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The Healthy Crew, Clean Vessel, and Set Departure Date Triad: Successful Control of Outbreaks of COVID-19 On Board Four Cargo Vessels. Prehosp Disaster Med 2021; 36:611-620. [PMID: 34240693 PMCID: PMC8314200 DOI: 10.1017/s1049023x21000686] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Background: A variety of infectious diseases can cause outbreaks on board vessels, with both health and economic effects. Internationally, Coronavirus Disease 2019 (COVID-19) outbreaks have occurred on numerous cruise and cargo vessels and the containment measures, travel restrictions, and border closures continue to make it increasingly difficult for ship operators world-wide to be granted pratique, effect crew changes, and conduct trade. An effective outbreak management strategy is essential to achieve the outcome triad – healthy crew, clean vessel, and set departure date – while maintaining the safety of the on-shore workers and broader community and minimizing disruption to trade. This report describes the principles of COVID-19 outbreak responses on four cargo vessels, including the successful use of one vessel as a quarantine facility. Methods: Established principles of management and the experiences of COVID-19 outbreaks on cruise ships elsewhere informed a health-lead, multi-agency, strict 14-day quarantine (Q) regime based on: population density reduction on board; crew segregation; vessel cleaning and sanitation; infection risk zones, access, and control measures; health monitoring; case identification and management; food preparation and delivery; waste management control; communication; and welfare and security. Findings: Sixty-five crew were diagnosed with Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection (range 2-25; attack rate 10%-81%; 15 asymptomatic). No deaths were recorded, and only one crew was hospitalized for COVID-19-related symptoms but did not require intensive care support. Catering crew were among the cases on three vessels. All non-essential crew (n-EC) and most of the cases were disembarked. During the vessel’s Q period, no further cases were diagnosed on board, and no crew became symptomatic after completion of Q. The outbreak response duration was 15-17 days from initial decision. No serious health issues were reported, no response staff became infected, and only two Q protocol breaches occurred among crew. Interpretation: Despite increasing risk of outbreaks on cargo vessels, maritime trade and crew exchanges must continue. The potential consequences of COVID-19 outbreaks to human life and to trade necessitate a balanced response. The principles described can offer health, financial, operational, and safety advantages.
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Abstract
Since the World Health Organization's (WHO's) pandemic declaration on March 11, 2020, coronavirus disease 2019 (COVID-19) outbreaks have occurred on numerous maritime vessels and the containment measures, travel restrictions, and border closures continue to make it increasingly difficult for ship operators world-wide to be granted pratique, conduct trade, and conduct crew changes.Knowledge of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) circulating on-board a ship prior to its arrival has significant implications for the protection of shore-based maritime workers (ie, pilots, stevedores, and surveyors), the broader community, and trade. A useful approach is a graded assessment of the public health risk. The Western Australia (WA) experience and associated observed pitfalls in implementing the prediction equation for the potential presence of SARS-CoV-2 on-board based on five COVID-19 outbreaks on commercial and cruise vessels during 2020 is described.Despite best efforts, the qualitative and quantitative predictors of SARS-CoV-2 circulating on-board commercial vessels are failing to deliver the required certainty, and to date, the only accepted method of ascertaining the presence of SARS-CoV-2 remains the real-time reverse transcription polymerase chain reaction (rRT-PCR) testing reported by an accredited laboratory.Based on legal or regulatory requirements, germane processes, underpinned by robust and auditable processes and procedures, must be put in place to inform the risk assessment of SARS-CoV-2 circulating on-board vessels.
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Vicente D, Maves R, Elster E, Shwayhat A. U.S. Navy's Response to a Shipboard Coronavirus Outbreak: Considerations for a Medical Management Plan at Sea. Mil Med 2021; 186:23-26. [PMID: 33252640 PMCID: PMC7798889 DOI: 10.1093/milmed/usaa455] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 09/25/2020] [Accepted: 11/17/2020] [Indexed: 12/30/2022] Open
Affiliation(s)
- Diego Vicente
- Department of Surgery, Naval Medical Center San Diego, San Diego, CA 34800 San Diego, CA 92134, USA.,Department of Surgery, Uniformed Services University of the Health Sciences & the Walter Reed National Military Medical Center, Bethesda, MD 4301 Bethesda, MD 20814, USA
| | - Ryan Maves
- Department of Medicine, Naval Medical Center San Diego, San Diego, CA 34800 San Diego, CA 92134, USA.,Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 4301 Bethesda, MD 20814, USA
| | - Eric Elster
- Department of Surgery, Uniformed Services University of the Health Sciences & the Walter Reed National Military Medical Center, Bethesda, MD 4301 Bethesda, MD 20814, USA
| | - Alfred Shwayhat
- Department of Medicine, Naval Medical Center San Diego, San Diego, CA 34800 San Diego, CA 92134, USA.,Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 4301 Bethesda, MD 20814, USA
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4
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Affiliation(s)
- John D Malone
- Epidemiology and Immunization Services Branch, Health and Human Services Agency, County of San Diego, San Diego, California
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5
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Birrell PJ, Pebody RG, Charlett A, Zhang XS, De Angelis D. Real-time modelling of a pandemic influenza outbreak. Health Technol Assess 2018; 21:1-118. [PMID: 29058665 DOI: 10.3310/hta21580] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Real-time modelling is an essential component of the public health response to an outbreak of pandemic influenza in the UK. A model for epidemic reconstruction based on realistic epidemic surveillance data has been developed, but this model needs enhancing to provide spatially disaggregated epidemic estimates while ensuring that real-time implementation is feasible. OBJECTIVES To advance state-of-the-art real-time pandemic modelling by (1) developing an existing epidemic model to capture spatial variation in transmission, (2) devising efficient computational algorithms for the provision of timely statistical analysis and (3) incorporating the above into freely available software. METHODS Markov chain Monte Carlo (MCMC) sampling was used to derive Bayesian statistical inference using 2009 pandemic data from two candidate modelling approaches: (1) a parallel-region (PR) approach, splitting the pandemic into non-interacting epidemics occurring in spatially disjoint regions; and (2) a meta-region (MR) approach, treating the country as a single meta-population with long-range contact rates informed by census data on commuting. Model discrimination is performed through posterior mean deviance statistics alongside more practical considerations. In a real-time context, the use of sequential Monte Carlo (SMC) algorithms to carry out real-time analyses is investigated as an alternative to MCMC using simulated data designed to sternly test both algorithms. SMC-derived analyses are compared with 'gold-standard' MCMC-derived inferences in terms of estimation quality and computational burden. RESULTS The PR approach provides a better and more timely fit to the epidemic data. Estimates of pandemic quantities of interest are consistent across approaches and, in the PR approach, across regions (e.g. R0 is consistently estimated to be 1.76-1.80, dropping by 43-50% during an over-summer school holiday). A SMC approach was developed, which required some tailoring to tackle a sudden 'shock' in the data resulting from a pandemic intervention. This semi-automated SMC algorithm outperforms MCMC, in terms of both precision of estimates and their timely provision. Software implementing all findings has been developed and installed within Public Health England (PHE), with key staff trained in its use. LIMITATIONS The PR model lacks the predictive power to forecast the spread of infection in the early stages of a pandemic, whereas the MR model may be limited by its dependence on commuting data to describe transmission routes. As demand for resources increases in a severe pandemic, data from general practices and on hospitalisations may become unreliable or biased. The SMC algorithm developed is semi-automated; therefore, some statistical literacy is required to achieve optimal performance. CONCLUSIONS Following the objectives, this study found that timely, spatially disaggregate, real-time pandemic inference is feasible, and a system that assumes data as per pandemic preparedness plans has been developed for rapid implementation. FUTURE WORK RECOMMENDATIONS Modelling studies investigating the impact of pandemic interventions (e.g. vaccination and school closure); the utility of alternative data sources (e.g. internet searches) to augment traditional surveillance; and the correct handling of test sensitivity and specificity in serological data, propagating this uncertainty into the real-time modelling. TRIAL REGISTRATION Current Controlled Trials ISRCTN40334843. FUNDING This project was funded by the National Institute for Health Research (NIHR) Health Technology programme and will be published in full in Health Technology Assessment; Vol. 21, No. 58. See the NIHR Journals Library website for further project information. Daniela De Angelis was supported by the UK Medical Research Council (Unit Programme Number U105260566) and by PHE. She received funding under the NIHR grant for 10% of her time. The rest of her salary was provided by the MRC and PHE jointly.
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Affiliation(s)
- Paul J Birrell
- Medical Research Council Biostatistics Unit, Cambridge Institute of Public Health, University of Cambridge, Cambridge, UK
| | | | - André Charlett
- National Infections Service, Public Health England, London, UK
| | - Xu-Sheng Zhang
- National Infections Service, Public Health England, London, UK
| | - Daniela De Angelis
- Medical Research Council Biostatistics Unit, Cambridge Institute of Public Health, University of Cambridge, Cambridge, UK.,National Infections Service, Public Health England, London, UK
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6
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Jones RM, Xia Y. Annual Burden of Occupationally-Acquired Influenza Infections in Hospitals and Emergency Departments in the United States. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2018; 38:442-453. [PMID: 28697286 DOI: 10.1111/risa.12854] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 05/09/2017] [Accepted: 05/18/2017] [Indexed: 06/07/2023]
Abstract
Infections among health-care personnel (HCP) occur as a result of providing care to patients with infectious diseases, but surveillance is limited to a few diseases. The objective of this study is to determine the annual number of influenza infections acquired by HCP as a result of occupational exposures to influenza patients in hospitals and emergency departments (EDs) in the United States. A risk analysis approach was taken. A compartmental model was used to estimate the influenza dose received in a single exposure, and a dose-response function applied to calculate the probability of infection. A three-step algorithm tabulated the total number of influenza infections based on: the total number of occupational exposures (tabulated in previous work), the total number of HCP with occupational exposures, and the probability of infection in an occupational exposure. Estimated influenza infections were highly dependent upon the dose-response function. Given current compliance with infection control precautions, we estimated 151,300 and 34,150 influenza infections annually with two dose-response functions (annual incidence proportions of 9.3% and 2.1%, respectively). Greater reductions in infectious were achieved by full compliance with vaccination and IC precautions than with patient isolation. The burden of occupationally-acquired influenza among HCP in hospitals and EDs in the United States is not trivial, and can be reduced through improved compliance with vaccination and preventive measures, including engineering and administrative controls.
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Affiliation(s)
- Rachael M Jones
- School of Public Health, University of Illinois at Chicago, Chicago, IL, USA
| | - Yulin Xia
- School of Public Health, University of Illinois at Chicago, Chicago, IL, USA
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7
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Lo C, Mertz D, Loeb M. Assessing the reporting quality of influenza outbreaks in the community. Influenza Other Respir Viruses 2017; 11:556-563. [PMID: 29054122 PMCID: PMC5705690 DOI: 10.1111/irv.12516] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/14/2017] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND High-quality reporting of outbreak characteristics is fundamental to understand the behaviour of various strains of influenza virus and the impact of outbreak management strategies. However, few studies have systematically evaluated the quality of outbreak reporting. OBJECTIVES To conduct a systematic analysis and assessment for reporting quality of influenza outbreaks based on a modified version of the STROBE statement, and to examine characteristics associated with reporting quality. METHODS A literature search was conducted across 3 online databases (PubMed, Web of Science, MEDLINE) for reports of influenza outbreaks (pandemic H1N1, avian, seasonal). The quality of reports meeting our eligibility criteria was assessed using the Modified STROBE criteria and assigned a score of 30. Mean differences (MD) and 95% confidence intervals (CI) were reported for comparisons of study characteristics. RESULTS Sixty-four outbreak reports were available for analyses. The average Modified STROBE score was 20/30. Peer-reviewed articles were associated with a better quality of reporting (MD 2.79, 95% CI 0.79-4.78). Likewise, reports from authors affiliated with public health agencies were associated with better quality than those from academic institutions (MD 1.65, 95% CI-0.27-3.56). CONCLUSIONS The development of explicit reporting guidelines specifically geared towards reporting of outbreak investigations proved to be useful. Providing information on patient characteristics, investigation details in introduction and results, as well as addressing limitations that could have biased the findings, were frequently missing in the published reports.
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Affiliation(s)
- Calvin Lo
- Department of Pathology and Molecular MedicineMcMaster UniversityHamiltonONCanada
| | - Dominik Mertz
- Department of Pathology and Molecular MedicineMcMaster UniversityHamiltonONCanada
- Department of MedicineMcMaster UniversityHamiltonONCanada
- Department of Health Research Methods, Evidence and ImpactMcMaster UniversityHamiltonONCanada
- Michael G. DeGroote Institute for Infectious Diseases ResearchMcMaster UniversityHamiltonONCanada
| | - Mark Loeb
- Department of Pathology and Molecular MedicineMcMaster UniversityHamiltonONCanada
- Department of Health Research Methods, Evidence and ImpactMcMaster UniversityHamiltonONCanada
- Michael G. DeGroote Institute for Infectious Diseases ResearchMcMaster UniversityHamiltonONCanada
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8
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Qi RR, Wang JQ, Pan LL, Zhou W, Liu JL, Ju JT, Cai YL. Descriptive epidemiology of deployment-related medical conditions and shipboard training-related injuries in a Chinese Navy population. Public Health 2016; 141:170-177. [PMID: 27931995 DOI: 10.1016/j.puhe.2016.09.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2016] [Revised: 07/13/2016] [Accepted: 09/13/2016] [Indexed: 10/20/2022]
Abstract
OBJECTIVES To investigate the deployment-related medical conditions and shipboard tactical training-related injuries in a Chinese Navy population. STUDY DESIGN A retrospective study with the Chinese Navy was conducted. METHODS The medical records of 1543 Navy crewmembers from 2011 to 2015 were collected. The distribution and incidence rate (IR) of different types of medical conditions were provided and compared between the Aden Gulf deployment and nondeployment periods. The occurrence of military training-related injuries in crewmembers receiving 12-week shipboard tactical training was compared with that of 956 marines and 4371 recruits receiving combat and physical training, respectively. The anatomic locations and types of training-related injury were analyzed. RESULTS Compared with the nondeployment period, the percentages of the following injuries were significantly higher during deployment: injuries and certain other consequences of external causes (16.97% vs 7.76%), diseases of the musculoskeletal system and connective tissue (15.40% vs 10.34%) and mental and behavioral disorders (11.23% vs 3.45%); however, respiratory system diseases had a lower percentage (19.84% vs 28.35%). Far seas deployment significantly increased the IRs of acute upper respiratory infection, skin and eye infection, sprains and low back pain as well as aphthous ulcer, insomnia, and seasickness (P < 0.05, 0.01 or 0.001). Shipboard training induced higher IRs of injuries to the upper extremities, spine and back and head and face than physical training and a higher incidence of head and face injury than combat training (P < 0.05 or 0.001). Physical training had higher IRs of overuse injuries than shipboard and combat training (P < 0.001). The IR of fracture was higher during combat and physical training than shipboard training (P < 0.01 and 0.001). CONCLUSIONS The Chinese Navy has experienced novel health issues in crewmembers in recent years. Corresponding countermeasures should be taken to address deployment-related medical conditions and shipboard training-related injuries in the future.
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Affiliation(s)
- R-R Qi
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Second Military Medical University, 800 Xiang Yin Road, Shanghai, China
| | - J-Q Wang
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Second Military Medical University, 800 Xiang Yin Road, Shanghai, China
| | - L-L Pan
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Second Military Medical University, 800 Xiang Yin Road, Shanghai, China
| | - W Zhou
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Second Military Medical University, 800 Xiang Yin Road, Shanghai, China
| | - J-L Liu
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Second Military Medical University, 800 Xiang Yin Road, Shanghai, China
| | - J-T Ju
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Second Military Medical University, 800 Xiang Yin Road, Shanghai, China
| | - Y-L Cai
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Second Military Medical University, 800 Xiang Yin Road, Shanghai, China.
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Review Article: The Fraction of Influenza Virus Infections That Are Asymptomatic: A Systematic Review and Meta-analysis. Epidemiology 2016; 26:862-72. [PMID: 26133025 DOI: 10.1097/ede.0000000000000340] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND The fraction of persons with influenza virus infection, who do not report any signs or symptoms throughout the course of infection is referred to as the asymptomatic fraction. METHODS We conducted a systematic review and meta-analysis of published estimates of the asymptomatic fraction of influenza virus infections. We found that estimates of the asymptomatic fraction were reported from two different types of studies: first, outbreak investigations with short-term follow-up of potentially exposed persons and virologic confirmation of infections; second, studies conducted across epidemics typically evaluating rates of acute respiratory illness among persons with serologic evidence of infection, in some cases adjusting for background rates of illness from other causes. RESULTS Most point estimates from studies of outbreak investigations fell in the range 4%-28% with low heterogeneity (I = 0%) with a pooled mean of 16% (95% confidence interval = 13%, 19%). Estimates from the studies conducted across epidemics without adjustment were very heterogeneous (point estimates 0%-100%; I = 97%), while estimates from studies that adjusted for background illnesses were more consistent with point estimates in the range 65%-85% and moderate heterogeneity (I = 58%). Variation in estimates could be partially explained by differences in study design and analysis, and inclusion of mild symptomatic illnesses as asymptomatic in some studies. CONCLUSIONS Estimates of the asymptomatic fraction are affected by the study design, and the definitions of infection and symptomatic illness. Considerable differences between the asymptomatic fraction of infections confirmed by virologic versus serologic testing may indicate fundamental differences in the interpretation of these two indicators.
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10
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Jones RM, Xia Y. Occupational exposures to influenza among healthcare workers in the United States. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2016; 13:213-222. [PMID: 26556672 DOI: 10.1080/15459624.2015.1096363] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The objective of this study is to estimate the annual number of occupational exposures to influenza among healthcare workers that result from providing direct and supportive care to influenza patients in acute care, home care and long-term care settings. Literature review was used to identify healthcare utilization for influenza, and worker activity patterns. This information was used, with Monte Carlo simulation, to tabulate the mean annual number of occupational exposures. Given a medium-sized epidemic with a 6% annual symptomatic influenza incidence proportion, the mean number of occupational exposures was estimated to be 81.8 million annually. Among the approximately 14 million healthcare workers, this corresponds to 5.8 exposures per worker annually, on average. Exposures, however, are likely concentrated among subsets of healthcare workers. Occupational exposures were most numerous in ambulatory care settings (38%), followed by long-term care facilities (30%) and home care settings (21%). The annual number of occupational exposures to influenza is high, but not every occupational exposure will result in infection. Some infection control activities, like patient isolation, can reduce the number of occupational exposures.
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Affiliation(s)
- Rachael M Jones
- a Division of Environmental and Occupational Health Sciences, School of Public Health, University of Illinois at Chicago , Chicago , Illinois
| | - Yulin Xia
- a Division of Environmental and Occupational Health Sciences, School of Public Health, University of Illinois at Chicago , Chicago , Illinois
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11
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Transmission of the First Influenza A(H1N1)pdm09 Pandemic Wave in Australia Was Driven by Undetected Infections: Pandemic Response Implications. PLoS One 2015; 10:e0144331. [PMID: 26692335 PMCID: PMC4687009 DOI: 10.1371/journal.pone.0144331] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 10/15/2015] [Indexed: 02/03/2023] Open
Abstract
Background During the first wave of influenza A(H1N1)pdm09 in Victoria, Australia the rapid increase in notified cases and the high proportion with relatively mild symptoms suggested that community transmission was established before cases were identified. This lead to the hypothesis that those with low-level infections were the main drivers of the pandemic. Methods A deterministic susceptible-infected-recovered model was constructed to describe the first pandemic wave in a population structured by disease severity levels of asymptomatic, low-level symptoms, moderate symptoms and severe symptoms requiring hospitalisation. The model incorporated mixing, infectivity and duration of infectiousness parameters to calculate subgroup-specific reproduction numbers for each severity level. Results With stratum-specific effective reproduction numbers of 1.82 and 1.32 respectively, those with low-level symptoms, and those with asymptomatic infections were responsible for most of the transmission. The effective reproduction numbers for infections resulting in moderate symptoms and hospitalisation were less than one. Sensitivity analyses confirmed the importance of parameters relating to asymptomatic individuals and those with low-level symptoms. Conclusions Transmission of influenza A(H1N1)pdm09 was largely driven by those invisible to the health system. This has implications for control measures–such as distribution of antivirals to cases and contacts and quarantine/isolation–that rely on detection of infected cases. Pandemic plans need to incorporate milder scenarios, with a graded approach to implementation of control measures.
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Van Kerkhove MD, Cooper MJ, Cost AA, Sanchez JL, Riley S. Risk factors for severe outcomes among members of the United States military hospitalized with pneumonia and influenza, 2000-2012. Vaccine 2015; 33:6970-6. [PMID: 26494627 PMCID: PMC4822334 DOI: 10.1016/j.vaccine.2015.09.115] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 08/31/2015] [Accepted: 09/15/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND The progression from hospitalization for a respiratory infection to requiring substantial supportive therapy is a key stage of the influenza severity pyramid. Respiratory infections are responsible for 300,000-400,000 medical encounters each year among US military personnel, some of which progress to severe acute respiratory infections. METHODS We obtained data on 11,086 hospitalizations for pneumonia and influenza (P&I) among non-recruit US military service members during the period of 1 January 2000 through 31 December 2012. From these, we identified 512 P&I hospitalizations that progressed to severe episodes using standard case definitions. We evaluated the effect of demographic and occupational characteristics, co-morbid conditions, and history of influenza vaccination on the risk of a hospitalized P&I case becoming a severe case. We also evaluated the risk of a severe outcome and the length of time since influenza vaccination (within 180, 60, and 30 days). RESULTS The median age of subjects at the time of the P&I episode was 32 years (range, 28-40) and subjects were predominantly male (89.5%). In a univariate analysis, demographic risk factors for a severe episode included service in the US Air Force (RR=1.6 relative to US Army, 95%CI 1.3-2.1), US Coast Guard (RR=2.1, 1.2-3.7) or US Navy (RR=1.4, 1.1-1.8). Being born in the US and recent influenza vaccination (within 180 days of episode) were protective against developing severe disease. Among co-morbid conditions, univariate risk factors for severe disease included chronic renal or liver disease (RR=4.98, 95%CI 4.1-6.1), diseases of the circulatory system (RR=3.1, 95%CI 2.6-3.7), diabetes mellitus (RR=2.3, 95%CI 1.5-3.6), obesity (RR=1.6, 95%CI 1.2-2.1), cancer (RR=1.6, 95%CI 1.3-2.0), and chronic obstructive pulmonary disease (RR=1.4, 95%CI 1.1-1.7). Although many of the risk factors found to be significant in univariate analysis were no longer significant under a multivariate analysis, receipt of any influenza vaccine within 180 days of episode remained protective (RR=0.81, 95%CI 0.67-0.99), while serving in the US Coast Guard (RR=1.9, 95%CI 1.1-3.4) or US Air Force (RR=1. 5, 95%CI 1.2-2.0), presence of renal or liver disease (RR=3.6, 95%CI 2.9-4.6), and diseases of the circulatory system (RR=2.2, 95%CI 1.8-2.8), remained significantly associated with a higher risk of developing severe disease. CONCLUSIONS In a large cohort, after adjusting for many possible risk factors, influenza vaccination was protective against severe episodes among P&I hospitalizations. The service-specific (US Coast Guard or US Air Force) increased risk may represent some differences in data (e.g., coding or reporting practices) as opposed to genuine differences in physiological outcome. Our findings suggest that renal and liver disease as well as diseases of the circulatory system may contribute to influenza severity in this population independently of age and other potential comorbidities. These findings provide additional evidence for the prioritization of specific risk groups within the US military for influenza vaccination.
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Affiliation(s)
- Maria D Van Kerkhove
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London W2 1 PG, UK; Center for Global Health, Institut Pasteur, Paris 75015, France.
| | - Michael J Cooper
- Armed Forces Health Surveillance Center, 11800 Tech Road, Suite 220, Silver Spring, MD 20904, USA
| | - Angelia A Cost
- Armed Forces Health Surveillance Center, 11800 Tech Road, Suite 220, Silver Spring, MD 20904, USA; Cherokee Nation Technology Solutions, in support of the Armed Forces Health Surveillance Center, 11800 Tech Road, Suite 220, Silver Spring, MD 20904, USA
| | - Jose L Sanchez
- Cherokee Nation Technology Solutions, in support of the Armed Forces Health Surveillance Center, 11800 Tech Road, Suite 220, Silver Spring, MD 20904, USA
| | - Steven Riley
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London W2 1 PG, UK
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Sanchez JL, Cooper MJ, Myers CA, Cummings JF, Vest KG, Russell KL, Sanchez JL, Hiser MJ, Gaydos CA. Respiratory Infections in the U.S. Military: Recent Experience and Control. Clin Microbiol Rev 2015; 28:743-800. [PMID: 26085551 PMCID: PMC4475643 DOI: 10.1128/cmr.00039-14] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
This comprehensive review outlines the impact of military-relevant respiratory infections, with special attention to recruit training environments, influenza pandemics in 1918 to 1919 and 2009 to 2010, and peacetime operations and conflicts in the past 25 years. Outbreaks and epidemiologic investigations of viral and bacterial infections among high-risk groups are presented, including (i) experience by recruits at training centers, (ii) impact on advanced trainees in special settings, (iii) morbidity sustained by shipboard personnel at sea, and (iv) experience of deployed personnel. Utilizing a pathogen-by-pathogen approach, we examine (i) epidemiology, (ii) impact in terms of morbidity and operational readiness, (iii) clinical presentation and outbreak potential, (iv) diagnostic modalities, (v) treatment approaches, and (vi) vaccine and other control measures. We also outline military-specific initiatives in (i) surveillance, (ii) vaccine development and policy, (iii) novel influenza and coronavirus diagnostic test development and surveillance methods, (iv) influenza virus transmission and severity prediction modeling efforts, and (v) evaluation and implementation of nonvaccine, nonpharmacologic interventions.
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Affiliation(s)
- Jose L Sanchez
- Armed Forces Health Surveillance Center, Silver Spring, Maryland, USA
| | - Michael J Cooper
- Armed Forces Health Surveillance Center, Silver Spring, Maryland, USA
| | | | - James F Cummings
- Armed Forces Health Surveillance Center, Silver Spring, Maryland, USA
| | - Kelly G Vest
- Armed Forces Health Surveillance Center, Silver Spring, Maryland, USA
| | - Kevin L Russell
- Armed Forces Health Surveillance Center, Silver Spring, Maryland, USA
| | - Joyce L Sanchez
- Mayo Clinic, Division of General Internal Medicine, Rochester, Minnesota, USA
| | - Michelle J Hiser
- Armed Forces Health Surveillance Center, Silver Spring, Maryland, USA Oak Ridge Institute for Science and Education, Postgraduate Research Participation Program, U.S. Army Public Health Command, Aberdeen Proving Ground, Aberdeen, Maryland, USA
| | - Charlotte A Gaydos
- International STD, Respiratory, and Biothreat Research Laboratory, Division of Infectious Diseases, Johns Hopkins University, Baltimore, Maryland, USA
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14
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Fatal influenza outbreak aboard a sport fishing vessel in San Diego, California. Travel Med Infect Dis 2014; 13:102-3. [PMID: 25534296 DOI: 10.1016/j.tmaid.2014.12.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 12/01/2014] [Indexed: 11/20/2022]
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Khuntirat B, Yoon IK, Chittaganpitch M, Krueger WS, Supawat K, Blair PJ, Putnam SD, Gibbons RV, Buddhari D, Sawanpanyalert P, Heil GL, Friary JA, Gray GC. High rate of A(H1N1)pdm09 infections among rural Thai villagers, 2009-2010. PLoS One 2014; 9:e106751. [PMID: 25188434 PMCID: PMC4154756 DOI: 10.1371/journal.pone.0106751] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 08/09/2014] [Indexed: 11/18/2022] Open
Abstract
Background Pandemic influenza A(H1N1)pdm09 emerged in Thailand in 2009. A prospective longitudinal adult cohort and household transmission study of influenza-like illness (ILI) was ongoing in rural Thailand at the time of emergence. Symptomatic and subclinical A(H1N1)pdm09 infection rates in the cohort and among household members were evaluated. Methods A cohort of 800 Thai adults underwent active community-based surveillance for ILI from 2008–2010. Acute respiratory samples from ILI episodes were tested for A(H1N1)pdm09 by qRT-PCR; acute and 60-day convalescent blood samples were tested by A(H1N1)pdm09 hemagglutination inhibition assay (HI). Enrollment, 12-month and 24-month follow-up blood samples were tested for A(H1N1)pdm09 seroconversion by HI. Household members of influenza A-infected cohort subjects with ILI were enrolled in household transmission investigations in which day 0 and 60 blood samples and acute respiratory samples were tested by either qRT-PCR or HI for A(H1N1)pdm09. Seroconversion between annual blood samples without A(H1N1)pdm09-positive ILI was considered as subclinical infection. Results The 2-yr cumulative incidence of A(H1N1)pdm09 infection in the cohort in 2009/2010 was 10.8% (84/781) with an annual incidence of 1.2% in 2009 and 9.7% in 2010; 83.3% of infections were subclinical (50% in 2009 and 85.9% in 2010). The 2-yr cumulative incidence was lowest (5%) in adults born ≤1957. The A(H1N1)pdm09 secondary attack rate among household contacts was 47.2% (17/36); 47.1% of these infections were subclinical. The highest A(H1N1)pdm09 secondary attack rate among household contacts (70.6%, 12/17) occurred among children born between 1990 and 2003. Conclusion Subclinical A(H1N1)pdm09 infections in Thai adults occurred frequently and accounted for a greater proportion of all A(H1N1)pdm09 infections than previously estimated. The role of subclinical infections in A(H1N1)pdm09 transmission has important implications in formulating strategies to predict and prevent the spread of A(H1N1)pdm09 and other influenza virus strains.
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Affiliation(s)
- Benjawan Khuntirat
- Department of Virology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - In-Kyu Yoon
- Department of Virology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | | | - Whitney S. Krueger
- College of Public Health and Health Professions and Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
| | - Krongkaew Supawat
- National Institute of Health, Ministry of Public Health, Nonthaburi, Thailand
| | | | - Shannon D. Putnam
- Naval Health Research Center, San Diego, California, United States of America
| | - Robert V. Gibbons
- Department of Virology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Darunee Buddhari
- Department of Virology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | | | - Gary L. Heil
- College of Public Health and Health Professions and Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
| | - John A. Friary
- College of Public Health and Health Professions and Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
| | - Gregory C. Gray
- College of Public Health and Health Professions and Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
- * E-mail:
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Vera DM, Hora RA, Murillo A, Wong JF, Torre AJ, Wang D, Boulay D, Hancock K, Katz JM, Ramos M, Loayza L, Quispe J, Reaves EJ, Bausch DG, Chowell G, Montgomery JM. Assessing the impact of public health interventions on the transmission of pandemic H1N1 influenza a virus aboard a Peruvian navy ship. Influenza Other Respir Viruses 2014; 8:353-9. [PMID: 24506160 PMCID: PMC4181484 DOI: 10.1111/irv.12240] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/13/2014] [Indexed: 01/08/2023] Open
Abstract
Background Limited data exist on transmission dynamics and effectiveness of control measures for influenza in confined settings. Objectives To investigate the transmission dynamics of a 2009 pandemic H1N1 influenza A outbreak aboard a Peruvian Navy ship and quantify the effectiveness of the implemented control measures. Methods We used surveillance data and a simple stochastic epidemic model to characterize and evaluate the effectiveness of control interventions implemented during an outbreak of 2009 pandemic H1N1 influenza A aboard a Peruvian Navy ship. Results The serological attack rate for the outbreak was 49·1%, with younger cadets and low-ranking officers at greater risk of infection than older, higher-ranking officers. Our transmission model yielded a good fit to the daily time series of new influenza cases by date of symptom onset. We estimated a reduction of 54·4% in the reproduction number during the period of intense control interventions. Conclusion Our results indicate that the patient isolation strategy and other control measures put in place during the outbreak reduced the infectiousness of isolated individuals by 86·7%. Our findings support that early implementation of control interventions can limit the spread of influenza epidemics in confined settings.
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Khaokham CB, Selent M, Loustalot FV, Zarecki SM, Harrington D, Hoke E, Faix DJ, Ortiguerra R, Alvarez B, Almond N, McMullen K, Cadwell B, Uyeki TM, Blair PJ, Waterman SH. Seroepidemiologic investigation of an outbreak of pandemic influenza A H1N1 2009 aboard a US Navy vessel--San Diego, 2009. Influenza Other Respir Viruses 2013; 7:791-8. [PMID: 23496798 PMCID: PMC5781214 DOI: 10.1111/irv.12100] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/03/2013] [Indexed: 11/28/2022] Open
Abstract
Background During summer 2009, a US Navy ship experienced an influenza‐like illness outbreak with 126 laboratory‐confirmed cases of pandemic influenza A (H1N1) 2009 virus among the approximately 2000‐person crew. Methods During September 24–October 9, 2009, a retrospective seroepidemiologic investigation was conducted to characterize the outbreak. We administered questionnaires, reviewed medical records, and collected post‐outbreak sera from systematically sampled crewmembers. We used real‐time reverse transcription‐PCR or microneutralization assays to detect evidence of H1N1 virus infection. Results Retrospective serologic data demonstrated that the overall H1N1 virus infection attack rate was 32%. Weighted H1N1 virus attack rates were higher among marines (37%), junior‐ranking personnel (34%), and persons aged 19–24 years (36%). In multivariable analysis, a higher risk of illness was found for women versus men (odds ratio [OR] = 2·2; 95% confidence interval [CI]: 1·1–4·4), marines versus navy personnel (OR = 1·7; 95% CI, 1·0–2·9), and those aged 19–24 versus ≥35 years (OR = 3·9; 95% CI, 1·2–12·8). Fifty‐three percent of infected persons did not recall respiratory illness symptoms. Among infected persons, only 35% met criteria for acute respiratory illness and 11% for influenza‐like illness. Conclusions Approximately half of H1N1 infections were asymptomatic, and thus, the attack rate was higher than estimated by clinical illness alone. Enhanced infection control measures including pre‐embarkation illness screening, improved self‐reporting of illness, isolation of ill and quarantine of exposed contacts, and prompt antiviral chemoprophylaxis and treatment might be useful in controlling shipboard influenza outbreaks.
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Affiliation(s)
- Christina B Khaokham
- Epidemic Intelligence Service, Centers for Disease Control and Prevention, Atlanta, GA, USA.
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