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"Raja, Amber I"
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A SARS-CoV-2 outbreak in a plastics manufacturing plant
2023
Background
A SARS-CoV-2 outbreak with an attack rate of 14.3% was reported at a plastics manufacturing plant in England.
Methods
Between 23
rd
March and 13
th
May 2021, the COVID-OUT team undertook a comprehensive outbreak investigation, including environmental assessment, surface sampling, molecular and serological testing, and detailed questionnaires, to identify potential SARS-CoV-2 transmission routes, and workplace- and worker-related risk factors.
Results
While ventilation, indicated using real-time CO
2
proxy measures, was generally adequate on-site, the technical office with the highest localized attack rate (21.4%) frequently reached peaks in CO
2
of 2100ppm. SARS-CoV-2 RNA was found in low levels (Ct ≥35) in surface samples collected across the site. High noise levels (79dB) were recorded in the main production area, and study participants reported having close work contacts (73.1%) and sharing tools (75.5%). Only 20.0% of participants reported using a surgical mask and/or FFP2/FFP3 respirator at least half the time and 71.0% expressed concerns regarding potential pay decreases and/or unemployment due to self-isolation or workplace closure.
Conclusions
The findings reinforce the importance of enhanced infection control measures in manufacturing sectors, including improved ventilation with possible consideration of CO
2
monitoring, utilising air cleaning interventions in enclosed environments, and provision of good-quality face masks (i.e., surgical masks or FFP2/FFP3 respirators) especially when social distancing cannot be maintained. Further research on the impacts of job security-related concerns is warranted.
Journal Article
A SARS-CoV-2 outbreak investigation at a storage and distribution centre in England: an assessment of worker- and workplace-related risk factors
2024
An outbreak of SARS-CoV-2 (1 March to 10 May 2021) with an attack rate of 26.5% among approximately 1150 workers at a storage and distribution centre in England prompted a multidisciplinary outbreak investigation (5 May to 6 August 2021), with the aim of better understanding worker- and workplace-related risk factors for viral transmission in the warehousing sector. Overall, environmental factors (e.g., ventilation, humidity and temperature) were assessed to be appropriate at the facility. Nevertheless, 39 (51.3%) surface samples from across the site tested positive for low/ very low levels of SARS-CoV-2 RNA (Ct value ≥ 32.0 for all). Among the study participants, of whom 35.6% were confirmed or suspected cases, 95.5% reported having received COVID-19 prevention training, 100.0% reported handwashing, and 80.0% reported use of face coverings at work. Notably, 43.9% and 19.0% reported working with a symptomatic and a positive contact respectively. Furthermore, 80.5% and 46.3% had concerns regarding reduction in their income and future unemployment, respectively, due to self-isolation. The findings of this study suggest that, in addition to targeted workplace infection control measures and tailored work area specific risk assessments, an enhanced and equitable sick leave policy may help limit presenteeism and viral transmission in large workplaces.
Journal Article
Socioeconomic risk markers of arthropod-borne virus (arbovirus) infections: a systematic literature review and meta-analysis
by
Portela Souza, André
,
Pescarini, Julia M.
,
Vaughan, Aisling M
in
Animals
,
Arbovirus Infections - epidemiology
,
Arboviruses
2022
IntroductionArthropod-borne viruses (arboviruses) are of notable public health importance worldwide, owing to their potential to cause explosive outbreaks and induce debilitating and potentially life-threatening disease manifestations. This systematic review and meta-analysis aims to assess the relationship between markers of socioeconomic position (SEP) and infection due to arboviruses with mosquito vectors.MethodsWe conducted a systematic search on PubMed, Embase, and LILACS databases to identify studies published between 1980 and 2020 that measured the association of SEP markers with arbovirus infection. We included observational studies without geographic location or age restrictions. We excluded studies from grey literature, reviews and ecological studies. Study findings were extracted and summarised, and pooled estimates were obtained using random-effects meta-analyses.ResultsWe identified 36 observational studies using data pertaining to 106 524 study participants in 23 geographic locations that empirically examined the relationship between socioeconomic factors and infections caused by seven arboviruses (dengue, chikungunya, Japanese encephalitis, Rift Valley fever, Sindbis, West Nile and Zika viruses). While results were varied, descriptive synthesis pointed to a higher risk of arbovirus infection associated with markers of lower SEP, including lower education, income poverty, low healthcare coverage, poor housing materials, interrupted water supply, marital status (married, divorced or widowed), non-white ethnicities and migration status. Pooled crude estimates indicated an increased risk of arboviral infection associated with lower education (risk ratio, RR 1.5 95% CI 1.3 to 1.9); I2=83.1%), interruption of water supply (RR 1.2; 95% CI 1.1 to 1.3; I2=0.0%) and having been married (RR 1.5 95% CI 1.1 to 2.1; I2=85.2%).ConclusionEvidence from this systematic review suggests that lower SEP increases the risk of acquiring arboviral infection; however, there was large heterogeneity across studies. Further studies are required to delineate the relationship between specific individual, household and community-level SEP indicators and arbovirus infection risks to help inform targeted public health interventions.PROSPERO registration numberCRD42019158572.
Journal Article
Epidemic preparedness: Prenatal Zika virus screening during the next epidemic
by
Martelli, Celina M Turchi
,
Raja, Amber I
,
Qiao, Luxi
in
Analysis
,
Antiviral drugs
,
Arboviruses
2021
Zika virus (ZIKV) is a vectorborne infectious agent of global public health significance due to its potential to cause severe teratogenic outcomes. The question of whether health systems should consider adopting screening programmes for ZIKV infections during pregnancy warrants consideration. In this analysis, we apply the Wilson-Jungner framework to appraise the potential utility of a prenatal ZIKV screening programme, outline potential screening strategies within the case-finding pathway, and consider other epidemiological factors that may influence the planning of such a screening programme. Our evaluation of a potential prenatal ZIKV screening programme highlights factors affirming its usefulness, including the importance of Congenital Zika Syndrome as a public health problem and the existence of analogous congenital prenatal screening programmes for STORCH agents (syphilis, toxoplasmosis, others (eg, human immunodeficiency virus, varicella-zoster virus, parvovirus B19), rubella, cytomegalovirus, and herpes simplex virus). However, our assessment also reveals key barriers to implementation, such as the need for more accurate diagnostic tests, effective antiviral treatments, increased social service capacity, and surveillance. Given that the reemergence of ZIKV is likely, we provide a guiding framework for policymakers and public health leaders that can be further elaborated and adapted to different contexts in order to reduce the burden of adverse ZIKV-related birth outcomes during future outbreaks.
Journal Article
Binding and neutralising antibodies to respiratory syncytial virus and influenza A virus in serum and bronchoalveolar lavage fluid of healthy adults in the United States: A cross-sectional study
by
Ashare, Alix
,
Connor, Ruth I.
,
Wieland-Alter, Wendy F.
in
Adult
,
Adults
,
Allergy and Immunology
2025
Using serum and bronchoalveolar lavage (BAL) fluid collected from 20 healthy adults (23–37 years, 55 % female) in the United States, we measured immunoglobulin (Ig) A, IgG, and neutralising activity against respiratory syncytial virus (RSV) and influenza A (H1N1) virus. RSV-binding IgA and IgG measurements in serum were positively correlated with those in BAL. For influenza A (H1N1) virus, serum and BAL IgA antibodies were positively correlated, whereas IgG antibodies did not show a significant correlation. RSV-specific and influenza A (H1N1)-specific neutralising activity did not correlate between serum and BAL samples. These results demonstrate virus-specific correlations between antibodies in the serum and BAL that may not necessarily reflect correlations in functional activity. Further work is needed to confirm our preliminary observations, and define the immune correlates of neutralising activity to these and other respiratory viruses in the lower respiratory tract.
Journal Article
Investigation of a SARS-CoV-2 Outbreak at an Automotive Manufacturing Site in England
by
Frost, Gillian
,
Morgan, Derek
,
Coldwell, Matthew
in
Antibodies
,
Carbon dioxide
,
Coronaviruses
2022
Workplace-related outbreaks of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continue to occur globally. The manufacturing sector presents a particular concern for outbreaks, and a better understanding of transmission risks are needed. Between 9 March and 24 April 2021, the COVID-19 (coronavirus disease 2019) Outbreak Investigation to Understand Transmission (COVID-OUT) study undertook a comprehensive investigation of a SARS-CoV-2 outbreak at an automotive manufacturing site in England. The site had a total of 266 workers, and 51 SARS-CoV-2 infections. Overall, ventilation, humidity, and temperature at the site were assessed to be appropriate for the number of workers and the work being conducted. The company had implemented a number of infection control procedures, including provision of face coverings, spacing in the work, and welfare areas to allow for social distancing. However, observations of worker practices identified lapses in social distancing, although all were wearing face coverings. A total of 38 workers, including four confirmed cases, participated in the COVID-OUT study. The majority of participants received COVID-19 prevention training, though 42.9% also reported that their work required close physical contact with co-workers. Additionally, 73.7% and 34.2% had concerns regarding reductions in future income and future unemployment, respectively, due to self-isolation. This investigation adds to the growing body of evidence of SARS-CoV-2 outbreaks from the manufacturing sector. Despite a layered COVID-19 control strategy at this site, cases clustered in areas of high occupancy and close worker proximity.
Journal Article
A primate model of severe malarial anaemia: a comparative pathogenesis study
2019
Severe malarial anaemia (SMA) is the most common life-threatening complication of
Plasmodium falciparum
infection in African children. SMA is characterised by haemolysis and inadequate erythropoiesis, and is associated with dysregulated inflammatory responses and reduced complement regulatory protein levels (including CD35). However, a deeper mechanistic understanding of the pathogenesis requires improved animal models. In this comparative study of two closely related macaque species, we interrogated potential causal factors for their differential and temporal relationships to onset of SMA. We found that rhesus macaques inoculated with blood-stage
Plasmodium coatneyi
developed SMA within 2 weeks, with no other severe outcomes, whereas infected cynomolgus macaques experienced only mild/ moderate anaemia. The abrupt drop in haematocrit in rhesus was accompanied by consumption of haptoglobin (haemolysis) and poor reticulocyte production. Rhesus developed a greater inflammatory response than cynomolgus macaques, and had lower baseline levels of CD35 on red blood cells (RBCs) leading to a significant reduction in the proportion of CD35
+
RBCs during infection. Overall, severe anaemia in rhesus macaques infected with
P. coatneyi
has similar features to SMA in children. Our comparisons are consistent with an association of low baseline CD35 levels on RBCs and of early inflammatory responses with the pathogenesis of SMA.
Journal Article
Induction of immunity following vaccination with a chemically attenuated malaria vaccine correlates with persistent antigenic stimulation
by
Batzloff, Michael R
,
Gnidehou, Sedami
,
Kumar, Sanjai
in
Adoptive transfer
,
Antigens
,
cellular immunity
2018
Objectives Blood stage malaria parasites attenuated with seco‐cyclopropyl pyrrolo indole (CPI) analogues induce robust immunity in mice to homologous and heterologous malaria parasites and are being considered for the development of a human vaccine. However, it is not understood how attenuated parasites induce immunity. We showed that following vaccination, parasite DNA persisted in blood for several months, raising the possibility that ongoing immune stimulation may be critical. However, parasites were not seen microscopically beyond 24 h postvaccination. We aimed to provide a mechanistic understanding of immune induction. Methods Mice were vaccinated with chemically attenuated Plasmodium chabaudi parasites. PCR and adoptive transfer studies were used to determine the presence of parasites and antigen in vivo. In other experiments, Plasmodium falciparum parasitised red blood cells were attenuated in vitro and RNA and antigen expression studied. Results We show that blood transferred from vaccinated mice into naïve mice activates T cells and induces complete protective immunity in the recipient mice strongly suggesting that there is persistence of parasite antigen postvaccination. This is supported by the presence of parasite RNA in vaccinated mice and both RNA and antigen expression in P. falciparum cultures treated with CPI drugs in vitro. In addition, drugs that block parasite growth also prevent the induction of immunity in vaccinated mice, indicating that some growth of attenuated parasites is required for immune induction. Conclusions Attenuated parasites persist at submicroscopic levels in the blood of mice postvaccination with the ability to activate T cells and induce ongoing protective immune responses. Chemical treatment in vitro is a way to generate attenuated malaria parasites that can be used as a vaccine. We show that attenuated parasites persist in vivo and that this persistence is responsible for ongoing immune induction.
Journal Article
Methotrexate hampers immunogenicity to BNT162b2 mRNA COVID-19 vaccine in immune-mediated inflammatory disease
2021
ObjectiveTo investigate the humoral and cellular immune response to messenger RNA (mRNA) COVID-19 vaccines in patients with immune-mediated inflammatory diseases (IMIDs) on immunomodulatory treatment.MethodsEstablished patients at New York University Langone Health with IMID (n=51) receiving the BNT162b2 mRNA vaccination were assessed at baseline and after second immunisation. Healthy subjects served as controls (n=26). IgG antibody responses to the spike protein were analysed for humoral response. Cellular immune response to SARS-CoV-2 was further analysed using high-parameter spectral flow cytometry. A second independent, validation cohort of controls (n=182) and patients with IMID (n=31) from Erlangen, Germany, were also analysed for humoral immune response.ResultsAlthough healthy subjects (n=208) and patients with IMID on biologic treatments (mostly on tumour necrosis factor blockers, n=37) demonstrate robust antibody responses (over 90%), those patients with IMID on background methotrexate (n=45) achieve an adequate response in only 62.2% of cases. Similarly, patients with IMID on methotrexate do not demonstrate an increase in CD8+ T-cell activation after vaccination.ConclusionsIn two independent cohorts of patients with IMID, methotrexate, a widely used immunomodulator for the treatment of several IMIDs, adversely affected humoral and cellular immune response to COVID-19 mRNA vaccines. Although precise cut-offs for immunogenicity that correlate with vaccine efficacy are yet to be established, our findings suggest that different strategies may need to be explored in patients with IMID taking methotrexate to increase the chances of immunisation efficacy against SARS-CoV-2 as has been demonstrated for augmenting immunogenicity to other viral vaccines.
Journal Article
High-efficiency and air-stable P3HT-based polymer solar cells with a new non-fullerene acceptor
by
Durrant, James R.
,
Holliday, Sarah
,
Wadsworth, Andrew
in
140/125
,
639/301/299/946
,
639/624/1075/524
2016
Solution-processed organic photovoltaics (OPV) offer the attractive prospect of low-cost, light-weight and environmentally benign solar energy production. The highest efficiency OPV at present use low-bandgap donor polymers, many of which suffer from problems with stability and synthetic scalability. They also rely on fullerene-based acceptors, which themselves have issues with cost, stability and limited spectral absorption. Here we present a new non-fullerene acceptor that has been specifically designed to give improved performance alongside the wide bandgap donor poly(3-hexylthiophene), a polymer with significantly better prospects for commercial OPV due to its relative scalability and stability. Thanks to the well-matched optoelectronic and morphological properties of these materials, efficiencies of 6.4% are achieved which is the highest reported for fullerene-free P3HT devices. In addition, dramatically improved air stability is demonstrated relative to other high-efficiency OPV, showing the excellent potential of this new material combination for future technological applications.
In organic photovoltaics, the best performing devices usually involve low-bandgap polymers whose limited solubility and stability constrain the scalability of organic solar cells. Here, Holliday
et al
. develop a new acceptor and pair it with canonical P3HT to obtain 6.4% efficient and stable devices.
Journal Article