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P V Coyle

Publications and source records attributed to P V Coyle.

At least 19 recordsLinked to original sources
PubMed2006

Human metapneumovirus in adults: a short case series.

This study was carried out to further the available information on adult cases of human metapneumovirus (hMPV), a recently described cause of respiratory infection. Among a cohort of 741 symptomatic patients tested since 2003, the virus was diagnosed in six adults using reverse transcriptase polymerase chain reaction. Of the six, two were from the community, two were hospital inpatients with chronic obstructive pulmonary disease and two were immunocompromised patients, both of whom required ventilation and later died. This report discusses the clinical features, epidemiology and diagnosis of hMPV, highlighting that this infection may be associated with death in high-risk adults. For adults presenting with respiratory symptoms and a background of pre-existing respiratory disease or who are immunocompromised, nucleic acid-based techniques are a cost-effective means of making the viral diagnosis in a clinically relevant time frame.

Aged↗
PubMed2005

Childhood respiratory infections and hospital admissions for COPD.

BACKGROUND: Chronic Obstructive Pulmonary Disease (COPD) exacerbations are associated with viral infections. We wished to determine if respiratory viral infection of children in the community was associated with hospital admissions of patients with exacerbations of COPD. METHODS: We collected data over a 45-month period from the Northern Ireland Regional Virus Laboratory and from a general hospital in the same locality. We studied the relationship between upper respiratory infections in children and COPD admissions. We also examined the role of school holidays. RESULTS: Correlations were seen between the frequency of all viral infections in children and the number of adult COPD hospitalizations (P<0.005). Subgroup analysis showed distinct relationships with epidemics of; influenza A (P<0.001), influenza B (P<0.05), adenovirus (P=0.05), respiratory syncytial virus (P<0.005) and hospital admissions of patients with COPD. There were significantly fewer COPD admissions in the week after the start of a school holiday period (P<0.05). CONCLUSIONS: When children are hospitalized with viral respiratory infection there is an associated rise in adult COPD admissions. This suggests exacerbations of COPD are associated with epidemics of respiratory viruses. When children are on school holidays there is a reduction in COPD admissions in the community. This provides further support for respiratory viruses in the pathogenesis of COPD exacerbations.

Adolescent↗
PubMed2004

Herpes simplex type 1 shedding is associated with reduced hospital survival in patients receiving assisted ventilation in a tertiary referral intensive care unit.

The impact of shedding of herpes simplex virus type 1 (HSV-1) on hospital survival of patients receiving assisted ventilation in an adult tertiary referral, acute trauma intensive care unit was assessed. The study was designed to address a clinical impression linking HSV-1 recovery with poor survival. Two hundred and forty-one males and 152 females were enrolled into a longitudinal cohort study. Combined throat swabs and tracheal secretions were tested for HSV-1 shedding using a nested nucleic acid amplification protocol; patients were ranked as nonshedders, shedders, and high-level shedders. Nonparametric analysis assessed the impact of shedding on hospital survival and logistic regression measured the confounding influence of sex, age, and the Acute Physiology, Age and Chronic Health Evaluation (APACHE II) score. Linear-by-linear association determined the influence of the level of shedding on hospital survival. The observed mortality rate was 113/393 (28.8%). Patients shedding HSV-1 106/393 (27%) had a significant reduction in hospital survival 66/106 (62%) in HSV-1 shedders compared with 217/287 (75.6%) in nonshedders (P = 0.002). This difference remained significant when adjusted for age and sex (P = 0.026). Respective mortality figures for HSV-1 shedders and nonshedders were 43/106 (40.6%) and 70/287 (24.4%) (P = 0.002). HSV-1 shedding was associated with a significant reduction in hospital survival amongst patients receiving assisted ventilation. Hospital mortality in HSV-1 shedders was increased by 16.2% over nonshedders. The role of HSV-1 in this setting needs to be addressed.

Adolescent↗
PubMed2004

Early experience with chronic hepatitis C in Northern Ireland: epidemiology and response to monotherapy.

UNLABELLED: Chronic hepatitis C virus (HCV) infection has become a major health problem affecting an estimated 170 million people worldwide. The epidemiology of HCV and its response to treatment in Northern Ireland has not been described before. Our aims were to determine the epidemiology, histological stage, suitability for treatment and response to treatment in patients with hepatitis C presenting to one clinic in Northern Ireland. All patients were prospectively recruited with hepatitis C attending the Liver Clinic, Royal Victoria Hospital during the period December 1992 to June 1997. Sixty patients (33 male, mean age 44 years, range 19-84 years) who tested anti-HCV antibody positive were identified. The predominant genotypes were 1b (33%), 3a (28%) and 1a (26%). Most patients (78%) were asymptomatic at the time of detection and only four (7%) gave a history of jaundice. The most common modes of transmission were i.v. drug use in 30 (50%) and blood products in 20 (33%) patients. Forty-eight (86%) of the 56 patients tested were PCR positive for HCV RNA. Fifty-one patients (85%) underwent liver biopsy of whom 13 had cirrhosis (22% of original group). Twenty-nine patients were suitable for treatment, but three declined treatment and only 26 (43%) started interferon-alpha. During treatment 17 (65%) patients became PCR negative and eight (31%) remained PCR negative 12 months after completion of therapy. Liver histology was assessed before and after interferon treatment in 17 patients and showed no change in total necroinflammatory scores (p = 0.1) or staging of architectural change (p = 0.55). CONCLUSIONS: The epidemiology and response to therapy of HCV in Northern Ireland appear comparable to elsewhere in the UK. Only a minority of anti-HCV positive non-haemophiliac patients progress to have interferon therapy suggesting that the cost of treating chronic HCV may not be as great as initially thought.

Adult↗
PubMed2003

Clinical assessment of a generic DNA amplification assay for the identification of respiratory adenovirus infections.

BACKGROUND: respiratory adenoviruses are common, often resulting in serious sporadic and epidemic infections and impaired immunity can dramatically increase their severity. They are now thought capable of establishing latency. Diagnosis by culture is slow while direct antigen detection by immunofluorescence lacks sensitivity. Molecular diagnosis can be both rapid and sensitive but the genetic heterogeneity of adenoviruses poses problems. OBJECTIVES: to design a generic adenovirus nested polymerase chain amplification assay designed to be capable of detecting all respiratory adenoviruses. This was achieved through optimised thermal cycling and the development of a generic degenerate primer set targeting the adenovirus hexon gene. STUDY DESIGN: this was a cross-sectional study on 172 respiratory specimens from hospital-based patients, and one from a general practice, in Northern Ireland. A comparison was made between the amplification assay, virus culture and immunofluorescence. RESULTS: the nested polymerase chain reaction (nPCR) assay had a generic capacity for adenovirus detection and an analytical sensitivity of 6.4x10(2) copies/ml. Using an expanded gold standard (defined as a true positive or a true negative where a specimen was positive or negative by at least two of the study assays, respectively), PCR had a clinical sensitivity and specificity of 46/46 (100%) and 15/126 (91.3%), respectively. Patients with acute respiratory adenovirus infections were more likely to be male (chi(2), p=0.005) and to present with a fever (chi(2), p=0.02) than patients diagnosed with another respiratory virus. Co-infection was identified in 12/172 patients. CONCLUSIONS: the nested amplification assay proved highly sensitive in both the analytical and clinical settings for the detection of respiratory adenovirus infections.

Adenovirus Infections, Human↗
PubMed2003

Emergence of herpes simplex type 1 as the main cause of recurrent genital ulcerative disease in women in Northern Ireland.

BACKGROUND: Genital herpes is a common infection affecting some 20% of sexually active people. Although herpes simplex virus (HSV) types 1 and 2 can both establish genital latency, reactivation from the sacral ganglia favours HSV-2. Over the past decade the incidence of type 1 genital infection in women has greatly increased. OBJECTIVES: To determine whether the increased prevalence of HSV-1 genital infection was benign or influencing the pattern of virus recovery in recurrent infection. STUDY DESIGN: A retrospective analysis of laboratory computer records was undertaken. Patients attending six genitourinary medicine (GUM) departments, over an 80 months period, were identified. Recurrent infection was confirmed where virus was recovered from at least two separate episodes of genital ulceration that were separated by an interval of 12 or more weeks. Episodes were further analysed for frequency, age, gender and virus type. RESULTS: Sixty nine patients with recurrent genital herpetic infection were identified. HSV-1 and HSV-2 were predominantly recovered from recurrent genital infections in females (34 HSV-1 vs. ten HSV-2) and males (one HSV-1 vs. 24 HSV-2), respectively (P>0.001). The mean age of females and males, at the initial diagnosis, was 26 and 39 years. There was no difference in the recurrence rate by type. CONCLUSIONS: HSV-1 has become the commonest cause of recurrent genital ulceration in Northern Ireland, almost entirely due its recent increased prevalence in women over the last decade. Women are experiencing genital herpetic infections at an earlier age than men.

Adolescent↗
PubMed2002

Clinical utility of nested multiplex RT-PCR for group F adenovirus, rotavirus and norwalk-like viruses in acute viral gastroenteritis in children and adults.

BACKGROUND: The diagnosis of viral gastroenteritis can be carried out by non-molecular techniques such as electron microscopy (EM), enzyme-immunoassay and latex agglutination tests and various molecular techniques. Normally molecular detection requires the use of three separate protocols to detect the three main causes of viral gastroenteritis, adenoviruses, rotaviruses and norwalk-like viruses (NLV) which have different types of nucleic acid. The development of a sensitive and specific assay which could detect these targets would have major advantages for the clinical virology laboratory. OBJECTIVES: The aims of the present study were to develop a sensitive and specific multiplex molecular assay and to apply it to the detection of viral agents in clinical cases of acute gastroenteritis. STUDY DESIGN: The multiplex assay was designed using Access RT-PCR (Promega). Primers were researched and selected for their specificity and broad range detection of the viral agents across the various genotypes of group A rotaviruses, NLV and group F adenoviruses. RESULTS: From September 2000 to August 2001 we tested 1945 clinical specimens. Rotavirus infections were detected in 190 with an age range from 12 days to 8 years old. Group F adenovirus was detected in 96 patients ranging from 15 days to 10 years old. A further single case of group F adenovirus was detected in an adult of 75 years old. NLVs were detected in 132 patients. There were 55 infections in children less than 7 years old. In 10 different outbreaks involving 130 adult patients there were 57 NLV positives. Sporadic NLV infection was detected in 11 of 600 adult patients. There were 4 patients with dual infections. CONCLUSIONS: The assay detailed here has proved an invaluable tool for the investigation of acute gastroenteritis in specimens from patients of all ages. We found it convenient to use a single mastermix with a single protocol to test all specimens from patients of all ages. NLV in children is often overlooked and/or under reported, particularly where less sensitive assays such as EM are being employed for diagnosis.

Adenoviruses, Human↗
PubMed2001

Non-detection of Chlamydia species in carotid atheroma using generic primers by nested PCR in a population with a high prevalence of Chlamydia pneumoniae antibody.

BACKGROUND: The association of Chlamydia pneumoniae with atherosclerosis is controversial. We investigated the presence of C. pneumoniae and other Chlamydia spp. in atheromatous carotid artery tissue. METHODS: Forty elective carotid endarterectomy patients were recruited (27 males, mean age 65 and 13 females mean age 68), 4 had bilateral carotid endarterectomies (n= 44 endarterectomy specimens). Control specimens were taken from macroscopically normal carotid artery adjacent to the atheromatous lesions (internal controls), except in 8 cases where normal carotid arteries from post mortem (external controls) were used. Three case-control pairs were excluded when the HLA DRB gene failed to amplify from the DNA. Genus specific primers to the major outer membrane protein (MOMP) gene were used in a nested polymerase chain reaction (nPCR) in 41 atheromatous carotid specimens and paired controls. PCR inhibition was monitored by spiking with target C. trachomatis. Atheroma severity was graded histologically. Plasma samples were tested by microimmunofluorescence (MIF) for antibodies to C. pneumoniae, C. trachomatis and C. psittaci and the corresponding white cells were tested for Chlamydia spp. by nPCR. RESULTS: C. pneumoniae was not detected in any carotid specimen. Twenty-five of 38 (66%) plasma specimens were positive for C. pneumoniae IgG, 2/38 (5%) for C. trachomatis IgG and 1/38 (3%) for C. psittaci IgG. CONCLUSIONS: We were unable to show an association between the presence of Chlamydia spp. and atheroma in carotid arteries in the presence of a high seroprevalence of C. pneumoniae antibodies in Northern Ireland.

Adult↗
PubMed2001

Clinical utility of a nested nucleic acid amplification format in comparison to viral culture for the diagnosis of mucosal herpes simplex infection in a genitourinary medicine setting.

BACKGROUND: Nested nucleic acid amplification tests are often thought too sensitive or prone to generating false positive results for routine use. The current study investigated the specificity and clinical utility of a routine multiplex nested assay for mucosal herpetic infections. METHODS: Ninety patients, categorised into those clinically diagnosed to (a) have and (b) not have herpetic infection, were enrolled. Swabs from oral and ano-genital sites were assayed by the nested assay and culture and the results assessed against clinical evaluation for diagnosing herpetic infections; cell content was also recorded. RESULTS: Twenty-six and 64 patients were thought to (a) have and (b) not have mucosal herpetic infection. Taking the clinical evaluation as indicating the presence of herpetic infection, the nested polymerase chain reaction and culture had respective sensitivities of 19/26 (73%) and 12/26 (46%) (Chi2 p = 0.02). There was no significant difference in specificities between nPCR62/64 (97%) and culture 63/64 (98%) (Chi2 p = 1.0). Cell content was important for viral detection by nPCR (Chi2 p = 0.07) but not culture. Nesting was found necessary for sensitivity and did not reduce specificity. Assay under-performance appeared related to sub-optimal cell content (20%) but may have reflected clinical over-diagnosis. The results suggest the need for validating specimen cell quality. CONCLUSIONS: This study questions the value of routine laboratory confirmation of mucosal herpetic infection. The adoption of a more discriminatory usage of laboratory diagnostic facilities for genital herpetic infection, taking account of cell content, and restricting it to those cases where it actually affects patient management, may be warranted.

Animals↗
PubMed2001

Gastroenteritis outbreaks associated with Norwalk-like viruses and their investigation by nested RT-PCR.

BACKGROUND: Norwalk-like viruses are the most common cause of gastroenteritis outbreaks and sporadic cases of vomiting and diarrhoea. In healthy individuals infection is often mild and short-lived but in debilitated patients infection can be severe. It is essential that the virus laboratory can offer a sensitive and specific test, delivered in a timely manner. METHODS: We have developed a nested reverse transcriptase PCR based on published primers against the RNA polymerase gene and after comparison with electronmicroscopy used the assay to investigate 31 outbreaks of gastroenteritis. These were in diverse situations including nursing homes, small district hospitals, large general hospitals, a ferry ship, hotels, restaurants and staff canteens. RESULTS: A positive diagnosis was made in 30/31 outbreaks investigated giving an overall outbreak positive detection rate of 97%. At an individual patient level there was a positive diagnostic rate of 11.5% in a large hospital environment to 100% in smaller outbreak situations. The average patient positive rate was 34%. In addition we investigated 532 control faecal specimens from adults. Of these 530 were negative and 2 were repeatedly positive. CONCLUSIONS: It is essential that insensitive electronmicroscopy is replaced with the more sensitive reverse transcription PCR assays. These tests should be made available "on call" at weekends and public holidays. It is also important that outbreaks of NLV infection are monitored using sensitive RT-PCR assays so that the laboratory information can be used in ascertaining the spread and duration of the outbreak.

Adolescent↗
PubMed2001

A comparison of nested polymerase chain reaction and immunofluorescence for the diagnosis of respiratory infections in children with bronchiolitis, and the implications for a cohorting strategy.

Cohorting bronchiolitis patients infected with respiratory syncytial virus (RSV) and/or influenza viruses is paramount in preventing cross-infection of these viruses in hospital. Nested polymerase chain reaction (nPCR) was compared with immunofluorescence (IF) for the detection of RSV subtypes A and B in children with suspected bronchiolitis. Co-infection with influenza A(H3N2), Chlamydia spp. and picornavirus/rhinovirus was also investigated using molecular techniques.A total of 50 nasopharyngeal secretions collected from babies admitted with bronchiolitis in the month of January 2000, comprising IF RSV positive (N= 27) and RSV negative (N= 23) specimens, were tested for both RSV subtypes, influenza A(H3N2), Chlamydia spp. and picornavirus/rhinovirus by nPCR. Nested PCR detected 28 specimens positive for RSV (RSV A = 20, RSV B = 8), which was two more than detected by IF. Influenza A(H3N2) was detected in three specimens, Chlamydia trachomatis in one, and picornavirus in 11, of which nine were confirmed to be rhinovirus by nPCR. Dual infection was detected in five cases using nPCR. Nested PCR proved useful in detecting RSV and influenza A(H3N2) infections missed by IF, and also other respiratory tract pathogens not routinely investigated. The clinical implications and risk of cross-infection with potentially virulent viruses due to inaccurate results from insensitive techniques, highlights the need for molecular assays such as nPCR to be employed as a routine method of investigation, provided as part of the laboratory service. Cohorting of patients with clinical bronchiolitis should continue, whilst awaiting laboratory confirmation.

Bronchiolitis↗
PubMed2001

Nested multiplex polymerase chain reaction for the diagnosis of cutaneous herpes simplex and herpes zoster infections and a comparison with electronmicroscopy.

Herpes simplex virus (HSV) and varicella zoster virus (VZV) are common causes of cutaneous and mucocutaneous vesicular eruptions. Laboratory diagnostic techniques include Tzanck smears, electronmicroscopy, antigen detection and viral culture. This paper describes a nested multiplex polymerase chain reaction with respective sensitivities of 0.0001, 0.01 and 0.1 TCID50 for VZV, HSV-1 and HSV-2. The assay was used in (a) a salvage capacity for slides already processed for electronmicroscopy, and (b) as a front-line assay for prospectively processed specimens. Sixty-two glass slides with vesicle lymph/scrapings from 58 patients with suspected cutaneous herpetic lesions were examined. The clinical presentations were described as atypical/not specified (24), VZV (20) or HSV (18), and involved eruptions from diverse anatomical sites, including the genitalia. Of the 62 specimens, 6 and 38 were positive by electronmicroscopy and multiplex PCR respectively, giving a comparative sensitivity of 16% for electronmicroscopy. Nested multiplex PCR identified 15 VZV and 20 HSV-1 infections. Where the clinical details indicated either HSV or VZV (38/62), nested multiplex PCR was statistically likely to be reactive (26/38 vs. 9/24) (chi2 P = 0.000004) whereas electronmicroscopy was not (4/38 vs. 2/24) (chi2 P= 0.77). Where the clinical details indicated VZV (20/62) or HSV (18/62), nested multiplex PCR was statistically more likely to confirm VZV (10/20 vs. 5/42) (chi2 P= 0.001) or HSV (9/18 vs. 11/44) (chi2 P = 0.05) respectively. Two suspected HSV and 6 suspected VZV infections were shown to be VZV and HSV respectively by nested multiplex PCR.

Adolescent↗
PubMed2000

Parvovirus B19 in kidney transplant patients.

Renal transplant patients were screened for the presence of parvovirus B19, before transplantation and monthly for 4 months after transplantation, by means of a sensitive nested PCR assay. Upon screening plasma from 110 patients, we found that two asymptomatic patients were B19 DNA positive. One of these patients was PCR positive in the plasma sample taken 2 months after transplantation; the plasma contained anti-B19 IgG antibodies before transplant and throughout the follow-up period, with an increase in the IgG level in the second posttransplant sample coinciding with the detection of B19 DNA. IgM antibodies to B19 were not detected in this patient. Because, for this patient, the donor's spleen DNA was also B19 DNA positive, we suspect B19 transmission from the donor and limited B19 replication, inasmuch as this patient already had a primed immune response to B19. The other patient was PCR positive in the pretransplant and in the plasma sample taken 1 month after transplant and contained a strong anti-B19 IgG response in the pretransplant sample and throughout the follow-up period-and anti-B19 IgM antibodies were not detected before or after transplantation. By testing samples taken from this patient at 2 weeks, 2 months, and 3 months before transplantation, we were able to determine that the infection occurred shortly before transplantation. Unexpectedly, this graft failed and was removed 2 days after transplantation despite a negative cross-match. A pathological examination of the kidney indicated acute vascular rejection, suggesting a possible role for B19 in this complication.

Antibodies, Viral↗
PubMed2000

Hepatitis C virus: an important occupational hazard?

Infection with Hepatitis C virus (HCV) is estimated to affect 3% of the world's population and is an important cause of liver disease. It is most commonly transmitted by percutaneous exposure. Although current evidence does not suggest an increased prevalence of HCV infection among healthcare workers, transmission of infection following occupational exposure has been demonstrated. An average transmission rate of 1.8%, following percutaneous injury, has been reported. The risk of transmission is higher from patients with viraemia, as measured by a positive polymerase chain reaction for HCV RNA. After exposure to HCV, healthcare workers should be actively followed up, initially using a test to detect viral RNA. This may facilitate earlier diagnosis and treatment. Recent reports in the UK, of transmission of infection to patients from HCV infected healthcare workers, have prompted a review of the appropriateness of HCV infected individuals undertaking exposure prone procedures.

HIV Infections↗
PubMed2000

The relationship between elevated fibrinogen and markers of infection: a comparison of seasonal cycles.

To test the hypothesis that higher levels of fibrinogen in winter are related to infections via the acute phase response, we assessed seasonal variation in fibrinogen and C-reactive protein, together with three other responses to infection: white cell count, human herpesvirus-6 IgG antibody and interleukin-6. Monthly blood samples from 24 subjects aged 75+ years were assessed for fibrinogen, C-reactive protein, white cell count, and human herpesvirus-6 IgG antibody. Interleukin-6 was measured in seven. Seasonal variation of these measures was determined by the population-mean cosinor procedure. Fibrinogen had a significant seasonal variation with a winter peak (mid-February) 1.26 g/l above the corresponding summer trough. C-reactive protein had a late-February peak, 3.71 mg/l above the summer trough. No seasonal rhythm was found in any other response to infection investigated. This study provides no evidence that winter infections are responsible for the seasonal variation in fibrinogen or C-reactive protein. The explanation for the seasonal changes in these proteins remains unknown.

Aged↗