Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 40
Filter
1.
J Prim Health Care ; 16(1): 33-40, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38546766

ABSTRACT

Introduction The value of family health history as a means to understanding health risk has been long known. Its value in a precision medicine context is also now becoming apparent. General practitioners (GPs) are considered to play a key role in the collection, and investigation, of family health history, but it remains widely reported as being both poorly and infrequently undertaken. Little is known about this practice in Aotearoa New Zealand (NZ). Aim This study aimed to explore current practices in relation to the ascertainment of family health history, with a view towards precision medicine. Methods Semi-structured interviews were conducted with 10 GPs recruited from one urban area of NZ. The interviews were subjected to a thematic analysis. Results Family health history information was used to varying degrees in four areas - risk ascertainment, patient engagement with a diagnosis, social context and building relationships. Patient cultural considerations were rarely mentioned. Reliability of information provided by patients, resource constraints, context driven consults and electronic health record limitations are potential indicators of current limits of family health history. Discussion Our findings present a baseline of current practice and echo larger studies from overseas. As precision medicine is not yet routine, a unique opportunity exists for consideration to be given to establishing specific roles within the NZ health system to enable equitable practice of, and subsequent health gains from, the use of family/whanau health history information as part of precision medicine.


Subject(s)
General Practice , General Practitioners , Humans , New Zealand , Reproducibility of Results , Family Practice , Qualitative Research
2.
J Bioeth Inq ; 20(4): 633-638, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37707767

ABSTRACT

As COVID-19 and its variants spread across Australia at differing paces and intensity, the country's response to the risk of infection and contagion revealed an intensification of bordering practices as a form of risk mitigation with disparate impacts on different segments of the Australian community. Australia's international border was closed for both inbound and outbound travel, with few exceptions, while states and territories, Indigenous communities, and local government areas were subject to a patchwork of varying restrictions. By focusing on borders at various levels, our research traces how the logics of medico-legal bordering have filtered down from the international to the intra-national, and indeed, into hyper-local spaces. This is not just apparent in the COVID-19 moment but in previous pandemics of 1918 to 1919 influenza and smallpox, in which practices of quarantine and lockdowns were both unevenly distributed and implemented on multiple scales of social organization. An interdisciplinary approach between history and law reveals that human movement during pandemic times in Australia has been regulated in a manner that sees mobility as a risk to public health capable of mitigation through the strict enforcement of borders as a technology of both confinement and exclusion.


Subject(s)
COVID-19 , Pandemics , Humans , Australia/epidemiology , COVID-19/epidemiology , Quarantine , Public Health
3.
Parasitology ; 142(10): 1270-7, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26036271

ABSTRACT

Timely diagnosis of the nematode Angiostrongylus vasorum in dogs is important in view of severe and permanent lung and cardiovascular lesions that may occur. The performance of the classical Baermann coprological method was compared with ELISAs for the serological detection of circulating antigen and specific antibodies and with Polymerase chain reaction (PCR) performed on EDTA blood, feces and tracheal swabs of serial samples from experimentally inoculated dogs over 13 weeks post inoculation (wpi) (n = 16) and following anthelmintic treatment (n = 6). Patency was observed from 6.7 to 7.6 wpi in all dogs, Baermann results were then mostly positive (116/119, 97%) during the patent period, with wide variations in the numbers of first stage larvae numbers. Blood PCR was tested positive on 1-2 occasions in 11/16 dogs in the pre-patent period, while all tested positive by antibody-detection ELISA by 6 wpi. The proportion of dogs testing positive by fecal PCR and antigen-detection ELISA rose early in the patent period. Tracheal swabs were occasionally DNA-positive in 3/16 dogs starting from 10 wpi. Following treatment, larval excretion stopped within 3 weeks and blood PCR results became negative within 1 week (5/6 dogs), while 4/6 dogs were positive for parasite DNA in tracheal swabs. Parasite antigen and specific antibodies both persisted in the blood for 3-9 weeks after treatment, with average optical densities and the proportion of positive dogs falling gradually, while results using other tests were much more variable. Results indicate that the earliest and most consistent results are obtained by the ELISAs, which can also be used for monitoring dogs after anthelmintic treatment.


Subject(s)
Anthelmintics/therapeutic use , Dog Diseases/diagnosis , Dog Diseases/drug therapy , Feces/parasitology , Strongylida Infections/drug therapy , Strongylida Infections/veterinary , Angiostrongylus/immunology , Angiostrongylus/physiology , Animals , Antibodies, Helminth/blood , Dogs , Enzyme-Linked Immunosorbent Assay/standards , Enzyme-Linked Immunosorbent Assay/veterinary , Polymerase Chain Reaction/standards , Polymerase Chain Reaction/veterinary , Sensitivity and Specificity , Strongylida Infections/diagnosis
4.
Vet Rec ; 177(2): 46, 2015 Jul 11.
Article in English | MEDLINE | ID: mdl-25934261

ABSTRACT

The nematode parasite Angiostrongylus vasorum is an increasingly important cause of respiratory and other diseases in dogs. Geographical spread from previously limited endemic foci has occurred rapidly. This paper investigates parasite epidemiology around the location of the first reported case in Scotland in 2009: by detection of A vasorum-specific DNA in gastropod intermediate hosts, and in dogs circulating DNA and specific antibodies, and first stage larvae in faeces. Overall prevalence in gastropods was 6.7 per cent (16/240), with parasite DNA found in slugs in the Arion ater and Arion hortensis species aggregates and the snail Helix aspersa (syn. Cornu aspersum). Of 60 dogs presenting with clinical signs compatible with angiostrongylosis, none tested positive using PCR on peripheral blood or Baermann test on faeces, and none of 35 tested for circulating anti-A vasorum antibodies were positive. PCR prevalence in gastropods was highest (11 per cent) in the park frequented by the canine angiostrongylosis index case. Molecular survey for infection in gastropods is a potentially informative and efficient method for characterising the distribution of A vasorum and therefore local risk of canine infection. However, there appears to be a complex relationship between prevalence in gastropods and emergence of canine clinical disease, which requires further work to advance understanding of parasite transmission and geographical disease spread.


Subject(s)
Angiostrongylus/isolation & purification , Dog Diseases/parasitology , Endemic Diseases/veterinary , Gastropoda/parasitology , Strongylida Infections/veterinary , Animals , Dog Diseases/epidemiology , Dogs , Health Surveys , Polymerase Chain Reaction/veterinary , Scotland/epidemiology , Strongylida Infections/epidemiology , Strongylida Infections/parasitology
5.
Exp Parasitol ; 148: 40-8, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25447124

ABSTRACT

Cryptosporidiosis, a gastroenteric disease characterised mainly by diarrheal illnesses in humans and mammals is caused by infection with the protozoan parasite Cryptosporidium. Treatment options for cryptosporidiosis are limited, with the current therapeutic nitazoxanide, only partly efficacious in immunocompetent individuals. The parasite lacks de novo purine synthesis, and is exclusively dependant on purine salvage from its host. Inhibition of the inosine 5' monophosphate dehydrogenase (IMPDH), a purine salvage enzyme that is essential for DNA synthesis, thereby offers a potential drug target against this parasite. In the present study, a yeast-two-hybrid system was used to identify Phylomer peptides within a library constructed from the genomes of 25 phylogenetically diverse bacteria that targeted the IMPDH of Cryptosporidium parvum (IMPcp) and Cryptosporidium hominis (IMPch). We identified 38 unique interacting Phylomers, of which, 12 were synthesised and screened against C. parvum in vitro. Two Phylomers exhibited significant growth inhibition (81.2-83.8% inhibition; P < 0.05), one of which consistently exhibited positive interactions with IMPcp and IMPch during primary and recapitulation yeast two-hybrid screening and did not interact with either of the human IMPDH proteins. The present study highlightsthe potential of Phylomer peptides as target validation tools for Cryptosporidium and other organisms and diseases because of their ability to bind with high affinity to target proteins and disrupt function.


Subject(s)
Cryptosporidium/genetics , Genome, Bacterial/genetics , IMP Dehydrogenase/genetics , Peptides/genetics , Amino Acid Sequence , Animals , Base Sequence , Cattle , Cell Line, Tumor , Cryptosporidium/drug effects , Cryptosporidium/enzymology , DNA, Protozoan/isolation & purification , Dose-Response Relationship, Drug , Humans , IMP Dehydrogenase/metabolism , Molecular Sequence Data , Oocysts , Peptide Library , Peptides/chemistry , Peptides/pharmacology , Peptides/toxicity , Plasmids/genetics , Two-Hybrid System Techniques
6.
Public Health ; 128(11): 1017-22, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25443131

ABSTRACT

OBJECTIVES: In the UK, women aged 50-70 are offered breast cancer screening every three years. Screening participation rates in London have been particularly low. Low rates have been associated with low socio-economic status, and some ethnic groups have been observed to be underserved by cancer screening. This paper reports on a telephone reminder intervention in London Newham, an area of high deprivation and ethnic diversity. STUDY DESIGN: Observational study of planned intervention. METHODS: Women invited for breast screening were telephoned to confirm receipt of the invitation letter, remind invitees of their upcoming appointment, and to provide further information. Aggregate data at general practice level on invitation to and attendance at breast screening and on numbers reached by telephone were analysed by logistic regression. RESULTS: For the 29 participating GP practices (10,928 invitees) overall uptake in 2010 was higher compared to the previous screening round in 2007 (67% vs. 51%; p < 0.001). On average 59% of invitees were reached by the reminder calls. A 10% increase in women reached resulted in an 8% increase in the odds of women attending their screening appointment (95% CI: 5%-11%), after adjusting for 2007 attendance rates. Practices with a higher proportion of South Asian women were associated with a larger uptake adjusted for 2007 uptake and population reached by the telephone intervention, (4% increase in odds of attendance per 10% increase in South Asian population, CI 1%-7%, p = 0.003) while practices with a higher proportion of black women were associated with a smaller uptake similarly adjusted. (11% decrease in odds of attendance per 10% increase in black population, CI 9%-16%, p < 0.001). CONCLUSIONS: A language- and culture-sensitive programme of reminder calls substantially improved breast cancer screening uptake.


Subject(s)
Breast Neoplasms/prevention & control , Early Detection of Cancer/statistics & numerical data , Health Promotion/methods , Health Services Accessibility/statistics & numerical data , Information Dissemination/methods , Reminder Systems , Telephone , Aged , Cultural Diversity , Ethnicity/statistics & numerical data , Female , Humans , London , Middle Aged , Program Evaluation , Socioeconomic Factors , State Medicine
7.
J Comp Pathol ; 150(4): 357-60, 2014 May.
Article in English | MEDLINE | ID: mdl-24679855

ABSTRACT

Severe infestation with Aelurostrongylus abstrusus was identified in the lungs and small intestine of a 2-month-old kitten that died due to verminous pneumonia and enteritis. On clinical examination, the kitten had dyspnoea, pneumonia, pleural effusion, ascites and diarrhoea. An interstitial pattern was evident radiographically in the lungs. The kitten died before treatment could be instituted. On gross and histopathological examination, there was severe interstitial pneumonia and large numbers of A. abstrusus eggs and larvae were present in alveoli, together with fewer adult nematodes in small bronchioles. The mucosa of the small intestine was invaded by large numbers of A. abstrusus larvae. The findings were consistent with a hyperinfection syndrome due to A. abstrusus.


Subject(s)
Cat Diseases/parasitology , Enteritis/veterinary , Pneumonia/veterinary , Strongylida Infections/veterinary , Animals , Cat Diseases/pathology , Cats , Enteritis/parasitology , Enteritis/pathology , Fatal Outcome , Pneumonia/parasitology , Pneumonia/pathology , Strongylida Infections/complications , Strongylida Infections/pathology
8.
Parasitology ; 139(14): 1924-38, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22917112

ABSTRACT

SUMMARY Molecular phylogeography has revolutionised our ability to infer past biogeographic events from cross-sectional data on current parasite populations. In ecological parasitology, this approach has been used to address fundamental questions concerning host-parasite co-evolution and geographic patterns of spread, and has raised many technical issues and problems of interpretation. For applied parasitologists, the added complexity inherent in adding population genetic structure to perceived parasite distributions can sometimes seem to cloud rather than clarify approaches to control. In this paper, we use case studies firstly to illustrate the potential extent of cryptic diversity in parasite and parasitoid populations, secondly to consider how anthropogenic influences including movement of domestic animals affect the geographic distribution and host associations of parasite genotypes, and thirdly to explore the applied relevance of these processes to parasites of socio-economic importance. The contribution of phylogeographic approaches to deeper understanding of parasite biology in these cases is assessed. Thus, molecular data on the emerging parasites Angiostrongylus vasorum in dogs and wild canids, and the myiasis-causing flies Lucilia spp. in sheep and Cochliomyia hominovorax in humans, lead to clear implications for control efforts to limit global spread. Broader applications of molecular phylogeography to understanding parasite distributions in an era of rapid global change are also discussed.


Subject(s)
Parasites/classification , Parasites/genetics , Parasitic Diseases/prevention & control , Parasitic Diseases/parasitology , Phylogeography , Animals , Genetic Variation , Host-Parasite Interactions , Humans , Parasitic Diseases/epidemiology , Population Dynamics , Species Specificity
9.
Vet Parasitol ; 173(3-4): 255-61, 2010 Oct 29.
Article in English | MEDLINE | ID: mdl-20692767

ABSTRACT

Infection with the nematode Angiostrongylus vasorum is an emerging cause of canine disease in Europe and part of North America, yet published data on its epidemiology in endemic areas are lacking. This study tested faecal samples from 897 dogs attending veterinary practices in the southern part of Great Britain, a long standing endemic focus. Among 790 dogs presenting with respiratory or other signs broadly suggestive of angiostrongylosis, 16% tested positive on a single Baermann's examination, compared with 2% of healthy dogs in the same catchment areas. Risk factors for positive tests included age (higher risk in younger dogs), season (more cases earlier in the calendar year), and worming history (lower risk if given milbemycin oxime in the past 12 weeks). Sex, neutering status and breed were not significant in terms of risk of testing positive. The most common clinical signs in infected dogs were respiratory, along with non-specific signs such as lethargy and exercise intolerance, while bleeding, neurological and gastrointestinal signs were also recorded. Around half the dogs sampled that showed signs of extra-pulmonary disease also had respiratory signs. Direct faecal smears and Baermann's tests read after one hour detected 56% and 83% of diagnosed cases respectively. The data confirm that A. vasorum is commonly associated with disease in endemic areas, which manifests with a broad range of signs at primary care level. Information on risk factors is useful in diagnosis and control, and forms a basis for further epidemiological investigation.


Subject(s)
Angiostrongylus/isolation & purification , Dog Diseases/parasitology , Strongylida Infections/veterinary , Animals , Dog Diseases/epidemiology , Dogs , Feces/parasitology , Female , Logistic Models , Male , Parasite Egg Count/veterinary , Risk Factors , Seasons , Strongylida Infections/epidemiology , Strongylida Infections/parasitology , United Kingdom/epidemiology
10.
Infect Genet Evol ; 10(4): 561-8, 2010 May.
Article in English | MEDLINE | ID: mdl-20139034

ABSTRACT

Angiostrongylus vasorum is an emerging parasite that is currently distributed through Western Europe and parts of South America. An isolated population is also present in Newfoundland, Canada. This presents a risk of onward spread into North America, but its origin is unknown. To ascertain the phylogeographic relationships and genetic diversity of A. vasorum within the western Palaearctic and eastern Nearctic ecozones, a total of 143 adult and larval nematode specimens were collected from foxes (Vulpes vulpes) and dogs (Canis lupus familiaris) in Canada, Denmark, France, Germany, Ireland, the Netherlands, Portugal and the United Kingdom, and a coyote (Canis latrans) in Canada. DNA was extracted and the second internal transcribed spacer and two mitochondrial loci were amplified and sequenced. Multiple haplotypes (n=35) based on combined mitochondrial sequences (1078bp) of the partial cytochrome oxidase subunit I (COI), large subunit ribosomal RNA (rrnL) and the complete nicotinamide adenine dinucleotide dehydrogenase 3 (NADH3) sequences, were observed throughout the Palaearctic countries sampled; however, only a single haplotype was observed for the Canadian A. vasorum population. The likely origin of A. vasorum in Newfoundland is therefore inferred to be within the western Palaearctic. There was no evidence of genetic segregation of parasites in dogs, foxes and coyotes, supporting the hypothesis that transmission occurs between wild and domestic canids. The transmission dynamics and population structure of this nematode are further discussed.


Subject(s)
Angiostrongylus/genetics , DNA, Helminth/genetics , Dogs/parasitology , Foxes/parasitology , Strongylida Infections/veterinary , Analysis of Variance , Animals , Canada , DNA, Intergenic/genetics , DNA, Mitochondrial/genetics , Electron Transport Complex IV/genetics , Europe , Evolution, Molecular , Geography , Haplotypes , Microsatellite Repeats , Phylogeny , Strongylida Infections/parasitology
11.
Vet Parasitol ; 166(1-2): 112-8, 2009 Dec 03.
Article in English | MEDLINE | ID: mdl-19717239

ABSTRACT

The parasitic nematode Angiostrongylus vasorum is an emerging challenge for companion animal and wildlife health, with reported increases in both distribution and incidence in Europe. To facilitate improved detection of this parasite, a SYBR green real-time polymerase chain reaction (PCR) was developed to amplify a region of the second internal transcribed spacer (ITS-2) of A. vasorum from both definitive and intermediate host samples. The PCR assay was capable of detecting a single of plasmid DNA containing the entire ITS-2 region, a single first stage larva (L1) in 200 microl canine EDTA blood, a single L1 in 200 mg of canine faeces and a single L3 in 10mg of Biomphalaria glabrata tissue. The assay exhibited a high level of specificity to A. vasorum and whilst it potentially amplifies DNA of other Angiostrongylus species, it did not amplify DNA from a range of other common canine parasitic nematodes. Field evaluation of the PCR assay was conducted by screening canine EDTA blood and faecal samples from suspected cases of A. vasorum infection and compared with Baermann's detection, and also by screening a range of gastropod species from an endemic area. Real-time quantitative PCR offers a more efficient means of detecting A. vasorum infection with a lower limit of detection than traditional diagnostic tests, and it therefore has important clinical and epidemiological applications.


Subject(s)
Angiostrongylus/physiology , Dog Diseases/diagnosis , Dog Diseases/parasitology , Polymerase Chain Reaction/methods , Snails/parasitology , Strongylida Infections/veterinary , Angiostrongylus/genetics , Angiostrongylus/isolation & purification , Animals , Benzothiazoles , Biomphalaria/parasitology , DNA, Ribosomal Spacer/genetics , Diamines , Dogs , Feces/parasitology , Host-Parasite Interactions , Larva , Organic Chemicals , Quinolines , Sensitivity and Specificity , Strongylida Infections/diagnosis , Strongylida Infections/parasitology
12.
Parasitology ; 136(7): 783-92, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19416553

ABSTRACT

Little is known of the prevalence and life-cycle of trypanosomes in mammals native to Australia. Native Australian trypanosomes have previously been identified in marsupials in the eastern states of Australia, with one recent report in brush-tailed bettongs (Bettongia penicillata), or woylie in Western Australia in 2008. This study reports a novel Trypanosoma sp. identified in blood smears, from 7 critically endangered Gilbert's potoroos (Potorous gilbertii) and 3 quokkas (Setonix brachyurus) in Western Australia. Trypanosomes were successfully cultured in vitro and showed morphological characteristics similar to members of the subgenus Herpetosoma. Phylogenetic analysis of 18S rRNA gene sequences identified 2 different novel genotypes A and B that are closely related to trypanosomes previously isolated from a common wombat (Vombatus ursinus) in Victoria, Australia. The new species is proposed to be named Trypanosoma copemani n. sp.


Subject(s)
Animals, Wild/parasitology , Macropodidae/parasitology , Potoroidae/parasitology , Trypanosoma/classification , Trypanosomiasis/veterinary , Animals , DNA, Protozoan/analysis , DNA, Protozoan/isolation & purification , Molecular Sequence Data , Phylogeny , Polymerase Chain Reaction/methods , RNA, Ribosomal, 18S/genetics , Sequence Analysis, DNA , Species Specificity , Trypanosoma/genetics , Trypanosoma/isolation & purification , Trypanosoma/ultrastructure , Trypanosomiasis/parasitology
13.
Parasitology ; 136(1): 107-15, 2009 Jan.
Article in English | MEDLINE | ID: mdl-19126274

ABSTRACT

Angiostrongylus vasorum is a nematode parasite of sylvan and domestic species of the family Canidae. It has a broad but patchy distribution worldwide, and there is evidence for geographical spread and increasing incidence of infection in recent years. While historically Angiostrongylus-like nematodes identified in dogs and foxes have been described as A. vasorum in Europe and Angiocaulus raillieti in South America, more recent taxonomic revision has amalgamated these into a single species, A. vasorum. Here we report, for the first time, the molecular characterization of isolates of A. vasorum from Germany, Portugal, Denmark and the United Kingdom on the basis of the mitochondrial COI gene and the second ribosomal internal transcribed spacer. When compared with isolates from Brazil, sequence analysis revealed 2 distinct genotypes. Estimated rates of evolution based on COI sequences for both nematode and host are consistent with the hypothesis that the presence of A. vasorum in South America is a result of an ancient evolutionary event. Angiostrongylus vasorum in South America potentially represents a separate species to that observed in Europe.


Subject(s)
Angiostrongylus/classification , Canidae/parasitology , Phylogeny , Angiostrongylus/genetics , Animals , Base Sequence , DNA, Ribosomal Spacer/genetics , Electron Transport Complex IV/genetics , Europe , Genetic Variation , Molecular Sequence Data , Sequence Alignment , South America
14.
J Parasitol ; 94(2): 557-60, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18564765

ABSTRACT

To further investigate the recently described avian piroplasm, Babesia kiwiensis, blood samples were collected from 13 wild-caught and 8 zoo-captive brown kiwi (Apteryx mantelli) and screened for the presence of piroplasm DNA using a nested-polymerase chain reaction (PCR) targeting the 18S rRNA gene of most members of Piroplasmida. All captive birds gave a negative PCR result, while 12 wild-caught birds were PCR positive. The nearly full-length 18S rRNA gene for B. kiwiensis was sequenced. Upon phylogenetic analysis, it was found to belong to the babesid group of piroplasms and was ancestral, yet genetically similar, to the Babesia canis-related species. An insight into the current taxonomy of the avian piroplasms is also given. An Ixodes anatis tick collected from 1 of the North Island brown kiwi was also screened using PCR and was found to be positive for B. kiwiensis DNA.


Subject(s)
Babesia/genetics , Babesiosis/veterinary , Bird Diseases/parasitology , Palaeognathae/parasitology , Animals , Animals, Wild , Animals, Zoo , Arachnid Vectors/parasitology , Babesia/classification , Babesiosis/parasitology , Babesiosis/transmission , Bird Diseases/transmission , DNA, Ribosomal/chemistry , Ixodes/parasitology , Molecular Sequence Data , New Zealand , Phylogeny , Polymerase Chain Reaction/veterinary , RNA, Ribosomal, 18S/genetics , Sequence Alignment
15.
Aust Vet J ; 85(11): 459-63, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17970851

ABSTRACT

This study reports on the epidemiology of Babesia gibsoni in American Pit Bull Terriers living in a region of western Victoria in southern Australia. Both American Pit Bull Terriers (n = 100) and other dog breeds (n = 51) were screened for B gibsoni using immunofluorescent antibody testing (IFAT) and/or polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). A questionnaire was also completed by each dog owner, ascertaining the husbandry and habits of the dogs sampled. Fourteen dogs were positive for B gibsoni using IFAT and/or PCR-RFLP and all were American Pit Bull Terriers. Dogs that were male and/or had been bitten by or were biters of other American Pit Bull Terriers were more likely to be B gibsoni positive, thus suggesting that blood-to-blood transmission contributes to the spread of this disease between dogs.


Subject(s)
Babesia/isolation & purification , Babesiosis/veterinary , Dog Diseases/transmission , Polymorphism, Restriction Fragment Length , Animal Husbandry/methods , Animals , Babesiosis/blood , Babesiosis/epidemiology , Babesiosis/transmission , Base Sequence , Bites and Stings/parasitology , Breeding , DNA/chemistry , DNA, Protozoan/chemistry , Disease Transmission, Infectious/veterinary , Dog Diseases/blood , Dog Diseases/epidemiology , Dogs , Female , Fluorescent Antibody Technique, Indirect/veterinary , Male , Polymerase Chain Reaction/veterinary , Risk Factors , Sex Factors , Victoria/epidemiology
16.
Exp Parasitol ; 117(2): 115-23, 2007 Oct.
Article in English | MEDLINE | ID: mdl-17543304

ABSTRACT

Babesia gibsoni is a protozoan parasite of dogs worldwide yet both an effective treatment and a reliable method for detecting subclinical cases of this emerging infection remain elusive. Experimental B. gibsoni infections were established in vivo to investigate the efficacy of combined atovaquone and azithromycin drug therapy and to determine the detection limits of a nested-PCR, IFAT and microscopy during various stages of infection. While atovaquone and azithromycin produced a reduction in parasitaemia, it did not eliminate the parasite and drug resistance appeared to develop in one dog. Polymerase chain reaction was found to be most useful in detecting infection in the pre-acute and acute stages, while IFAT was most reliable during chronic infections. Microscopy is suggested to be only effective for detecting acute stage infections. This study also describes the detection of B. gibsoni in tissue samples during chronic infections for the first time, suggesting possible sequestration of this parasite.


Subject(s)
Anti-Infective Agents/therapeutic use , Atovaquone/therapeutic use , Azithromycin/therapeutic use , Babesia/isolation & purification , Babesiosis/veterinary , Dog Diseases/drug therapy , Acute Disease , Animals , Anti-Infective Agents/pharmacology , Antibodies, Protozoan/blood , Atovaquone/pharmacology , Azithromycin/pharmacology , Babesia/drug effects , Babesia/genetics , Babesia/immunology , Babesiosis/diagnosis , Babesiosis/drug therapy , Chronic Disease , DNA, Protozoan/analysis , Dog Diseases/diagnosis , Dog Diseases/parasitology , Dogs , Drug Resistance , Female , Fluorescent Antibody Technique/veterinary , Parasitemia/diagnosis , Parasitemia/parasitology , Parasitemia/veterinary , Polymerase Chain Reaction/veterinary
17.
Vet Parasitol ; 144(1-2): 20-7, 2007 Mar 15.
Article in English | MEDLINE | ID: mdl-17127005

ABSTRACT

Canine piroplasmosis is an emerging disease worldwide, with multiple species of piroplasm now recognised to infect dogs. A nested polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay was developed for the detection and differentiation of each of the piroplasm species currently known to infect dogs on the basis of the 18S ribosomal RNA gene. The assay can potentially amplify and discriminate between Theileria annae, Theileria equi, Babesia conradae, Babesia gibsoni, Babesia sp. (Coco) and each of the Babesia canis subspecies. Non-canine piroplasm species can also potentially be detected using the described assay, however amplification of Neospora caninum was also observed. The PCR was found to have a high detection limit, capable of detecting a 2.7x10(-7)% parasitaemia or the equivalent of 1.2 molecules of target DNA when using DNA extracted from whole EDTA blood and detected a parasitaemia of 2.7x10(-5)% using blood applied to both Flinders Technology Associates (FTA) cards and IsoCodetrade mark Stix. The application of blood samples to filter paper may greatly assist in piroplasm identification in regions of the world where local technologies for molecular characterisation are limited. The assay reported here has the potential to be standardised for routine screening of dogs for piroplasmosis.


Subject(s)
Babesia , Babesiosis/veterinary , Dog Diseases/diagnosis , Dog Diseases/parasitology , Phylogeny , Polymorphism, Restriction Fragment Length , Animals , Babesia/classification , Babesia/isolation & purification , Babesiosis/diagnosis , Babesiosis/parasitology , Base Sequence , DNA, Protozoan/chemistry , DNA, Protozoan/genetics , Dogs , Gene Amplification , Polymerase Chain Reaction/methods , Polymerase Chain Reaction/veterinary , RNA, Ribosomal, 18S/chemistry , RNA, Ribosomal, 18S/genetics , Sensitivity and Specificity , Species Specificity
18.
Vet Parasitol ; 144(3-4): 261-9, 2007 Mar 31.
Article in English | MEDLINE | ID: mdl-17088022

ABSTRACT

The prevalence of hematozoan infections (Hepatozoon canis and Babesia sp., particularly Babesia canis vogeli) in canids from Venezuela, Thailand and Spain was studied by amplification and sequencing of the 18S rRNA gene. H. canis infections caused simultaneously by two different isolates were confirmed by RFLP analysis in samples from all the geographic regions studied. In Venezuela, blood samples from 134 dogs were surveyed. Babesia infections were found in 2.24% of the dogs. Comparison of sequences of the 18S rRNA gene indicated that protozoan isolates were genetically identical to B. canis vogeli from Japan and Brazil. H. canis infected 44.77 per cent of the dogs. A representative sample of Venezuelan H. canis isolates (21.6% of PCR-positives) was sequenced. Many of them showed 18S rRNA gene sequences identical to H. canis Spain 2, albeit two less frequent genotypes were found in the sample studied. In Thailand, 20 dogs were analyzed. No infections caused by Babesia were diagnosed, whereas 30 per cent of the dogs were positive to hematozoan infection. Two protozoa isolates showing 99.7-100% identity to H. canis Spain 2 were found. In Spain, 250 dogs were studied. B. canis vogeli infected 0.01% of the animals. The sequence of the 18S rRNA gene in Spanish isolates of this protozoa was closely related to those previously deposited in GenBank (> 99% identity). Finally, 20 red foxes were screened for hematozoans employing semi-nested PCR and primers designed to detect Babesia/Theileria. Fifty percent of the foxes were positive to Theileria annae. In addition, it was found that the PCR assay was able as well to detect Hepatozoon infections. Thirty five percent of the foxes were infected with two different H. canis isolates showing 99.8-100% identity to Curupira 1 from Brazil.


Subject(s)
Dog Diseases/parasitology , Eukaryota/genetics , Eukaryota/isolation & purification , Protozoan Infections, Animal/parasitology , Animals , DNA, Protozoan/genetics , Dog Diseases/epidemiology , Dogs , Molecular Epidemiology , Phylogeny , Protozoan Infections, Animal/epidemiology , Spain/epidemiology , Thailand/epidemiology , Venezuela/epidemiology
19.
Vet Parasitol ; 142(3-4): 238-47, 2006 Dec 20.
Article in English | MEDLINE | ID: mdl-16919391

ABSTRACT

As a continuation of our studies on molecular epizootiology of piroplasmosis in Spain and other countries, we present in this contribution the finding of new hosts for some piroplasms, as well as information on their 18S rRNA gene sequences. Genetic data were complemented with sequences of apocytochrome b gene (whenever possible). The following conclusions were drawn from these molecular studies: Theileria annulata is capable of infecting dogs, since it was diagnosed in a symptomatic animal. According to cytochrome b sequences, isolates from cows and dog present slight differences. The same isolates showed, however, identical sequence in the 18S rRNA gene. This exemplifies well the usefulness of the mitochondrial gene for examining infra-specific variation. Babesia bovis is an occasional parasite of equines, since it was detected in two symptomatic horses. We found evidence of genetic polymorphism occurring in the 18S rRNA gene of Spanish T. equi-like and B. ovis isolates. B. bennetti from Spanish seagull is loosely related to B. ovis, and might represent a genetically distinct branch of babesids. A partial sequence of a cytochrome b pseudogene was obtained for the first time in Babesia canis rossi from South Africa. The pseudogene is distantly related to B. bigemina cytochrome b gene. These new findings confirm the ability of some piroplasms to infect multiple hosts, as well as the existence of a relatively wide genetic polymorphisms with respect to the cytochrome b gene. On the other hand, the existence of mtDNA-like pseudogenes of possible nuclear location in piroplasms is interesting due to their possible impact on molecular phylogeny studies.


Subject(s)
Babesiosis/veterinary , Cytochromes b/genetics , Piroplasmida/genetics , RNA, Ribosomal, 18S/genetics , Theileriasis/epidemiology , Animals , Babesiosis/blood , Babesiosis/epidemiology , Cattle , DNA Primers/chemistry , Dogs , Goats , Horses , Molecular Sequence Data , Phylogeny , Piroplasmida/classification , Piroplasmida/isolation & purification , Polymerase Chain Reaction/veterinary , Sequence Analysis, DNA/veterinary , Spain/epidemiology , Theileriasis/blood
20.
Integr Comp Biol ; 44(2): 130-9, 2004 Apr.
Article in English | MEDLINE | ID: mdl-21680493

ABSTRACT

An allochthonous input can modify trophic relationships, by providing an external resource that is normally limiting within a system. The subsidy may not only elicit a growth response of the primary producers via a bottom-up effect, but it also may lead to runaway herbivore growth in the absence of increased predation. If the consumer is migratory and predation is similarly dampened in the alternative system, the increased numbers may produce a top-down cascade of direct and indirect effects on an ecosystem that may be a great distance from the source of the subsidy. In an extreme case, it can lead to a catastrophic shift in ecosystem functioning as a result of biotic exploitation that produces an alternative stable state. The loss of resilience is particularly sensitive to herbivore density which can result in two different outcomes to the vegetation on which the consumer feeds. Over-compensatory growth of above-ground biomass gives way to sward destruction and near irreversible changes in soil properties as density of a herbivore increases. A striking temporal asymmetry exists between a reduction in the consumer population and recovery of damaged vegetation and degraded soils.

SELECTION OF CITATIONS
SEARCH DETAIL