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Cordery R, Purba AK, Begum L, Mills E, Mosavie M, Vieira A, Jauneikaite E, Leung RCY, Siggins MK, Ready D, Hoffman P, Lamagni T, Sriskandan S. Frequency of transmission, asymptomatic shedding, and airborne spread of Streptococcus pyogenes in schoolchildren exposed to scarlet fever: a prospective, longitudinal, multicohort, molecular epidemiological, contact-tracing study in England, UK. THE LANCET. MICROBE 2022; 3:e366-e375. [PMID: 35544097 PMCID: PMC9042792 DOI: 10.1016/s2666-5247(21)00332-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 11/24/2021] [Accepted: 11/29/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND Despite recommendations regarding prompt treatment of cases and enhanced hygiene measures, scarlet fever outbreaks increased in England between 2014 and 2018. We aimed to assess the effects of standard interventions on transmission of Streptococcus pyogenes to classroom contacts, households, and classroom environments to inform future guidance. METHODS We did a prospective, longitudinal, multicohort, molecular epidemiological, contact-tracing study in six settings across five schools in Greater London, UK. Schools and nurseries were eligible to participate if they had reported two cases of scarlet fever within 10 days of each other among children aged 2-8 years from the same class, with the most recent case arising in the preceding 48 h. We cultured throat swabs from children with scarlet fever, classroom contacts, and household contacts at four timepoints. We also cultured hand swabs and cough plates from all cases in years 1 and 2 of the study, and from classroom contacts in year 2. Surface swabs from toys and other fomites in classrooms were cultured in year 1, and settle plates from classrooms were collected in year 2. Any sample with S pyogenes detected was recorded as positive and underwent emm genotyping and genome sequencing to compare with the outbreak strain. FINDINGS Six classes, comprising 12 cases of scarlet fever, 17 household contacts, and 278 classroom contacts were recruited between March 1 and May 31, 2018 (year 1), and between March 1 and May 31, 2019 (year 2). Asymptomatic throat carriage of the outbreak strains increased from 11 (10%) of 115 swabbed children in week 1, to 34 (27%) of 126 in week 2, to 26 (24%) of 108 in week 3, and then five (14%) of 35 in week 4. Compared with carriage of outbreak S pyogenes strains, colonisation with non-outbreak and non-genotyped S pyogenes strains occurred in two (2%) of 115 swabbed children in week 1, five (4%) of 126 in week 2, six (6%) of 108 in week 3, and in none of the 35 children in week 4 (median carriage for entire study 2·8% [IQR 0·0-6·6]). Genome sequencing showed clonality of outbreak isolates within each of six classes, confirming that recent transmission accounted for high carriage. When transmissibility was tested, one (9%) of 11 asymptomatic carriers of emm4 and five (36%) of 14 asymptomatic carriers of emm3.93 had a positive cough plate. The outbreak strain was identified in only one (2%) of 60 surface swabs taken from three classrooms; however, in the two classrooms with settle plates placed in elevated locations, two (17%) of 12 and six (50%) of 12 settle plates yielded the outbreak strain. INTERPRETATION Transmission of S pyogenes in schools is intense and might occur before or despite reported treatment of cases, underlining a need for rapid case management. Despite guideline adherence, heavy shedding of S pyogenes by few classroom contacts might perpetuate outbreaks, and airborne transmission has a plausible role in its spread. These findings highlight the need for research to improve understanding and to assess effectiveness of interventions to reduce airborne transmission of S pyogenes. FUNDING Action Medical Research, UK Research Innovation, and National Institute for Health Research.
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Affiliation(s)
- Rebecca Cordery
- London Health Protection Teams, Public Health England, London, UK
| | - Amrit K Purba
- London Health Protection Teams, Public Health England, London, UK
| | - Lipi Begum
- London Health Protection Teams, Public Health England, London, UK
| | - Ewurabena Mills
- Department of Infectious Disease, Imperial College London, London, UK
| | - Mia Mosavie
- Department of Infectious Disease, Imperial College London, London, UK,NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Imperial College London, London, UK
| | - Ana Vieira
- Department of Infectious Disease, Imperial College London, London, UK,NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Imperial College London, London, UK,MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Elita Jauneikaite
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Imperial College London, London, UK,MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK,Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, UK
| | - Rhoda C Y Leung
- Department of Infectious Disease, Imperial College London, London, UK
| | - Matthew K Siggins
- Department of Infectious Disease, Imperial College London, London, UK,MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Derren Ready
- National Infection Service, Public Health England, London, UK,NIHR Health Protection Research Unit in Behavioural Science and Evaluation, University of Bristol, Bristol, UK
| | - Peter Hoffman
- National Infection Service, Public Health England, London, UK
| | - Theresa Lamagni
- National Infection Service, Public Health England, London, UK,NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Imperial College London, London, UK
| | - Shiranee Sriskandan
- Department of Infectious Disease, Imperial College London, London, UK; NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Imperial College London, London, UK; MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK.
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Parsons IT, Gifford RM, Stacey MJ, Lamb LE, O'Shea MK, Woods DR. Does vitamin D supplementation prevent SARS-CoV-2 infection in military personnel? Review of the evidence. BMJ Mil Health 2021; 167:280-286. [PMID: 33504571 PMCID: PMC7843210 DOI: 10.1136/bmjmilitary-2020-001686] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 11/15/2020] [Accepted: 11/21/2020] [Indexed: 01/19/2023]
Abstract
For most individuals residing in Northwestern Europe, maintaining replete vitamin D status throughout the year is unlikely without vitamin D supplementation and deficiency remains common. Military studies have investigated the association with vitamin D status, and subsequent supplementation, with the risk of stress fractures particularly during recruit training. The expression of nuclear vitamin D receptors and vitamin D metabolic enzymes in immune cells additionally provides a rationale for the potential role of vitamin D in maintaining immune homeostasis. One particular area of interest has been in the prevention of acute respiratory tract infections (ARTIs). The aims of this review were to consider the evidence of vitamin D supplementation in military populations in the prevention of ARTIs, including SARS-CoV-2 infection and consequent COVID-19 illness. The occupational/organisational importance of reducing transmission of SARS-CoV-2, especially where infected young adults may be asymptomatic, presymptomatic or paucisymptomatic, is also discussed.
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Affiliation(s)
- Iain T Parsons
- Academic Department of Military Medicine, Royal Centre for Defence Medicine, Birmingham, UK
- School of Cardiovascular Medicine and Life Sciences, King's College London, London, UK
| | - R M Gifford
- Academic Department of Military Medicine, Royal Centre for Defence Medicine, Birmingham, UK
- British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, Midlothian, UK
| | - M J Stacey
- Academic Department of Military Medicine, Royal Centre for Defence Medicine, Birmingham, UK
| | - L E Lamb
- Academic Department of Military Medicine, Royal Centre for Defence Medicine, Birmingham, UK
| | - M K O'Shea
- Academic Department of Military Medicine, Royal Centre for Defence Medicine, Birmingham, UK
| | - D R Woods
- Academic Department of Military Medicine, Royal Centre for Defence Medicine, Birmingham, UK
- Carnegie School of Sport, Leeds Beckett University, Leeds, UK
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Group A Streptococcus infections in children: from virulence to clinical management. Curr Opin Infect Dis 2019; 31:224-230. [PMID: 29601325 DOI: 10.1097/qco.0000000000000452] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
PURPOSE OF REVIEW Recent findings have open new perspectives on group A Streptococcus (GAS) virulence understanding with special focus on the carrier stage and new hopes for an efficient vaccine against this important pathogen. RECENT FINDINGS Understanding of carriage state, transmission and role of virulence factors in invasive infections have been recently active research fields questioning the link between carriage and infections and highlighting the potential to prevent invasive diseases. New roles for already well known virulence factors, such as Streptolysin O, M protein or NAD(+)-glycohydrolase have been discovered. Immunological studies have also shown diversity in both clinical and immunological responses toward various GAS antigens raising questions, and hopes, for the development of an efficient global vaccine candidate. SUMMARY A greater understanding of GAS virulence strategies, and their associated clinical manifestations, may be obtained by shifting our research scope toward virulence determinant interactions and cooperation rather than focusing on individual virulence factor or specific strain characterization only.
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Phillips R, Martin-Bates AJ, Withnall R. Unusual case of suspected recurrent scarlet fever in a UK serviceman. J ROY ARMY MED CORPS 2018; 164:130-131. [PMID: 29653937 DOI: 10.1136/jramc-2018-000961] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 04/04/2018] [Indexed: 11/04/2022]
Abstract
The UK prevalence of scarlet fever, a Group A streptococcal infection, is increasing. We present an unusual case of suspected recurrent scarlet fever in a member of the UK Armed Forces. Treatments, occupational implication and public health measures to mitigate the risk of disease spread.
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Affiliation(s)
- Rachel Phillips
- RMO 3 Signals Regiment, DPHC Bulford, Salisbury, Wiltshire, UK
| | | | - R Withnall
- Academic Department of Military General Practice and Primary Care, Royal Centre for Defence Medicine, Birmingham, UK
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