Harriet Mcfadzean

Mrs. Harriet Mcfadzean


Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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26 June 2023 in Animals
Verified
Journal Article
Open access
PDF file
HMHarriet Mcfadzean
Harriet Mcfadzean
NJNicholas Johnson
Nicholas Johnson
PPPaul Paul Phipps
Paul Paul Phipps
VSVanessa Swinson
Vanessa Swinson
LBLisa Boden
Lisa Boden
Babesia divergens is a zoonotic piroplasm that infects both cattle and humans in Europe. Disease transmission occurs through Ixodes ricinus tick bites, a species that is increasing in abundance and distribution across Europe in response to climate and land-use changes. Developments in agri-environment policy and changing consumer demands may also have unintended consequences on tick-borne disease rates. Currently, B. divergens surveillance in British cattle is limited, rendering temporal trend analysis and the detection of potential zoonotic hotspots impossible. The objective of this study was to assess syndromic surveillance as a means of determining babesiosis distribution in British cattle, and to evaluate the intrinsic disease risk factors in order to respond to disease threats posed by changing environments. Samples from 95 clinically affected cattle on 70 unique holdings were screened for Babesia spp., using established blood smear examination techniques and a B. divergens-specific PCR method, between April and December 2021. B. divergens was detected in 45/95 animals (47.4%), with PCR offering the advantage of identification at species level. Infection with Anaplasma phagocytophilum was detected in 19/95 animals (20%). Co-infection was detected in five animals. The cases were recorded across multiple geographic regions and throughout the sampling period. Univariate logistic regression analysis failed to identify any statistically significant risk factors for B. divergens presence. This study demonstrates that bovine babesiosis is geographically widespread throughout England and Wales, placing a large proportion of the cattle population at risk of infection, with the potential for zoonotic transmission to humans.

17 August 2021 in Veterinary Record Case Reports
Verified
Journal Article
Open access
PDF file
HMHarriet Mcfadzean
Harriet Mcfadzean
NJNicholas Johnson
Nicholas Johnson
LPL. Paul Phipps
L. Paul Phipps
RHRebecca L. Hobbs
Rebecca L. Hobbs
In April 2020, animals in a herd of 180 dairy cows began displaying pyrexia, milk drop and condition loss. Some animals aborted while others developed anaemia and red‐coloured urine. Copious ticks were noted on affected animals. Blood smear examination performed on sick animals detected piroplasms within erythrocytes, and a pan‐piroplasm PCR and sequencing confirmed the presence of Babesia divergens . Further PCR testing detected Anaplasma phagocytophilum in some of the animals. In a number of animals, co‐infection with both pathogens was demonstrated. A range of control measures were implemented with varying levels of success, and clinical cases continued until winter housing of cows in November. A total of 61 animals were affected. The main contributory factor in this case was likely buying in of large numbers of naïve animals into an endemic tick area. Co‐infection also potentially increased severity of disease. The difficulties in controlling this outbreak are discussed.

10 August 2023 in Pathogens
Verified
Journal Article
Open access
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Ternenge Thaddaeus ApaaTernenge Thaddaeus Apaa
Ternenge Thaddaeus Apaa
HMHarriet Mcfadzean
Harriet Mcfadzean
SGSara Gandy
Sara Gandy
KHKayleigh M. Hansford
Kayleigh M. Hansford
JMJolyon Medlock
Jolyon Medlock
NJNicholas Johnson
Nicholas Johnson
Anaplasma phagocytophilum (A. phagocytophilum) is the aetiological agent of tick-borne fever in cattle and sheep, and granulocytic anaplasmosis in human and dogs. Livestock, companion animal and human infections with A. phagocytophilum have been reported globally. Across England and Wales, two isolates (called ecotypes) have been reported in ticks. This study examined A. phagocytophilum isolates present in livestock and wildlife in Great Britain (GB), with a particular focus on cattle. Clinical submissions (EDTA blood) from cattle (n = 21) and sheep (n = 3) were received by APHA for tick-borne disease testing and the animals were confirmed to be infected with A. phagocytophilum using a PCR targeting the Msp2 gene. Further submissions from roe deer (n = 2), red deer (n = 2) and Ixodes ricinus ticks (n = 22) were also shown to be infected with A. phagocytophilum. Subsequent analysis using a nested PCR targeting the groEL gene and sequencing confirmed the presence of ecotype I in cattle, sheep, red deer and Ixodes ricinus, and ecotype II in roe deer and I. ricinus removed from deer carcasses. Despite the presence of two ecotypes, widely distributed in ticks from England and Wales, only ecotype I was detected in cattle in this study.

5 March 2024 in Journal of General Virology
Verified
Journal Article
Open access
HDHannah Davies
Hannah Davies
ADAkbar DASTJERDI
Akbar DASTJERDI
DEDavid James Everest
David James Everest
TFTobias Floyd
Tobias Floyd
RCRachael Collins
Rachael Collins
RRRudolf Reichel
Rudolf Reichel
Tusaviruses in the genus Protoparvovirus of family Parvoviridae were first identified in a diarrhoeic Tunisian child in 2014. Thereafter, high prevalence of a genetically similar virus was demonstrated in faeces from caprine and ovine species in Hungary. Here, we describe an investigation into the cause of scabby lip lesions in a 6 month-old lamb, submitted from a farm experiencing weight loss and scouring in lambs in England. Transmission electron microscopy visualised small circular particles of 18 and 22 nm in diameter in lip lesions identified as tusavirus and flumine parvovirus by Next Generation Sequencing. Liver, kidney, lung, small intestine content and faeces were also strongly positive for the tusavirus DNA as well as 10 % of faecal samples of the flock collected 2 months after the initial lip sampling. NS1 and VP1 amino acid sequences of this tusavirus displayed 99.5 and 92.89 % identity to those of a human tusavirus, respectively. These amino acid identities were at 95.5 and 89.68 % when compared to those of a goat tusavirus. Phylogenetic analysis of the NS1 and VP1 also grouped the virus in the genus Protoparvovirus and close to tusaviruses detected in human, ovine and caprine species. Wider surveillance of the virus indicated a broader geographical distribution for the virus in England. Histology of the lip tissue revealed localised areas of epidermal hyperplasia and hyperkeratosis affecting haired skin, with mild leucocyte infiltration of the subjacent dermis, but no changes to implicate virus involvement. Flumine parvovirus was concluded to be an environment contaminant. Broader studies in prevalence of these virus in UK sheep flocks and human population, animal models and experimental infections could provide insights into the pathogenesis of these novel viruses and their zoonotic potential.

21 April 2021 in Avian Pathology
Verified
Journal Article
Closed access
HMHarriet Mcfadzean
Harriet Mcfadzean
ASAlex Schock
Alex Schock
ESEmma Stubberfield
Emma Stubberfield
RCRoderick M. Card
Roderick M. Card
JTJill Thomson
Jill Thomson
DWDavid Welchman
David Welchman
This paper describes a retrospective analysis of necrotizing typhlitis in common rheas (Rhea americana) diagnosed in the United Kingdom by the Animal & Plant Health Agency (APHA). From January 2008 to January 2020, seven cases of spirochaetal typhlitis associated with Brachyspira spp. were identified using the Veterinary Investigation Diagnosis Analysis database. Gross examination was combined with selective anaerobic culture, polymerase chain reaction, and histopathology to diagnose typhlitis associated with spirochaetal infection. Whole-genome sequencing was subsequently utilized on archived isolates from six of the seven submissions, overcoming issues with traditional testing methods and yielded gains in the identification of Brachyspira to species level. Brachyspira hyodysenteriae, an organism traditionally associated with typhlitis in rheas, was isolated in three sequenced submissions. One of these also demonstrated co-infection with Brachyspira intermedia. Brachyspira suanatina, Brachyspira hampsonii, and Brachyspira alvinipulli were identified by sequencing as single infections in the remaining three animals. This report demonstrates the ability of Brachyspira species other than B. hyodysenteriae to colonize the caeca of rheas presenting with typhlitis. Additionally, the B. alvinipulli isolate harboured a tva(A) gene, indicating higher potential pleuromutilin resistance, which has not previously been described in this Brachyspira species. This study discusses the epidemiology of examined cases and examines the potential role other species may play in these outbreaks.

22 March 2025 in Pathogens
Verified
Journal Article
Open access
PDF file
HLHope Elektra Leverett
Hope Elektra Leverett
Ternenge Thaddaeus ApaaTernenge Thaddaeus Apaa
Ternenge Thaddaeus Apaa
HMHarriet Mcfadzean
Harriet Mcfadzean
NJNicholas Johnson
Nicholas Johnson
Babesia species have been detected in deer across Europe, and deer grazing in the same location as livestock may increase the risk of transmission of species such as the parasite B. divergens. Bovine babesiosis and the cost of treatment increase the economic burden on farmers. To determine the presence of Babesia species in wild deer populations in the counties of Devon and Somerset, Southwest England, blood samples were collected from red (Cervus elaphus) and fallow (Dama dama) deer as part of routine deer management during late 2022 and early 2023. Extracted DNA samples were tested for the presence of piroplasm DNA by polymerase chain reaction. Amplicons were sequenced to identify the species present in samples based on single-nucleotide polymorphisms within the 18S rRNA gene. Two species of Babesia were detected: a B. divergens/capreoli species detected in both red and fallow deer and a Babesia species related to B. odocoilei in a single fallow deer, a species that has been detected in deer across Great Britain. The presence of B. divergens/capreoli in deer blood from these areas provides evidence that wild deer could serve as a reservoir for this parasite within Southern England.