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Hamond C, Browne AS, de Wilde LH, Hornsby RL, LeCount K, Anderson T, Stuber T, Cranford HM, Browne SK, Blanchard G, Horner D, Taylor ML, Evans M, Angeli NF, Roth J, Bisgard KM, Salzer JS, Schafer IJ, Ellis BR, Alt DP, Schlater L, Nally JE, Ellis EM. Assessing rodents as carriers of pathogenic Leptospira species in the U.S. Virgin Islands and their risk to animal and public health. Sci Rep 2022; 12:1132. [PMID: 35064157 PMCID: PMC8782869 DOI: 10.1038/s41598-022-04846-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 12/30/2021] [Indexed: 11/09/2022] Open
Abstract
Leptospirosis is a global zoonotic disease caused by pathogenic bacteria of the genus Leptospira. We sought to determine if rodents in U.S. Virgin Islands (USVI) are carriers of Leptospira. In total, 140 rodents were sampled, including 112 Mus musculus and 28 Rattus rattus. A positive carrier status was identified for 64/140 (45.7%); 49 (35.0%) were positive by dark-field microscopy, 60 (42.9%) by culture, 63 (45.0%) by fluorescent antibody testing, and 61 (43.6%) by real-time polymerase chain reaction (rtPCR). Molecular typing indicated that 48 isolates were L. borgpetersenii and 3 were L. kirschneri; the remaining nine comprised mixed species. In the single culture-negative sample that was rtPCR positive, genotyping directly from the kidney identified L. interrogans. Serotyping of L. borgpetersenii isolates identified serogroup Ballum and L. kirschneri isolates as serogroup Icterohaemorrhagiae. These results demonstrate that rodents are significant Leptospira carriers and adds to understanding the ecoepidemiology of leptospirosis in USVI.
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Affiliation(s)
- Camila Hamond
- APHIS, U.S. Department of Agriculture, National Veterinary Services Laboratories, Ames, IA, USA
- U.S. Department of Agriculture, NCAH Leptospira Working Group, Ames, IA, USA
| | - A Springer Browne
- Epidemic Intelligence Service, Division of Scientific Education and Professional Development, Centers for Disease Control and Prevention, Atlanta, GA, USA
- U.S. Virgin Islands Department of Health, Christiansted, VI, USA
- Domestic Animal Health Analytics Team, Center for Epidemiology and Animal Health, United States Department of Agriculture, Fort Collins, CO, USA
| | - Leah H de Wilde
- U.S. Virgin Islands Department of Health, Christiansted, VI, USA
| | - Richard L Hornsby
- U.S. Department of Agriculture, NCAH Leptospira Working Group, Ames, IA, USA
- Infectious Bacterial Diseases Research Unit, National Animal Disease Center-USDA-ARS, 1920 Dayton Avenue, Ames, IA, 50010, USA
| | - Karen LeCount
- APHIS, U.S. Department of Agriculture, National Veterinary Services Laboratories, Ames, IA, USA
- U.S. Department of Agriculture, NCAH Leptospira Working Group, Ames, IA, USA
| | - Tammy Anderson
- APHIS, U.S. Department of Agriculture, National Veterinary Services Laboratories, Ames, IA, USA
- U.S. Department of Agriculture, NCAH Leptospira Working Group, Ames, IA, USA
| | - Tod Stuber
- APHIS, U.S. Department of Agriculture, National Veterinary Services Laboratories, Ames, IA, USA
- U.S. Department of Agriculture, NCAH Leptospira Working Group, Ames, IA, USA
| | | | - Stephanie K Browne
- U.S. Virgin Islands Department of Health, Christiansted, VI, USA
- Council for State and Territorial Epidemiologists, Atlanta, GA, USA
| | - Gerard Blanchard
- U.S. Department of Agriculture, Wildlife Services, Charlotte Amalie, VI, USA
| | | | - Marissa L Taylor
- U.S. Virgin Islands Department of Health, Christiansted, VI, USA
| | - Michael Evans
- U.S. Fish and Wildlife Service, Fredericksted, VI, USA
| | - Nicole F Angeli
- U.S. Virgin Islands Department of Planning and Natural Resources, Fredericksted, VI, USA
| | - Joseph Roth
- U.S. Virgin Islands Department of Health, Christiansted, VI, USA
| | - Kristine M Bisgard
- Division of Scientific Education and Professional Development, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Johanna S Salzer
- Bacterial Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Ilana J Schafer
- Bacterial Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Brett R Ellis
- U.S. Virgin Islands Department of Health, Christiansted, VI, USA
| | - David P Alt
- U.S. Department of Agriculture, NCAH Leptospira Working Group, Ames, IA, USA
- Infectious Bacterial Diseases Research Unit, National Animal Disease Center-USDA-ARS, 1920 Dayton Avenue, Ames, IA, 50010, USA
| | - Linda Schlater
- APHIS, U.S. Department of Agriculture, National Veterinary Services Laboratories, Ames, IA, USA
- U.S. Department of Agriculture, NCAH Leptospira Working Group, Ames, IA, USA
| | - Jarlath E Nally
- U.S. Department of Agriculture, NCAH Leptospira Working Group, Ames, IA, USA.
- Infectious Bacterial Diseases Research Unit, National Animal Disease Center-USDA-ARS, 1920 Dayton Avenue, Ames, IA, 50010, USA.
| | - Esther M Ellis
- U.S. Virgin Islands Department of Health, Christiansted, VI, USA
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Thindwa D, Wolter N, Pinsent A, Carrim M, Ojal J, Tempia S, Moyes J, McMorrow M, Kleynhans J, von Gottberg A, French N, Cohen C, Flasche S. Estimating the contribution of HIV-infected adults to household pneumococcal transmission in South Africa, 2016–2018: A hidden Markov modelling study. PLoS Comput Biol 2021; 17:e1009680. [PMID: 34941865 PMCID: PMC8699682 DOI: 10.1371/journal.pcbi.1009680] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 11/24/2021] [Indexed: 12/17/2022] Open
Abstract
Human immunodeficiency virus (HIV) infected adults are at a higher risk of pneumococcal colonisation and disease, even while receiving antiretroviral therapy (ART). To help evaluate potential indirect effects of vaccination of HIV-infected adults, we assessed whether HIV-infected adults disproportionately contribute to household transmission of pneumococci. We constructed a hidden Markov model to capture the dynamics of pneumococcal carriage acquisition and clearance observed during a longitudinal household-based nasopharyngeal swabbing study, while accounting for sample misclassifications. Households were followed-up twice weekly for approximately 10 months each year during a three-year study period for nasopharyngeal carriage detection via real-time PCR. We estimated the effect of participant’s age, HIV status, presence of a HIV-infected adult within the household and other covariates on pneumococcal acquisition and clearance probabilities. Of 1,684 individuals enrolled, 279 (16.6%) were younger children (<5 years-old) of whom 4 (1.5%) were HIV-infected and 726 (43.1%) were adults (≥18 years-old) of whom 214 (30.4%) were HIV-infected, most (173, 81.2%) with high CD4+ count. The observed range of pneumococcal carriage prevalence across visits was substantially higher in younger children (56.9–80.5%) than older children (5–17 years-old) (31.7–50.0%) or adults (11.5–23.5%). We estimate that 14.4% (95% Confidence Interval [CI]: 13.7–15.0) of pneumococcal-negative swabs were false negatives. Daily carriage acquisition probabilities among HIV-uninfected younger children were similar in households with and without HIV-infected adults (hazard ratio: 0.95, 95%CI: 0.91–1.01). Longer average carriage duration (11.4 days, 95%CI: 10.2–12.8 vs 6.0 days, 95%CI: 5.6–6.3) and higher median carriage density (622 genome equivalents per millilitre, 95%CI: 507–714 vs 389, 95%CI: 311.1–435.5) were estimated in HIV-infected vs HIV-uninfected adults. The use of ART and antibiotics substantially reduced carriage duration in all age groups, and acquisition rates increased with household size. Although South African HIV-infected adults on ART have longer carriage duration and density than their HIV-uninfected counterparts, they show similar patterns of pneumococcal acquisition and onward transmission. We assessed the contribution of HIV-infected adults to household pneumococcal transmission by applying a hidden Markov model to pneumococcal cohort data comprising 115,595 nasopharyngeal samples from 1,684 individuals in rural and urban settings in South Africa. We estimated 14.4% of sample misclassifications (false negatives), representing 85.6% sensitivity of a test that was used to detect pneumococcus. Pneumococcal carriage prevalence and acquisition rates, and average duration were usually higher in younger or older children than adults. The use of ART and antibiotics reduced the average carriage duration across all age and HIV groups, and carriage acquisition risks increased in larger household sizes. Despite the longer average carriage duration and higher median carriage density in HIV-infected than HIV-uninfected adults, we found similar carriage acquisition and onward transmission risks in the dual groups. These findings suggest that vaccinating HIV-infected adults on ART with PCV would reduce their risk for pneumococcal disease but may add little to the indirect protection against carriage of the rest of the population.
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Affiliation(s)
- Deus Thindwa
- Centre for the Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- * E-mail:
| | - Nicole Wolter
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa
- School of Pathology, University of the Witwatersrand, Johannesburg, South Africa
| | - Amy Pinsent
- Centre for the Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Aquarius Population Health, London, United Kingdom
| | - Maimuna Carrim
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa
| | - John Ojal
- Centre for the Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom
- KEMRI-Wellcome Trust Research Programme, Geographic Medicine Centre, Kilifi, Kenya
| | - Stefano Tempia
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa
- Influenza Program, Centers for Disease Control and Prevention, Pretoria, South Africa
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
- MassGenics, Duluth, Georgia, United States of America
| | - Jocelyn Moyes
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa
| | - Meredith McMorrow
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Jackie Kleynhans
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa
- School of Public Health, Faculty of Health Science, University of the Witwatersrand, Johannesburg, South Africa
| | - Anne von Gottberg
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa
- School of Pathology, University of the Witwatersrand, Johannesburg, South Africa
| | - Neil French
- Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Institute of Infection, Veterinary and Ecological Science, Department of Clinical Infection, Microbiology, and Immunology, University of Liverpool, Liverpool, United Kingdom
| | | | - Cheryl Cohen
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa
- School of Public Health, Faculty of Health Science, University of the Witwatersrand, Johannesburg, South Africa
| | - Stefan Flasche
- Centre for the Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom
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3
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Affiliation(s)
- K C Coffey
- VA Maryland Healthcare System and University of Maryland School of Medicine, Baltimore
| | - Daniel J Diekema
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City
| | - Daniel J Morgan
- VA Maryland Healthcare System and University of Maryland School of Medicine, Baltimore
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4
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Arav Y, Klausner Z, Fattal E. Theoretical investigation of pre-symptomatic SARS-CoV-2 person-to-person transmission in households. Sci Rep 2021; 11:14488. [PMID: 34262069 PMCID: PMC8280150 DOI: 10.1038/s41598-021-93579-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Accepted: 06/25/2021] [Indexed: 01/10/2023] Open
Abstract
Since its emergence, the phenomenon of SARS-CoV-2 transmission by seemingly healthy individuals has become a major challenge in the effort to achieve control of the pandemic. Identifying the modes of transmission that drive this phenomenon is a perquisite in devising effective control measures, but to date it is still under debate. To address this problem, we have formulated a detailed mathematical model of discrete human actions (such as coughs, sneezes, and touching) and the continuous decay of the virus in the environment. To take into account those discrete and continuous events we have extended the common modelling approach and employed a hybrid stochastic mathematical framework. This allowed us to calculate higher order statistics which are crucial for the reconstruction of the observed distributions. We focused on transmission within a household, the venue with the highest risk of infection and validated the model results against the observed secondary attack rate and the serial interval distribution. Detailed analysis of the model results identified the dominant driver of pre-symptomatic transmission as the contact route via hand-face transfer and showed that wearing masks and avoiding physical contact are an effective prevention strategy. These results provide a sound scientific basis to the present recommendations of the WHO and the CDC.
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Affiliation(s)
- Yehuda Arav
- Department of Applied Mathematics, Israel Institute for Biological Research, PO Box 19, 7410001, Ness-Ziona, Israel.
| | - Ziv Klausner
- Department of Applied Mathematics, Israel Institute for Biological Research, PO Box 19, 7410001, Ness-Ziona, Israel
| | - Eyal Fattal
- Department of Applied Mathematics, Israel Institute for Biological Research, PO Box 19, 7410001, Ness-Ziona, Israel
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5
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Nicolelis MAL, Raimundo RLG, Peixoto PS, Andreazzi CS. The impact of super-spreader cities, highways, and intensive care availability in the early stages of the COVID-19 epidemic in Brazil. Sci Rep 2021; 11:13001. [PMID: 34155241 PMCID: PMC8217556 DOI: 10.1038/s41598-021-92263-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 05/26/2021] [Indexed: 02/07/2023] Open
Abstract
Although international airports served as main entry points for SARS-CoV-2, the factors driving the uneven geographic spread of COVID-19 cases and deaths in Brazil remain mostly unknown. Here we show that three major factors influenced the early macro-geographical dynamics of COVID-19 in Brazil. Mathematical modeling revealed that the "super-spreading city" of São Paulo initially accounted for more than 85% of the case spread in the entire country. By adding only 16 other spreading cities, we accounted for 98-99% of the cases reported during the first 3 months of the pandemic in Brazil. Moreover, 26 federal highways accounted for about 30% of SARS-CoV-2's case spread. As cases increased in the Brazilian interior, the distribution of COVID-19 deaths began to correlate with the allocation of the country's intensive care units (ICUs), which is heavily weighted towards state capitals. Thus, severely ill patients living in the countryside had to be transported to state capitals to access ICU beds, creating a "boomerang effect" that contributed to skew the distribution of COVID-19 deaths. Therefore, if (i) a lockdown had been imposed earlier on in spreader-capitals, (ii) mandatory road traffic restrictions had been enforced, and (iii) a more equitable geographic distribution of ICU beds existed, the impact of COVID-19 in Brazil would be significantly lower.
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Affiliation(s)
- Miguel A L Nicolelis
- Department of Neurobiology, Duke University Medical Center, Box 103905, Durham, NC, 27710, USA.
- Department of Biomedical Engineering, Duke University, Durham, NC, USA.
- Department of Neurology, Duke University, Durham, NC, USA.
- Department of Neurosurgery, Duke University, Durham, NC, USA.
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA.
- Edmond and Lily Safra International Institute of Neurosciences, Natal, Brazil.
| | - Rafael L G Raimundo
- Department of Engineering and Environment and Postgraduate Program in Ecology and Environmental Monitoring (PPGEMA), Center for Applied Sciences and Education, Federal University of Paraíba-Campus IV, Rio Tinto, Paraíba, Brazil
| | - Pedro S Peixoto
- Department of Applied Mathematics, Institute of Mathematics and Statistics, University of São Paulo, São Paulo, Brazil
| | - Cecilia S Andreazzi
- Laboratory of Biology and Parasitology of Wild Reservoir Mammals, IOC, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
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6
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Yang Q, Saldi TK, Gonzales PK, Lasda E, Decker CJ, Tat KL, Fink MR, Hager CR, Davis JC, Ozeroff CD, Muhlrad D, Clark SK, Fattor WT, Meyerson NR, Paige CL, Gilchrist AR, Barbachano-Guerrero A, Worden-Sapper ER, Wu SS, Brisson GR, McQueen MB, Dowell RD, Leinwand L, Parker R, Sawyer SL. Just 2% of SARS-CoV-2-positive individuals carry 90% of the virus circulating in communities. Proc Natl Acad Sci U S A 2021; 118:e2104547118. [PMID: 33972412 PMCID: PMC8166196 DOI: 10.1073/pnas.2104547118] [Citation(s) in RCA: 82] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 04/11/2021] [Indexed: 12/20/2022] Open
Abstract
We analyze data from the fall 2020 pandemic response efforts at the University of Colorado Boulder, where more than 72,500 saliva samples were tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using qRT-PCR. All samples were collected from individuals who reported no symptoms associated with COVID-19 on the day of collection. From these, 1,405 positive cases were identified. The distribution of viral loads within these asymptomatic individuals was indistinguishable from what has been previously observed in symptomatic individuals. Regardless of symptomatic status, ∼50% of individuals who test positive for SARS-CoV-2 seem to be in noninfectious phases of the disease, based on having low viral loads in a range from which live virus has rarely been isolated. We find that, at any given time, just 2% of individuals carry 90% of the virions circulating within communities, serving as viral "supercarriers" and possibly also superspreaders.
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Affiliation(s)
- Qing Yang
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, CO 80303
| | - Tassa K Saldi
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303
| | - Patrick K Gonzales
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303
| | - Erika Lasda
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303
| | - Carolyn J Decker
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80303
- HHMI, University of Colorado Boulder, Boulder, CO 80303
| | - Kimngan L Tat
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303
| | - Morgan R Fink
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303
| | - Cole R Hager
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303
| | - Jack C Davis
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303
| | | | - Denise Muhlrad
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80303
- HHMI, University of Colorado Boulder, Boulder, CO 80303
| | - Stephen K Clark
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303
- Darwin Biosciences Inc., Boulder, CO 80303
| | - Will T Fattor
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303
| | - Nicholas R Meyerson
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303
- Darwin Biosciences Inc., Boulder, CO 80303
| | - Camille L Paige
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303
- Darwin Biosciences Inc., Boulder, CO 80303
| | - Alison R Gilchrist
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, CO 80303
| | | | - Emma R Worden-Sapper
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, CO 80303
| | - Sharon S Wu
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, CO 80303
- Interdisciplinary Quantitative Biology Program, University of Colorado Boulder, Boulder, CO 80303
| | - Gloria R Brisson
- Wardenburg Health Center, University of Colorado Boulder, Boulder, CO 80303
| | - Matthew B McQueen
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO 80303
| | - Robin D Dowell
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, CO 80303
- Department of Computer Science, University of Colorado Boulder, Boulder, CO 80303
| | - Leslie Leinwand
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, CO 80303
| | - Roy Parker
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303;
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80303
- HHMI, University of Colorado Boulder, Boulder, CO 80303
| | - Sara L Sawyer
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303;
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, CO 80303
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7
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Affiliation(s)
| | - Jane Plumb
- Group B Strep Support, Haywards Heath, UK
| | - Jim Gray
- Birmingham Women's and Children's NHS Foundation Trust, Birmingham, UK
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Hart WS, Maini PK, Thompson RN. High infectiousness immediately before COVID-19 symptom onset highlights the importance of continued contact tracing. eLife 2021; 10:e65534. [PMID: 33899740 PMCID: PMC8195606 DOI: 10.7554/elife.65534] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 04/25/2021] [Indexed: 01/03/2023] Open
Abstract
Background Understanding changes in infectiousness during SARS-COV-2 infections is critical to assess the effectiveness of public health measures such as contact tracing. Methods Here, we develop a novel mechanistic approach to infer the infectiousness profile of SARS-COV-2-infected individuals using data from known infector-infectee pairs. We compare estimates of key epidemiological quantities generated using our mechanistic method with analogous estimates generated using previous approaches. Results The mechanistic method provides an improved fit to data from SARS-CoV-2 infector-infectee pairs compared to commonly used approaches. Our best-fitting model indicates a high proportion of presymptomatic transmissions, with many transmissions occurring shortly before the infector develops symptoms. Conclusions High infectiousness immediately prior to symptom onset highlights the importance of continued contact tracing until effective vaccines have been distributed widely, even if contacts from a short time window before symptom onset alone are traced. Funding Engineering and Physical Sciences Research Council (EPSRC).
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Affiliation(s)
- William S Hart
- Mathematical Institute, University of OxfordOxfordUnited Kingdom
| | - Philip K Maini
- Mathematical Institute, University of OxfordOxfordUnited Kingdom
| | - Robin N Thompson
- Mathematics Institute, University of WarwickCoventryUnited Kingdom
- Zeeman Institute for Systems Biology and Infectious Disease Epidemiology Research, University of WarwickCoventryUnited Kingdom
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9
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Nettleton WD. Interpreting SARS-CoV-2 Diagnostic Tests: Common Questions and Answers. Am Fam Physician 2021; 103:465-472. [PMID: 33856162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
SARS-CoV-2 is the novel coronavirus that causes COVID-19. The spectrum of asymptomatic, presymptomatic, and symptomatic SARS-CoV-2 transmission presents challenges for evaluating SARS-CoV-2 test performance for diagnostic or screening purposes and for interpreting test results. Molecular and antigen tests can detect current SARS-CoV-2 infection and are used to diagnose COVID-19. Clinicians should consider a test's characteristics, test timing in relation to symptom onset, and the pretest probability of disease when interpreting results. Molecular and antigen SARS-CoV-2 tests both have high specificity. However, antigen tests generally have lower sensitivity and thus greater potential for false-negative results. Pretest probability of disease should be based on a patient's exposure to someone with a confirmed or probable case, signs or symptoms of COVID-19, local or population-specific COVID-19 prevalence, and presence of an alternative diagnosis. Using a leaf plot is an efficient way to visualize posttest probability of disease based on estimated pretest probability and the test's sensitivity and specificity. A negative molecular or antigen test result might not rule out SARS-CoV-2 infection when pretest probability is high, depending on the test's sensitivity. A symptom-based approach is preferred over a test-based approach for discontinuing isolation precautions for most patients with COVID-19 because prolonged shedding of viral RNA does not necessarily correlate with infectivity. Antibody tests might help identify past SARS-CoV-2 infection if performed two to four weeks after symptom onset; however, because of uncertainty about the extent and durability of postinfection or vaccine-induced immunity, they should not yet be used to infer immunity or guide discontinuation of personal protective measures.
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Affiliation(s)
- William D Nettleton
- Western Michigan University Homer Stryker MD School of Medicine, Kalamazoo, MI, USA
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10
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Marcus JE, Frankel DN, Pawlak MT, Casey TM, Cybulski RJ, Enriquez E, Okulicz JF, Yun HC. Risk Factors Associated With COVID-19 Transmission Among US Air Force Trainees in a Congregant Setting. JAMA Netw Open 2021; 4:e210202. [PMID: 33630090 PMCID: PMC7907953 DOI: 10.1001/jamanetworkopen.2021.0202] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
IMPORTANCE Owing to concerns of coronavirus disease 2019 (COVID-19) outbreaks, many congregant settings are forced to close when cases are detected because there are few data on the risk of different markers of transmission within groups. OBJECTIVE To determine whether symptoms and laboratory results on the first day of COVID-19 diagnosis are associated with development of a case cluster in a congregant setting. DESIGN, SETTING, AND PARTICIPANTS This cohort study of trainees with COVID-19 from May 11 through August 24, 2020, was conducted at Joint Base San Antonio-Lackland, the primary site of entry for enlistment in the US Air Force. Symptoms and duration, known contacts, and cycle threshold for trainees diagnosed by reverse transcription-polymerase chain reaction were collected. A cycle threshold value represents the number of nucleic acid amplification cycles that occur before a specimen containing the target material generates a signal greater than the predetermined threshold that defines positivity. Cohorts with 5 or more individuals with COVID-19 infection were defined as clusters. Participants included 10 613 trainees divided into 263 parallel cohorts of 30 to 50 people arriving weekly for 7 weeks of training. EXPOSURES All trainees were quarantined for 14 days on arrival. Testing was performed on arrival, on day 14, and anytime during training when indicated. Protective measures included universal masking, physical distancing, and rapid isolation of trainees with COVID-19. MAIN OUTCOMES AND MEASURES Association between days of symptoms, specific symptoms, number of symptoms, or cycle threshold values of individuals diagnosed with COVID-19 via reverse transcription-polymerase chain reaction and subsequent transmission within cohorts. RESULTS In this cohort study of 10 613 US Air Force basic trainees in 263 cohorts, 403 trainees (3%) received a diagnosis of COVID-19 in 129 cohorts (49%). Among trainees with COVID-19 infection, 318 (79%) were men, and the median (interquartile range [IQR]) age was 20 (19-23) years; 204 (51%) were symptomatic, and 199 (49%) were asymptomatic. Median (IQR) cycle threshold values were lower in symptomatic trainees compared with asymptomatic trainees (21.2 [18.4-27.60] vs 34.8 [29.3-37.4]; P < .001). Cohorts with clusters of individuals with COVID-19 infection were predominantly men (204 cohorts [89%] vs 114 cohorts [64%]; P < .001), had more symptomatic trainees (146 cohorts [64%] vs 53 cohorts [30%]; P < .001), and had more median (IQR) symptoms per patient (3 [2-5] vs 1 [1-2]; P < .001) compared with cohorts without clusters. Within cohorts, subsequent development of clusters of 5 or more individuals with COVID-19 infection compared with those that did not develop clusters was associated with cohorts that had more symptomatic trainees (31 of 58 trainees [53%] vs 43 of 151 trainees [28%]; P = .001) and lower median (IQR) cycle threshold values (22.3 [18.4-27.3] vs 35.3 [26.5-37.8]; P < .001). CONCLUSIONS AND RELEVANCE In this cohort study of US Air Force trainees living in a congregant setting during the COVID-19 pandemic, higher numbers of symptoms and lower cycle threshold values were associated with subsequent development of clusters of individuals with COVID-19 infection. These values may be useful if validated in future studies.
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Affiliation(s)
- Joseph E. Marcus
- Infectious Diseases Service, Brooke Army Medical Center, Joint Base San Antonio, Texas
| | - Dianne N. Frankel
- Trainee Health Surveillance, 559th Medical Group, Joint Base San Antonio–Lackland, Texas
| | - Mary T. Pawlak
- Trainee Health Surveillance, 559th Medical Group, Joint Base San Antonio–Lackland, Texas
| | - Theresa M. Casey
- Trainee Health Surveillance, 559th Medical Group, Joint Base San Antonio–Lackland, Texas
| | - Robert J. Cybulski
- Clinical Microbiology, Department of Pathology and Area Laboratory Services, Brooke Army Medical Center, Joint Base San Antonio, Texas
| | - Erin Enriquez
- Trainee Health Surveillance, 559th Medical Group, Joint Base San Antonio–Lackland, Texas
| | - Jason F. Okulicz
- Infectious Diseases Service, Brooke Army Medical Center, Joint Base San Antonio, Texas
| | - Heather C. Yun
- Infectious Diseases Service, Brooke Army Medical Center, Joint Base San Antonio, Texas
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11
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Johansson MA, Quandelacy TM, Kada S, Prasad PV, Steele M, Brooks JT, Slayton RB, Biggerstaff M, Butler JC. SARS-CoV-2 Transmission From People Without COVID-19 Symptoms. JAMA Netw Open 2021; 4:e2035057. [PMID: 33410879 PMCID: PMC7791354 DOI: 10.1001/jamanetworkopen.2020.35057] [Citation(s) in RCA: 570] [Impact Index Per Article: 190.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 12/07/2020] [Indexed: 12/26/2022] Open
Abstract
Importance Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiology of coronavirus disease 2019 (COVID-19), is readily transmitted person to person. Optimal control of COVID-19 depends on directing resources and health messaging to mitigation efforts that are most likely to prevent transmission, but the relative importance of such measures has been disputed. Objective To assess the proportion of SARS-CoV-2 transmissions in the community that likely occur from persons without symptoms. Design, Setting, and Participants This decision analytical model assessed the relative amount of transmission from presymptomatic, never symptomatic, and symptomatic individuals across a range of scenarios in which the proportion of transmission from people who never develop symptoms (ie, remain asymptomatic) and the infectious period were varied according to published best estimates. For all estimates, data from a meta-analysis was used to set the incubation period at a median of 5 days. The infectious period duration was maintained at 10 days, and peak infectiousness was varied between 3 and 7 days (-2 and +2 days relative to the median incubation period). The overall proportion of SARS-CoV-2 was varied between 0% and 70% to assess a wide range of possible proportions. Main Outcomes and Measures Level of transmission of SARS-CoV-2 from presymptomatic, never symptomatic, and symptomatic individuals. Results The baseline assumptions for the model were that peak infectiousness occurred at the median of symptom onset and that 30% of individuals with infection never develop symptoms and are 75% as infectious as those who do develop symptoms. Combined, these baseline assumptions imply that persons with infection who never develop symptoms may account for approximately 24% of all transmission. In this base case, 59% of all transmission came from asymptomatic transmission, comprising 35% from presymptomatic individuals and 24% from individuals who never develop symptoms. Under a broad range of values for each of these assumptions, at least 50% of new SARS-CoV-2 infections was estimated to have originated from exposure to individuals with infection but without symptoms. Conclusions and Relevance In this decision analytical model of multiple scenarios of proportions of asymptomatic individuals with COVID-19 and infectious periods, transmission from asymptomatic individuals was estimated to account for more than half of all transmissions. In addition to identification and isolation of persons with symptomatic COVID-19, effective control of spread will require reducing the risk of transmission from people with infection who do not have symptoms. These findings suggest that measures such as wearing masks, hand hygiene, social distancing, and strategic testing of people who are not ill will be foundational to slowing the spread of COVID-19 until safe and effective vaccines are available and widely used.
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Affiliation(s)
- Michael A. Johansson
- COVID-19 Response, US Centers for Disease Control and Prevention, Atlanta, Georgia
- Office of the Deputy Directory for Infectious Diseases, US Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Talia M. Quandelacy
- COVID-19 Response, US Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Sarah Kada
- COVID-19 Response, US Centers for Disease Control and Prevention, Atlanta, Georgia
| | | | - Molly Steele
- COVID-19 Response, US Centers for Disease Control and Prevention, Atlanta, Georgia
| | - John T. Brooks
- COVID-19 Response, US Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Rachel B. Slayton
- COVID-19 Response, US Centers for Disease Control and Prevention, Atlanta, Georgia
- Office of the Deputy Directory for Infectious Diseases, US Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Matthew Biggerstaff
- COVID-19 Response, US Centers for Disease Control and Prevention, Atlanta, Georgia
- Office of the Deputy Directory for Infectious Diseases, US Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Jay C. Butler
- Office of the Deputy Directory for Infectious Diseases, US Centers for Disease Control and Prevention, Atlanta, Georgia
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12
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Psevdos G, Papamanoli A, Barrett N, Bailey L, Thorne M, Ford F, Lobo Z. Halting a SARS-CoV-2 outbreak in a US Veterans Affairs nursing home. Am J Infect Control 2021; 49:115-119. [PMID: 33157181 PMCID: PMC7607299 DOI: 10.1016/j.ajic.2020.10.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/21/2020] [Accepted: 10/21/2020] [Indexed: 12/14/2022]
Abstract
A Veterans Affairs long term care facility on Long Island New York was confronted with a COVID-19 outbreak in late March to Mid-April 2020. Faced with a dwindling supply of PPE, the Infection Control team distributed supplies saved for a possible Ebola outbreak. A COVID unit was created within the nursing home facilitating the geographic isolation of cases; universal testing of residents and employees allowed for the implementation of proper quarantine measures. It was a multidisciplinary team approach led by the Infection Control team that successfully contained this outbreak.
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Affiliation(s)
- George Psevdos
- Division of Infectious Diseases, Veterans Affairs Medical Center, Northport, NY.
| | | | - Nancy Barrett
- Division of Nursing, Infection Control, Veterans Affairs Medical Center, Northport, NY
| | - Lisa Bailey
- Division of Nursing, Infection Control, Veterans Affairs Medical Center, Northport, NY
| | - Monique Thorne
- Division of Nursing, Infection Control, Veterans Affairs Medical Center, Northport, NY
| | - Florence Ford
- Division of Nursing, Infection Control, Veterans Affairs Medical Center, Northport, NY
| | - Zeena Lobo
- Division of Infectious Diseases, Veterans Affairs Medical Center, Northport, NY
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13
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Cloutier L, Merindol N, Pépin G, Marcoux-Huard C, Vasil PA, Houle C, Todkar S, Lehoux MC, Houle N, Germain H, Danylo A. Asymptomatic carriers of COVID-19 in a confined adult community population in Quebec: A cross-sectional study. Am J Infect Control 2021; 49:120-122. [PMID: 32835745 PMCID: PMC7441982 DOI: 10.1016/j.ajic.2020.08.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 08/10/2020] [Accepted: 08/11/2020] [Indexed: 12/28/2022]
Abstract
Several countries have undertaken social distancing measures to stop SARS-CoV-2 spread. Asymptomatic carriers' prevalence is unknown and would provide essential information on hidden viral circulation. In our cross-sectional study, 1.82% of 330 asymptomatic confined individuals living in the community carried SARS-CoV-2 despite no contact with declared cases, raising concerns about unnoticed transmission.
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Affiliation(s)
- Lyne Cloutier
- Département des sciences infirmières, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada.
| | - Natacha Merindol
- Département de chimie, biochimie et physique, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada; Centre Intégré Universitaire de Santé et Services Sociaux de la Mauricie-et-Centre-du-Québec, Trois-Rivières, Québec, Canada
| | - Geneviève Pépin
- Département de biologie médicale, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada
| | - Caroline Marcoux-Huard
- Direction de santé publique et responsabilité populationnelle, Centre Intégré Universitaire de Santé et Services Sociaux de la Mauricie-et-du-Centre-du-Québec, Trois-Rivières, Québec, Canada
| | - Pier-Alexandre Vasil
- Direction de santé publique et responsabilité populationnelle, Centre Intégré Universitaire de Santé et Services Sociaux de la Mauricie-et-du-Centre-du-Québec, Trois-Rivières, Québec, Canada
| | - Claudia Houle
- Département de biologie médicale, Centre Intégré Universitaire de Santé et des Services Sociaux de la Mauricie-et-du-Centre-du-Québec, Trois-Rivières, Québec, Canada; Département de microbiologie infectiologie et immunologie, faculté de médecine, Université de Montréal, Montréal, Québec, Canada
| | - Shweta Todkar
- Département des sciences infirmières, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada
| | - Marie-Claude Lehoux
- Centre Intégré Universitaire de Santé et Services Sociaux de la Mauricie-et-Centre-du-Québec, Trois-Rivières, Québec, Canada
| | - Nathalie Houle
- Département des sciences infirmières, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada
| | - Hugo Germain
- Département de chimie, biochimie et physique, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada; Centre Intégré Universitaire de Santé et Services Sociaux de la Mauricie-et-Centre-du-Québec, Trois-Rivières, Québec, Canada
| | - Alexis Danylo
- Département de biologie médicale, Centre Intégré Universitaire de Santé et des Services Sociaux de la Mauricie-et-du-Centre-du-Québec, Trois-Rivières, Québec, Canada; Département de microbiologie infectiologie et immunologie, faculté de médecine, Université de Montréal, Montréal, Québec, Canada
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14
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Teherán AA, Camero Ramos G, Prado de la Guardia R, Hernández C, Herrera G, Pombo LM, Avila AA, Flórez C, Barros EC, Perez-Garcia L, Paniz-Mondolfi A, Ramírez JD. Epidemiological characterisation of asymptomatic carriers of COVID-19 in Colombia: a cross-sectional study. BMJ Open 2020; 10:e042122. [PMID: 33293326 PMCID: PMC7722836 DOI: 10.1136/bmjopen-2020-042122] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 11/14/2020] [Accepted: 11/23/2020] [Indexed: 01/05/2023] Open
Abstract
INTRODUCTION Asymptomatic carriers (AC) of the new SARS-CoV-2 represent an important source of spread for COVID-19. Early diagnosis of these cases is a powerful tool to control the pandemic. Our objective was to characterise patients with AC status and identify associated sociodemographic factors. METHODS Using a cross-sectional design and the national database of daily occurrence of COVID-19, we characterised both socially and demographically all ACs. Additional correspondence analysis and logistic regression model were performed to identify characteristics associated with AC state (OR, 95% CI). RESULTS 76.162 ACs (12.1%; 95% CI 12.0% to 12.2%) were identified, mainly before epidemiological week 35. Age≤26 years (1.18; 1.09 to 1.28), male sex (1.51; 1.40 to 1.62), cases imported from Venezuela, Argentina, Brazil, Germany, Puerto Rico, Spain, USA or Mexico (12.6; 3.03 to 52.5) and autochthonous cases (22.6; 5.62 to 91.4) increased the risk of identifying ACs. We also identified groups of departments with moderate (1.23; 1.13 to 1.34) and strong (19.8; 18.6 to 21.0) association with ACs. CONCLUSION Sociodemographic characteristics strongly associated with AC were identified, which may explain its epidemiological relevance and usefulness to optimise mass screening strategies and prevent person-to-person transmission.
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Affiliation(s)
- Aníbal A Teherán
- Grupo de investigación COMPLEXUS, Fundación Universitaria Juan N Corpas, Bogotá, Colombia
- Grupo de Investigaciones Microbiológicas-UR (GIMUR), Departamento de Biología, Facultad de Ciencias Naturales, Universidad del Rosario, Bogotá, Colombia
| | | | | | - Carolina Hernández
- Grupo de Investigaciones Microbiológicas-UR (GIMUR), Departamento de Biología, Facultad de Ciencias Naturales, Universidad del Rosario, Bogotá, Colombia
| | - Giovanny Herrera
- Grupo de Investigaciones Microbiológicas-UR (GIMUR), Departamento de Biología, Facultad de Ciencias Naturales, Universidad del Rosario, Bogotá, Colombia
| | - Luis M Pombo
- Grupo de investigación COMPLEXUS, Fundación Universitaria Juan N Corpas, Bogotá, Colombia
| | - Albert Alejandro Avila
- Cruz Roja Colombiana Seccional Cundinamarca-Bogotá, Bogota, Colombia
- Hospital Simon Bolívar, Bogotá, Colombia
| | | | | | - Luis Perez-Garcia
- Grupo de Investigaciones Microbiológicas-UR (GIMUR), Departamento de Biología, Facultad de Ciencias Naturales, Universidad del Rosario, Bogotá, Colombia
| | | | - Juan David Ramírez
- Grupo de Investigaciones Microbiológicas-UR (GIMUR), Departamento de Biología, Facultad de Ciencias Naturales, Universidad del Rosario, Bogotá, Colombia
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15
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Pathak SK, Pandey S, Pandey A, Salunke AA, Thivari P, Ratna HVK, Chawla J. Focus on uncommon symptoms of COVID-19: Potential reason for spread of infection. Diabetes Metab Syndr 2020; 14:1873-1874. [PMID: 32998094 PMCID: PMC7493791 DOI: 10.1016/j.dsx.2020.09.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 09/08/2020] [Accepted: 09/10/2020] [Indexed: 12/15/2022]
Abstract
Focus on uncommon symptoms of COVID-19: Potential reason for spread of infection.
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Affiliation(s)
- Subodh Kumar Pathak
- Department of Orthopaedics, MMIMSR, M M Deemed to be University, Ambala, India.
| | | | - Apurva Pandey
- Department of Radiation Oncology, MMIMSR, M M Deemed to be University, Ambala, India.
| | | | - Praveen Thivari
- Department of Orthopaedics, MMIMSR, M M Deemed to be University, Ambala, India.
| | - Harish V K Ratna
- Department of Orthopaedics, MMIMSR, M M Deemed to be University, Ambala, India.
| | - Jasneet Chawla
- Department of Orthopaedics, MMIMSR, M M Deemed to be University, Ambala, India.
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16
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Álvez F. SARS-CoV2 coronavirus: so far polite with children. Debatable immunological and non-immunological evidence. Allergol Immunopathol (Madr) 2020; 48:500-506. [PMID: 32771236 PMCID: PMC7332921 DOI: 10.1016/j.aller.2020.05.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 05/22/2020] [Indexed: 02/06/2023]
Abstract
The reasons for the relative resistance of children to certain infections such as that caused by coronavirus SARS-CoV2 are not yet fully clear. Deciphering these differences can provide important information about the pathogenesis of the disease. Regarding the SARS-CoV2 virus, children are at the same risk of infection as the general population of all ages, with the most serious cases being found in infants. However, it has been reported that the disease is much less frequent than in adults and that most cases are benign or moderate (even with high viral loads), provided there are no other risk factors or underlying diseases. It is not clear why they have lower morbidity and virtually no mortality. A series of findings, relationships and behavioral patterns between the infectious agent and the child host may account for the lower incidence and a greatly attenuated clinical presentation of the disease in children.
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Affiliation(s)
- F Álvez
- Vaccines and Pediatric Infections (GENVIP), Infectious Diseases and Vaccines Unit (UNIV), University Clinical Hospital, Santiago de Compostela, Spain; Spanish Society of Pediatric Infectology, Spain.
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17
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Liao RJ, Ji-Ke CN, Zhang T, Liao Q, Li L, Zhu TY, Bian SY. Coronavirus disease 2019 epidemic in impoverished area: Liangshan Yi autonomous prefecture as an example. Infect Dis Poverty 2020; 9:112. [PMID: 32787916 PMCID: PMC7422473 DOI: 10.1186/s40249-020-00706-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 06/22/2020] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND The outbreak of coronavirus disease 2019 (COVID-19) had spread worldwide. Although the world has intensively focused on the epidemic center during this period of time, it is imperative to emphasize that more attention should also be paid to some impoverished areas in China since they are more vulnerable to disease outbreak due to their weak health service capacities. Therefore, this study took Liangshan Yi Autonomous Prefecture as an example to analyze the COVID-19 epidemic in the impoverished area, evaluate the control effect and explore future control strategies. METHODS In this study, we collected information including age, gender, nationality, occupation, and address of all COVID-19 cases reported from 25 January 2020 to 23 April 2020 in Liangshan Prefecture from the Nationwide Notifiable Infectious Diseases Reporting Information System (NIDRIS), which were used under license and not publicly available. Additionally, we retrieved other information of cases through epidemiological investigation reports reviewing. Data were analyzed using the software Excel 2010 and SPSS 17.0. The geographic distribution of cases was mapped using ArcGIS10.2. RESULTS By 23 April 2020, a total of 13 COVID-19 cases and two asymptomatic SARS-CoV-2 carriers were reported in Liangshan, in three family clusters. Among the cases, eight cases had a history of sojourning in Hubei Province (61.54%), of which six were related to Wuhan. Cases aged under 44 years accounted for 61.54%, with no child case. The delay of patients' hospital visiting, and the low degree of cooperation in epidemiological investigation are problems. CONCLUSIONS During the study period, Liangshan was well under control. This was mainly contributed to strict preventive strategies aimed at local culture, inter-sectoral coordination and highly degree of public cooperation. Besides, some possible environmentally and culturally preventive factors (e.g., rapid air flow and family concept) would affect disease prevention and control. In the next step, the health education about COVID-19 should be strengthened and carried out according to the special culture of ethnic minorities to enhance public awareness of timely medical treatment.
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Affiliation(s)
- Ru-Jun Liao
- Sichuan Center for Disease Control and Prevention, Chengdu, 610041, Sichuan Province, China
| | - Chun-Nong Ji-Ke
- Liangshan Prefecture Center for Disease Control and Prevention, Xichang, 615000, Sichuan Province, China
| | - Tao Zhang
- Department of Epidemiology and Health Statistics, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, 610041, Sichuan Province, China
| | - Qiang Liao
- Liangshan Prefecture Center for Disease Control and Prevention, Xichang, 615000, Sichuan Province, China
| | - Ling Li
- Sichuan Center for Disease Control and Prevention, Chengdu, 610041, Sichuan Province, China
| | - Tian-Yu Zhu
- Liangshan Prefecture Center for Disease Control and Prevention, Xichang, 615000, Sichuan Province, China
| | - Shao-Yong Bian
- Liangshan Prefecture Center for Disease Control and Prevention, Xichang, 615000, Sichuan Province, China.
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18
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Qin W, Sun J, Xu P, Gong T, Li X, Liu L, Hu J, Wang Y, Xie S, Li K, Chang H, Lyu Y. The descriptive epidemiology of coronavirus disease 2019 during the epidemic period in Lu'an, China: achieving limited community transmission using proactive response strategies. Epidemiol Infect 2020; 148:e132. [PMID: 32611465 PMCID: PMC7360947 DOI: 10.1017/s0950268820001478] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 06/23/2020] [Accepted: 06/25/2020] [Indexed: 12/21/2022] Open
Abstract
Hubei province in China has had the most confirmed coronavirus disease 2019 (COVID-19) cases and has reported sustained transmission of the disease. Although Lu'an city is adjacent to Hubei province, its community transmission was blocked at the early stage, and the impact of the epidemic was limited. Therefore, we summarised the overall characteristics of the entire epidemic course in Lu'an to help cities with a few imported cases better contain the epidemic. A total of 69 confirmed COVID-19 cases and 11 asymptomatic carriers were identified in Lu'an during the epidemic from 12 January to 21 February 2020. Fifty-two (65.0%) cases were male, and the median age was 40 years. On admission, 56.5% of cases had a fever as the initial symptom, and pneumonia was present in 89.9% of cases. The mean serial interval and the mean duration of hospitalisation were 6.5 days (95% CI: 4.8-8.2) and 18.2 days (95% CI: 16.8-19.5), respectively. A total of 16 clusters involving 60 cases (17 first-generation cases and 43 secondary cases) were reported during the epidemic. We observed that only 18.9% (7/37) index cases resulted in community transmission during the epidemic in Lu'an, indicating that the scale of the epidemic was limited to a low level in Lu'an city. An asymptomatic carrier caused the largest cluster, involving 13 cases. Spread of COVID-19 by asymptomatic carriers represents an enormous challenge for countries responding to the pandemic.
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Affiliation(s)
- Wei Qin
- Lu'an Municipal Center for Disease Control and Prevention, Lu'an, Anhui, China
| | - Jie Sun
- Lu'an Municipal Center for Disease Control and Prevention, Lu'an, Anhui, China
| | - Pengpeng Xu
- Lu'an Municipal Center for Disease Control and Prevention, Lu'an, Anhui, China
| | - Tianqi Gong
- Lu'an Municipal Center for Disease Control and Prevention, Lu'an, Anhui, China
| | - Xiude Li
- Lu'an Municipal Center for Disease Control and Prevention, Lu'an, Anhui, China
| | - Lei Liu
- Lu'an Municipal Center for Disease Control and Prevention, Lu'an, Anhui, China
| | - Jieying Hu
- Lu'an Municipal Center for Disease Control and Prevention, Lu'an, Anhui, China
| | - Yao Wang
- Lu'an Municipal Center for Disease Control and Prevention, Lu'an, Anhui, China
| | - Shaoyu Xie
- Lu'an Municipal Center for Disease Control and Prevention, Lu'an, Anhui, China
| | - Kaichun Li
- Lu'an Municipal Center for Disease Control and Prevention, Lu'an, Anhui, China
| | - Hongwei Chang
- Lu'an Municipal Center for Disease Control and Prevention, Lu'an, Anhui, China
| | - Yong Lyu
- Lu'an Municipal Center for Disease Control and Prevention, Lu'an, Anhui, China
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Bartsch SM, Wong KF, Stokes-Cawley OJ, McKinnell JA, Cao C, Gussin GM, Mueller LE, Kim DS, Miller LG, Huang SS, Lee BY. Knowing More of the Iceberg: How Detecting a Greater Proportion of Carbapenem-Resistant Enterobacteriaceae Carriers Influences Transmission. J Infect Dis 2020; 221:1782-1794. [PMID: 31150539 PMCID: PMC7213567 DOI: 10.1093/infdis/jiz288] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 05/30/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Clinical testing detects a fraction of carbapenem-resistant Enterobacteriaceae (CRE) carriers. Detecting a greater proportion could lead to increased use of infection prevention and control measures but requires resources. Therefore, it is important to understand the impact of detecting increasing proportions of CRE carriers. METHODS We used our Regional Healthcare Ecosystem Analyst-generated agent-based model of adult inpatient healthcare facilities in Orange County, California, to explore the impact that detecting greater proportions of carriers has on the spread of CRE. RESULTS Detecting and placing 1 in 9 carriers on contact precautions increased the prevalence of CRE from 0% to 8.0% countywide over 10 years. Increasing the proportion of detected carriers from 1 in 9 up to 1 in 5 yielded linear reductions in transmission; at proportions >1 in 5, reductions were greater than linear. Transmission reductions did not occur for 1, 4, or 5 years, varying by facility type. With a contact precautions effectiveness of ≤70%, the detection level yielding nonlinear reductions remained unchanged; with an effectiveness of >80%, detecting only 1 in 5 carriers garnered large reductions in the number of new CRE carriers. Trends held when CRE was already present in the region. CONCLUSION Although detection of all carriers provided the most benefits for preventing new CRE carriers, if this is not feasible, it may be worthwhile to aim for detecting >1 in 5 carriers.
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Affiliation(s)
- Sarah M Bartsch
- Public Health Computational and Operations Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
- Global Obesity Prevention Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Kim F Wong
- Center for Simulation and Modeling, University of Pittsburgh, Pennsylvania
| | - Owen J Stokes-Cawley
- Public Health Computational and Operations Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
- Global Obesity Prevention Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - James A McKinnell
- Infectious Disease Clinical Outcomes Research Unit, Los Angeles Biomedical Research Institute, Harbor-UCLA Medical Center, Los Angeles, California
- Torrance Memorial Medical Center, Torrance, California
| | - Chenghua Cao
- Division of Infectious Diseases, University of California–Irvine Health School of Medicine, Irvine, California
- Health Policy Research Institute, University of California–Irvine Health School of Medicine, Irvine, California
| | - Gabrielle M Gussin
- Division of Infectious Diseases, University of California–Irvine Health School of Medicine, Irvine, California
- Health Policy Research Institute, University of California–Irvine Health School of Medicine, Irvine, California
| | - Leslie E Mueller
- Public Health Computational and Operations Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
- Global Obesity Prevention Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Diane S Kim
- Division of Infectious Diseases, University of California–Irvine Health School of Medicine, Irvine, California
- Health Policy Research Institute, University of California–Irvine Health School of Medicine, Irvine, California
| | | | - Susan S Huang
- Division of Infectious Diseases, University of California–Irvine Health School of Medicine, Irvine, California
- Health Policy Research Institute, University of California–Irvine Health School of Medicine, Irvine, California
| | - Bruce Y Lee
- Public Health Computational and Operations Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
- Global Obesity Prevention Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
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Islam MZ, Johannesen TB, Lilje B, Urth TR, Larsen AR, Angen Ø, Larsen J. Investigation of the human nasal microbiome in persons with long- and short-term exposure to methicillin-resistant Staphylococcus aureus and other bacteria from the pig farm environment. PLoS One 2020; 15:e0232456. [PMID: 32353071 PMCID: PMC7192431 DOI: 10.1371/journal.pone.0232456] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 04/15/2020] [Indexed: 12/15/2022] Open
Abstract
Since its emergence in the early 2000s, livestock-associated methicillin-resistant Staphylococcus aureus clonal complex 398 (LA-MRSA CC398) has led to an increasing number of human infections in Denmark and other European countries with industrial pig production. LA-MRSA CC398 is primarily associated with skin infections among pig farm workers but is also increasingly recognized as a cause of life-threatening disease among elderly and immunocompromised people. Pig farm workers may serve as vehicles for the spread of LA-MRSA CC398 and other farm-origin bacteria between farms and into the general population. Yet, little is known about the bacterial community dynamics in pig farm workers and other persons with long- and short-term exposure to the pig farm environment. To gain insight into this, we investigated the nasal microbiomes in pig farm workers during a workweek on four LA-MRSA CC398-positive pig farms, as well as in short-term visitors two hours before, immediately after, and 48 hours after a 1-hour visit to another LA-MRSA CC398-positive pig farm. S. aureus and LA-MRSA CC398 carriage was quantified by means of culture, and the composition of the bacterial communities was investigated through sequencing of the 16S rRNA gene. Pig farm workers often carried LA-MRSA CC398 and other bacteria from the pig farm environment, both at work and at home, although at lower levels at home. In contrast, short-term visitors were subject to a less dramatic and rapidly reversible change in the nasal bacterial community composition. These results suggest that pig farm workers may be an important source of LA-MRSA CC398 and perhaps other pathogens of human and veterinary relevance.
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Affiliation(s)
- Md Zohorul Islam
- Department of Bacteria, Parasites, and Fungi, Statens Serum Institut, Copenhagen, Denmark
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Thor Bech Johannesen
- Department of Bacteria, Parasites, and Fungi, Statens Serum Institut, Copenhagen, Denmark
| | - Berit Lilje
- Department of Bacteria, Parasites, and Fungi, Statens Serum Institut, Copenhagen, Denmark
| | - Tinna Ravnholt Urth
- Department of Infectious Disease Epidemiology and Prevention, Statens Serum Institut, Copenhagen, Denmark
| | - Anders Rhod Larsen
- Department of Bacteria, Parasites, and Fungi, Statens Serum Institut, Copenhagen, Denmark
| | - Øystein Angen
- Department of Bacteria, Parasites, and Fungi, Statens Serum Institut, Copenhagen, Denmark
| | - Jesper Larsen
- Department of Bacteria, Parasites, and Fungi, Statens Serum Institut, Copenhagen, Denmark
- * E-mail:
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Abstract
Asymptomatic individuals in the context of malarial disease are subjects who carry a parasite load, but do not show clinical symptoms. A correct understanding of the influence of asymptomatic individuals on transmission dynamics will provide a comprehensive description of the complex interplay between the definitive host (female Anopheles mosquito), intermediate host (human), and agent (Plasmodium parasite). The goal of this article is to conduct a rigorous mathematical analysis of a new compartmentalized malaria model accounting for asymptomatic human hosts for the purpose of calculating the basic reproductive number ([Formula: see text]) and determining the bifurcations that might occur at the onset of disease-free equilibrium. A point of departure of this model from others appearing in the literature is that the asymptomatic compartment is decomposed into two mutually disjoint sub-compartments by making use of the naturally acquired immunity of the population under consideration. After deriving the model, a qualitative analysis is carried out to classify the stability of the equilibria of the system. Our results show that the dynamical system is locally asymptotically stable provided that [Formula: see text]. However, this stability is not global, owning to the occurrence of a sub-critical bifurcation in which additional non-trivial sub-threshold equilibrium solutions appear in response to a specified parameter being perturbed. To ensure that the model does not undergo a backward bifurcation, we demand an auxiliary parameter denoted [Formula: see text] in addition to the threshold constraint [Formula: see text]. The authors hope that this qualitative analysis will fill in the gaps of what is currently known about asymptomatic malaria and aid in designing strategies that assist the further development of malaria control and eradication efforts.
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Affiliation(s)
- Jacob B Aguilar
- Department of Mathematics and Sciences, Saint Leo University, Saint Leo, FL, 33574, USA
| | - Juan B Gutierrez
- Department of Mathematics, University of Texas at San Antonio, San Antonio, TX, 78249, USA.
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Essangui E, Eboumbou Moukoko CE, Nguedia N, Tchokwansi M, Banlanjo U, Maloba F, Fogang B, Donkeu C, Biabi M, Cheteug G, Kemleu S, Elanga-Ndille E, Lehman L, Ayong L. Demographical, hematological and serological risk factors for Plasmodium falciparum gametocyte carriage in a high stable transmission zone in Cameroon. PLoS One 2019; 14:e0216133. [PMID: 31022294 PMCID: PMC6483257 DOI: 10.1371/journal.pone.0216133] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 04/15/2019] [Indexed: 01/22/2023] Open
Abstract
Presence of mature gametocyte forms of malaria parasites in peripheral blood is a key requirement for malaria transmission. Yet, studies conducted in most malaria transmission zones report the absence of gametocyte in the majority of patients. We therefore sought to determine the risk factors of both all-stage and mature gametocyte carriage in an area with high stable transmission of Plasmodium falciparum in Cameroon. Gametocyte positivity was determined using three complementary methods: thick blood smear microscopy, RT-PCR and RT-LAMP, whereas exposure to the infection was assessed by enzyme-linked immunosorbent assay. Of 361 malaria endemic residents randomly included in the study (mean age: 28±23 years, age range: 2–100 years, male/female sex ratio: 1.1), 87.8% were diagnosed with P. falciparum infection, of whom 45.7% presented with fever (axillary body temperature ≥37.5°C). Mature gametocyte positivity was 1.9% by thick blood smear microscopy and 8.9% by RT-PCR targeting the mature gametocyte transcript, Pfs25. The gametocyte positivity rate was 24.1% and 36.3% by RT-PCR or RT-LAMP, respectively, when targeting the sexual stage marker, Pfs16. Multivariate analyses revealed anemia as a common independent risk factor for both mature and all-stage gametocyte carriage, whereas fever and low anti-gametocyte antibody levels were independently associated with all-stage gametocyte carriage only. Taken together, the data suggest important differences in risk factors of gametocyte carriage depending on stage analyzed, with anemia, fever and low antiplasmodial plasma antibody levels representing the major contributing risk factors.
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Affiliation(s)
- Estelle Essangui
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Sciences, University of Douala, Douala, Cameroon
| | - Carole Else Eboumbou Moukoko
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
| | - Niels Nguedia
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
| | | | - Umaru Banlanjo
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
| | - Franklin Maloba
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Sciences, University of Buea, Buea, Cameroon
| | - Balotin Fogang
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Sciences, University of Yaounde, Yaounde, Cameroon
| | - Christiane Donkeu
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Sciences, University of Yaounde, Yaounde, Cameroon
| | - Marie Biabi
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Sciences, University of Douala, Douala, Cameroon
| | - Glwadys Cheteug
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Sciences, University of Buea, Buea, Cameroon
| | - Sylvie Kemleu
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Health Sciences, University of Buea, Buea, Cameroon
| | - Emmanuel Elanga-Ndille
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Centre for Research in Infectious Diseases, Yaounde, Cameroon
| | - Léopold Lehman
- Faculty of Sciences, University of Douala, Douala, Cameroon
| | - Lawrence Ayong
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- * E-mail:
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French SK, Pearl DL, Peregrine AS, Jardine CM. Baylisascaris procyonis infection in raccoons: A review of demographic and environmental factors influencing parasite carriage. Vet Parasitol Reg Stud Reports 2019; 16:100275. [PMID: 31027589 DOI: 10.1016/j.vprsr.2019.100275] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 12/22/2018] [Accepted: 02/18/2019] [Indexed: 11/18/2022]
Abstract
Baylisascaris procyonis, the roundworm of raccoons (Procyon lotor), is an emerging helminthic zoonosis in North America. Since the larval form is capable of causing neurological disease in more than 150 species of birds and mammals including humans, understanding factors that influence carriage of the parasite by raccoons is important for mitigating risk. This review examines the current literature to identify major demographic and environmental risk factors associated with B. procyonis carriage in wild raccoons. Raccoon age and season of sample collection were most commonly identified as risk factors, with increased prevalence found in juvenile animals and when sample collection occurred in the fall. Human urbanization and agricultural land use were also observed as potential risk factors; however, there are inconsistencies in the direction of influence these risk factors have on the prevalence of infection. Further investigation into the role of environmental risk factors is required to better understand how human activities influence parasite carriage in raccoons. Additionally, future research using multivariable statistical models guided by epidemiological principles to control for confounding variables and identify interaction effects will help clarify the effect of these demographic and environmental factors. Developing a better understanding of the primary risk factors for parasite carriage in raccoons will help identify areas of higher risk for environmental contamination and will aid in the development and refinement of education and management programs to reduce the risk of human exposure.
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Affiliation(s)
- Shannon K French
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, 50 Stone Rd E, Guelph, ON N1G 2W1, Canada; Canadian Wildlife Health Cooperative, Ontario Veterinary College, University of Guelph, 50 Stone Rd E, Guelph, ON N1G 2W1, Canada.
| | - David L Pearl
- Department of Population Medicine, Ontario Veterinary College, University of Guelph, 50 Stone Rd E, Guelph, ON N1G 2W1, Canada; Canadian Wildlife Health Cooperative, Ontario Veterinary College, University of Guelph, 50 Stone Rd E, Guelph, ON N1G 2W1, Canada.
| | - Andrew S Peregrine
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, 50 Stone Rd E, Guelph, ON N1G 2W1, Canada.
| | - Claire M Jardine
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, 50 Stone Rd E, Guelph, ON N1G 2W1, Canada; Canadian Wildlife Health Cooperative, Ontario Veterinary College, University of Guelph, 50 Stone Rd E, Guelph, ON N1G 2W1, Canada.
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Daly RF, House J, Stanek D, Stobierski MG. Compendium of Measures to Prevent Disease Associated with Animals in Public Settings, 2017. J Am Vet Med Assoc 2018; 251:1268-1292. [PMID: 29154705 DOI: 10.2460/javma.251.11.1268] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Semple A, O'Currain E, O'Donovan D, Hanahoe B, Keady D, Ní Riain U, Moylett E. Successful termination of sustained transmission of resident MRSA following extensive NICU refurbishment: an intervention study. J Hosp Infect 2018; 100:329-336. [PMID: 30009868 DOI: 10.1016/j.jhin.2018.07.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 07/06/2018] [Indexed: 02/01/2023]
Abstract
BACKGROUND Neonatal sepsis is a leading cause of morbidity and mortality in neonatal units worldwide. Meticillin-resistant Staphylococcus aureus (MRSA) has become a leading causative pathogen. Many neonatal units experience endemic colonization and infection of their infants, which is often very challenging to successfully eradicate. AIM To assess the impact of neonatal unit refurbishment and redesign on endemic MRSA colonization and infection. METHODS A retrospective review was carried out over an eight-year period in a 14-cot, level 2-3 neonatal unit in University Hospital Galway, a large university teaching hospital in the West of Ireland. Surveillance, colonization, and infection data for a four-year period pre and four-year period post neonatal unit refurbishment are described. Clinical and microbiological data were collected on all MRSA-colonized and -infected infants between 2008 and 2015. Molecular typing data are available for MRSA isolates. An interrupted time-series design was used, with unit refurbishment as the intervention. FINDINGS Our neonatal unit had a pattern of sustained transmission of endemic resident MRSA strains which we could not eradicate despite repeated standard infection control interventions. Complete unit refurbishment led to successful termination of sustained transmission of these strains. Colonization decreased and no infants were actively infected post refurbishment of the unit. CONCLUSION We report successful termination of sustained transmission of endemic strains of MRSA from our neonatal unit following complete unit redesign and refurbishment.
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Affiliation(s)
- A Semple
- Academic Department of Paediatrics, National University of Ireland, Galway, Ireland.
| | - E O'Currain
- Academic Department of Paediatrics, National University of Ireland, Galway, Ireland
| | - D O'Donovan
- Academic Department of Paediatrics, National University of Ireland, Galway, Ireland
| | - B Hanahoe
- Division of Clinical Microbiology, University Hospital, Galway, Ireland
| | - D Keady
- Discipline of Bacteriology, School of Medicine, National University of Ireland, Galway, Ireland
| | - U Ní Riain
- Discipline of Bacteriology, School of Medicine, National University of Ireland, Galway, Ireland
| | - E Moylett
- Academic Department of Paediatrics, National University of Ireland, Galway, Ireland
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Leangapichart T, Rolain JM, Memish ZA, Al-Tawfiq JA, Gautret P. Emergence of drug resistant bacteria at the Hajj: A systematic review. Travel Med Infect Dis 2017; 18:3-17. [PMID: 28652197 DOI: 10.1016/j.tmaid.2017.06.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 06/15/2017] [Accepted: 06/22/2017] [Indexed: 02/07/2023]
Abstract
BACKGROUND Hajj is the annual mass gathering of Muslims, and is a reservoir and potential source of bacterial transmission. The emergence of bacterial transmission, including multi-drug resistance (MDR) bacteria, during Hajj has not been systematically assessed. METHODS Articles in Pubmed, Scopus, and Google scholar were identified using controlled words relating to antibiotic resistance (AR) at the Hajj from January 2002 to January 2017. Eligible studies were identified by two researchers. AR patterns of bacteria were obtained for each study. RESULTS We included 31 publications involving pilgrims, Hajj workers or local patients attending hospitals in Mecca, Mina, and the Medina area. Most of these publications provided antibiotic susceptibility results. Ten of them used the PCR approach to identify AR genes. MRSA carriage was reported in pilgrims and food handlers at a rate of 20%. Low rates of vancomycin-resistant gram-positive bacteria were reported in pilgrims and patients. The prevalence of third-generation cephalosporin-resistant bacteria was common in the Hajj region. Across all studies, carbapenem-resistant bacteria were detected in fewer than 10% of E.coli isolates tested but up to 100% in K. pneumoniae and A. baumannii. Colistin-resistant Salmonella enterica, including mcr-1 colistin-resistant E.coli and K.pneumoniae were only detected in the pilgrim cohorts. CONCLUSION This study provides an overview of the prevalence of MDR bacteria at the Hajj. Pilgrims are at high risk of AR bacterial transmission and may carry and transfer these bacteria when returning to their home countries. Thus, pilgrims should be instructed by health care practitioners about hygiene practices aiming at reducing traveler's diarrhea and limited use of antibiotics during travel in order to reduce the risk of MDR bacterial transmission.
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Affiliation(s)
- Thongpan Leangapichart
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Émergentes (URMITE) CNRS-IRD UMR 6236, Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille-Université, Marseille, France
| | - Jean-Marc Rolain
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Émergentes (URMITE) CNRS-IRD UMR 6236, Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille-Université, Marseille, France
| | - Ziad A Memish
- Ministry of Health, Riyadh, Saudi Arabia; Alfaisal University, College of Medicine, Riyadh, Saudi Arabia; Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, USA
| | - Jaffar A Al-Tawfiq
- Johns Hopkins Aramco Healthcare, Dhahran, Saudi Arabia; Indiana University School of Medicine, Indianapolis, IN, USA
| | - Philippe Gautret
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Émergentes (URMITE) CNRS-IRD UMR 6236, Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille-Université, Marseille, France.
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Blakiston M, Roberts SA, Freeman JT, Heffernan H. Household transmission of NDM-producing E. coli in New Zealand. N Z Med J 2017; 130:63-65. [PMID: 28337042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This report describes the introduction of an extensively antibiotic-resistant carbapenemase-producing Escherichia coli into a hospital in Auckland, New Zealand, by a patient who was a household contact of recent travellers to the Indian subcontinent. The carbapenemase was identified as New Delhi metallo-β-lactamase (NDM) and reflects probable household transmission in the context of a recent upsurge in NDM-producing Enterobacteriaceae isolation in New Zealand. The observations in this report suggest that hospital screening practices to identify carbapenemase-producing Enterobacteriaceae (CPE) colonised patients may need to be extended to include travellers to high-risk countries who were not hospitalised during their trip, and possibly also their close contacts.
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Affiliation(s)
| | - Sally A Roberts
- Microbiology Department, LabPlus, Auckland City Hospital, Auckland
| | - Joshua T Freeman
- Microbiology Department, LabPlus, Auckland City Hospital, Auckland
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Abstract
To quantify the effect of hospital and community-based transmission and control measures on Clostridium difficile infection (CDI), we constructed a transmission model within and between hospital, community, and long-term care-facility settings. By parameterizing the model from national databases and calibrating it to C. difficile prevalence and CDI incidence, we found that hospitalized patients with CDI transmit C. difficile at a rate 15 (95% CI 7.2-32) times that of asymptomatic patients. Long-term care facility residents transmit at a rate of 27% (95% CI 13%-51%) that of hospitalized patients, and persons in the community at a rate of 0.1% (95% CI 0.062%-0.2%) that of hospitalized patients. Despite lower transmission rates for asymptomatic carriers and community sources, these transmission routes have a substantial effect on hospital-onset CDI because of the larger reservoir of hospitalized carriers and persons in the community. Asymptomatic carriers and community sources should be accounted for when designing and evaluating control interventions.
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Weinberger DM, Grant LR, Weatherholtz RC, Warren JL, O'Brien KL, Hammitt LL. Relating Pneumococcal Carriage Among Children to Disease Rates Among Adults Before and After the Introduction of Conjugate Vaccines. Am J Epidemiol 2016; 183:1055-62. [PMID: 27188949 DOI: 10.1093/aje/kwv283] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 10/13/2015] [Indexed: 11/12/2022] Open
Abstract
The use of pneumococcal conjugate vaccines (PCVs) in children has a strong indirect effect on disease rates in adults. When children are vaccinated with PCVs, other serotypes that are not targeted by the vaccine can increase in frequency (serotype replacement) and reduce the direct and indirect benefits of the vaccine. To understand and predict the likely impacts of serotype replacement, it is important to know how patterns in the transmission of serotypes among children relate to disease rates in adults. We used data on pneumococcal carriage and disease from Navajo Nation children and adults collected before and after the routine use of PCVs (1998-2012). Using regression models within a Bayesian framework, we found that serotype-specific carriage and invasiveness (disease incidence divided by carriage prevalence) had similar patterns in children and adults. Moreover, carriage in children, invasiveness in children, and a serotype-specific random intercept (which captured additional variation associated with the serotypes) could predict the incidence serotype-specific pneumococcal disease in adults 18-39 years of age and those 40 years of age or older in the era of routine use of PCVs. These models could help us predict the effects of future pneumococcal vaccine use in children on disease rates in adults, and the modeling approach developed here could be used to test these findings in other settings.
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Chironna M, Loconsole D, De Robertis AL, Morea A, Scalini E, Quarto M, Tafuri S, Germinario C, Manzionna M. Clonal Spread of a Unique Strain of Macrolide-Resistant Mycoplasma Pneumoniae Within a Single Family in Italy. Medicine (Baltimore) 2016; 95:e3160. [PMID: 26986172 PMCID: PMC4839953 DOI: 10.1097/md.0000000000003160] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Macrolide-resistant Mycoplasma pneumoniae (MR-MP) is an increasing problem worldwide. This study describes the clonal spread of a unique strain of MR-MP within a single family. On January 23, 2015, nasopharyngeal swabs and sputum samples were collected from the index case (a 9-year-old girl) in southern Italy. The patient had pneumonia and was initially treated with clarithromycin. MR-MP infection was suspected due to prolonged symptoms despite appropriate antibiotic therapy. Two further cases of pneumonia occurred in relatives (a 7-year-old cousin and the 36-year-old mother of the index case); therefore, respiratory samples were also collected from other family members. Sequence analysis identified mutations associated with resistance to macrolides. Both P1 major adhesion protein typing and multiple loci variable-number tandem repeat analysis (MLVA) typing were performed to assess the relatedness of the strains. The index case, the cousin, the mother, and another 4 family members (twin siblings of the index case, a 3-year-old cousin, and the grandmother) were positive for MR-MP. All strains harbored the mutation A2063G, had the same P1 subtype (1), and were MLVA (7/4/5/7/2) type Z. In addition, the index case's aunt (31 years of age and the probable source of infection) harbored an M pneumoniae strain with the same molecular profile; however, this strain was susceptible to macrolides. This cluster of MR-MP infection/carriage caused by a clonal strain suggests a high transmission rate within this family and highlights the need for increased awareness among clinicians regarding the circulation of MR-MP. Novel strategies for the treatment and prevention of M pneumoniae infections are required.
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Affiliation(s)
- Maria Chironna
- From the Department of Biomedical Sciences and Human Oncology-Hygiene Section (MC, DL, ALDR, AM, MQ, ST, CG), University of Bari; and Paediatric Unit of the Maternal and Child Health Department of "San Giacomo" Hospital of Monopoli (ES, MM), Bari, Italy
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Siddiqui TR, Bibi S, Mustufa MA, Ayaz SM, Khan A. High prevalence of typhoidal Salmonella enterica serovars excreting food handlers in Karachi-Pakistan: a probable factor for regional typhoid endemicity. J Health Popul Nutr 2015; 33:27. [PMID: 26825058 PMCID: PMC5025978 DOI: 10.1186/s41043-015-0037-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 12/01/2015] [Indexed: 06/05/2023]
Abstract
BACKGROUND Typhoid fever is the persistent cause of morbidity worldwide. Salmonella enterica serovar's carriers among food handlers have the potential to disseminate this infection on large scale in the community. The purpose of this study was to determine the prevalence of typhoidal S. enterica serovars among food handlers of Karachi. METHODS This cross-sectional study was conducted in Karachi metropolis. A total of 220 food handlers were recruited on the basis of inclusion criteria from famous food streets of randomly selected five towns of Karachi. Three consecutive stool samples were collected from each food handler in Carry Blair transport media. Culture, biochemical identification, serotyping, and antimicrobial susceptibility tests for S. enterica serovars were done. RESULTS Out of 220 food handlers, 209 consented to participate, and among them, 19 (9.1%) were positive for S. enterica serovars. Serotyping of these isolates showed that 9 (4.3%) were typhoidal S. serovars while 10 (4.7%) were non-typhoidal S. serovars. Of the typhoidal S. serovars, 7 were S. enterica serovar Typhi and 1 each of S. enterica serovar Paratyphi A and B. The resistance pattern of these isolates showed that 77.7% were resistant to ampicillin and 11.1% to cotrimoxazole. All typhoidal S. enterica serovar isolates were sensitive to chloramphenicol, ceftriaxone, cefixime, nalidixic acid, and ofloxacin. CONCLUSIONS Carrier rate of typhoidal S. enterica serovars in food handlers working in different food streets of Karachi is very high. These food handlers might be contributing to the high endemicity of typhoid fever in Karachi, Pakistan.
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Affiliation(s)
- Taranum Ruba Siddiqui
- Gastroenterology and Hepatology unit, Pakistan Medical Research Council, Research Center, Jinnah Postgraduate Medical Center, Refiquee Shaheed Road, Karachi, 75510, Pakistan.
| | - Safia Bibi
- Gastroenterology and Hepatology unit, Pakistan Medical Research Council, Research Center, Jinnah Postgraduate Medical Center, Refiquee Shaheed Road, Karachi, 75510, Pakistan
| | - Muhammad Ayaz Mustufa
- Pakistan Medical Research Council, Research Center, National Institute of Child Health, Karachi, Pakistan
| | - Sobiya Mohiuddin Ayaz
- Gastroenterology and Hepatology unit, Pakistan Medical Research Council, Research Center, Jinnah Postgraduate Medical Center, Refiquee Shaheed Road, Karachi, 75510, Pakistan
| | - Adnan Khan
- Microbiology Department, University of Karachi, Karachi, Pakistan
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Amissah NA, Chlebowicz MA, Ablordey A, Sabat AJ, Tetteh CS, Prah I, van der Werf TS, Friedrich AW, van Dijl JM, Rossen JW, Stienstra Y. Molecular Characterization of Staphylococcus aureus Isolates Transmitted between Patients with Buruli Ulcer. PLoS Negl Trop Dis 2015; 9:e0004049. [PMID: 26360794 PMCID: PMC4567303 DOI: 10.1371/journal.pntd.0004049] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 08/11/2015] [Indexed: 12/18/2022] Open
Abstract
Background Buruli ulcer (BU) is a skin infection caused by Mycobacterium ulcerans. The wounds of most BU patients are colonized with different microorganisms, including Staphylococcus aureus. Methodology This study investigated possible patient-to-patient transmission events of S. aureus during wound care in a health care center. S. aureus isolates from different BU patients with overlapping visits to the clinic were whole-genome sequenced and analyzed by a gene-by-gene approach using SeqSphere+ software. In addition, sequence data were screened for the presence of genes that conferred antibiotic resistance. Principal Findings SeqSphere+ analysis of whole-genome sequence data confirmed transmission of methicillin resistant S. aureus (MRSA) and methicillin susceptible S. aureus among patients that took place during wound care. Interestingly, our sequence data show that the investigated MRSA isolates carry a novel allele of the fexB gene conferring chloramphenicol resistance, which had thus far not been observed in S. aureus. Buruli ulcer (BU) is a skin infection caused by Mycobacterium ulcerans. The wounds of most BU patients are colonized with different microorganisms, including Staphylococcus aureus. This study investigated patient-to-patient transmission events during wound care in a health care center. S. aureus isolates from patients who visited the health center at the same time points were analyzed using whole-genome sequencing. Analysis of sequence data confirmed transmission of methicillin resistant S. aureus and methicillin susceptible S. aureus among patients that took place during wound care.
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Affiliation(s)
- Nana Ama Amissah
- Department of Internal Medicine/Infectious Diseases, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
- Department of Bacteriology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
- * E-mail:
| | - Monika A. Chlebowicz
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Anthony Ablordey
- Department of Bacteriology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Artur J. Sabat
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Caitlin S. Tetteh
- Department of Bacteriology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Isaac Prah
- Department of Bacteriology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Tjip S. van der Werf
- Department of Internal Medicine/Infectious Diseases, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Alex W. Friedrich
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Jan Maarten van Dijl
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - John W. Rossen
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Ymkje Stienstra
- Department of Internal Medicine/Infectious Diseases, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
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Kolesin ID, Zhitkova EM. [Analysis of the Mechanism of a Three-Wave Epidemic Influenza A Virus Cvcle]. Biofizika 2015; 60:542-546. [PMID: 26349219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A three-wave epidemic cycle caused by a new serotype agent is simulated. The mechanism of stepwise recession in a stratum of the susceptible persons is examined. A group of asymptomatic infected individuals as well as an antigen activity index, which regulates the intensity of input streams into the groups of infected patients, are introduced into the model. Morbidity rate is additionally regulated by the virulence. The model is identified according to the observations of the three-wave passage of Hong-Kong serotype (H3N2). On the basis of the simulation results it is shown that a leading role in upgrading the virulence capacity of the agent and in replenishment of the morbid group is assigned to the asymptomatic infected individuals.
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Abdallah Y, Kaddu-Mulindwa D, Nankunda J, Musoke PM. Prevalence and immediate outcome of candida colonized preterm neonates admitted to Special Care Unit of Mulago Hospital, Kampala Uganda. Afr Health Sci 2015; 15:197-205. [PMID: 25834549 DOI: 10.4314/ahs.v15i1.26] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Candida species is the third commonest cause of sepsis among neonates. Colonization by Candida is a predictor for candidemia among preterm neonates. OBJECTIVES To determine prevalence of early Candida colonization and early outcome among colonized preterm neonates admitted to Mulago hospital Special Care Unit. METHODS A prospective observational cohort was conducted between December 2008 and April 2009. Preterm neonates aged >72 hours and less than one week were screened for Candida colonization of the groin, oral pharynx and rectum using CHROMagar. Colonized neonates were followed up for 14 days. Blood cultures were done for those with signs of septicaemia. The Fisher's exact tests and logistic regression were conducted for factors associated with colonization and mortality among colonized neonates. P values of < 0.05 were considered significant and confidence interval of 95% was used. RESULTS Candida colonization occurred in 50/213 (23.5%) neonates. Gestational age ≤ 30 weeks was the only factor independently associated with colonization (p = 0.005). Of the colonized 14/46 (30.4%) died and 13/46 (28.3%) developed mucocutaneous candidiasis. No candidemia was identified. Multiple site colonization was independently associated with mortality (p=0.035). CONCLUSION The consequence of high colonization observed in this study needs to be further elucidated in Uganda.
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Affiliation(s)
- Yaser Abdallah
- Department of Paediatrics and Child Health, Makerere University College of Health Sciences
| | | | - Jolly Nankunda
- Department of Paediatrics and Child Health, Makerere University College of Health Sciences
| | - Philippa M Musoke
- Department of Paediatrics and Child Health, Makerere University College of Health Sciences
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von Baum H, Schmidt C, Svoboda D, Bock-Hensley O, Wendt C. Risk Factors for Methicillin-Resistant Staphylococcus Aureus Carriage in Residents of German Nursing Homes. Infect Control Hosp Epidemiol 2015; 23:511-5. [PMID: 12269448 DOI: 10.1086/502098] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Objectives:To determine the prevalence of and the risk factors for methicillin-resistant Staphylococcus aureus (MRSA) carriage in nursing home residents in the Rhine-Neckar region of southern Germany.Design:Point-prevalence survey.Setting:Forty-seven nursing homes in the region.Participants:All residents of the approached nursing homes who agreed to participate.Methods:After informed consent was obtained, all participants had their nares swabbed, some personal data collected, or both. All swabs were examined for growth of MRSA All S. aureus isolates underwent oxacillin susceptibility testing and polymerase chain reaction for demonstration of the meek gene. All MRSA isolates were typed using pulsed-field gel electrophoresis after digestion with SmaI.Results:Swabs from 3,236 nursing home residents yielded 36 MRSA strains, contributing to a prevalence rate of 1.1%. Significant risk factors for MRSA carriage in the multivariate analysis were the presence of wounds or urinary catheters, limited mobility, admission to a hospital during the preceding 3 months, or stay in a medium-size nursing home. One predominant MRSA strain could be detected in 30 of the 36 MRSA carriers.Conclusions:The prevalence of MRSA in German nursing homes is still low. These residents seemed to acquire their MRSA in the hospital and transfer it to their nursing home. Apart from well-known risk factors for the acquisition of MRSA we identified the size of the nursing home as an independent risk factor. This might be due to an increased use of antimicrobials in nursing homes of a certain size.
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Affiliation(s)
- H von Baum
- Hygiene-Institut, University of Heidelberg, Germany
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Vriens MR, Fluit AC, Troelstra A, Verhoef J, van der Werken C. Is Methicillin-Resistant Staphylococcus Aureus More Contagious than Methicillin-Susceptible S. Aureus in a Surgical Intensive Care Unit? Infect Control Hosp Epidemiol 2015; 23:491-4. [PMID: 12269444 DOI: 10.1086/502094] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Background and Objective:In the Netherlands, the prevalence of methicillin resistance among Staphylococcus aureus isolates has been kept to less than 1% by using active screening programs and isolation. At the University Medical Center Utrecht (UMCU), an active screening program for methicillin-resistant S. aureus (MRSA) in the surgical intensive care unit (ICU) was implemented in 1986. Between 1992 and 2001, only 6 patients with MRSA were admitted to the surgical ICU. However, 4 of these 6 strains were able to spread to 23 other patients and 15 healthcare workers (HCWs). We were surprised by the epidemic behavior of these strains and wondered whether this was exceptional for S. aureus or whether methicillin-susceptible S. aureus (MSSA) was also spreading in the ICU.Design:A 2-month, prospective, observational study to investigate the incidence and spread of MSSA in the surgical ICU of UMCU and historical data collected during a 10-year period regarding MRSA.Setting:A 10-bed surgical ICU in a 1,042-bed teaching hospital.Results:Weekly swabs revealed the presence of MSSA in 11 (24%) of 45 patients and 16 (22%) of 72 HCWs. Of all 4,105 patient–HCW contacts, there were only 21 episodes in which both the patient and the HCW were found to carry MSSA. With the use of pulsed-field gel electrophoresis, no identical strains could be identified.Conclusion:In our surgical ICU, MRSA seems to spread more easily than MSSA, probably because of selection under antibiotic pressure or a still unknown intrinsic factor within MRSA.
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Affiliation(s)
- Menno R Vriens
- Department of Surgery, Eijkman Winkler Institute, University Medical Center, Utrecht, The Netherlands
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Bischoff WE, Tucker BK, Wallis ML, Reboussin BA, Pfaller MA, Hayden FG, Sherertz RJ. Preventing the Airborne Spread ofStaphylococcus aureusby Persons With the Common Cold: Effect of Surgical Scrubs, Gowns, and Masks. Infect Control Hosp Epidemiol 2015; 28:1148-54. [PMID: 17828691 DOI: 10.1086/520734] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2007] [Accepted: 05/14/2007] [Indexed: 11/04/2022]
Abstract
Objective.Transmission ofStaphylococcus aureusvia air may play an important role in healthcare settings. This study investigates the impact of barrier precautions on the spread of airborneS. aureusby volunteers with experimentally induced rhinovirus infection (ie, the common cold).Design.Prospective nonrandomized study.Setting.Wake Forest University School of Medicine (Winston-Salem, NC).Participants.A convenience sample of 10 individuals with nasalS. aureuscarriage selected from 593 students screened for carriage.Intervention.AirborneS. aureusdispersal was studied in the 10 participants under the following clothing conditions: street clothes, surgical scrubs, surgical scrubs and a gown, and the latter plus a face mask. After a 4-day baseline period, volunteers were exposed to a rhinovirus, and their clinical course was followed for 12 days. Daily swabs of nasal specimens, pharynx specimens, and skin specimens were obtained for quantitative culture, and cold symptoms were documented. Data were analyzed by random-effects negative binomial models.Results.All participants developed a common cold. Incidence rate ratios (IRRs) indicated that, compared with airborne levels ofS. aureusduring sessions in which street clothes were worn, airborne levels decreased by 75% when surgical scrubs were worn (P<.001), by 80% when scrubs and a surgical gown were worn (P<.001), and by 82% when scrubs, a gown, and a face mask were worn (P<.001). The addition of a mask to the surgical scrubs and gown did not reduce the airborne dispersal significantly (IRR, 0.92;P>.05). Male volunteers shed twice as muchS. aureusas females (incidence rate ratio, 2.04;P= .013). The cold did not alter the efficacy of the barrier precautions.Conclusions.Scrubs reduced the spread of airborneS. aureus, independent of the presence of a rhinovirus-induced cold. Airborne dispersal of S. aureus during sessions in which participants wore surgical scrubs was not significantly different from that during sessions in which gowns and gowns plus masks were also worn.
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Affiliation(s)
- Werner E Bischoff
- Section on Infectious Diseases, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
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Mosser JF, Grant LR, Millar EV, Weatherholtz RC, Jackson DM, Beall B, Craig MJ, Reid R, Santosham M, O'Brien KL. Nasopharyngeal carriage and transmission of Streptococcus pneumoniae in American Indian households after a decade of pneumococcal conjugate vaccine use. PLoS One 2014; 9:e79578. [PMID: 24465365 PMCID: PMC3894936 DOI: 10.1371/journal.pone.0079578] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 09/24/2013] [Indexed: 12/03/2022] Open
Abstract
Background Young children played a major role in pneumococcal nasopharyngeal carriage, acquisition, and transmission in the era before pneumococcal conjugate vaccine (PCV) use. Few studies document pneumococcal household dynamics in the routine-PCV7 era. Methods We investigated age-specific acquisition, household introduction, carriage clearance, and intra-household transmission in a prospective, longitudinal, observational cohort study of pneumococcal nasopharyngeal carriage in 300 American Indian households comprising 1,072 participants between March 2006 and March 2008. Results Pneumococcal acquisition rates were 2–6 times higher in children than adults. More household introductions of new pneumococcal strains were attributable to children <9 years than adults ≥17 years (p<0.001), and older children (2–8 years) than younger children (<2 years) (p<0.008). Compared to children <2 years, carriage clearance was more rapid in older children (2–4 years, HRclearance 1.53 [95% CI: 1.22, 1.91]; 5–8 years, HRclearance 1.71 [1.36, 2.15]) and adults (HRclearance 1.75 [1.16, 2.64]). Exposure to serotype-specific carriage in older children (2–8 years) most consistently increased the odds of subsequently acquiring that serotype for other household members. Conclusions In this community with a high burden of pneumococcal colonization and disease and routine PCV7 use, children (particularly older children 2–8 years) drive intra-household pneumococcal transmission: first, by acquiring, introducing, and harboring pneumococcus within the household, and then by transmitting acquired serotypes more efficiently than household members of other ages.
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Affiliation(s)
- Jonathan F Mosser
- Center for American Indian Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Lindsay R Grant
- Center for American Indian Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Eugene V Millar
- Infectious Disease Clinical Research Program, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Robert C Weatherholtz
- Center for American Indian Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Delois M Jackson
- Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Bernard Beall
- Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Mariddie J Craig
- White Mountain Apache Tribe, Whiteriver, Arizona, United States of America
| | - Raymond Reid
- Center for American Indian Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Mathuram Santosham
- Center for American Indian Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Katherine L O'Brien
- Center for American Indian Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
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Rinsky JL, Nadimpalli M, Wing S, Hall D, Baron D, Price LB, Larsen J, Stegger M, Stewart J, Heaney CD. Livestock-associated methicillin and multidrug resistant Staphylococcus aureus is present among industrial, not antibiotic-free livestock operation workers in North Carolina. PLoS One 2013; 8:e67641. [PMID: 23844044 PMCID: PMC3699663 DOI: 10.1371/journal.pone.0067641] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 05/20/2013] [Indexed: 12/18/2022] Open
Abstract
Objectives Administration of antibiotics to food animals may select for drug-resistant pathogens of clinical significance, such as methicillin-resistant Staphylococcus aureus (MRSA). In the United States, studies have examined prevalence of MRSA carriage among individuals exposed to livestock, but prevalence of multidrug-resistant S. aureus (MDRSA) carriage and the association with livestock raised with versus without antibiotic selective pressure remains unclear. We aimed to examine prevalence, antibiotic susceptibility, and molecular characteristics of S. aureus among industrial livestock operation (ILO) and antibiotic-free livestock operation (AFLO) workers and household members in North Carolina. Methods Participants in this cross-sectional study were interviewed and provided a nasal swab for S. aureus analysis. Resulting S. aureus isolates were assessed for antibiotic susceptibility, multi-locus sequence type, and absence of the scn gene (a marker of livestock association). Results Among 99 ILO and 105 AFLO participants, S. aureus nasal carriage prevalence was 41% and 40%, respectively. Among ILO and AFLO S. aureus carriers, MRSA was detected in 7% (3/41) and 7% (3/42), respectively. Thirty seven percent of 41 ILO versus 19% of 42 AFLO S. aureus-positive participants carried MDRSA. S. aureus clonal complex (CC) 398 was observed only among workers and predominated among ILO (13/34) compared with AFLO (1/35) S. aureus-positive workers. Only ILO workers carried scn-negative MRSA CC398 (2/34) and scn-negative MDRSA CC398 (6/34), and all of these isolates were tetracycline resistant. Conclusions Despite similar S. aureus and MRSA prevalence among ILO and AFLO-exposed individuals, livestock-associated MRSA and MDRSA (tetracycline-resistant, CC398, scn-negative) were only present among ILO-exposed individuals. These findings support growing concern about antibiotics use and confinement in livestock production, raising questions about the potential for occupational exposure to an opportunistic and drug-resistant pathogen, which in other settings including hospitals and the community is of broad public health importance.
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Affiliation(s)
- Jessica L. Rinsky
- Department of Epidemiology, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Maya Nadimpalli
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Steve Wing
- Department of Epidemiology, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Devon Hall
- Rural Empowerment Association for Community Help (REACH), Warsaw, North Carolina, United States of America
| | - Dothula Baron
- Rural Empowerment Association for Community Help (REACH), Warsaw, North Carolina, United States of America
| | - Lance B. Price
- Department of Environmental and Occupational Health, George Washington University, Washington, District of Columbia, United States of America
| | - Jesper Larsen
- Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark
| | - Marc Stegger
- Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark
| | - Jill Stewart
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Christopher D. Heaney
- Department of Environmental Health Sciences, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States of America
- Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States of America
- * E-mail:
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Garcia-Graells C, van Cleef BAGL, Larsen J, Denis O, Skov R, Voss A. Dynamic of livestock-associated methicillin-resistant Staphylococcus aureus CC398 in pig farm households: a pilot study. PLoS One 2013; 8:e65512. [PMID: 23741497 PMCID: PMC3669288 DOI: 10.1371/journal.pone.0065512] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2012] [Accepted: 05/01/2013] [Indexed: 11/18/2022] Open
Abstract
The aim of this study was to determine the long-term carriage rates and transmission dynamics of methicillin-resistant Staphylococcus aureus (MRSA) in pig farmers and their household members. During a 6-month period in 2009-2010, 4 pig farms in Denmark, Belgium, and the Netherlands, respectively, were studied for the presence of MRSA. The proportion of persistent carriers was significantly higher among farmers than among household members (87% vs. 11%) and significantly higher in household members from Belgium compared to those from Denmark and the Netherlands (29% vs. 0% vs. 6%). Determinant analysis of MRSA carriage revealed that pig contact was the most important determinant for MRSA carriage among household members and that the increased MRSA carriage rate observed among household members from Belgium is linked to country-specific differences in pig exposure. These findings demonstrated that even in pig farms with very high carriage rates of MRSA both in livestock and farmers, the risk for household members to acquire MRSA is limited and still depends strongly on pig exposure. By restricting access to the stables and exposure to pigs, MRSA acquisition by household members could be greatly reduced.
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Affiliation(s)
- Cristina Garcia-Graells
- Laboratoire de Référence MRSA-Staphylocoques, Department of Microbiology, Erasme Hospital-Université Libre de Bruxelles, Brussels, Belgium.
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Ismail AQ, Ismail R, Anthony M. Vegan carriage of group B streptococcus: a questionnaire study utilising social media. J Perinat Med 2013; 41:227. [PMID: 23095184 DOI: 10.1515/jpm-2012-0172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Accepted: 07/30/2012] [Indexed: 11/15/2022]
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Nurhonen M, Cheng AC, Auranen K. Pneumococcal transmission and disease in silico: a microsimulation model of the indirect effects of vaccination. PLoS One 2013; 8:e56079. [PMID: 23457504 PMCID: PMC3566073 DOI: 10.1371/journal.pone.0056079] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Accepted: 01/09/2013] [Indexed: 11/18/2022] Open
Abstract
Background The degree and time frame of indirect effects of vaccination (serotype replacement and herd immunity) are key determinants in assessing the net effectiveness of vaccination with pneumococcal conjugate vaccines (PCV) in control of pneumococcal disease. Using modelling, we aimed to quantify these effects and their dependence on coverage of vaccination and the vaccine's efficacy against susceptibility to pneumococcal carriage. Methods and Findings We constructed an individual-based simulation model that explores the effects of large-scale PCV programmes and applied it in a developed country setting (Finland). A population structure with transmission of carriage taking place within relevant mixing groups (families, day care groups, schools and neighbourhoods) was considered in order to properly assess the dependency of herd immunity on coverage of vaccination and vaccine efficacy against carriage. Issues regarding potential serotype replacement were addressed by employing a novel competition structure between multiple pneumococcal serotypes. Model parameters were calibrated from pre-vaccination data about the age-specific carriage prevalence and serotype distribution. The model predicts that elimination of vaccine-type carriage and disease among those vaccinated and, due to a substantial herd effect, also among the general population takes place within 5–10 years since the onset of a PCV programme with high (90%) coverage of vaccination and moderate (50%) vaccine efficacy against acquisition of carriage. A near-complete replacement of vaccine-type carriage by non-vaccine-type carriage occurs within the same time frame. Conclusions The changed patterns in pneumococcal carriage after PCV vaccination predicted by the model are unequivocal. The overall effect on disease incidence depends crucially on the magnitude of age- and serotype-specific case-to-carrier ratios of the remaining serotypes relative to those of the vaccine types. Thus the availability of reliable data on the incidence of both pneumococcal carriage and disease is essential in assessing the net effectiveness of PCV vaccination in a given epidemiological setting.
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Affiliation(s)
- Markku Nurhonen
- Department of Vaccination and Immune Protection, National Institute for Health and Welfare, Helsinki, Finland.
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Pazdiora P, Böhmová Z, Kubátová A, Menclová I, Morávková I, Průchová J, Prechová M, Spácilová M. Screening family and sexual contacts of HBsAg+ persons in the Pilsen region. Epidemiol Mikrobiol Imunol 2012; 61:51-57. [PMID: 23173297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
THE AIM OF THE STUDY To detect HBsAg-positive persons and to offer their family and sexual contacts, after screening for viral hepatitis B (VHB) markers, free vaccination against the infection. MATERIAL AND METHODS In collaboration with laboratories, all persons with confirmed HBsAg in the Pilsen Region (549,618 population) were prospectively detected. From these persons, the following data were collected: reason for examination, clinical diagnosis, and ethnicity/nationality. Their family and sexual contacts were screened for serologic markers (HBsAg, anti-HBc, anti-HBs) and vaccinated. RESULTS Between 1997-2005, 1,053 HBsAg+ persons were routinely detected by the laboratories in the Pilsen Region. The average age of the infected persons was 41.7 years (range 0-90 years). At the time of the detection, 63.4% of the HBsAg positives were clinically "healthy" carriers. Within the monitored period there was a considerable increase in the HBsAg positivity rate among immigrants (particularly from Vietnam). Of 908 family and sexual contacts, 18% were positive for hepatitis B markers. The highest seropositivity rates (33.9% and 27.7%) were found in siblings and parents, respectively, of the HBsAg+ persons. So far 77.5% of the susceptible contacts have used the opportunity for free vaccination. CONCLUSION The study has proven the importance of detecting HBsAg carriers and vaccinating their contacts. Special attention should be paid to immigrant families, particularly from Asia. Consistent vaccination of family and sexual contacts of HBsAg+ persons can contribute to a more rapid elimination of hepatitis B in the Czech Republic.
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Affiliation(s)
- Petr Pazdiora
- Department of Epidemiology, Charles University Faculty Hospital, Pilsen, Czech Republic.
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Jafari R, Maghsood AH, Fallah M. Prevalence of Cryptosporidium infection among livestock and humans in contact with livestock in Hamadan district, Iran, 2012. J Res Health Sci 2012; 13:86-89. [PMID: 23772009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2012] [Accepted: 12/22/2012] [Indexed: 06/02/2023] Open
Abstract
BACKGROUND Cryptosporidium is a protozoan parasite causes cryptosporidial diarrhea, which is typically a short-lasting benign infection, but can become severe and non-resolving in immunocompromised individuals. The aim of the present study was to determinate the prevalence of Cryptosporidium infection in livestock and humans that were in contact with livestock in Hamadan district, Iran. METHODS In this cross sectional study a total of 660 fecal specimens were collected; 228, 195 and 237 from humans, whom raising livestock, their calves and lambs/goats, respectively in spring 2012. Samples were concentrated by formalin-ether concentration technique and examined using cold modified Ziehl-Neelsen staining method. RESULTS Two (0.87%) out of 228, 25 (12.8%) out of 195 and 6 (2.5%) out of 237 fecal samples of humans, calves and lambs/goats were positive for Cryptosporidium oocysts, respectively. There was no significant relationship between the infection to Cryptosporidium and demographic variables of humans. However, Cryptosporidium infection rate was higher in diarrheic calves (OR=3.81; 95% CI: 1.30, 11.21; P=0.010). CONCLUSION Despite studies conducted in some regions of Iran that resulted in a relatively high rate of infection in humans in contact with livestock, our results showed low prevalence and low carrier status in the asymptomatic persons in Hamadan region. Because the infection in calves and lambs/goats was relatively high, these animals could be probable reservoir of infection for humans in this area.
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Affiliation(s)
- Rasool Jafari
- Department of Medical Parasitology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
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Bao HF, Li D, Sun P, Zhou Q, Hu J, Bai XW, Fu YF, Lu ZJ, Liu ZX. The infectivity and pathogenicity of a foot-and-mouth disease virus persistent infection strain from oesophageal-pharyngeal fluid of a Chinese cattle in 2010. Virol J 2011; 8:536. [PMID: 22166050 PMCID: PMC3298542 DOI: 10.1186/1743-422x-8-536] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Accepted: 12/14/2011] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Foot-and mouth disease (FMD) is an acute, febrile, and contagious vesicular disease affecting cloven-hoofed animals. Some animals may become persistent infected carriers when they contact FMD virus (FMDV), and persistent infected animals are a dangerous factor to cause FMD outbreak. FINDINGS 300 OP (oesophageal-pharyngeal) fluid samples were collected from cattle without clinic symptom after one month FMD circulated in 2010 in China. A FMDV strain was isolated when a positive OP sample was passed in BHK21 cell line. The strain, named O/CHN/2010/33-OP, was detected to be O/Myanmar/1998 lineage with VP1 DNA sequence comparison. In order to testify its infectivity, two cattle were challenged with OP fluid and three pigs were put into the same pen for direct contact infection. The result showed that one of the cattle and one of the pigs appeared FMD clinic symptoms respectively. Furthermore, two cattle (three pigs were also put into the same pen for direct contact infection) and three pigs were inoculated with O/CHN/2010/33-OP cell passaged strain. The result showed that one of the challenged pigs appeared FMD clinic symptoms. Two cattle and three pigs in the same pen did not appeared FMD clinic symptoms, but the sera antibody and their OP fluid of two cattle were positive. Meanwhile, the spinal cords of three pigs in the same pen with two cattle were positive detected with multiplex- RT-PCR. CONCLUSION The persistent infection strain O/CHN/2010/33-OP has infectivity and pathogenicity to cattle and pigs, and infected cattle may transmit the virus to pigs although its virulence was lower than the circulated strain O/CHN/Mya98/2010.
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Affiliation(s)
- Hui-Fang Bao
- State Key Laboratory of Veterinary Etiologic Biology, Key laboratory of Animal Virology of Ministry of Agriculture, National Foot-and-Mouth Disease Reference Laboratory of China, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu 730046, China
| | - Dong Li
- State Key Laboratory of Veterinary Etiologic Biology, Key laboratory of Animal Virology of Ministry of Agriculture, National Foot-and-Mouth Disease Reference Laboratory of China, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu 730046, China
| | - Pu Sun
- State Key Laboratory of Veterinary Etiologic Biology, Key laboratory of Animal Virology of Ministry of Agriculture, National Foot-and-Mouth Disease Reference Laboratory of China, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu 730046, China
| | - Qiang Zhou
- State Key Laboratory of Veterinary Etiologic Biology, Key laboratory of Animal Virology of Ministry of Agriculture, National Foot-and-Mouth Disease Reference Laboratory of China, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu 730046, China
| | - Jun Hu
- Xinjiang Animal health supervision Institute, Urumuqi 830060, China
| | - Xing-Wen Bai
- State Key Laboratory of Veterinary Etiologic Biology, Key laboratory of Animal Virology of Ministry of Agriculture, National Foot-and-Mouth Disease Reference Laboratory of China, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu 730046, China
| | - Yuan-Fang Fu
- State Key Laboratory of Veterinary Etiologic Biology, Key laboratory of Animal Virology of Ministry of Agriculture, National Foot-and-Mouth Disease Reference Laboratory of China, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu 730046, China
| | - Zeng-Jun Lu
- State Key Laboratory of Veterinary Etiologic Biology, Key laboratory of Animal Virology of Ministry of Agriculture, National Foot-and-Mouth Disease Reference Laboratory of China, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu 730046, China
| | - Zai-Xin Liu
- State Key Laboratory of Veterinary Etiologic Biology, Key laboratory of Animal Virology of Ministry of Agriculture, National Foot-and-Mouth Disease Reference Laboratory of China, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu 730046, China
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Newell DG, Elvers KT, Dopfer D, Hansson I, Jones P, James S, Gittins J, Stern NJ, Davies R, Connerton I, Pearson D, Salvat G, Allen VM. Biosecurity-based interventions and strategies to reduce Campylobacter spp. on poultry farms. Appl Environ Microbiol 2011; 77:8605-14. [PMID: 21984249 PMCID: PMC3233073 DOI: 10.1128/aem.01090-10] [Citation(s) in RCA: 165] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Accepted: 09/29/2011] [Indexed: 12/14/2022] Open
Abstract
The prevention and control of Campylobacter colonization of poultry flocks are important public health strategies for the control of human campylobacteriosis. A critical review of the literature on interventions to control Campylobacter in poultry on farms was undertaken using a systematic approach. Although the focus of the review was on aspects appropriate to the United Kingdom poultry industry, the research reviewed was gathered from worldwide literature. Multiple electronic databases were employed to search the literature, in any language, from 1980 to September 2008. A primary set of 4,316 references was identified and scanned, using specific agreed-upon criteria, to select relevant references related to biosecurity-based interventions. The final library comprised 173 references. Identification of the sources of Campylobacter in poultry flocks was required to inform the development of targeted interventions to disrupt transmission routes. The approach used generally involved risk factor-based surveys related to culture-positive or -negative flocks, usually combined with a structured questionnaire. In addition, some studies, either in combination or independently, undertook intervention trials. Many of these studies were compromised by poor design, sampling, and statistical analysis. The evidence for each potential source and route of transmission on the poultry farm was reviewed critically, and the options for intervention were considered. The review concluded that, in most instances, biosecurity on conventional broiler farms can be enhanced and this should contribute to the reduction of flock colonization. However, complementary, non-biosecurity-based approaches will also be required in the future to maximize the reduction of Campylobacter-positive flocks at the farm level.
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Affiliation(s)
- D G Newell
- Foodborne Zoonoses Consultancy, Silver Birches, Wherwell, Andover SP11 7AW, United Kingdom.
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Ferreira JP, Anderson KL, Correa MT, Lyman R, Ruffin F, Reller LB, Fowler VG. Transmission of MRSA between companion animals and infected human patients presenting to outpatient medical care facilities. PLoS One 2011; 6:e26978. [PMID: 22102871 PMCID: PMC3213111 DOI: 10.1371/journal.pone.0026978] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Accepted: 10/07/2011] [Indexed: 11/18/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a significant pathogen in both human and veterinary medicine. The importance of companion animals as reservoirs of human infections is currently unknown. The companion animals of 49 MRSA-infected outpatients (cases) were screened for MRSA carriage, and their bacterial isolates were compared with those of the infected patients using Pulsed-Field Gel Electrophoresis (PFGE). Rates of MRSA among the companion animals of MRSA-infected patients were compared to rates of MRSA among companion animals of pet guardians attending a “veterinary wellness clinic” (controls). MRSA was isolated from at least one companion animal in 4/49 (8.2%) households of MRSA-infected outpatients vs. none of the pets of the 50 uninfected human controls. Using PFGE, patient-pets MRSA isolates were identical for three pairs and discordant for one pair (suggested MRSA inter-specie transmission p-value = 0.1175). These results suggest that companion animals of MRSA-infected patients can be culture-positive for MRSA, representing a potential source of infection or re-infection for humans. Further studies are required to better understand the epidemiology of MRSA human-animal inter-specie transmission.
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Affiliation(s)
- Jorge Pinto Ferreira
- Department of Population Health and Pathobiology-PHP, North Carolina State University-NCSU College of Veterinary Medicine, Raleigh, North Carolina, United States of America.
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Affiliation(s)
- Tian Yang
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China
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Zhang WL, Zhao J, Li W. [Influencing factors of mother-infant vertical transmission of hepatitis B virus]. Zhongguo Dang Dai Er Ke Za Zhi 2011; 13:644-646. [PMID: 21849114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
OBJECTIVE To study the factors influencing mother-infant vertical transmission of hepatitis B virus (HBV). METHODS A total of 635 pregnant women with chronic hepatitis B or chronic asymptomatic HBV carriers were enrolled. The rate of HBV infection was compared between the infants born from the pregnant women of different HBV-DNA load, different ways of delivery and different liver functions at birth and 3 months after birth. The newborn infants were routinely injected with hepatitis B immunoglobulin (200 IU) and hepatitis B vaccine (10 μg) within 12 hrs of birth. The newborns presenting HBV infection within 24 hrs of birth by serum test were re-injected with hepatitis B immunoglobulin (200 IU) 14 days after birth. RESULTS The rate of HBV infection in infants with maternal HBV-DNA load >10(5) copies/mL was higher than in those with maternal HBV-DNA load ≤ 10(5) copies/mL at birth (14.4% vs 4.1%; P<0.01) and 3 months after birth (4.7% vs 0; P<0.01).The rate of HBV infection at 3 months was lower than at birth in both groups. The rate of HBV infection in infants born by natural labor was higher than in those born by caesarean birth at birth (P<0.05), however, by 3 months after birth, the rate of HBV infection between the two groups was similar. The rate of HBV infection was higher in infants born to chronic asymptomatic HBV carrier mothers than that in infants born to chronic hepatitis B mothers at birth (P<0.01), but there were no significant differences in the two groups 3 months later. CONCLUSIONS The maternal HBV-DNA load is correlated with the rate of HBV infection of infants. It might thus be an effective way to reduce the rate of HBV infection in infants by decreasing maternal HBV-DNA load. With the administration of hepatitis B immunoglobulin and hepatitis B vaccine, the delivery way and the liver function of pregnant women may not to be factors influencing mother-infant HBV vertical transmission.
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Affiliation(s)
- Wei-Li Zhang
- Department of Pediatrics, Shanghai Public Health Clinical Center, Shanghai, China.
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