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"Douthwaite, Sam"
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Clinical features and novel presentations of human monkeypox in a central London centre during the 2022 outbreak: descriptive case series
2022
AbstractObjectiveTo characterise the clinical features of monkeypox infection in humans.DesignDescriptive case series.SettingA regional high consequences infectious disease centre with associated primary and secondary care referrals, and affiliated sexual health centres in south London between May and July 2022.Participants197 patients with polymerase chain reaction confirmed monkeypox infection.ResultsThe median age of participants was 38 years. All 197 participants were men, and 196 identified as gay, bisexual, or other men who have sex with men. All presented with mucocutaneous lesions, most commonly on the genitals (n=111 participants, 56.3%) or in the perianal area (n=82, 41.6%). 170 (86.3%) participants reported systemic illness. The most common systemic symptoms were fever (n=122, 61.9%), lymphadenopathy (114, 57.9%), and myalgia (n=62, 31.5%). 102/166 (61.5%) developed systemic features before the onset of mucocutaneous manifestations and 64 (38.5%) after (n=4 unknown). 27 (13.7%) presented exclusively with mucocutaneous manifestations without systemic features. 71 (36.0%) reported rectal pain, 33 (16.8%) sore throat, and 31 (15.7%) penile oedema. 27 (13.7%) had oral lesions and 9 (4.6%) had tonsillar signs. 70/195 (35.9%) participants had concomitant HIV infection. 56 (31.5%) of those screened for sexually transmitted infections had a concomitant sexually transmitted infection. Overall, 20 (10.2%) participants were admitted to hospital for the management of symptoms, most commonly rectal pain and penile swelling.ConclusionsThese findings confirm the ongoing unprecedented community transmission of monkeypox virus among gay, bisexual, and other men who have sex with men seen in the UK and many other non-endemic countries. A variable temporal association was observed between mucocutaneous and systemic features, suggesting a new clinical course to the disease. New clinical presentations of monkeypox infection were identified, including rectal pain and penile oedema. These presentations should be included in public health messaging to aid early diagnosis and reduce onward transmission.
Journal Article
Longitudinal observation and decline of neutralizing antibody responses in the three months following SARS-CoV-2 infection in humans
by
Martinez-Nunez, Rocio
,
Edgeworth, Jonathan D.
,
Graham, Carl
in
38/109
,
631/250/2152
,
631/250/254
2020
Antibody responses to SARS-CoV-2 can be detected in most infected individuals 10–15 d after the onset of COVID-19 symptoms. However, due to the recent emergence of SARS-CoV-2 in the human population, it is not known how long antibody responses will be maintained or whether they will provide protection from reinfection. Using sequential serum samples collected up to 94 d post onset of symptoms (POS) from 65 individuals with real-time quantitative PCR-confirmed SARS-CoV-2 infection, we show seroconversion (immunoglobulin (Ig)M, IgA, IgG) in >95% of cases and neutralizing antibody responses when sampled beyond 8 d POS. We show that the kinetics of the neutralizing antibody response is typical of an acute viral infection, with declining neutralizing antibody titres observed after an initial peak, and that the magnitude of this peak is dependent on disease severity. Although some individuals with high peak infective dose (ID
50
> 10,000) maintained neutralizing antibody titres >1,000 at >60 d POS, some with lower peak ID
50
had neutralizing antibody titres approaching baseline within the follow-up period. A similar decline in neutralizing antibody titres was observed in a cohort of 31 seropositive healthcare workers. The present study has important implications when considering widespread serological testing and antibody protection against reinfection with SARS-CoV-2, and may suggest that vaccine boosters are required to provide long-lasting protection.
Neutralizing antibody responses of patients infected with SARS-CoV-2 peak at 3–4 weeks post onset of symptoms, then decline to low levels over the course of 3 months in some individuals.
Journal Article
Comparative assessment of multiple COVID-19 serological technologies supports continued evaluation of point-of-care lateral flow assays in hospital and community healthcare settings
2020
There is a clear requirement for an accurate SARS-CoV-2 antibody test, both as a complement to existing diagnostic capabilities and for determining community seroprevalence. We therefore evaluated the performance of a variety of antibody testing technologies and their potential use as diagnostic tools. Highly specific in-house ELISAs were developed for the detection of anti-spike (S), -receptor binding domain (RBD) and -nucleocapsid (N) antibodies and used for the cross-comparison of ten commercial serological assays-a chemiluminescence-based platform, two ELISAs and seven colloidal gold lateral flow immunoassays (LFIAs)-on an identical panel of 110 SARS-CoV-2-positive samples and 50 pre-pandemic negatives. There was a wide variation in the performance of the different platforms, with specificity ranging from 82% to 100%, and overall sensitivity from 60.9% to 87.3%. However, the head-to-head comparison of multiple sero-diagnostic assays on identical sample sets revealed that performance is highly dependent on the time of sampling, with sensitivities of over 95% seen in several tests when assessing samples from more than 20 days post onset of symptoms. Furthermore, these analyses identified clear outlying samples that were negative in all tests, but were later shown to be from individuals with mildest disease presentation. Rigorous comparison of antibody testing platforms will inform the deployment of point-of-care technologies in healthcare settings and their use in the monitoring of SARS-CoV-2 infections.
Journal Article
An innovative approach to increase viral hepatitis diagnoses and linkage to care using opt-out testing and an integrated care pathway in a London Emergency Department
2018
Therapies that halt progression of chronic hepatitis B virus (HBV) and achieve a cure for chronic hepatitis C virus (HCV) have encouraged development of innovative strategies to diagnose and link patients to care. We describe the prevalence and risk factors for HBV and HCV infections and use of an opt-out hepatitis testing and integrated linkage to care pathway in a London Emergency Department (ED). ED patients aged ≥16 years having routine blood tests from 15 February-28 March 2016 were tested for hepatitis, unless opted out. Hepatitis B surface antigen (HBsAg) and hepatitis C antibody tests (HCV-Ab, including a confirmatory hepatitis C antigen test (HCV-Ag)) were pre-selected on electronic blood test requests. Linkage to care (attending one clinic appointment) was offered to HBsAg and HCV-Ag patients (new or known-disengaged with care diagnoses). Weighted prevalence estimates and risk factors for seropositivity adjusted by demographics and survey weights were calculated using logistic regression. Hepatitis testing uptake was 56% (3,290/5,865). Overall, 26 HBsAg (10 new diagnoses) and 63 HCV-Ab patients were identified of which 32 were HCV-Ag positive (10 new diagnoses). Weighted seroprevalence of HBsAg was 0.50% (95% CI 0.3-0.8%); HCV-Ab 2.0% (95% CI 1.5-2.7%) and HCV-Ag 1.2% (95% CI 0.8-1.7%). Risk factors for infection were being male (HBsAg: aOR 4.1, 95% CI 1.5-11.3), of non-White British ethnicity (HBsAg: aOR>11) or being homeless (HCV-Ag: aOR 18.9, 95% CI 6.9-51.4). We achieved a high linkage to care uptake for HBsAg (93%) and HCV-Ag (78%) among patients who were contacted and required linkage. A pre-selected hepatitis testing ordering system facilitated a high testing uptake. New and disengaged with care diagnoses and a high HCV prevalence were identified demonstrating the potential to identify and link patients to care in this setting. Strategies connecting clinical care with community outreach services are key for improving patient linkage to care.
Journal Article
Rapid genome sequencing in hospitals to identify potential vaccine-escape SARS-CoV-2 variants
by
Snell, Luke B
,
Flaviani, Flavia
,
Alcolea-Medina, Adela
in
Correspondence
,
COVID-19
,
COVID-19 - diagnosis
2021
SARS-CoV-2 genome sequencing is embedded in academic and public health laboratories, but whether there are benefits to rapid sequencing in front-line hospital laboratories is unclear. [...]we did PCR-based genotyping of all new SARS-CoV-2 cases for three south London hospitals (Guy's and St Thomas', King's College, and Princess Royal University) using the AusDiagnostics SARS-CoV-2 Typing Panel (16-well) on the AusDiagnostics HighPlex, sequencing any non-typeable results. Previous studies have shown the ability of this technology to provide sequencing data in 24 h.8 This workflow can complete in 8 h, allowing whole-genome sequencing and variant reporting to be completed on the same day as sample positivity.
Journal Article
Clinical practice guideline management of blood borne viruses within the haemodialysis unit
by
Douthwaite, Sam
,
Garthwaite, Elizabeth
,
Lines, Simon
in
Guidelines
,
Guidelines and Policy
,
Internal Medicine
2019
Some people who are receiving dialysis treatment have virus infection such as hepatitis B, hepatitis C and/or HIV that is present in their blood. These infections can be transmitted to other patients if blood is contaminated by the blood of another with a viral infection. Haemodialysis is performed by passing blood from a patient through a dialysis machine, and multiple patients receive dialysis within a dialysis unit. Therefore, there is a risk that these viruses may be transmitted around the dialysis session. This documents sets out recommendations for minimising this risk.
There are sections describing how machines and equipment should be cleaned between patients. There are also recommendations for dialysing patients with hepatitis B away from patients who do not have hepatitis B. Patients should be immunised against hepatitis B, ideally before starting dialysis if this is possible. There are guidelines on how and when to do this, for checking whether immunisation is effective, and for administering booster doses of vaccine. Finally there is a section on the measures that should be taken if a patient receiving dialysis is identified as having a new infection of hepatitis B, hepatitis C or HIV.
Journal Article
Detecting SARS-CoV-2 at point of care: preliminary data comparing loop-mediated isothermal amplification (LAMP) to polymerase chain reaction (PCR)
by
Lee, Karla A.
,
Horsfall, Rachel
,
Lochlainn, Mary Ni
in
Coronaviruses
,
COVID-19
,
Diagnostic software
2020
Background
A cost effective and efficient diagnostic tool for COVID-19 as near to the point of care (PoC) as possible would be a game changer in the current pandemic. We tested reverse transcription loop mediated isothermal amplification (RT-LAMP), a method which can produce results in under 30 min, alongside standard methods in a real-life clinical setting.
Methods
This prospective service improvement project piloted an RT-LAMP method on nasal and pharyngeal swabs on 21 residents of a high dependency care home, with two index COVID-19 cases, and compared it to multiplex tandem reverse transcription polymerase chain reaction (RT-PCR). We recorded vital signs of patients to correlate clinical and laboratory information and calculated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of a single swab using RT-LAMP compared with the current standard, RT-PCR, as per Standards for Reporting Diagnostic Accuracy Studies (STARD) guidelines.
Results
The novel method accurately detected 8/10 RT-PCR positive cases and identified a further 3 positive cases. Eight further cases were negative using both methods. Using repeated RT-PCR as a “gold standard”, the sensitivity and specificity of a single novel test were 80 and 73% respectively. PPV was 73% and NPV was 83%. Incorporating retesting of low signal RT-LAMP positives improved the specificity to 100%. We also speculate that hypothermia may be a significant early clinical sign of COVID-19.
Conclusions
RT-LAMP testing for SARS-CoV-2 was found to be promising, fast and to work equivalently to RT-PCR methods. RT-LAMP has the potential to transform COVID-19 detection, bringing rapid and accurate testing to the PoC. RT-LAMP could be deployed in mobile community testing units, care homes and hospitals to detect disease early and prevent spread.
Journal Article
Clinical utility of targeted SARS-CoV-2 serology testing to aid the diagnosis and management of suspected missed, late or post-COVID-19 infection syndromes: Results from a pilot service implemented during the first pandemic wave
2021
During the first wave of the global COVID-19 pandemic the clinical utility and indications for SARS-CoV-2 serological testing were not clearly defined. The urgency to deploy serological assays required rapid evaluation of their performance characteristics. We undertook an internal validation of a CE marked lateral flow immunoassay (LFIA) (SureScreen Diagnostics) using serum from SARS-CoV-2 RNA positive individuals and pre-pandemic samples. This was followed by the delivery of a same-day named patient SARS-CoV-2 serology service using LFIA on vetted referrals at central London teaching hospital with clinical interpretation of result provided to the direct care team. Assay performance, source and nature of referrals, feasibility and clinical utility of the service, particularly benefit in clinical decision-making, were recorded. Sensitivity and specificity of LFIA were 96.1% and 99.3% respectively. 113 tests were performed on 108 participants during three-week pilot. 44% participants (n = 48) had detectable antibodies. Three main indications were identified for serological testing; new acute presentations potentially triggered by recent COVID-19 e.g. pulmonary embolism (n = 5), potential missed diagnoses in context of a recent COVID-19 compatible illness (n = 40), and making infection control or immunosuppression management decisions in persistently SARS-CoV-2 RNA PCR positive individuals (n = 6). We demonstrate acceptable performance characteristics, feasibility and clinical utility of using a LFIA that detects anti-spike antibodies to deliver SARS-CoV-2 serology service in adults and children. Greatest benefit was seen where there is reasonable pre-test probability and results can be linked with clinical advice or intervention. Experience from this pilot can help inform practicalities and benefits of rapidly implementing new tests such as LFIAs into clinical service as the pandemic evolves.
Journal Article
Unified metagenomic method for rapid detection of microorganisms in clinical samples
2024
Background
Clinical metagenomics involves the genomic sequencing of all microorganisms in clinical samples ideally after depletion of human DNA to increase sensitivity and reduce turnaround times. Current human DNA depletion methods preferentially preserve either DNA or RNA containing microbes, but not both simultaneously. Here we describe and present data using a practical and rapid mechanical host-depletion method allowing simultaneous detection of RNA and DNA microorganisms linked with nanopore sequencing.
Methods
The human cells from respiratory samples are lysed mechanically using 1.4 mm zirconium-silicate spheres and the human DNA is depleted using a nonspecific endonuclease. The RNA is converted to dsDNA to allow the simultaneous sequencing of DNA and RNA.
Results
The method decreases human DNA concentration by a median of eight Ct values while detecting a broad range of RNA & DNA viruses, bacteria, including atypical pathogens (
Legionella
,
Chlamydia
,
Mycoplasma
) and fungi (
Candida, Pneumocystis, Aspergillus
). The first automated reports are generated after 30 min sequencing from a 7 h end-to-end workflow. Sensitivity and specificity for bacterial detection are 90% and 100%, respectively, and viral detection are 92% and 100% after 2 h of sequencing. Prospective validation on 33 consecutive lower respiratory tract samples from ventilated patients with suspected pneumonia shows 60% concordance with routine testing, detection of additional pathogens in 21% of samples and pathogen genomic assembly achieve for 42% of viruses and 33% of bacteria.
Conclusions
Although further workflow refinement and validation on samples containing a broader range of pathogens is required, it holds promise as a clinically deployable workflow suitable for evaluation in routine microbiology laboratories.
Plain language summary
Metagenomics is the analysis of genetic material from microbes such as bacteria and viruses in a sample. There are limitations with existing metagenomics methods, such as not being able to detect the full range of microbes present in a sample. This paper introduces an approach that identifies multiple types of microbes. This is accomplished through the mechanical disruption of human cells, which allows for an effective depletion of human genetic material. Our method demonstrates encouraging preliminary results within a 7 h process, achieving good sensitivity for the detection of bacteria and viruses. We demonstrate the identification of relevant microbes in samples from patients with respiratory infections. This technique holds promise for adoption in clinical settings, potentially enhancing our ability to diagnose respiratory infections quickly.
Alcolea-Medina et al. develop a rapid, unified metagenomics method for the detection of bacteria, fungi, and viruses from clinical respiratory samples. This method reduces human DNA content, allowing efficient pathogen detection and possibility of same-day reporting to meet requirements of clinical implementation.
Journal Article
Universal testing for hepatitis B and hepatitis C in the emergency department: a cost-effectiveness and budget impact analysis of two urban hospitals in the United Kingdom
2022
Background
Numerous studies have shown the effectiveness of testing for hepatitis B (HBV) and hepatitis C (HCV) in emergency departments (ED), due to the elevated prevalence amongst attendees. The aim of this study was to conduct a cost-effectiveness analysis of universal opt-out HBV and HCV testing in EDs based on 2 long-term studies of the real-world effectiveness of testing in 2 large ED’s in the UK.
Methods
A Markov model was used to evaluate ED-based HBV and HCV testing versus no ED testing, in addition to current testing practice. The two EDs had a HBV HBsAg prevalence of 0.5–0.9% and an HCV RNA prevalence of 0.9–1.0%. The analysis was performed from a UK health service perspective, over a lifetime time horizon. Costs are reported in British pounds (GBP), and outcomes as quality adjusted life years (QALYs), with both discounted at 3.5% per year. Incremental cost-effectiveness ratios (ICER) are calculated as costs per QALY gained. A willingness-to-pay threshold of £20,000/QALY was used. The cost-effectiveness was estimated for both infections, in both ED’s.
Results
HBV and HCV testing were highly cost-effective in both settings, with ICERs ranging from £7,177 to £12,387 per QALY gained. In probabilistic analyses, HBV testing was 89–94% likely to be cost-effective at the threshold, while HCV testing was 94–100% likely to be cost-effective, across both settings. In deterministic sensitivity analyses, testing remained cost-effective in both locations at ≥ 0.25% HBsAg prevalence, and ≥ 0.49% HCV RNA prevalence. This is much lower than the prevalence observed in the two EDs included in this study.
Conclusions
HBV and HCV testing in urban EDs is highly cost-effective in the UK, and can be cost-effective at relatively low prevalence. These results should be reflected in UK and European hepatitis testing guidelines.
Journal Article