Local control and survival after stereotactic radiosurgery for colorectal cancer brain metastases: an international multicenter analysis

OBJECTIVE

The goal of this study was to characterize local tumor control (LC), overall survival (OS), and safety of stereotactic radiosurgery for colorectal brain metastasis (CRBM).

METHODS

Ten international institutions participating in the International Radiosurgery Research Foundation provided data for this retrospective case series. This study included 187 patients with CRBM (281 tumors), with a median age of 62 years and 56.7% being male. Most patients (53.5%) had solitary tumors, although 10.7% had > 5 tumors. The median tumor volume was 2.7 cm3 (IQR 0.22-8.1 cm3), and the median margin dose was 20 Gy (IQR 18-22 Gy).

RESULTS

The 3-year LC and OS rates were 72% and 20%, respectively. Symptomatic adverse radiation effects occurred in 1.6% of patients. In the multivariate analysis, age > 65 years and tumor volume > 4.0 cm3 were significant predictors of tumor progression (hazard ratio [HR] 2.6, 95% CI 1.4-4.9; p = 0.003 and HR 3.4, 95% CI 1.7-6.9; p < 0.001, respectively). Better performance status (Karnofsky Performance Scale score > 80) was associated with a reduced risk of tumor progression (HR 0.38, 95% CI 0.19-0.73; p = 0.004). Patient age > 62 years (HR 1.6, 95% CI 1.1-2.3; p = 0.03) and the presence of active extracranial disease (HR 1.7, 95% CI 1.1-2.4; p = 0.009) were significantly associated with worse OS.

CONCLUSIONS

Stereotactic radiosurgery offers a high LC rate and a low rate of symptomatic adverse radiation effects for the majority of CRBMs. The OS and LC favored younger patients with high functional performance scores and inactive extracranial disease.

Local Control and Survival Outcomes After Stereotactic Radiosurgery for Brain Metastases From Gastrointestinal Primaries: An International Multicenter Analysis

BACKGROUND

There are limited data regarding outcomes for patients with gastrointestinal (GI) primaries and brain metastases treated with stereotactic radiosurgery (SRS).

OBJECTIVE

To examine clinical outcomes after SRS for patients with brain metastases from GI primaries and evaluate potential prognostic factors.

METHODS

The International Radiosurgery Research Foundation centers were queried for patients with brain metastases from GI primaries managed with SRS. Primary outcomes were local control (LC) and overall survival (OS). Kaplan-Meier analysis was used for univariate analysis (UVA) of prognostic factors. Factors significant on UVA were evaluated with a Cox multivariate analysis proportional hazards model. Logistic regressions were used to examine correlations with RN.

RESULTS

We identified 263 eligible patients with 543 brain metastases. Common primary sites were rectal (31.2%), colon (31.2%), and esophagus (25.5%) with a median age of 61.6 years (range: 37-91.4 years) and a median Karnofsky performance status (KPS) of 90% (range: 40%-100%). One-year and 2-year LC rates were 83.5% (95% CI: 78.9%-87.1%) and 73.0% (95% CI: 66.4%-78.5%), respectively. On UVA, age >65 years ( P = .001), dose <20 Gy ( P = .006) for single-fraction plans, KPS <90% ( P < .001), and planning target volume ≥2cc ( P = .007) were associated with inferior LC. All factors other than dose were significant on multivariate analysis ( P ≤ .002). One-year and 2-year OS rates were 68.0% (95% CI: 61.5%-73.6%) and 31.2% (95% CI: 24.6%-37.9%), respectively. Age > 65 years ( P = .006), KPS <90% ( P = .005), and extracranial metastases ( P = .05) were associated with inferior OS.

CONCLUSION

SRS resulted in comparable LC with common primaries. Age and KPS were associated with both LC and OS with planning target volume and extracranial metastases correlating with LC and OS, respectively. These factors should be considered in GI cancer patient selection for SRS.

Investigation of hospital discharge cases and SARS-CoV-2 introduction into Lothian care homes

BACKGROUND

The first epidemic wave of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Scotland resulted in high case numbers and mortality in care homes. In Lothian, over a third of care homes reported an outbreak while there was limited testing of hospital patients discharged to care homes.

AIM

Investigate hospital discharges as a source of SARS-CoV-2 introduction into care homes during the first epidemic wave.

METHODS

A clinical review was performed for all discharges from hospitals to care homes starting 1st March 2020 to 31st May 2020. Episodes were ruled out based on coronavirus disease (COVID-19) test history, clinical assessment at discharge, whole genome sequencing (WGS) data and an infectious period of 14 days. Clinical samples were processed for WGS, and consensus genomes generated were used for analysis by cluster investigation and virus epidemiological tool (CIVET). Patient timelines were obtained using electronic hospital records.

FINDINGS

In total 787 hospital discharges to care homes were identified. Out of these 776 (99%) were ruled out for hospital discharge introduction. However, for 10 episodes the results were inconclusive as there was low genomic diversity in consensus genomes or no sequencing data. Only one discharge episode had a genomic, time and location link to positive cases during hospital admission leading to 10 further positive cases in the care home.

CONCLUSION

Majority of hospital discharges were ruled out for introduction into Lothian care homes highlighting the importance of screening all new admissions when faced with a novel emerging virus and no vaccine available.

Primary hypothyroidism presenting as neuropsychiatric symptoms and pituitary enlargement in a young woman: illustrative case

BACKGROUND

Pituitary adenomas are the most common cause of pituitary enlargement and can potentially warrant surgical intervention. However, there are physiological causes of pituitary enlargement that can be reversed with hormone replacement alone.

OBSERVATIONS

A 29-year-old female presented with acute onset paranoia to the psychiatry department. A computed tomography scan of the head revealed a 2.3 cm sellar mass with confirmation on magnetic resonance imaging. Testing showed a markedly elevated thyroid-stimulating hormone 1,600 µIU/mL (0.470-4.200 µIU/mL), suggesting pituitary hyperplasia. Treatment with levothyroxine replacement resulted in marked improvement in symptoms and resolution of pituitary hyperplasia on four month follow up.

LESSONS

This rare presentation of severe primary hypothyroidism highlights the importance of evaluating for physiological causes of pituitary enlargement.

Comparing Sex-Specific Outcomes After Medial Patellofemoral Ligament Reconstruction for Patellar Instability: A Systematic Review

BACKGROUND

The impact of patient sex on outcomes after medial patellofemoral ligament ligament reconstruction (MPFLR) has not been well studied.

PURPOSE

To conduct a systematic review to determine sex-based differences in outcomes after MPFLR for patellar instability and the proportion of studies examining this as a primary or secondary purpose.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic review was performed using the PubMed, Cochrane Library, PubMed Central, Ovid, and Embase databases according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Studies were included if they were written in English, were performed on humans, consisted of patients who underwent MPFLR with allograft or autograft, evaluated at least 1 of the selected outcomes comparing male and female patients, and had statistical analysis available for relevant findings. Excluded were case reports, review studies or systematic reviews, studies that did not evaluate at least 1 sex-specific outcome, studies that included other injuries associated with patellofemoral instability injury, cadaveric studies, and those in which patients underwent concomitant procedures.

RESULTS

The initial search yielded 3470 studies; 2647 studies remained after removing duplicates. Of the 401 studies that underwent full-text review, 10 met all inclusion criteria and were included for quantitative analysis. A meta-analysis could not be performed given the heterogeneity within the data set. Of the 2647 studies evaluated in this study, only 2 (0.08%) studies examined the impact of patient sex on MPFLR outcomes as a primary purpose and only 8 (0.30%) studies explored it as a secondary purpose.

CONCLUSION

Only 0.38% of the articles compared outcomes between male and female patients after MPFLR. The limited data available were too heterogenous to draw any concrete conclusions about the impact of patient sex on outcomes after MPFLR. Further research in this area is warranted, as findings may influence treatment plans and improve patient outcomes.

Increasing drug-related mortality rates over the last decade in Scotland are not just due to an ageing cohort: A retrospective longitudinal cohort study

BACKGROUND

In Europe, North America, and Australia, mortality due to drug-related (DR) causes amongst people who inject drugs (PWID) is a major issue. Our objective was to characterise temporal trends in DR mortality rates in a large cohort of PWID in Scotland over the past decade, all of whom had been diagnosed with hepatitis C virus (HCV) infection, and to investigate factors associated with DR mortality.

METHODS

Retrospective longitudinal cohort study linking Scotland's national HCV Diagnosis Database and deaths registry. The study cohort consisted of all individuals with likely injection drug use-related route of HCV acquisition, who had been diagnosed with HCV between 1991 and 2018, and were alive and aged under 65 years on 1 January 2009. We used Lexis expansion to adjust for ageing cohort effects and calculated the mortality rate from an underlying/contributing DR cause over the period 2009-2018. We fitted Poisson regression models to estimate the temporal trend adjusting for attained age, sex, referral setting, region, and viraemic status at baseline.

RESULTS

Amongst the study population (n = 35,065; 236,914 person-years), a total of 1900 DR deaths occurred; the DR mortality rate increased from 5.6/1000 [101 deaths] in 2009 to 12.4/1000 [342] person-years in 2018. Increasing trends were observed for all age-groups except 55-64 years. The overall DR mortality rate was highest for referrals for HCV testing from prison (11.0/1000) and hospital settings (10.0/1000). Mortality increased with calendar time period, with significantly raised adjusted rate ratios (RRs) from 2015 (RR=1.40, 95% CI:1.16-1.69) to 2018 (RR=2.23, 95% CI:1.88-2.64), compared with 2011-2012, for older age (35-44: RR=1.37, 95% CI:1.20-1.56; 45-54: RR=1.32, CI:1.14-1.53) compared with <35 years, for persons diagnosed with HCV since 2009 (RR=1.34, 95% CI:1.21-1.49), and for prison and hospital referrals (RRs of 1.30, 1.37) compared with GP referrals.

CONCLUSION

Increasing DR mortality rates in Scotland over the past decade are not just due to an ageing cohort. Harm reduction services will likely need to expand and adapt to reverse the recent upward trends in DR mortality in PWID.

National population prevalence of antibodies to SARS-CoV-2 among pregnant women in Scotland during the second wave of the COVID-19 pandemic: a prospective national serosurvey

OBJECTIVES

This study aimed to determine SARS-CoV-2 seroprevalence among pregnant women in the Scottish population during the second wave of the COVID-19 pandemic.

STUDY DESIGN

Prospective national serosurvey.

METHODS

We tested 13,428 residual samples retrieved from pregnant women participating in the first trimester combined ultrasound and biochemical screening for fetal trisomy across Scotland for SARS-CoV-2 antibodies over a 6-month period from November 2020 to April 2021. Seroprevalence estimates were adjusted for the sensitivity and specificity of the assays and weighted to reference populations.

RESULTS

Seroprevalence rates in the antenatal samples significantly increased from 5.5% (95% confidence interval [CI] 4.7%-6.5%) in the 5-week period up to and including International Organization for Standardization (ISO) Week 51 (w/b Monday 14 December 2020) to 11.3% (95% CI 10.1%-12.6%) in the 5-week period up to and including ISO Week 14 (w/b Monday 5 April 2021). Increasing seroprevalence trends across the second wave were observed among all age groups.

CONCLUSIONS

By the end of the second wave of the COVID-19 pandemic, approximately one in 10 women tested around the end of the first trimester of pregnancy had antibodies to SARS-CoV-2, suggesting that the vast majority were still susceptible to COVID-19 as they progressed to the later stages of pregnancy, when risks from infection are elevated for both mother and baby.

Increased case-finding and uptake of direct-acting antiviral treatment essential for micro-elimination of hepatitis C among people living with HIV: a national record linkage study

OBJECTIVES

Micro-elimination of hepatitis C virus (HCV) in people living with HIV (PLHIV) and co-infected with HCV has been proposed as a key contribution to the overall goal of HCV elimination. While other studies have examined micro-elimination in HIV-treated cohorts, few have considered HCV micro-elimination among those not treated for HIV or at a national level.

METHODS

Through data linkage of national and sentinel surveillance data, we examined the extent of HCV testing, diagnosis and treatment among a cohort of PLHIV in Scotland identified through the national database of HIV-diagnosed individuals, up to the end of 2017.

RESULTS

Of 5018 PLHIV, an estimated 797 (15%) had never been tested for HCV and 70 (9%) of these had undiagnosed chronic HCV. The odds of never having been tested for HCV were the highest in those not on HIV treatment [adjusted odds ratio (aOR) = 7.21, 95% confidence interval (CI): 5.15-10.10). Overall HCV antibody positivity was 11%, and it was at its highest among people who inject drugs (49%). Most of those with chronic HCV (91%) had attended an HCV treatment clinic but only half had been successfully treated (54% for those on HIV treatment, 12% for those not) by the end of 2017. The odds of never having been treated for HCV were the highest in those not on HIV treatment (aOR = 3.60, 95% CI: 1.59-8.15).

CONCLUSIONS

Our data demonstrate that micro-elimination of HCV in PLHIV is achievable but progress will require increased effort to engage and treat those co-infected, including those not being treated for their HIV.

Physical Plasticity of the Brain and Deep Brain Stimulation Lead: Evolution in the First Post-operative Week

Background: Deep brain stimulation (DBS) is a therapy for movement disorders and psychiatric conditions. In the peri-operative period, brain shift occurs as the consequence of events related to the brain surgery which results in post-operative lead deformation. Objective: To quantify post-operative 3-dimensional DBS lead deformation after implantation. Methods: In 13 patients who had DBS lead implantation, we performed preoperative magnetic resonance imaging (MRI), preoperative computed tomography (CT) scans after placement of fiducial markers, and post-operative CT scans immediately, 24-48 h, and 7 days after implantation. The MRI scans were used to define brain orientation and merged with CT scans. Lead deviation was determined relative to a theoretical linear lead path defined by the skull entry and target lead tip points. Results: In the sagittal plane, we distinguished an initial period after surgery (<48 h) characterized by a deviation of the lead toward the rostral direction and a late period (over 1 week) characterized by a lead deviation toward the caudal direction. In the coronal plane, there was higher probability of lead deviation in the lateral than medial direction. During 7 days after implantation, there was net movement of the center of the lead anteriorly, and the half of the lead close to the entry point moved medially. These deviations appeared normative since all patients included in this study had benefits from DBS therapy with total power of charged comparable to those described in literature. Conclusion: DBS lead deviation occurs during 7 days after implantation. The range of deviation described in this study was not associated to adverse clinical effects and may be considered normative. Future multicenter studies would be helpful to define guide lines on DBS lead deformation and its contribution to clinical outcome.

A European multicentre evaluation of detection and typing methods for human enteroviruses and parechoviruses using RNA transcripts

Polymerase chain reaction (PCR) detection has become the gold standard for diagnosis and typing of enterovirus (EV) and human parechovirus (HPeV) infections. Its effectiveness depends critically on using the appropriate sample types and high assay sensitivity as viral loads in cerebrospinal fluid samples from meningitis and sepsis clinical presentation can be extremely low. This study evaluated the sensitivity and specificity of currently used commercial and in-house diagnostic and typing assays. Accurately quantified RNA transcript controls were distributed to 27 diagnostic and 12 reference laboratories in 17 European countries for blinded testing. Transcripts represented the four human EV species (EV-A71, echovirus 30, coxsackie A virus 21, and EV-D68), HPeV3, and specificity controls. Reported results from 48 in-house and 15 commercial assays showed 98% detection frequencies of high copy (1000 RNA copies/5 µL) transcripts. In-house assays showed significantly greater detection frequencies of the low copy (10 copies/5 µL) EV and HPeV transcripts (81% and 86%, respectively) compared with commercial assays (56%, 50%; P = 7 × 10-5 ). EV-specific PCRs showed low cross-reactivity with human rhinovirus C (3 of 42 tests) and infrequent positivity in the negative control (2 of 63 tests). Most or all high copy EV and HPeV controls were successfully typed (88%, 100%) by reference laboratories, but showed reduced effectiveness for low copy controls (41%, 67%). Stabilized RNA transcripts provide an effective, logistically simple and inexpensive reagent for evaluation of diagnostic assay performance. The study provides reassurance of the performance of the many in-house assay formats used across Europe. However, it identified often substantially reduced sensitivities of commercial assays often used as point-of-care tests.

Assessing the impact of mailing self-sampling kits for human papillomavirus testing to unscreened non-responder women in Manitoba

Background

CervixCheck, Manitoba's cervical cancer screening program, conducted a pilot study to assess whether screening participation could be improved in unscreened women by offering a mailed self-sampling kit for human papillomavirus (hpv) testing instead of a Pap test.

Methods

In a prospective cohort study design, a sample of unscreened women (n = 1052) who had been sent an invitation letter from CervixCheck in the past but who did not respond were randomized to either an intervention group or a control group. The intervention group received a mailed hpv self-sampling kit; the control group received no additional communication. Returned hpv self-sampling swabs were analyzed by a provincial laboratory. After 6 months, screening participation in the two study groups was compared using a logistic regression model adjusted for age and area of residence (urban or rural). Secondary outcomes included hpv positivity, specimen inadequacy, compliance with follow-up, and time to colposcopy.

Results

Screening participation was significantly higher in the intervention group than in the control group (n = 51, 9.6%, vs. n = 13, 2.5%; odds ratio: 4.7; 95% confidence interval: 2.56 to 8.77). Geographic area of residence (urban or rural) and age were not statistically significant.

Conclusions

The study demonstrated that hpv self-sampling kits can enhance screening participation in unscreened non-responder women in the setting of an organized screening program. Next steps should include additional research to determine the best implementation strategy for hpv self-sampling in Manitoba.

Prevalence of mixed genotype hepatitis C virus infections in the UK as determined by genotype-specific PCR and deep sequencing

The incidence of mixed genotype hepatitis C virus (HCV) infections in the UK is largely unknown. As the efficacy of direct-acting antivirals is variable across different genotypes, treatment regimens are tailored to the infecting genotype, which may pose issues for the treatment of underlying genotypes within undiagnosed mixed genotype HCV infections. There is therefore a need to accurately diagnose mixed genotype infections prior to treatment. PCR-based diagnostic tools were developed to screen for the occurrence of mixed genotype infections caused by the most common UK genotypes, 1a and 3, in a cohort of 506 individuals diagnosed with either of these genotypes. The overall prevalence rate of mixed infection was 3.8%; however, this rate was unevenly distributed, with 6.7% of individuals diagnosed with genotype 3 harbouring genotype 1a strains and only 0.8% of samples from genotype 1a patients harbouring genotype 3 (P < .05). Mixed infection samples consisted of a major and a minor genotype, with the latter constituting less than 21% of the total viral load and, in 67% of cases, less than 1% of the viral load. Analysis of a subset of the cohort by Illumina PCR next-generation sequencing resulted in a much greater incidence rate than obtained by PCR. This may have occurred due to the nonquantitative nature of the technique and despite the designation of false-positive thresholds based on negative controls.

Imported case of measles in a university setting leading to an outbreak of measles in Edinburgh, Scotland from September to December 2016

In September 2016, an imported case of measles in Edinburgh in a university student resulted in a further 17 confirmed cases during October and November 2016. All cases were genotype D8 and were associated with a virus strain most commonly seen in South East Asia. Twelve of the 18 cases were staff or students at a university in Edinburgh and 17 cases had incomplete or unknown measles mumps rubella (MMR) vaccination status. The public health response included mass follow-up of all identified contacts, widespread communications throughout universities in Edinburgh and prompt vaccination clinics at affected campuses. Imported cases of measles pose a significant risk to university student cohorts who may be undervaccinated, include a large number of international students and have a highly mobile population. Public health departments should work closely with universities to promote MMR uptake and put in place mass vaccination plans to prevent rapidly spreading measles outbreaks in higher educational settings in future.

Emergence of a novel GII.17 norovirus – End of the GII.4 era?

In the winter of 2014/15 a novel GII.P17-GII.17 norovirus strain (GII.17 Kawasaki 2014) emerged, as a major cause of gastroenteritis outbreaks in China and Japan. Since their emergence these novel GII.P17-GII.17 viruses have replaced the previously dominant GII.4 genotype Sydney 2012 variant in some areas in Asia but were only detected in a limited number of cases on other continents. This perspective provides an overview of the available information on GII.17 viruses in order to gain insight in the viral and host characteristics of this norovirus genotype. We further discuss the emergence of this novel GII.P17-GII.17 norovirus in context of current knowledge on the epidemiology of noroviruses. It remains to be seen if the currently dominant norovirus strain GII.4 Sydney 2012 will be replaced in other parts of the world. Nevertheless, the public health community and surveillance systems need to be prepared in case of a potential increase of norovirus activity in the next seasons caused by this novel GII.P17-GII.17 norovirus.

Burden of influenza B virus infections in Scotland in 2012/13 and epidemiological investigations between 2000 and 2012

We describe the burden of influenza B infections in Scotland during a 13-year study period. Influenza A and B viruses cocirculated throughout the period, with numbers of influenza B cases approaching or exceeding those of influenza A during six influenza seasons. Influenza B viruses of both Victoria and Yamagata lineage were detected in two of six seasons investigated. For the 2012/13 season, influenza B accounted for 44.4% of all influenzas, with the highest incidence in those under the age of five years. Influenza B virus infections led to fewer admissions to an intensive care unit (ICU) and a lower mortality rate than influenza A (37 vs 81 ICU admissions and three vs 29 deaths) during the 2012/13 season. However, a quarter of those admitted to ICU with influenza B had not been immunised and 60% had not received specific influenza antiviral therapy. This highlights the need for consistent influenza vaccination and prompt usage of antiviral treatment for identified risk groups. Combining the newly introduced vaccination programme for children with the use of a tetravalent vaccine may provide the opportunity to improve the control of influenza B in those with the highest influenza B burden, children and young adolescents.

Comparison of diagnostic clinical samples and environmental sampling for enterovirus and parechovirus surveillance in Scotland, 2010 to 2012

Human enteroviruses (EV) and parechoviruses (HPeV) within the family Picornaviridae are the most common causes of viral central nervous system (CNS)-associated infections including meningitis and neonatal sepsis-like disease. The frequencies of EV and HPeV types identified in clinical specimens collected in Scotland over an eight-year period were compared to those identified in sewage surveillance established in Edinburgh. Of the 35 different EV types belonging to four EV species (A to D) and the four HPeV types detected in this study, HPeV3 was identified as the most prevalent picornavirus in cerebrospinal fluid samples, followed by species B EV. Interestingly, over half of EV and all HPeV CNS-associated infections were observed in young infants (younger than three months). Detection of species A EV including coxsackievirus A6 and EV71 in clinical samples and sewage indicates that these viruses are already widely circulating in Scotland. Furthermore, species C EV were frequently identified EV in sewage screening but they were not present in any of 606 EV-positive clinical samples studied, indicating their likely lower pathogenicity. Picornavirus surveillance is important not only for monitoring the changing epidemiology of these infections but also for the rapid identification of spread of emerging EV and/or HPeV types.

Atypical hand, foot, and mouth disease associated with coxsackievirus A6 infection, Edinburgh, United Kingdom, January to February 2014

In January to February 2014, 16 hand, foot and mouth disease (HFMD) cases were identified in Edinburgh, United Kingdom. All presented with atypical features, with most (n=13) resembling eczema herpeticum or chickenpox. Coxsackievirus A6 (CV-A6) was identified in all the typed cases (n=11). As atypical forms of HFMD associated with CV-A6 are likely to emerge throughout Europe, clinicians should be alert to unusual clinical presentations of HFMD and virologists aware of effective diagnostic testing and enterovirus typing methods.

Comparing HIV viral load assays and frequency of low level virological rebound in clinical practice

Research suggests that some low-level virological rebound results occurring for no obvious clinical cause, in patients stable on antiretroviral therapy (ART), may be a consequence of the viral load assay used. We compared the relative frequency of clinically unexplained low-level virological rebound results when using the Roche HIV Taqman version-1 (CTM v1), the Roche HIV Taqman version-2 (CTM v2) and the Abbott RealTime (Abbott RT) assays in clinical practice. In all, 247 patients from our centre who had their viral loads measured by the three different assays over a period of 3 consecutive years (each assay used for a period of 1 year each) were included in the study. Low-level virological rebound was defined as <1000 copies/ml. Over similar time periods, there was significant discrepancy between the three assays when considering the proportion of clinically unexplained low-level virological rebound results in patients stable on ART: the CTM v2 assay produced the highest percentage (93%), CTM v1 much lower (65%) and Abbott RT even less (35%). There is further research required regarding what, if any, implications this has for patients who experience clinically unexplained low-level virological rebound on the more sensitive assays.

Prison and community outbreak of severe respiratory infection due to adenovirus type 14p1 in Tayside, UK

BACKGROUND

This report describes the investigation and public health management of a community-based outbreak of severe adenovirus serotype 14p1 respiratory infection affecting the Tayside area during 2011. It is the first report of an adenovirus outbreak involving prisons.

METHODS

An outbreak-based/incident management approach was carried out. Alerts were sent out to local doctors, general practitioners, prison healthcare staff and consultants so that cases could be identified prospectively. Sequencing of hexon, fibre and E1A regions of adenovirus were carried out to genotype the viruses.

RESULTS

Fifteen cases were identified in total, including 13 confirmed cases and 2 possible cases. There were 3 deaths amongst the 13 confirmed cases, with a case fatality rate of 23%. Eight of the cases had a direct association with one of the two prisons in the area.

CONCLUSIONS

We advise that surveillance measures for adenovirus infection and guidelines for the management of critically ill patients should be developed in order to identify outbreaks at an early stage and allow patients to receive appropriate treatment. Adenovirus infection should be borne in mind as a cause of severe pneumonia in closed settings such as prisons.

Genome-wide single nucleotide polymorphism-based assay for high-resolution epidemiological analysis of the methicillin-resistant Staphylococcus aureus hospital clone EMRSA-15

The EMRSA-15 clone is a major cause of nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infections in the UK and elsewhere but existing typing methodologies have limited capacity to discriminate closely related strains, and are often poorly reproducible between laboratories. Here, we report the design, development and validation of a genome-wide single nucleotide polymorphism (SNP) typing method and compare it to established methods for typing of EMRSA-15. In order to identify discriminatory SNPs, the genomes of 17 EMRSA-15 strains, selected to represent the breadth of genotypic and phenotypic diversity of EMRSA-15 isolates in Scotland, were determined and phylogenetic reconstruction was carried out. In addition to 17 phylogenetically informative SNPs, five binary markers were included to form the basis of an EMRSA-15 genotyping assay. The SNP-based typing assay was as discriminatory as pulsed-field gel electrophoresis, and significantly more discriminatory than staphylococcal protein A (spa) typing for typing of a representative panel of diverse EMRSA-15 strains, isolates from two EMRSA-15 hospital outbreak investigations, and a panel of bacteraemia isolates obtained in healthcare facilities in the east of Scotland during a 12-month period. The assay is a rapid, and reproducible approach for epidemiological analysis of EMRSA-15 clinical isolates in Scotland. Unlike established methods the DNA sequence-based method is ideally suited for inter-laboratory comparison of identified genotypes, and its flexibility lends itself to supplementation with additional SNPs or markers for the identification of novel S. aureus strains in other regions of the world.

Cytokine responses in patients with mild or severe influenza A(H1N1)pdm09

BACKGROUND

Influenza virus affects millions of people worldwide each year. More severe infection occurs in the elderly, very young and immunocompromised. In 2009, a new variant of swine origin (influenza A(H1N1)pdm09 virus) emerged that produced severe disease in young healthy adults.

OBJECTIVES

The aim of this study was to determine whether cytokine concentrations are associated with clinical outcome in patients infected influenza A(H1N1)pdm09 virus.

STUDY DESIGN

Plasma concentration of 32 cytokines and growth factors were measured using a multiplex bead immunoassay and conventional ELISA in four patient groups. Patients with severe and mild influenza A(H1N1)pdm09 virus infection, rhinovirus infection and healthy volunteers were investigated. In addition, serial samples of respiratory secretions from five patients with severe influenza A(H1N1)pdm09 virus infection were examined.

RESULTS

The majority of cytokines measured were elevated in patients with viral respiratory infections compared to the healthy controls. Concentrations of IL-6, IL-10, IL-15, IP-10, IL-2R, HGF, ST2 and MIG were significantly higher (p<0.05) and EGF significantly lower (p=0.0001) in patients with severe influenza A(H1N1)pdm09 virus infection compared to those with mild influenza A(H1N1)pdm09 virus and rhinovirus infection.

CONCLUSIONS

A number of cytokines were found to be substantially elevated in patients with severe influenza A(H1N1)pdm09 virus infection. This supports and extends other published work suggesting a role for proinflammatory cytokines in influenza-induced lung pathology. Interestingly, EGF was significantly lower in patients with severe infection suggesting it is actively suppressed. As EGF has a role in role in cell proliferation and tissue repair, it may protect the lung from host or virus mediated damage.

Psittacosis outbreak in Tayside, Scotland, December 2011 to February 2012

A Tayside outbreak of psittacosis December 2011–February 2012 involved three confirmed and one probable cases. Confirmed cases were indistinguishable by sequencing of polymerase chain reaction (PCR) products. The epidemiological pattern suggested person-to-person spread as illness onset dates were consistent with the incubation period and no single common exposure could explain the infections. In particular the only common exposure for a healthcare worker case is overlap in place and time with the symptomatic index case.

High detection frequency and viral loads of human rhinovirus species A to C in fecal samples; diagnostic and clinical implications

Human rhinoviruses (HRVs) can be divided into three species; HRV-A to HRV-C. Up to 148 different HRV (sero)types have been identified to date. Because of sequence similarity between 5'-NCR of HRVs and enteroviruses (EVs), it is problematic to design EV-specific RT-PCR assays. The aims of this study were to assess the rate of false-detection of different rhinoviruses by EV RT-PCR, and to evaluate the diagnostic and clinical significance of such cross-reactivity. In vitro RNA transcripts of HRV A-C created from cDNA templates were quantified spectrophotometrically. Six hundred twenty-one stool samples screened as part of routine diagnostic for EV, 17 EV-positive stool samples referred for typing, 288 stool samples submitted for gastroenteritis investigations, and 1,500 CSF samples were included in the study. EV-specific RT-PCR detected RNA transcripts of HRV-A1b, HRV-B14, and HRV-Crpat18 but with 10-1,000 reduced sensitivity compared to EV transcripts. Screening fecal samples by EV RT-PCR identified 13 positive samples identified subsequently as rhinoviruses; a further 26 HRV-positive samples were identified by nested HRV RT-PCR. All individuals were hospitalized and presented mostly with diarrhea. A total of 26 HRV types were identified (HRV-A: 46%; HRV-B: 13%; HRV-C: 41%). Results confirm that EV-specific RT-PCR can detect HRVs, and at a practical level, identify potential problems of interpretation if fecal samples are used for surrogate screening in cases of suspected viral meningitis. High detection frequencies (10%) and viral loads in stool samples provide evidence for enteric replication of HRV, and its association with enteric disease requires further etiological studies.

The emergence of oseltamivir-resistant pandemic influenza A(H1N1) 2009 virus amongst hospitalised immunocompromised patients in Scotland, November-December, 2009

To investigate the frequency of oseltamivir resistance in circulating strains of the 2009 influenza A(H1N1) pandemic virus in Scotland, 1,802 samples from 1,608 infected hospitalised patients were screened by the H275Y discriminatory RT-PCR. Among these, we identified 10 patients who developed the H275Y mutation. All of them were immunocompromised and were under treatment or had been treated previously with oseltamivir.

The emergence of oseltamivir-resistant pandemic influenza A (H1N1) 2009 virus amongst hospitalised immunocompromised patients in Scotland, November-December, 2009

To investigate the frequency of oseltamivir resistance in circulating strains of the 2009 influenza A(H1N1) pandemic virus in Scotland, 1,802 samples from 1,608 infected hospitalised patients were screened by the H275Y discriminatory RT-PCR. Among these, we identified 10 patients who developed the H275Y mutation. All of them were immunocompromised and were under treatment or had been treated previously with oseltamivir.

Specific association of human parechovirus type 3 with sepsis and fever in young infants, as identified by direct typing of cerebrospinal fluid samples

BACKGROUND

Human parechoviruses (HPeVs), along with human enteroviruses (HEVs), are associated with neonatal sepsis and meningitis. We determined the relative importance of these viruses and the specific HPeV types involved in the development of central nervous system-associated disease.

METHODS

A total of 1575 cerebrospinal fluid (CSF) samples obtained during 2006-2008 were screened for HPeV by means of nested polymerase chain reaction. All samples for which results were positive were typed by sequencing of viral protein (VP) 3/VP1. Screening for HEV was performed in parallel, as was detection of HPeV in respiratory and fecal surveillance samples, to identify virus types circulating in the general population.

RESULTS

HPeV was detected in 14 CSF samples obtained exclusively from young infants (age, <3 months) with sepsis or pyrexia. The frequency of detection of HPeVs varied greatly by year, with the highest frequency (7.2%) noted in 2008 exceeding that of HEVs. Direct typing of CSF samples revealed that all infections were caused by HPeV type 3, a finding that is in contrast to the predominant circulation of HPeV1 in contemporary respiratory and fecal surveillance samples.

CONCLUSION

HPeV was a significant cause of severe sepsis and fever with central nervous system involvement in young infants, rivaling enteroviruses. The specific targeting of young infants by HPeV type 3 may reflect a difference in tissue tropism between virus types or a lack of protection of young infants by maternal antibody consequent to the recent emergence of HPeV.

Retrospective immunohistochemical study of VDR, RXR, Ki-67, and Bcl-2 expression in primary and metastatic osteosarcoma

e21516

Background: Osteosarcoma (OS) is a highly malignant tumor with a peak incidence in adolescents and young adults. Patient's prognosis is limited to clinical parameters whereas molecular markers of tumor aggression are yet to be identified. Vitamin D (Vit D) has been postulated as a novel therapeutic option for a variety of malignancies such as breast and prostatic carcinomas. The biologic effect of vitamins is mainly mediated through receptors. Vit D receptors (VDRs) are members of the steroid hormone superfamily and are ubiquitous in a various tissues including bone. Upon activation by its ligand, VDR combines with retinoid receptor (RXR) forming a heterodimer initiating a cascade of cellular events. How Vit D induces its antineoplastic activity in OS remains to be elucidated. Methods: Immunohistochemical analysis for VDR, RXR, Ki-67, and bcl-2 was performed on 87 OS specimens to evaluate differentiation, proliferation and apoptosis. Clinical data including site of the primary tumor, presence or absence of metastasis, therapeutic regimens, and outcome were recorded. Results: The mean age of OS patients is 25.7 years (range 7–68). Fifty-four patients were <30 years. Thirty-five OSs were conventional, 17 chondroblastic, 6 giant cell, 6 fibroblastic, 6 mixed, 3 telangiectatic, and 2 epithelioid variants. Twelve of the 87 samples were metastatic. All metastatic OSs were high grade, located in the lungs with a mean age of 25 years (range 7–52). The majority of the OSs expressed VDR (74/87, 85%) and RXR (72/78, 92%). Proliferative activity varied between tumors types with highest Ki-67 percentage noticed in conventional variant (29%), followed by chondroblastic variant (16%). Metastatic tumors consistently had the highest proliferative activity as compared to primary tumors (35%). None of the tumors studied was immunoreactive for bcl-2. Conclusions: Our results demonstrate that VDR and RXR are expressed on most OSs. A significant relationship exists between tumor histologic types and proliferative activity. Metastatic OSs appears to have a significantly higher level of proliferative activity as compared to primary tumors. These results would establish a foundation for elucidating mechanisms by which Vit D induces its antineoplastic activity in OS.

No significant financial relationships to disclose.

Specific and sensitive diagnosis of syphilis using a real-time PCR for Treponema pallidum

A real-time PCR assay with a Taqman probe was developed that targeted the polA gene of Treponema pallidum. The test was validated using an analytical panel (n = 140) and a clinical panel of genital samples (n = 112) from patients attending a sexually transmitted infections clinic. High sensitivities and specificities of 94-100% were achieved using two real-time PCR platforms, the Rotor-Gene and the iCycler. The assay can be completed within 2 h, enabling reporting in <8 h. This fast and robust assay is suitable for implementation in routine laboratories for diagnosing primary syphilis.