcare-associated clostridium difficile
No full textEpidemic C. difficile (027/BI/NAP1) has rapidly emerged in the past decade as the leading cause of antibiotic-associated diarrhea worldwide. However, the key events in evolutionary history leading to its emergence and the subsequent patterns of global spread remain unknown. Here, we define the global population structure of C. difficile 027/BI/NAP1 using whole-genome sequencing and phylogenetic analysis. We show that two distinct epidemic lineages, FQR1 and FQR2, not one as previously thought, emerged in North America within a relatively short period after acquiring the same fluoroquinolone resistance–conferring mutation and a highly related conjugative transposon. The two epidemic lineages showed distinct patterns of global spread, and the FQR2 lineage spread more widely, leading to healthcare-associated outbreaks in the UK, continental Europe and Australia. Our analysis identifies key genetic changes linked to the rapid transcontinental dissemination of epidemic C. difficile 027/BI/NAP1 and highlights the routes by which it spreads through the global healthcare system
Disputatio Medica De Generatione Hominis In Ovo / Quam, ... Sub Praesidio ... Dn. Johannis Jacobi Waldschmied/ Medicinae Doctoris ... exhibet Author Dominicus Beddevole, Genevensis, In Auditorio Medico d. 3. Septemb. ...
No full textDISPUTATIO MEDICA DE GENERATIONE HOMINIS IN OVO / QUAM, ... SUB PRAESIDIO ... DN. JOHANNIS JACOBI WALDSCHMIED/ MEDICINAE DOCTORIS ... EXHIBET AUTHOR DOMINICUS BEDDEVOLE, GENEVENSIS, IN AUDITORIO MEDICO D. 3. SEPTEMB. ...
Disputatio Medica De Generatione Hominis In Ovo / Quam, ... Sub Praesidio ... Dn. Johannis Jacobi Waldschmied/ Medicinae Doctoris ... exhibet Author Dominicus Beddevole, Genevensis, In Auditorio Medico d. 3. Septemb. ... (1)
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Consensu Et Author. Magnifici Ictorum Ordinis In Illustri Ad Salam Academia, Sub Praesidio ... Dn. Joh. Volk. Bechmanns ... Dissertationem Iuridicam De Iure Braxandi in Ictorum Auditorio ad diem Octobr. h.c. Publicae Eruditorum Censurae Subiiciet Paul. Christianus Arnoldus, Olsnen. Siles. Author & Respondens
No full textCONSENSU ET AUTHOR. MAGNIFICI ICTORUM ORDINIS IN ILLUSTRI AD SALAM ACADEMIA, SUB PRAESIDIO ... DN. JOH. VOLK. BECHMANNS ... DISSERTATIONEM IURIDICAM DE IURE BRAXANDI IN ICTORUM AUDITORIO AD DIEM OCTOBR. H.C. PUBLICAE ERUDITORUM CENSURAE SUBIICIET PAUL. CHRISTIANUS ARNOLDUS, OLSNEN. SILES. AUTHOR & RESPONDENS
Consensu Et Author. Magnifici Ictorum Ordinis In Illustri Ad Salam Academia, Sub Praesidio ... Dn. Joh. Volk. Bechmanns ... Dissertationem Iuridicam De Iure Braxandi in Ictorum Auditorio ad diem Octobr. h.c. Publicae Eruditorum Censurae Subiiciet Paul. Christianus Arnoldus, Olsnen. Siles. Author & Respondens ([1])
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De. Condictione L. Si quis Conductionis. 25. C. de locato conducto. Sub Praesidio Dn. Andreae Mylii ... Publice disputabit. Author. Johann Gottfried Schönfeld/ Zitt. Lus. die 11. Iunii. M.DC.XCVI.
No full textDE. CONDICTIONE L. SI QUIS CONDUCTIONIS. 25. C. DE LOCATO CONDUCTO. SUB PRAESIDIO DN. ANDREAE MYLII ... PUBLICE DISPUTABIT. AUTHOR. JOHANN GOTTFRIED SCHÖNFELD/ ZITT. LUS. DIE 11. IUNII. M.DC.XCVI.
De. Condictione L. Si quis Conductionis. 25. C. de locato conducto. Sub Praesidio Dn. Andreae Mylii ... Publice disputabit. Author. Johann Gottfried Schönfeld/ Zitt. Lus. die 11. Iunii. M.DC.XCVI. (1)
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There is a trend favoring vancomycin vs. metronidazole in treating severe C. difficile infection
No full textA critical appraisal and clinical application of Johnson S, Louie TJ, Gerding DN, et al. Vancomycin, metronidazole, or tolevamer for Clostridium difficile infection: results from two multinational, randomized, controlled trials. Clin Infect Dis. 2014;59(3):345-354. doi: 10.1093/cid/ciu31
Disputatio Moralis De Virtute Et Vitio Morali / Quam ... Sub Praesidio Dn. Henrici Iulii Scheurl ... In Illustri Academia Iulia Examinandam Publice proponit Paulus Gerding Rotheimensis ... Ad diem XIIX. Martii
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