Heller's myotomy and pneumatic dilatation in the treatment of achalasia: a population-based case-control study assessing long-term quality of life.

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.

False-positive PCR results linked to administration of seasonal influenza vaccine.

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.

Development and clinical validation of multiplex TaqMan® assays for rapid diagnosis of viral gastroenteritis.

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.

Hepatitis A outbreak predominantly affecting men who have sex with men in Northern Ireland, October 2008 to July 2009.

We describe an outbreak of hepatitis A which evolved in Northern Ireland between October 2008 and July 2009, against a background of large concurrent hepatitis A outbreaks in various parts of Europe. Thirty-eight cases were defined as outbreak cases using a stratified case definition; 36 were males with a median age of 29 years and of the 28 males whose sexual orientation was known, 26 were men who have sex with men(MSM). Detailed descriptive epidemiology data collected through standardised questionnaires, together with sequencing of a 289 bp fragment of the VP1/2PA region of the virus, significantly aided the understanding of the spread of the outbreak when non-MSM cases occurred. The sequence of the outbreak strain, genotype IA, was indistinguishable from that involved in a large outbreak in the Czech Republic. Although seeded in a generally susceptible Northern Ireland population, the outbreak remained mostly contained in MSM, showing this sub-population to be the most vulnerable despite ongoing hepatitis A vaccination programmes in genito-urinary medicine clinics.

Pimecrolimus 1% cream for oral erosive lichen planus: a 6-week randomized, double-blind, vehicle-controlled study with a 6-week open-label extension to assess efficacy and safety.

OBJECTIVE: To assess the efficacy and safety of topical pimecrolimus 1% cream in the treatment of oral erosive lichen planus. DESIGN: A 6-week randomized, double-blind, vehicle-controlled phase followed by a 6-week open-label phase. SETTING: Outpatients of the Department of Dermatology, University of Utah. PATIENTS: Twenty-one patients with oral erosive lichen planus were randomized and treated with either pimecrolimus 1% cream or vehicle cream. INTERVENTION: Pimecrolimus 1% cream, or its vehicle, were applied twice daily for 6 weeks to each side of the mouth with a 2×2 inch gauze pad folded in half and placed directly on the erosive lesion. MAIN OUTCOME MEASURES: Efficacy was based on clinical evaluation of Investigator's Global Assessment (IGA) of the overall severity of the disease, erythema, measurement of the size of any target erosion in millimetres, and assessment of spontaneous pain. Blood levels of pimecrolimus were monitored in all subjects on day 0 and repeated on day 7. RESULTS: Pimecrolimus 1% cream was superior to vehicle cream in reducing mean IGA, pain, and erosion size. For the vehicle group that entered the open-label phase, pimecrolimus 1% cream improved the mean IGA, pain, erosion size, and erythema. Pimecrolimus levels were detected in nine out of 10 of the pimecrolimus-treated subjects. These levels were consistently low. The pimecrolimus cream was well-tolerated. No clinically relevant, drug-related adverse events were reported. CONCLUSION: Pimecrolimus 1% cream was superior to vehicle in reducing pain, erythema, decreasing erosion size, and improving overall severity of disease when compared with vehicle treatment.

Immunovirological correlates in human rabies treated with therapeutic coma.

A 37-year-old woman was admitted to hospital and over the next 5 days developed a progressive encephalitis. Nuchal skin biopsy, analyzed using a Rabies TaqMan(c) PCR, demonstrated rabies virus RNA. She had a history in keeping with exposure to rabies whilst in South Africa, but had not received pre- or post-exposure prophylaxis. She was treated with a therapeutic coma according to the "Milwaukee protocol," which failed to prevent the death of the patient. Rabies virus was isolated from CSF and saliva, and rabies antibody was demonstrated in serum (from day 11 onwards) and cerebrospinal fluid (day 13 onwards). She died on day-35 of hospitalization. Autopsy specimens demonstrated the presence of rabies antigen, viral RNA, and viable rabies virus in the central nervous system.

Coxiella burnetii (Q fever) seroprevalence in cattle.

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.

Human seroprevalence to Coxiella burnetii (Q fever) in Northern Ireland.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Hantaviruses.

Since the recognition of the hantavirus pulmonary syndrome (HPS) in the USA in 1993, interest in hantavirus diseases has intensified worldwide. It is clear that hantaviruses have been historically responsible for a variety of human illnesses. Hantaviruses form a separate genus within the Bunyaviridae family. There are currently >20 recognised sero/genotypes and many others are under investigation. Each hantavirus type appears to be specific to a different rodent host. Virus phylogeny very closely reflects rodent phylogeny. The different hantavirus types are associated with different types of disease both in terms of target organs and disease severity. Two major diseases are recognised: haemorrhagic fever with renal syndrome (HFRS) and HPS. HFRS is primarily a disease of the old world while HPS is only recognised in the Americas. Over the past few decades the understanding and recognition of hantavirus disease throughout the world have greatly expanded. The number of recognised virus types continues to grow, as does the spectrum of hantavirus disease. There is evidence of hantavirus causing human disease in the British Isles, but at present it remains a largely uncharacterised disease.