Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 80
Filter
1.
Dis Esophagus ; 30(3): 1-7, 2017 02 01.
Article in English | MEDLINE | ID: mdl-26541271

ABSTRACT

Long-term health-related quality-of-life (HRQL) outcomes have not been widely reported in the treatment of achalasia. The aims of this study were to examine long-term disease-specific and general HRQL in achalasia patients using a population-based case-control method, and to assess HRQL between treatment interventions. Manometrically diagnosed achalasia cases (n = 120) were identified and matched with controls (n = 115) using a population-based approach. Participants completed general (SF-12) and disease-specific (Achalasia Severity Questionnaire [ASQ]) HRQL questionnaires, as appropriate, in a structured interview. Mean composite scores for SF-12 (Mental Component Summary score [MCS-12] and Physical Component Summary score [PCS-12]) and ASQ were compared between cases and controls, or between intervention groups, using an independent t-test. Adjusted mean differences in HRQL scores were evaluated using a linear regression model. Achalasia cases were treated with a Heller's myotomy (n = 43), pneumatic dilatation (n = 44), or both modalities (n = 33). The median time from last treatment to HRQL assessment was 5.7 years (interquartile range 2.4-11.5). Comparing achalasia patients with controls, PCS-12 was significantly worse (40.9 vs. 44.2, P = 0.01), but MCS-12 was similar. However, both PCS-12 (39.9 vs. 44.2, P = 0.03) and MCS-12 (46.7 vs. 53.5, P = 0.004) were significantly impaired in those requiring dual treatment compared with controls. Overall however, there was no difference in adjusted HRQL between patients treated with Heller's myotomy, pneumatic dilatation or both treatment modalities. In summary, despite treatment achalasia patients have significantly worse long-term physical HRQL compared with population controls. No HRQL differences were observed between the treatment modalities to suggest a benefit of one treatment over another.


Subject(s)
Dilatation/methods , Esophageal Achalasia/surgery , Esophagoscopy/methods , Laparoscopy/methods , Quality of Life , Adult , Aged , Case-Control Studies , Dilatation/psychology , Esophageal Achalasia/psychology , Esophagoscopy/psychology , Female , Humans , Ireland , Laparoscopy/psychology , Male , Middle Aged , Postoperative Period , Retrospective Studies , Surveys and Questionnaires , Time , Treatment Outcome
2.
Eur J Clin Microbiol Infect Dis ; 35(3): 481-7, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26796553

ABSTRACT

Gardnerella vaginalis plays an important role in bacterial vaginosis (BV,) while the role of genital Mollicutes is less obvious. The diagnosis of BV by use of the current Gram stain Nugent score is also suboptimal for defining the role of Mollicutes that lack a cell wall. Since bacterial load and diversity is an important prerequisite for BV, real-time quantitative polymerase chain reaction (qPCR) assays enable these to be assessed. The purpose of this study was to define the role of genital Mollicutes and potential patterns of synergy with G. vaginalis in women with BV. Vaginal swabs from 130 women categorised by Nugent score as BV (n = 28), intermediate (n = 22) and non-BV (n = 80) were tested against four qPCR TaqMan assays targeting G. vaginalis, Mycoplasma hominis, M. genitalium, Ureaplasma urealyticum and U. parvum. Statistical analyses were used to compare bacterial prevalence and load between the three groups of women. Mycoplasma hominis and G. vaginalis co-infection was significantly more common in BV (60.7 %) compared to intermediate (36.4 %) and non-BV (8.8 %) Nugent scores (p < 0.001). Significantly higher loads of M. hominis (p = 0.001) and G. vaginalis (p < 0.001) were detected in women with BV and the respective loads in M. hominis and G. vaginalis co-infections displayed a significant positive correlation (p < 0.001; r = 0.60). No significant associations were seen with the other Mollicutes. The findings strengthen the evidence of a role for M. hominis in BV and a potential synergy with G. vaginalis. This synergy could be an important trigger of the condition and sexual contact the conduit for the transmission of an otherwise commensal bacterium that could initiate it.


Subject(s)
Gardnerella vaginalis/physiology , Mycoplasma hominis/physiology , Vaginosis, Bacterial/diagnosis , Vaginosis, Bacterial/microbiology , Adolescent , Adult , Bacterial Load , Coinfection , Female , Humans , Prevalence , Symbiosis , Vaginosis, Bacterial/epidemiology , Young Adult
3.
Arch Virol ; 159(7): 1697-705, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24473708

ABSTRACT

Norovirus (NoV) gastroenteritis occurs in all age groups and is the most common cause of gastroenteritis in the community. However, detection methods and rates vary widely, and few data are available to compare these, particularly in Ireland. Detection of noroviruses through antigen and molecular-based strategies was carried out on 135 suspected NoV-positive samples, collected over the course of three NoV outbreaks, from 2002 to 2006, in the southern region of Ireland. A commercially available ELISA and a panel of six primer sets were evaluated to determine their suitability for NoV detection in Irish clinical samples. The key findings of this study were the detection of both GGI and GGII noroviruses by ELISA, but the detection of only GGII noroviruses by RT-PCR. In addition to this, a variation in the levels of detection from 9.4 % to 17.3 % was observed for conventional PCR assays, while a detection rate of 46.3 % was observed for the real-time PCR assay. A proportion (17.8 %) of samples were found to be negative by all detection strategies, suggesting the possibility of reporting false positives for these samples or low-copy positives that do not often repeat. Sequencing information from selected samples also revealed nucleotide polymorphisms, compromising efficient primer binding in the case of one primer pairing. Phylogenetic analysis of the partial polymerase gene identified NoV GII.4 as the dominant genotype, in accordance with previous NoV studies in Ireland. Investigating the NoV diversity of the circulating strains and the dynamics of strain replacement is important to better assess the efficacy of future NoV vaccines and to facilitate the early detection of changes in circulating NoV strains.


Subject(s)
Caliciviridae Infections/virology , Disease Outbreaks , Enzyme-Linked Immunosorbent Assay/methods , Norovirus/genetics , Norovirus/isolation & purification , Reverse Transcriptase Polymerase Chain Reaction/methods , Base Sequence , Caliciviridae Infections/epidemiology , DNA Primers , Genotype , Humans , Ireland/epidemiology , Molecular Sequence Data , Norovirus/classification , Phylogeny , Sequence Alignment , Time Factors
4.
J Med Virol ; 84(12): 2008-17, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23080510

ABSTRACT

Rotavirus is a major cause of gastroenteritis in young children worldwide. There have been several recent reports concerning rotavirus isolation from adults, particularly in the elderly, presenting with gastroenteritis. In this study, the authors report on rotavirus outbreaks in five separate elderly care facilities between April, and June 2011 in Ireland. The following genotypes were detected; G1P[8] (n = 5/11), G2P[4] (n = 2/11), and G9P[8] (n = 2/11). Thus, similarities to previous reports were found in that G1P[8] predominated, G9P[8] was still detected but G2P[4] was detected for the first time in a geriatric population in Ireland. Here also described is the detection of Group 2 lineage IIC rotavirus in Ireland for the first time.


Subject(s)
Disease Outbreaks , Rotavirus Infections/epidemiology , Rotavirus/genetics , Rotavirus/isolation & purification , Aged , Aged, 80 and over , Antigens, Viral/genetics , Base Sequence , Capsid Proteins/genetics , Female , Genetic Variation , Genotype , Humans , Ireland/epidemiology , Male , Phylogeny , RNA, Viral/genetics , Rotavirus/classification , Rotavirus Infections/virology , Sequence Alignment
5.
J Med Microbiol ; 61(Pt 3): 332-338, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22096134

ABSTRACT

False-positive PCR results usually occur as a consequence of specimen-to-specimen or amplicon-to-specimen contamination within the laboratory. Evidence of contamination at time of specimen collection linked to influenza vaccine administration in the same location as influenza sampling is described. Clinical, circumstantial and laboratory evidence was gathered for each of five cases of influenza-like illness (ILI) with unusual patterns of PCR reactivity for seasonal H1N1, H3N2, H1N1 (2009) and influenza B viruses. Two 2010 trivalent influenza vaccines and environmental swabs of a hospital influenza vaccination room were also tested for influenza RNA. Sequencing of influenza A matrix (M) gene amplicons from the five cases and vaccines was undertaken. Four 2009 general practitioner (GP) specimens were seasonal H1N1, H3N2 and influenza B PCR positive. One 2010 GP specimen was H1N1 (2009), H3N2 and influenza B positive. PCR of 2010 trivalent vaccines showed high loads of detectable influenza A and B RNA. Sequencing of the five specimens and vaccines showed greatest homology with the M gene sequence of Influenza A/Puerto Rico/8/1934 H1N1 virus (used in generation of influenza vaccine strains). Environmental swabs had detectable influenza A and B RNA. RNA detection studies demonstrated vaccine RNA still detectable for at least 66 days. Administration of influenza vaccines and clinical sampling in the same room resulted in the contamination with vaccine strains of surveillance swabs collected from patients with ILI. Vaccine contamination should therefore be considered, particularly where multiple influenza virus RNA PCR positive signals (e.g. H1N1, H3N2 and influenza B) are detected in the same specimen.


Subject(s)
False Positive Reactions , Influenza A Virus, H1N1 Subtype/isolation & purification , Influenza A Virus, H3N2 Subtype/isolation & purification , Influenza B virus/isolation & purification , Influenza Vaccines/administration & dosage , Influenza, Human/diagnosis , Polymerase Chain Reaction/methods , Adolescent , Adult , Aged , Environmental Microbiology , Female , Health Personnel , Humans , Influenza A Virus, H1N1 Subtype/genetics , Influenza A Virus, H3N2 Subtype/genetics , Influenza B virus/genetics , Influenza, Human/virology , Male , Middle Aged , Pharynx/virology , Sequence Analysis, DNA , Viral Matrix Proteins/genetics , Young Adult
6.
J Med Virol ; 83(9): 1650-6, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21739458

ABSTRACT

There is a need to provide rapid, sensitive, and often high throughput detection of pathogens in diagnostic virology. Viral gastroenteritis is a serious health issue often leading to hospitalization in the young, the immunocompromised and the elderly. The common causes of viral gastroenteritis include rotavirus, norovirus (genogroups I and II), astrovirus, and group F adenoviruses (serotypes 40 and 41). This article describes the work-up of two internally controlled multiplex, probe-based PCR assays and reports on the clinical validation over a 3-year period, March 2007 to February 2010. Multiplex assays were developed using a combination of TaqMan™ and minor groove binder (MGB™) hydrolysis probes. The assays were validated using a panel of 137 specimens, previously positive via a nested gel-based assay. The assays had improved sensitivity for adenovirus, rotavirus, and norovirus (97.3% vs. 86.1%, 100% vs. 87.8%, and 95.1% vs. 79.5%, respectively) and also more specific for targets adenovirus, rotavirus, and norovirus (99% vs. 95.2%, 100% vs. 93.6%, and 97.9% vs. 92.3%, respectively). For the specimens tested, both assays had equal sensitivity and specificity for astrovirus (100%). Overall the probe-based assays detected 16 more positive specimens than the nested gel-based assay. Post-introduction to the routine diagnostic service, a total of 9,846 specimens were processed with multiplex 1 and 2 (7,053 pediatric, 2,793 adult) over the 3-year study period. This clinically validated, probe-based multiplex testing algorithm allows highly sensitive and timely diagnosis of the four most prominent causes of viral gastroenteritis.


Subject(s)
Adenovirus Infections, Human/diagnosis , Astroviridae Infections/diagnosis , Caliciviridae Infections/diagnosis , Gastroenteritis/diagnosis , Molecular Diagnostic Techniques/methods , Multiplex Polymerase Chain Reaction , Rotavirus Infections/diagnosis , Adult , Child , DNA Primers , Feces/virology , Gastroenteritis/virology , Humans , Norovirus , Sensitivity and Specificity
7.
J Infect ; 61(1): 81-5, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20359495

ABSTRACT

SUMMARY OBJECTIVE: To evaluate the feasibility of conducting a definitive study to assess the impact of introducing a rapid PCR-based test for candidemia on antifungal drug prescribing. METHOD: Prospective, single centre, interrupted time series study consisting of three periods of six months' duration. The assay was available during the second period, during which the PCR assay was available for routine use by physicians Monday-Friday with guaranteed 24-h turnaround time. For each period total antifungal drug use, expressed as treatment-days, was recorded and an adjustment was made to exclude estimated use for proven candidemia. Also, during the intervention period, antifungal prescribing decisions for up to 72 h after each PCR result became available were recorded as either concordant or discordant with that result. RESULTS: While overall antifungal use remained relatively stable throughout, after adjustment for candidemia, there was a 38% reduction in use following introduction of the PCR test; however, this was nonsignificant at the 95% level. During the intervention period overall concordance between the PCR result and prescribing decisions was 84%. CONCLUSIONS: The PCR assay for candidemia was requested, prescribing decisions were generally concordant with the results produced and there was an apparent decrease in antifungal prescription, although this was sustained even after withdrawal of the intervention; these findings should be more thoroughly evaluated in a larger trial.


Subject(s)
Antifungal Agents/therapeutic use , Candidiasis/diagnosis , Critical Care/methods , Fungemia/diagnosis , Mycology/methods , Polymerase Chain Reaction/methods , Prescriptions/statistics & numerical data , Adult , Humans , Middle Aged , Pilot Projects , Prospective Studies
8.
Acta Paediatr ; 99(3): 394-8, 2010 Mar.
Article in English | MEDLINE | ID: mdl-20003105

ABSTRACT

AIM: The aim of this study was to determine if asthmatic children have viruses more commonly detected in lower airways during asymptomatic periods than normal children. METHODS: Fifty-five asymptomatic children attending elective surgical procedures (14 with stable asthma, 41 normal controls) underwent non-bronchoscopic bronchoalveolar lavage. Differential cell count and PCR for 13 common viruses were performed. RESULTS: Nineteen (35%) children were positive for at least one virus, with adenovirus being most common. No differences in the proportion of viruses detected were seen between asthmatic and normal 'control' children. Viruses other than adenovirus were associated with higher neutrophil counts, suggesting that they caused an inflammatory response in both asthmatics and controls (median BAL neutrophil count, 6.9% for virus detected vs. 1.5% for virus not detected, p = 0.03). CONCLUSIONS: Over one-third of asymptomatic children have a detectable virus (most commonly adenovirus) in the lower airway; however, this was not more common in asthmatics. Viruses other than adenovirus were associated with elevated neutrophils suggesting that viral infection can be present during relatively asymptomatic periods in asthmatic children.


Subject(s)
Asthma/virology , Respiratory Tract Infections/virology , Viruses/isolation & purification , Adenoviridae/isolation & purification , Adolescent , Bronchoalveolar Lavage Fluid/cytology , Bronchoalveolar Lavage Fluid/virology , Case-Control Studies , Cell Count , Child , Child, Preschool , Female , Humans , Infant , Male , Polymerase Chain Reaction , Viruses/genetics
9.
Epidemiol Infect ; 138(1): 21-7, 2010 Jan.
Article in English | MEDLINE | ID: mdl-19480726

ABSTRACT

Human cases of Q fever appear to be common in Northern Ireland compared to the rest of the British Isles. The purpose of this study was to describe the seroepidemiology of Coxiella burnetii infection in cattle in Northern Ireland in terms of seroprevalence and determinants of infection. A total of 5182 animals (from a stratified systematic random sample of 273 herds) were tested with a commercial C. burnetii phase 2 IgG ELISA. A total of 6.2% of animals and 48.4% of herds tested positively. Results from a multilevel logistic regression model indicated that the odds of cattle being infected with Q fever increased with age, Friesian breed, being from large herds and from dairy herds. Large dairy herd animal prevalence was 12.5% compared to 2.1% for small beef herds. Preliminary seroprevalence in sheep (12.3%), goats (9.3%), pigs (0%) rats (9.7%) and mice (3.2%) using indirect immunofluorescence is reported.


Subject(s)
Cattle Diseases/epidemiology , Q Fever/veterinary , Animals , Cattle , Coxiella burnetii/immunology , Goat Diseases/epidemiology , Goats , Humans , Immunoglobulin G/blood , Male , Mice , Northern Ireland/epidemiology , Population Surveillance , Q Fever/epidemiology , Rats , Rodent Diseases/epidemiology , Seroepidemiologic Studies , Sheep , Swine Diseases/epidemiology , Zoonoses
10.
J Med Microbiol ; 57(Pt 10): 1269-1272, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18809556

ABSTRACT

In contrast to the multitude of studies on fungal PCR assay methods, little work has been reported evaluating Candida PCR performance when using whole blood compared with serum in candidaemic patients. Here, a comparison of the performance of whole-blood and serum specimens using a set of real-time PCR Candida species assays is described. Specimens were collected prospectively from non-neutropenic adults who were recruited to a diagnostic clinical trial, the primary purpose of which was to verify the performance of the assays using serum; in all, 104 participants also had whole-blood specimens submitted for analysis in addition to the serum specimen. Of these participants, 10 had laboratory-confirmed candidaemia and 94 were categorized as being 'unlikely' to have invasive Candida infection. PCR results from the whole-blood specimens are presented here and compared with the results from serum specimens in this subgroup among whom both specimen types were obtained contemporaneously. All participants with candidaemia were PCR-positive from serum samples; however, only seven were PCR-positive from whole blood. All specimens from patients in the 'unlikely' category were PCR-negative in both types of specimen. Moreover, DNA extraction from serum required 1 h; extraction from whole blood required approximately 3 h. These data tentatively suggest that, overall, serum is an appropriate specimen for Candida PCR for detection of candidaemia in non-neutropenic adults.


Subject(s)
Candida/isolation & purification , Candidiasis/diagnosis , Critical Illness , DNA, Fungal/blood , Adult , Aged , Aged, 80 and over , DNA, Fungal/isolation & purification , Female , Humans , Male , Polymerase Chain Reaction , Sensitivity and Specificity , Time Factors
11.
Zoonoses Public Health ; 55(4): 189-94, 2008 May.
Article in English | MEDLINE | ID: mdl-18387140

ABSTRACT

Despite the widespread prevalence of infection with Coxiella burnetii, there have been few large population-based studies examining the epidemiology of this infection. The aim of this study was to examine the distribution and determinants of C. burnetii past infection in Northern Ireland (NI). Coxiella burnetii phase II specific IgG antibodies were measured by enzyme-linked immunosorbent assay in stored serum from 2,394 randomly selected subjects, aged 12-64, who had participated in population-based surveys of cardiovascular risk factors performed in 1986 and 1987. The overall prevalence of C. burnetii antibody positivity was 12.8%. The prevalence of sero-positivity was slightly higher in males than that in females (14.3% versus 11.2%, P = 0.02). Sero-positivity was low in children (<10%), increasing to 19.5% and 16.4% in males and females, respectively, in the 25-34 age group and subsequently remaining fairly steady with increasing age. Sero-positivity among farmers, at 48.8%, was significantly higher than the general population. More sero-positive than sero-negative women had a history of a miscarriage or still-birth (19.5% versus 9.8%, P < 0.001). In conclusion, this study demonstrated a high prevalence of evidence of past C. burnetii infection in NI. Associations between past C. burnetii infection and age, sex, social class, occupation and reproductive history were seen. We estimate that 20% of Q fever infections in NI occur in farmers.


Subject(s)
Animals, Domestic/microbiology , Antibodies, Bacterial/blood , Coxiella burnetii/immunology , Q Fever , Zoonoses , Abortion, Spontaneous/microbiology , Adolescent , Adult , Age Factors , Animals , Child , Disease Reservoirs/veterinary , Female , Humans , Ireland/epidemiology , Male , Middle Aged , Occupations , Pregnancy , Public Health , Q Fever/epidemiology , Q Fever/transmission , Q Fever/veterinary , Seroepidemiologic Studies , Sex Factors , Social Class
12.
Clin Infect Dis ; 46(6): 890-6, 2008 Mar 15.
Article in English | MEDLINE | ID: mdl-18260751

ABSTRACT

BACKGROUND: Invasive Candida infection among nonneutropenic, critically ill adults is a clinical problem that has received increasing attention in recent years. Poor performance of extant diagnostic modalities has promoted risk-based, preemptive prescribing in view of the poor outcomes associated with inadequate or delayed antifungal therapy; this risks unnecessary overtreatment. A rapid, reliable diagnostic test could have a substantial impact on therapeutic practice in this patient population. METHODS: Three TaqMan-based real-time polymerase chain reaction assays were developed that are capable of detecting the main medically important Candida species, categorized according to the likelihood of fluconazole susceptibility. Assay 1 detected Candida albicans, Candida parapsilosis, Candida tropicalis, and Candida dubliniensis. Assays 2 and 3 detected Candida glabrata and Candida krusei, respectively. The clinical performance of these assays, applied to serum, was evaluated in a prospective trial of nonneutropenic adults in a single intensive care unit. RESULTS: In all, 527 specimens were obtained from 157 participants. All 3 assays were run in parallel for each specimen; they could be completed within 1 working day. Of these, 23 specimens were obtained from 23 participants categorized as having proven Candida infection at the time of sampling. If a single episode of Candida famata candidemia was excluded, the estimated clinical sensitivity, specificity, and positive and negative predictive values of the assays in this trial were 90.9%, 100%, 100% and 99.8%, respectively. CONCLUSIONS: These data suggest that the described assays perform well in this population for enhancing the diagnosis of candidemia. The extent to which they may affect clinical outcomes, prescribing practice, and cost-effectiveness of care remains to be ascertained.


Subject(s)
Candida/isolation & purification , Candidiasis/diagnosis , Critical Illness , Fungemia/diagnosis , Polymerase Chain Reaction/methods , Adult , Candida/classification , Candida/genetics , Candidiasis/microbiology , DNA Primers , Female , Fungemia/microbiology , Humans , Male , Predictive Value of Tests , Research Design , Sensitivity and Specificity , Taq Polymerase
13.
Eur Respir J ; 31(6): 1221-6, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18287127

ABSTRACT

Latent viral infection has been implicated in the pathophysiology of chronic obstructive pulmonary disease (COPD). Epstein-Barr virus (EBV) is known to be important in pulmonary fibrosis. The current authors hypothesised that EBV is associated with the pathogenesis of COPD. Sputum samples were collected from patients both during exacerbations of COPD and when stable. A control group of smokers who did not have airways obstruction also had their sputum examined. The presence of EBV DNA was established and quantified using a real-time nucleic acid amplification assay. A total of 136 patients with COPD were recruited during an acute exacerbation and a total of 68 when stable. EBV was detected in 65 (48%) exacerbation cases and 31 (46%) stable patients. In the comparison group of 16 nonobstructed smokers, EBV was demonstrated in only one (6%) case. Risk of COPD in patients with EBV and who are smokers confers an odds ratio of 12.6. Epstein-Barr virus DNA is more frequently identified in the respiratory tract of chronic obstructive pulmonary disease patients in comparison with unaffected smokers. It is present both during exacerbation and when stable, suggesting that infection is persistent. Smokers who do not develop chronic obstructive pulmonary disease rarely have Epstein-Barr virus in their sputum. This finding may be of importance in the pathogenesis of chronic obstructive pulmonary disease.


Subject(s)
Epstein-Barr Virus Infections/diagnosis , Herpesvirus 4, Human/isolation & purification , Pulmonary Disease, Chronic Obstructive/virology , Sputum/virology , Aged , Case-Control Studies , Female , Humans , Male , Middle Aged , Odds Ratio , Polymerase Chain Reaction , Risk , Smoking
14.
J Med Microbiol ; 57(Pt 3): 296-303, 2008 Mar.
Article in English | MEDLINE | ID: mdl-18287291

ABSTRACT

The limitations of classical diagnostic methods for invasive Candida infections have led to the development of molecular techniques such as real-time PCR to improve diagnosis. However, the detection of low titres of Candida DNA in blood from patients with candidaemia requires the use of extraction methods that efficiently lyse yeast cells and recover small amounts of DNA suitable for amplification. In this study, a Candida-specific real-time PCR assay was used to detect Candida albicans DNA in inoculated whole blood specimens extracted using seven different extraction protocols. The yield and quality of total nucleic acids were estimated using UV absorbance, and specific recovery of C. albicans genomic DNA was estimated quantitatively in comparison with a reference (Qiagen kit/lyticase) method currently in use in our laboratory. The extraction protocols were also compared with respect to sensitivity, cost and time required for completion. The TaqMan PCR assay used to amplify the DNA extracts achieved high levels of specificity, sensitivity and reproducibility. Of the seven extraction protocols evaluated, only the MasterPure yeast DNA extraction reagent kit gave significantly higher total nucleic acid yields than the reference method, although nucleic acid purity was highest using either the reference or YeaStar genomic DNA kit methods. More importantly, the YeaStar method enabled C. albicans DNA to be detected with highest sensitivity over the entire range of copy numbers evaluated, and appears to be an optimal method for extracting Candida DNA from whole blood.


Subject(s)
Candida/isolation & purification , Candidiasis/diagnosis , DNA, Fungal/blood , DNA, Fungal/isolation & purification , Fungemia/diagnosis , Polymerase Chain Reaction/methods , Candida/classification , Candida/genetics , Candida albicans/classification , Candida albicans/genetics , Candida albicans/isolation & purification , Candidiasis/microbiology , DNA, Fungal/analysis , Fungemia/microbiology , Humans , Mycological Typing Techniques , Polymerase Chain Reaction/economics , Reagent Kits, Diagnostic , Reproducibility of Results , Sensitivity and Specificity , Time Factors
15.
J Med Microbiol ; 56(Pt 7): 964-970, 2007 Jul.
Article in English | MEDLINE | ID: mdl-17577063

ABSTRACT

In view of both the delay in obtaining identification by conventional methods following blood-culture positivity in patients with candidaemia and the close relationship between species and fluconazole (FLC) susceptibility, early speciation of positive blood cultures has the potential to influence therapeutic decisions. The aim was to develop a rapid test to differentiate FLC-resistant from FLC-sensitive Candida species. Three TaqMan-based real-time PCR assays were developed to identify up to six Candida species directly from BacT/Alert blood-culture bottles that showed yeast cells on Gram staining at the time of initial positivity. Target sequences in the rRNA gene complex were amplified, using a consensus two-step PCR protocol, to identify Candida albicans, Candida parapsilosis, Candida tropicalis, Candida dubliniensis, Candida glabrata and Candida krusei; these are the most commonly encountered Candida species in blood cultures. The first four of these (the characteristically FLC-sensitive group) were identified in a single reaction tube using one fluorescent TaqMan probe targeting 18S rRNA sequences conserved in the four species. The FLC-resistant species C. krusei and C. glabrata were detected in two further reactions, each with species-specific probes. This method was validated with clinical specimens (blood cultures) positive for yeast (n=33 sets) and the results were 100 % concordant with those of phenotypic identification carried out concomitantly. The reported assay significantly reduces the time required to identify the presence of C. glabrata and C. krusei in comparison with a conventional phenotypic method, from approximately 72 to <3 h, and consequently allows optimization of the antifungal regimen at an earlier stage.


Subject(s)
Antifungal Agents/pharmacology , Blood/microbiology , Candida/drug effects , Culture Media , Drug Resistance, Fungal , Fluconazole/pharmacology , Polymerase Chain Reaction/methods , Candida/classification , Candida/genetics , Candida/isolation & purification , Candida albicans/classification , Candida albicans/drug effects , Candida albicans/genetics , DNA, Fungal/analysis , DNA, Fungal/isolation & purification , Drug Resistance, Fungal/genetics , Fungemia/microbiology , Humans , Microbial Sensitivity Tests , Microbiological Techniques , Mycological Typing Techniques , Phenotype , Sensitivity and Specificity , Time Factors
16.
J Infect ; 55(2): 174-8, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17560655

ABSTRACT

OBJECTIVES: To describe the species distribution and antifungal susceptibility trends for documented episodes of candidemia at the Royal Hospitals, Belfast, 2001-2006. METHODS: Laboratory-based retrospective observational study of all episodes of candidemia. RESULTS: There were 151 episodes of candidemia. The species recovered were: 96 C. albicans; 26 C. glabrata; 18 C. parapsilosis; five C. tropicalis; four C. guilliermondii; one C. famata and one C. dubliniensis. We separated the data into two periods 2001-2003 and 2004-2006; contrary to the findings of other investigators, there was a notable trends toward increasing frequency of C. albicans and decreasing frequency of non-albicans species over time. Although the proportion of C. albicans, C. parapsilosis and C. tropicalis isolates susceptible to fluconazole was unchanged over time, a trend of decreased susceptibility of C. glabrata to fluconazole was noted over the six-year period. Overall, 73% and 7.7% of C. glabrata isolates had susceptible-dose-dependent and resistant phenotypes, respectively. The percentage of C. glabrata isolates susceptible to fluconazole (MIC <8 microg/ml) decreased from 36% in 2001-2003 to 0% in 2004-2006. Flucytosine resistance was detected in only 4 (2.7%) isolates. None of the isolates had an amphotericin B MIC <1 microg/ml. CONCLUSION: A shift towards increasing dominance of C. albicans contrasts both with reports from other countries and previous data from Northern Ireland. Upwards fluconazole MIC drift among C. glabrata has important implications for empirical therapeutic decisions.


Subject(s)
Antifungal Agents/pharmacology , Candida/drug effects , Candidiasis/classification , Candida/classification , Candida/isolation & purification , Candida glabrata/drug effects , Candidiasis/drug therapy , Candidiasis/epidemiology , Hospitals, University/statistics & numerical data , Humans , Medical Records Systems, Computerized , Microbial Sensitivity Tests , Northern Ireland/epidemiology , Prevalence , Retrospective Studies
17.
Oral Dis ; 13(4): 414-8, 2007 Jul.
Article in English | MEDLINE | ID: mdl-17577329

ABSTRACT

Oral surgery and stress can trigger and/or increase asymptomatic shedding of herpes simplex virus type-1 (HSV-1) into human saliva. In this investigation we examined the frequency of HSV-1 shedding in 32 patients undergoing an oral surgery procedure compared with 40 control patients attending for noninvasive treatment. Control patients comprised 18 migraine patients and 22 patients with temporomandibular (TMD) joint problems. Nested-PCR was carried out on oral rinses collected from each patient prior to treatment and 7 days post-treatment. Fifty-two of sixty-one seropositive patients were positive for HSV-1 DNA in one or both oral rinses. The frequencies of HSV-1 shedding for the oral surgery and control patients were 84.6% and 85.7% respectively. Seropositive patients who started shedding after treatment were significantly higher in oral surgery patients (46.2%) compared to control patients (34.3%). Shedding of HSV-1 in the oral cavity is not only increased by direct surgical trauma, but also appears to be common in migraine and TMD patients attending for general dental treatment. Thus pain or pain-induced stress as well as anxiety associated with dental treatment may also be a risk factor for asymptomatic shedding in specific seropositive patients attending for dental treatment.


Subject(s)
Herpesvirus 1, Human/isolation & purification , Oral Surgical Procedures , Saliva/virology , Virus Shedding , Adolescent , Adult , Aged , Antibodies, Viral/blood , Dental Anxiety/virology , Female , Follow-Up Studies , Herpesvirus 1, Human/immunology , Humans , Immunoglobulin G/blood , Male , Middle Aged , Migraine Disorders/therapy , Migraine Disorders/virology , Mouth Mucosa/virology , Occlusal Splints , Pain/virology , Risk Factors , Stress, Physiological/virology , Temporomandibular Joint Disorders/therapy , Temporomandibular Joint Disorders/virology , Tooth Extraction , Tooth, Impacted/surgery
18.
Eur J Clin Microbiol Infect Dis ; 25(3): 190-2, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16534565

ABSTRACT

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.


Subject(s)
Metapneumovirus , Paramyxoviridae Infections , Aged , Aged, 80 and over , Female , Humans , Male , Metapneumovirus/genetics , Metapneumovirus/isolation & purification , Middle Aged , Nose/virology , Paramyxoviridae Infections/diagnosis , Paramyxoviridae Infections/epidemiology , Paramyxoviridae Infections/mortality , Paramyxoviridae Infections/physiopathology , Pharynx/virology , Reverse Transcriptase Polymerase Chain Reaction , Sputum/virology , Trachea/virology
19.
Respir Med ; 100(3): 512-8, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16046259

ABSTRACT

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.


Subject(s)
Hospitalization/statistics & numerical data , Pulmonary Disease, Chronic Obstructive/epidemiology , Respiratory Tract Infections/epidemiology , Adolescent , Child , Child, Preschool , Female , Holidays , Humans , Male , Northern Ireland/epidemiology , Prevalence , Pulmonary Disease, Chronic Obstructive/virology , Respiratory Tract Infections/virology
20.
Ulster Med J ; 73(1): 25-31, 2004 May.
Article in English | MEDLINE | ID: mdl-15244122

ABSTRACT

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.


Subject(s)
Hepatitis C, Chronic/drug therapy , Hepatitis C, Chronic/epidemiology , Adult , Aged , Aged, 80 and over , Antiviral Agents/therapeutic use , Female , Humans , Interferon-alpha/therapeutic use , Male , Middle Aged , Northern Ireland/epidemiology , Prospective Studies
SELECTION OF CITATIONS
SEARCH DETAIL
...