260 research outputs found
Prevalence of Fimeria funduli (Protozoa: Eimeriidae) in the Longnose Killifish Fundulus similis from Horn Island, Mississippi
Eimeria funduli occurred in Fundulus similis from Horn Island, Mississippi, during 1980, in contrast with its apparent absence during 1978 and 1979. Prevalence of the parasite appears to be related to the unusually low salinity in Mississippi Sound, and in ponds and off the beaches of Horn Island. The low salinity may have promoted the migration of infective intermediate hosts from inshore waters to the island
Prevalence of Fimeria funduli (Protozoa: Eimeriidae) in the Longnose Killifish Fundulus similis from Horn Island, Mississippi
Eimeria funduli occurred in Fundulus similis from Horn Island, Mississippi, during 1980, in contrast with its apparent absence during 1978 and 1979. Prevalence of the parasite appears to be related to the unusually low salinity in Mississippi Sound, and in ponds and off the beaches of Horn Island. The low salinity may have promoted the migration of infective intermediate hosts from inshore waters to the island
A large-scale study of a poultry trading network in Bangladesh: implications for control and surveillance of avian influenza viruses
Since its first report in 2007, avian influenza (AI) has been endemic in Bangladesh. While live poultry marketing is widespread throughout the country and known to influence AI dissemination and persistence, trading patterns have not been described. The aim of this study is to assess poultry trading practices and features of the poultry trading networks which could promote AI spread, and their potential implications for disease control and surveillance. Data on poultry trading practices was collected from 849 poultry traders during a cross-sectional survey in 138 live bird markets (LBMs) across 17 different districts of Bangladesh. The quantity and origins of traded poultry were assessed for each poultry type in surveyed LBMs. The network of contacts between farms and LBMs resulting from commercial movements of live poultry was constructed to assess its connectivity and to identify the key premises influencing it
Economic factors influencing zoonotic disease dynamics: demand for poultry meat and seasonal transmission of avian influenza in Vietnam
While climate is often presented as a key factor influencing the seasonality of diseases, the importance of anthropogenic factors is less commonly evaluated. Using a combination of methods-wavelet analysis, economic analysis, statistical and disease transmission modelling-we aimed to explore the influence of climatic and economic factors on the seasonality of H5N1 Highly Pathogenic Avian Influenza in the domestic poultry population of Vietnam. We found that while climatic variables are associated with seasonal variation in the incidence of avian influenza outbreaks in the North of the country, this is not the case in the Centre and the South. In contrast, temporal patterns of H5N1 incidence are similar across these 3 regions: periods of high H5N1 incidence coincide with Lunar New Year festival, occurring in January-February, in the 3 climatic regions for 5 out of the 8 study years. Yet, daily poultry meat consumption drastically increases during Lunar New Year festival throughout the country. To meet this rise in demand, poultry production and trade are expected to peak around the festival period, promoting viral spread, which we demonstrated using a stochastic disease transmission model. This study illustrates the way in which economic factors may influence the dynamics of livestock pathogens
Biogeography of parasitic nematode communities in giant Galápagos tortoise: implications for conservation management
The Galápagos giant tortoise is an icon of the unique, endemic biodiversity of Galápagos, but little is known of its parasitic fauna. We assessed the diversity of parasitic nematode communities and their spatial distributions within four wild tortoise populations comprising three species across three Galápagos islands, and consider their implication for Galápagos tortoise conservation programmes. Coprological examinations revealed nematode eggs to be common, with more than 80% of tortoises infected within each wild population. Faecal samples from tortoises within captive breeding centres on Santa Cruz, Isabela and San Cristobal islands also were examined. Five different nematode egg types were identified: oxyuroid, ascarid, trichurid and two types of strongyle. Sequencing of the 18S small-subunit ribosomal RNA gene from adult nematodes passed with faeces identified novel sequences indicative of rhabditid and ascaridid species. In the wild, the composition of nematode communities varied according to tortoise species, which co-varied with island, but nematode diversity and abundance were reduced or altered in captive-reared animals. Evolutionary and ecological factors are likely responsible for the variation in nematode distributions in the wild. This possible species/island-parasite co-evolution has not been considered previously for Galápagos tortoises. We recommend that conservation efforts, such as the current Galápagos tortoise captive breeding/rearing and release programme, be managed with respect to parasite biogeography and host-parasite co-evolutionary processes in addition to the biogeography of the host
Recommended from our members
Phylogeny of fish-infecting Calyptospora species (Apicomplexa: Eimeriorina)
There are numerous species of apicomplexans that infect poikilothermic vertebrates, such as fishes, and possess unique morphological features that provide insight into the evolution of this important phylum of parasites. Here, the relationship of the fish-infecting Calyptospora species to other coccidians was investigated based on DNA sequence analysis. Genetic data from the small subunit ribosomal DNA region of the genome were obtained for three of the five nominal species in the genus Calyptospora. Phylogenetic analyses supported a monophyletic lineage sister to a group composed of mostly Eimeria species. The monophyly of Calyptospora species supports the validity of the family Calyptosporidae, but the sister relationship to Eimeria species might also suggest the Eimeriidae be expanded to encompass Calyptospora. The validity of the family Calyptosporidae has been questioned because it is delineated from the Eimeriidae largely based on life cycle characteristics and sporocyst morphology. In general, Eimeria species have a homoxenous life cycle, whereas the type species of Calyptospora is heteroxenous. In the absence of experimental transmission studies, it may be difficult to demonstrate whether all Calyptospora species are heteroxenous. Other distinct morphological characteristics of Calyptospora such as an incomplete sporocyst suture, an apical opening for sporozoite release, a thin veil surrounding sporocysts supported by sporopodia, and a lack of Stieda and sub-Stieda bodies suggest there may be adequate features to delineate these taxa. Even without life cycle data for all species, the morphology and genetic data provide a means to reliably classify Calyptospora species. Placement in either the Calyptosporidae or Eimeriidae is discussed, along with issues relating to the phylogeny of the genus Goussia
Comparison of microfluidic digital PCR and conventional quantitative PCR for measuring copy number variation
One of the benefits of Digital PCR (dPCR) is the potential for unparalleled precision enabling smaller fold change measurements. An example of an assessment that could benefit from such improved precision is the measurement of tumour-associated copy number variation (CNV) in the cell free DNA (cfDNA) fraction of patient blood plasma. To investigate the potential precision of dPCR and compare it with the established technique of quantitative PCR (qPCR), we used breast cancer cell lines to investigate HER2 gene amplification and modelled a range of different CNVs. We showed that, with equal experimental replication, dPCR could measure a smaller CNV than qPCR. As dPCR precision is directly dependent upon both the number of replicate measurements and the template concentration, we also developed a method to assist the design of dPCR experiments for measuring CNV. Using an existing model (based on Poisson and binomial distributions) to derive an expression for the variance inherent in dPCR, we produced a power calculation to define the experimental size required to reliably detect a given fold change at a given template concentration. This work will facilitate any future translation of dPCR to key diagnostic applications, such as cancer diagnostics and analysis of cfDNA
The pediatric rheumatology quality of life scale: validation of the English version in a US cohort of juvenile idiopathic arthritis
A sonographic spectrum of psoriatic arthritis: “the five targets”
Ultrasound is a rapidly evolving technique that is gaining an increasing success in the assessment of psoriatic arthritis. Most of the studies have been aimed at investigating its ability in the assessment of joints, tendons, and entheses in psoriatic arthritis patients. Less attention has been paid to demonstrate the potential of ultrasound in the evaluation of skin and nail. The aim of this pictorial essay was to show the main high-frequency grayscale and power Doppler ultrasound findings in patients with psoriatic arthritis at joint, tendon, enthesis, skin, and nail level
- …