Harry R Dalton

Glasgow Caledonian University, Glasgow, Scotland, United Kingdom

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Publications (81)585.55 Total impact

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    ABSTRACT: Autochthonous (locally acquired) hepatitis E is increasingly recognised in developed countries, and is thought to be a porcine zoonosis. A range of extra-hepatic manifestations of hepatitis E infection have been described, but have never been systematically studied.
    Alimentary Pharmacology & Therapeutics 10/2014; · 4.55 Impact Factor
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    ABSTRACT: To examine the incidence of hepatitis E (HepE) in individuals with acute liver injury severe enough to warrant treatment at a transplant unit.
    World journal of hepatology. 06/2014; 6(6):426-34.
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    Emerging infectious diseases. 06/2014; 20(6):1057-8.
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    ABSTRACT: For many years, hepatitis E was considered a disease found only in certain developing countries. In these geographical settings, hepatitis E virus (HEV) causes a self-limiting hepatitis in young adults, except in pregnant females, in whom the mortality is 25 %. Our understanding of HEV has changed radically in the past decade. It is now evident that HEV is a threat to global health. This review article considers the current concepts and future perspectives of HEV and its effects on human health, with particular reference to developed countries.
    Current Infectious Disease Reports 04/2014; 16(4):399.
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    ABSTRACT: Forty percent of patients with autoimmune hepatitis (AIH) present with acute jaundice/hepatitis. Such patients, when treated promptly, are thought to have a good prognosis. The objective of this study was to describe the natural history of AIH in patients presenting with jaundice/hepatitis and to determine whether the diagnosis could have been made earlier, before presentation. This study is a retrospective review of 2249 consecutive patients who presented with jaundice to the Jaundice Hotline clinic, Truro, Cornwall, UK, over 15 years (1998-2013) and includes a review of the laboratory data over a 23-year period (1990-2013). Of the 955 patients with hepatocellular jaundice, 47 (5%) had criterion-referenced AIH: 35 female and 12 male, the median age was 65 years (range 15-91 years); the bilirubin concentration was 139 μmol/l (range 23-634 μmol/l) and the alanine transaminase level was 687 IU/l (range 22-2519 IU/l). Among the patients, 23/46 (50%) were cirrhotic on biopsy; 11/47 (23%) died: median time from diagnosis to death, 5 months (range 1-59); median age, 72 years (range 59-91 years). All 8/11 patients who died of liver-related causes were cirrhotic. Weight loss (P=0.04) and presence of cirrhosis (P=0.004) and varices (P=0.015) were more common among those who died. Among patients who died from liver-related causes, 6/8 (75%) died less than 6 months from diagnosis. Cirrhosis at presentation and oesophageal varices were associated with early liver-related deaths (P=0.011, 0.002 respectively). Liver function test results were available in 33/47 (70%) patients before presentation. Among these patients, 16 (49%) had abnormal alanine transaminase levels previously, and eight (50%) were cirrhotic at presentation. AIH presenting as jaundice/hepatitis was mainly observed in older women: 50% of the patients were cirrhotic, and liver-related mortality was high. Some of these deaths were potentially preventable by earlier diagnosis, as the patients had abnormal liver function test results previously, which had not been investigated.
    European journal of gastroenterology & hepatology 04/2014; · 1.66 Impact Factor
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    ABSTRACT: The Glasgow Blatchford score (GBS) is a pre-endoscopic risk assessment tool for patients presenting with upper gastrointestinal haemorrhage. There are few data regarding use in patients with variceal bleeding, who are generally accepted as being at high risk. The aim of the study was to assess GBS in correctly identifying patients with subsequently proven variceal bleeding as 'high risk' and to compare GBS, admission and full Rockall scores in predicting clinical endpoints in this group. Data on consecutive patients with upper gastrointestinal haemorrhage presenting to four UK hospitals were collected. The GBS, admission and full Rockall scores were calculated and compared for the subgroup subsequently shown to have variceal bleeding. Area under the receiver operating curve (AUROC) was used to assess the scores ability to predict clinical endpoints within this variceal bleeding subgroup. A total of 1432 patients presented during the study period. Seventy-one (5%) had a final diagnosis of variceal bleeding. At presentation, none of this group had GBS less than 2, but six had an admission Rockall score of 0. In predicting need for blood transfusion, AUROC scores for GBS, full and admission Rockall scores were 0.68, 0.65 and 0.68, respectively. For endoscopic/surgical intervention the scores were 0.34, 0.51 and 0.55, respectively, and for predicting death the scores were 0.56, 0.72 and 0.70, respectively. None of these AUROC score comparisons were significant. At presentation, GBS correctly identifies patients with variceal bleeding as high risk and appears superior to the admission Rockall score. However, GBS and both Rockall scores are poor at predicting clinical outcome within this group.
    European journal of gastroenterology & hepatology 02/2014; · 1.66 Impact Factor
  • Harry R Dalton
    Transfusion Medicine and Hemotherapy 02/2014; 41(1):6-9. · 1.59 Impact Factor
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    ABSTRACT: The aim of the study was to determine whether Guillain-Barré syndrome (GBS) is associated with preceding hepatitis E virus infection. The frequency of hepatitis E virus (HEV) infections was determined by anti-HEV serology in a cohort of 201 patients with GBS and 201 healthy controls with a similar distribution in age, sex, and year of sampling. Blood samples from patients with GBS were obtained in the acute phase before treatment. In a subgroup of patients with GBS, blood, stool, and CSF samples were tested for HEV RNA. An increased ratio of anti-HEV immunoglobulin (Ig) M antibodies was found in 10 patients with GBS (5.0%) compared with 1 healthy control (0.5%, odds ratio 10.5, 95% confidence interval 1.3-82.6, p = 0.026). HEV RNA was detected in blood from 3 of these patients and additionally in feces from 1 patient. Seventy percent of anti-HEV IgM-positive patients had mildly increased liver function tests. All CSF samples tested negative for HEV RNA. The presence of anti-HEV IgM in patients with GBS was not related to age, sex, disease severity, or clinical outcome after 6 months. In the Netherlands, 5% of patients with GBS have an associated acute hepatitis E virus infection. Further research is required to determine whether HEV infections also precede GBS in other geographical areas.
    Neurology 01/2014; · 8.30 Impact Factor
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    ABSTRACT: To determine whether there is an association between an acute preceding hepatitis E virus (HEV) infection and neuralgic amyotrophy (NA), and if so, whether patients with HEV-related NA differ from patients without an associated HEV infection. HEV testing was conducted in a retrospective cohort of 28 Cornish patients with NA (2011-2013) and a prospective cohort of 38 consecutive Dutch patients with NA (2004-2007). Acute-phase serum samples were analyzed for the presence of anti-HEV immunoglobulin (Ig) M and IgG and HEV RNA (quantitative real-time PCR). Five cases (10.6%) of acute hepatitis E infection were identified in a total group of 47 patients with NA of whom serum samples were available. In 4 patients, HEV RNA was detected in serum samples taken at presentation. All patients with HEV-associated NA had clinical and electrophysiologic evidence of bilateral brachial plexus involvement. Anti-HEV IgM positivity was not related to age, sex, disease severity, disease course, or outcome. Acute hepatitis E is found in 10% of patients with NA from the United Kingdom and the Netherlands. Further research is required to investigate the role of HEV in NA in other geographical locations and to determine pathophysiologic mechanisms.
    Neurology 01/2014; · 8.30 Impact Factor
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    ABSTRACT: Pharyngeal pouch patients often present with dysphagia and risk perforation when undergoing gastroscopy. Knowledge of pharyngeal pouch incidence and predictive demographic features in patients referred for dysphagia would help determine those patients who should have barium swallow as an initial investigation. The prospectively collected data of 2,797 consecutive referrals were analysed. Logistic regression determined significant variables for predicting pharyngeal pouches. Of the 2,430 patients investigated [mean age = 67.7 years, range 17-103; 48.2 % male], 49 (2.0 %) had a pharyngeal pouch [mean age = 79.8 years (range 58-93); 53.1 % male]. Significant predictors of pharyngeal pouch were pharyngeal level dysphagia (odds ratio [OR] 3.8-19.2), age over 65 years (OR 2.2-14.1), symptom duration over 12 weeks (OR 1.1-3.9), and no weight loss (OR 1.1-5.5). Only 18 patients (36.7 %) underwent surgery for their pouch. Midsternal dysphagia alone occurred in 16 % of all patients with pouches. From our results we conclude that pharyngeal pouches in a dysphagic population are more common than previously recognised. Patients aged over 65 years with pharyngeal level dysphagia for more than 12 weeks should have a barium swallow as their initial investigation.
    Dysphagia 01/2014; · 1.94 Impact Factor
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    ABSTRACT: SUMMARY Hepatitis E virus (HEV) infection is a worldwide disease. An improved understanding of the natural history of HEV infection has been achieved within the last decade. Several reservoirs and transmission modes have been identified. Hepatitis E is an underdiagnosed disease, in part due to the use of serological assays with low sensitivity. However, diagnostic tools, including nucleic acid-based tests, have been improved. The epidemiology and clinical features of hepatitis E differ between developing and developed countries. HEV infection is usually an acute self-limiting disease, but in developed countries it causes chronic infection with rapidly progressive cirrhosis in organ transplant recipients, patients with hematological malignancy requiring chemotherapy, and individuals with HIV. HEV also causes extrahepatic manifestations, including a number of neurological syndromes and renal injury. Acute infection usually requires no treatment, but chronic infection should be treated by reducing immunosuppression in transplant patients and/or the use of antiviral therapy. In this comprehensive review, we summarize the current knowledge about the virus itself, as well as the epidemiology, diagnostics, natural history, and management of HEV infection in developing and developed countries.
    Clinical microbiology reviews 01/2014; 27(1):116-38. · 14.69 Impact Factor
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    ABSTRACT: Background & Aims: Upper gastrointestinal hemorrhage (UGIH) is a common cause of hospital admission. The Glasgow Blatchford score (GBS) is an accurate determinant of patients’ risk for hospital-based intervention or death. Patients with GBSs of 0 are at low risk for poor outcome and could be managed as outpatients. Some have therefore proposed extending the definition of low-risk patients by using a higher GBS cut-off value, possibly with an age adjustment. We compared 3 thresholds of the GBS and 2 age-adjusted modifications to identify the optimal cut-off value or modification. Methods We performed an observational study of 2305 consecutive patients presenting with UGIH at 4 centers (Scotland, England, Denmark, and New Zealand). The performance of each threshold and modification was evaluated based on sensitivity and specificity analyses, the proportion of low-risk patients identified, and outcomes of patients classified as low-risk. Results There were differences in age (P=.0001), need for intervention (P<.0001), mortality (P<.015), and GBS (P=.0001) among sites. All systems identified low-risk patients with high levels of sensitivity (>97%). The GBS at cut-offs ≤1 and ≤2, and both modifications, identified low-risk patients with higher levels of specificity (40%−49%) than the GBS with a cut-off of 0 (22% specificity, P<.001). The GBS at cut-off ≤2 had the highest specificity, but 3% of patients classified as low-risk patients had adverse outcomes. All GBS cut-offs, and score modifications, had low levels of specificity when tested in New Zealand (2.5%−11%). Conclusions A GBS cut-off ≤1and both GBS modifications identify almost twice as many low-risk patients with UGIH as a GBS at cut-off of 0. Implementing a protocol for outpatient management, based on one of these scores, could reduce hospital admissions by 15%−20%.
    Clinical Gastroenterology and Hepatology. 01/2014;
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    ABSTRACT: Background A nurse practitioner-led dysphagia service was introduced to improve appropriateness of investigations. Objective To determine the clinical outcomes and efficacy of this service. Design and patients A 7-year prospective audit of the first 2000 patients referred for investigation of dysphagia. Setting Royal Cornwall Hospitals NHS Trust. Intervention An innovative nurse practitioner-led telephone dysphagia hotline (DHL) assessment service for all patients and consultant review following investigation prior to discharge. Outcomes Clinical outcomes, service efficiency and cost effectiveness. Results 2000 patients (median age 70 years, 48% male) were referred in less than 7 years, 1775 being managed fully through the DHL. 67% patients had gastroscopy only, 13% barium swallow only and 8.8% both and 11.2% had no investigation. Reflux was the commonest cause (41.3%), 9% had peptic stricture, 10% malignancy 1.9% pharyngeal pouches and 0.8% achalasia. The did not attend rate was reduced from 3.9% to 1.1% and 151 patients either refused or did not require investigation saving a potential £53 040. Although some patients with pharyngeal pouches had gastroscopy as initial investigation, no complications resulted. Conclusions The nurse practitioner-led DHL service has improved efficiency and resulted in a safe prompt service to patients.
    Frontline Gastroenterology. 12/2013; 4:102-107.
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    ABSTRACT: Hepatitis E has been regarded as a disease of the developing world, where it causes large waterborne outbreaks and sporadic cases of hepatitis. Recent research has shown this received wisdom to be mistaken. Recent studies have shown that authochtonous (locally acquired) hepatitis E does occur in developed countries, is caused by hepatitis E virus (HEV) genotypes 3 and 4, and is zoonotic with pigs as the primary host. Most infections are clinically inapparent. However, acute symptomatic hepatitis E has a predilection for middle-aged and elderly men, with an excess mortality in patients with underlying chronic liver disease. Chronic infection occurs in the immunosuppressed with rapidly progressive cirrhosis if untreated, the treatment of choice being ribavirin monotherapy for 3 months. Hepatitis E has a range of extra-hepatic manifestations, including a spectrum of neurological syndromes. HEV can be transmitted by blood transfusion and has recently been found in donated blood in a number of countries. The diagnosis should be considered in any patient with a raised alanine aminotranferase, irrespective of age or travel history. The safety of blood products needs to be fully assessed, as a matter of priority, as blood donors are not currently screened for HEV.
    Current Opinion in Infectious Diseases 10/2013; 26(5):471-8. · 5.03 Impact Factor
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    Journal of Viral Hepatitis 09/2013; 20(s3). · 3.08 Impact Factor
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    Journal of Viral Hepatitis 09/2013; 20(s3). · 3.08 Impact Factor
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    Journal of Viral Hepatitis 09/2013; 20(s3). · 3.08 Impact Factor
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    ABSTRACT: BACKGROUND AND OBJECTIVES: Published prevalence figures for hepatitis E virus (HEV) reveal significant regional differences. Several studies have reported virus transmission via blood transfusion. The aim of this study was to establish HEV seroprevalence and investigate a potential HEV RNA presence in Scottish blood donors. MATERIALS AND METHODS: IgG and IgM were determined in individual serum samples. HEV RNA was investigated in plasma mini-pools corresponding to 43 560 individual donations using nested PCR. Samples amenable to reamplification with primers from a different region were considered confirmed positives, sequenced and analysed. RESULTS: A total of 73 of 1559 tested individual sera (4·7%) were IgG positive, none tested positive for IgM. Plasma mini-pool testing revealed an HEV RNA frequency of 1 in 14 520 donations. Three confirmed positives belonged, as expected to genotype 3. CONCLUSIONS: HEV IgG and RNA figures in Scottish blood donors are lower than those published for the rest of the UK, but sufficiently high to prompt further studies on potential transmission rates and effects of HEV infection, especially for immunosuppressed individuals.
    Vox Sanguinis 06/2013; · 2.85 Impact Factor
  • Nassim Kamar, Jacques Izopet, Harry R. Dalton
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    ABSTRACT: It is now well accepted that hepatitis E virus (HEV) infection can induce chronic hepatitis and cirrhosis in immunosuppressed patients. Chronic genotype-3 HEV infections were first reported in patients with a solid-organ transplant. Thereafter, cases of chronic HEV infection have been reported in patients with hematological disease and in those who are human immunodeficiency virus (HIV)-positive. HEV-associated extra-hepatic manifestations, including neurological symptoms, kidney injuries, and hematological disorders, have been also reported. In transplant patients, reducing the dosage of immunosuppressive drugs allows the virus to be cleared in some patients. In the remaining patients, as well as hematological patients and patients who are HIV-positive, anti-viral therapies, such as pegylated interferon and ribavirin, have been found to be efficient in eradicating HEV infection. This review summarizes our current knowledge of chronic HEV infection, its treatment, and the extra-hepatic manifestations induced by HEV.
    Journal of Clinical and Experimental Hepatology. 06/2013; 3(2):134–140.
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    ABSTRACT: BACKGROUND: Seronegative hepatitis is a recognized cause of liver failure requiring transplantation. The aetiology is unknown, but might relate to an unidentified virus or immune dysregulation. There are few data on seronegative hepatitis presenting to nontransplant centres. OBJECTIVES: To describe the clinical/laboratory features and natural history of seronegative hepatitis and compare these with viral/autoimmune hepatitis. METHODS: Cases of seronegative, viral and autoimmune hepatitis were identified from 2080 consecutive patients attending a rapid-access jaundice clinic over a 14-year period. RESULTS: Of 881 patients with hepatocellular jaundice, 27 (3%) had seronegative hepatitis, 44 (5%) autoimmune and 62 (7%) viral hepatitis (acute hepatitis A, B, C and E viruses). Fifteen out of 27 (56%) patients with seronegative hepatitis were male, median age 60 years (range 14-74). Peak bilirubin was 63 μmol/l (range 9-363), alanine aminotransferase 932 IU/l (range 503-3807). Duration of illness was 7 weeks (range 4-12). No patients developed liver failure or had further bouts of hepatitis. One patient developed acute lymphoblastic leukaemia shortly after presentation.There was no difference in age/sex of patients with seronegative hepatitis and those with viral hepatitis. Compared with autoimmune hepatitis (age 65 years, range 15-91), patients with seronegative hepatitis were younger (P=0.002) and more likely to be male (P=0.004). Patients with autoimmune hepatitis were more likely (P<0.0001) to have an albumin less than 35 g/l, international normalized ratio greater than 1.2, raised IgG and positive antinuclear/smooth muscle antibody, compared with patients with seronegative hepatitis. CONCLUSION: Seronegative hepatitis presenting to a nontransplant centre is generally a self-limiting illness. The aetiology is more likely to be viral than autoimmune.
    European journal of gastroenterology & hepatology 05/2013; · 1.66 Impact Factor

Publication Stats

2k Citations
585.55 Total Impact Points

Institutions

  • 2013–2014
    • Glasgow Caledonian University
      • Department of Life Sciences
      Glasgow, Scotland, United Kingdom
    • University Hospitals Birmingham NHS Foundation Trust
      Birmingham, England, United Kingdom
    • University of Exeter
      Exeter, England, United Kingdom
  • 2001–2013
    • Royal Cornwall Hospitals NHS Trust
      Truro, England, United Kingdom
  • 2012
    • The Bracton Centre, Oxleas NHS Trust
      Дартфорде, England, United Kingdom
    • Paul Sabatier University - Toulouse III
      Tolosa de Llenguadoc, Midi-Pyrénées, France
  • 2011
    • Centre Hospitalier Universitaire de Toulouse
      Tolosa de Llenguadoc, Midi-Pyrénées, France
  • 2008–2011
    • The Peninsula College of Medicine and Dentistry
      Plymouth, England, United Kingdom
  • 2009
    • Royal Devon and Exeter NHS Foundation Trust
      Exeter, England, United Kingdom
  • 2007
    • Auckland City Hospital
      Окленд, Auckland, New Zealand