Last data update: Jan 27, 2025. (Total: 48650 publications since 2009)
Records 1-20 (of 20 Records) |
Query Trace: Chiou H[original query] |
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Beyond misinformation: developing a public health prevention framework for managing information ecosystems
Ishizumi A , Kolis J , Abad N , Prybylski D , Brookmeyer KA , Voegeli C , Wardle C , Chiou H . Lancet Public Health 2024 The COVID-19 pandemic has highlighted how infodemics (defined as an overabundance of information, including misinformation and disinformation) pose a threat to public health and could hinder individuals from making informed health decisions. Although public health authorities and other stakeholders have implemented measures for managing infodemics, existing frameworks for infodemic management have been primarily focused on responding to acute health emergencies rather than integrated in routine service delivery. We review the evidence and propose a framework for infodemic management that encompasses upstream strategies and provides guidance on identifying different interventions, informed by the four levels of prevention in public health: primary, secondary, tertiary, and primordial prevention. On the basis of a narrative review of 54 documents (peer-reviewed and grey literature published from 1961 to 2023), we present examples of interventions that belong to each level of prevention. Adopting this framework requires proactive prevention and response through managing information ecosystems, beyond reacting to misinformation or disinformation. |
Social histories of public health misinformation and infodemics: case studies of four pandemics
Jin SL , Kolis J , Parker J , Proctor DA , Prybylski D , Wardle C , Abad N , Brookmeyer KA , Voegeli C , Chiou H . Lancet Infect Dis 2024 Recognition of misinformation as a public health threat and interest in infodemics, defined as an inundation of information accompanying an epidemic or acute health event, have increased worldwide. However, scientists have no consensus on how to best define and identify misinformation and other essential characteristics of infodemics. We conducted a narrative review of secondary historical sources to examine previous infodemics in relation to four infectious diseases associated with pandemics (ie, smallpox, cholera, 1918 influenza, and HIV) and challenge the assumption that misinformation is a new phenomenon associated with increased use of social media or with the COVID-19 pandemic. On the contrary, we found that the spread of health misinformation has always been a public health challenge that has necessitated innovative solutions from medical and public health communities. We suggest expanding beyond the narrow scope of addressing misinformation to manage information ecosystems, defined as how people consume, produce, interact with, and behave around information, which include factors such as trust, stigma, and scientific literacy. Although misinformation can spread on a global scale, this holistic approach advocates for community-level interventions that improve relationships and trust between medical or public health entities and local populations. |
Epitope(s) involving amino acids of the fusion loop of Japanese encephalitis virus envelope protein is(are) important to elicit protective immunity
Fan YC , Chen JM , Chen YY , Ke YD , Chang GJ , Chiou SS . J Virol 2024 e0177323 ![]() ![]() Dengue vaccine candidates have been shown to improve vaccine safety and efficacy by altering the residues or accessibility of the fusion loop on the virus envelope protein domain II (DII(FL)) in an ex vivo animal study. The current study aimed to comprehensively investigate the impact of DII(FL) mutations on the antigenicity, immunogenicity, and protective efficacy of Japanese encephalitis virus (JEV) virus-like particles (VLPs) in mice. We found the DII(FL) G106K/L107D (KD) and W101G/G106K/L107D (GKD) mutations altered the binding activity of JEV VLP to cross-reactive monoclonal antibodies but had no effect on their ability to elicit total IgG antibodies in mice. However, JEV VLPs with KD or GKD mutations induced significantly less neutralizing antibodies against JEV. Only 46% and 31% of the KD and GKD VLPs-immunized mice survived compared to 100% of the wild-type (WT) VLP-immunized mice after a lethal JEV challenge. In passive protection experiments, naïve mice that received sera from WT VLP-immunized mice exhibited a significantly higher survival rate of 46.7% compared to those receiving sera from KD VLP- and GKD VLP-immunized mice (6.7% and 0%, respectively). This study demonstrated that JEV DII(FL) is crucial for eliciting potently neutralizing antibodies and protective immunity against JEV. IMPORTANCE: Introduction of mutations into the fusion loop is one potential strategy for generating safe dengue and Zika vaccines by reducing the risk of severe dengue following subsequent infections, and for constructing live-attenuated vaccine candidates against newly emerging Japanese encephalitis virus (JEV) or Japanese encephalitis (JE) serocomplex virus. The monoclonal antibody studies indicated the fusion loop of JE serocomplex viruses primarily comprised non-neutralizing epitopes. However, the present study demonstrates that the JEV fusion loop plays a critical role in eliciting protective immunity in mice. Modifications to the fusion loop of JE serocomplex viruses might negatively affect vaccine efficacy compared to dengue and zika serocomplex viruses. Further studies are required to assess the impact of mutant fusion loop encoded by commonly used JEV vaccine strains on vaccine efficacy or safety after subsequent dengue virus infection. |
Global phylogeography and evolutionary history of Shigella dysenteriae type 1.
Njamkepo E , Fawal N , Tran-Dien A , Hawkey J , Strockbine N , Jenkins C , Talukder KA , Bercion R , Kuleshov K , Kolínská R , Russell JE , Kaftyreva L , Accou-Demartin M , Karas A , Vandenberg O , Mather AE , Mason CJ , Page AJ , Ramamurthy T , Bizet C , Gamian A , Carle I , Sow AG , Bouchier C , Wester AL , Lejay-Collin M , Fonkoua MC , Le Hello S , Blaser MJ , Jernberg C , Ruckly C , Mérens A , Page AL , Aslett M , Roggentin P , Fruth A , Denamur E , Venkatesan M , Bercovier H , Bodhidatta L , Chiou CS , Clermont D , Colonna B , Egorova S , Pazhani GP , Ezernitchi AV , Guigon G , Harris SR , Izumiya H , Korzeniowska-Kowal A , Lutyńska A , Gouali M , Grimont F , Langendorf C , Marejková M , Peterson LA , Perez-Perez G , Ngandjio A , Podkolzin A , Souche E , Makarova M , Shipulin GA , Ye C , Žemličková H , Herpay M , Grimont PA , Parkhill J , Sansonetti P , Holt KE , Brisse S , Thomson NR , Weill FX . Nat Microbiol 2016 1 16027 ![]() Together with plague, smallpox and typhus, epidemics of dysentery have been a major scourge of human populations for centuries(1). A previous genomic study concluded that Shigella dysenteriae type 1 (Sd1), the epidemic dysentery bacillus, emerged and spread worldwide after the First World War, with no clear pattern of transmission(2). This is not consistent with the massive cyclic dysentery epidemics reported in Europe during the eighteenth and nineteenth centuries(1,3,4) and the first isolation of Sd1 in Japan in 1897(5). Here, we report a whole-genome analysis of 331 Sd1 isolates from around the world, collected between 1915 and 2011, providing us with unprecedented insight into the historical spread of this pathogen. We show here that Sd1 has existed since at least the eighteenth century and that it swept the globe at the end of the nineteenth century, diversifying into distinct lineages associated with the First World War, Second World War and various conflicts or natural disasters across Africa, Asia and Central America. We also provide a unique historical perspective on the evolution of antibiotic resistance over a 100-year period, beginning decades before the antibiotic era, and identify a prevalent multiple antibiotic-resistant lineage in South Asia that was transmitted in several waves to Africa, where it caused severe outbreaks of disease. |
Enhanced Contact Investigations for Nine Early Travel-Related Cases of SARS-CoV-2 in the United States (preprint)
Burke RM , Balter S , Barnes E , Barry V , Bartlett K , Beer KD , Benowitz I , Biggs HM , Bruce H , Bryant-Genevier J , Cates J , Chatham-Stephens K , Chea N , Chiou H , Christiansen D , Chu VT , Clark S , Cody SH , Cohen M , Conners EE , Dasari V , Dawson P , DeSalvo T , Donahue M , Dratch A , Duca L , Duchin J , Dyal JW , Feldstein LR , Fenstersheib M , Fischer M , Fisher R , Foo C , Freeman-Ponder B , Fry AM , Gant J , Gautom R , Ghinai I , Gounder P , Grigg CT , Gunzenhauser J , Hall AJ , Han GS , Haupt T , Holshue M , Hunter J , Ibrahim MB , Jacobs MW , Jarashow MC , Joshi K , Kamali T , Kawakami V , Kim M , Kirking HL , Kita-Yarbro A , Klos R , Kobayashi M , Kocharian A , Lang M , Layden J , Leidman E , Lindquist S , Lindstrom S , Link-Gelles R , Marlow M , Mattison CP , McClung N , McPherson TD , Mello L , Midgley CM , Novosad S , Patel MT , Pettrone K , Pillai SK , Pray IW , Reese HE , Rhodes H , Robinson S , Rolfes M , Routh J , Rubin R , Rudman SL , Russell D , Scott S , Shetty V , Smith-Jeffcoat SE , Soda EA , Spitters C , Stierman B , Sunenshine R , Terashita D , Traub E , Vahey GM , Verani JR , Wallace M , Westercamp M , Wortham J , Xie A , Yousaf A , Zahn M . medRxiv 2020 2020.04.27.20081901 Background Coronavirus disease 2019 (COVID-19), the respiratory disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was first identified in Wuhan, China and has since become pandemic. As part of initial response activities in the United States, enhanced contact investigations were conducted to enable early identification and isolation of additional cases and to learn more about risk factors for transmission.Methods Close contacts of nine early travel-related cases in the United States were identified. Close contacts meeting criteria for active monitoring were followed, and selected individuals were targeted for collection of additional exposure details and respiratory samples. Respiratory samples were tested for SARS-CoV-2 by real-time reverse transcription polymerase chain reaction (RT-PCR) at the Centers for Disease Control and Prevention.Results There were 404 close contacts who underwent active monitoring in the response jurisdictions; 338 had at least basic exposure data, of whom 159 had ≥1 set of respiratory samples collected and tested. Across all known close contacts under monitoring, two additional cases were identified; both secondary cases were in spouses of travel-associated case patients. The secondary attack rate among household members, all of whom had ≥1 respiratory sample tested, was 13% (95% CI: 4 – 38%).Conclusions The enhanced contact tracing investigations undertaken around nine early travel-related cases of COVID-19 in the United States identified two cases of secondary transmission, both spouses. Rapid detection and isolation of the travel-associated case patients, enabled by public awareness of COVID-19 among travelers from China, may have mitigated transmission risk among close contacts of these cases.Competing Interest StatementThe authors have declared no competing interest.Funding StatementNo external funding was sought or received.Author DeclarationsAll relevant ethical guidelines have been followed; any necessary IRB and/or ethics committee approvals have been obtained and details of the IRB/oversight body are included in the manuscript.YesAll necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesData may be available upon reasonable request. |
Measuring the burden of infodemics: Summary of the methods and results of the Fifth WHO Infodemic Management Conference
Wilhelm E , Ballalai I , Belanger ME , Benjamin P , Bertrand-Ferrandis C , Bezbaruah S , Briand S , Brooks I , Bruns R , Bucci LM , Calleja N , Chiou H , Devaria A , Dini L , D'Souza H , Dunn AG , Eichstaedt JC , Evers Smaa , Gobat N , Gissler M , Gonzales IC , Gruzd A , Hess S , Ishizumi A , John O , Joshi A , Kaluza B , Khamis N , Kosinska M , Kulkarni S , Lingri D , Ludolph R , Mackey T , Mandić-Rajčević S , Menczer F , Mudaliar V , Murthy S , Nazakat S , Nguyen T , Nilsen J , Pallari E , Pasternak Taschner N , Petelos E , Prinstein MJ , Roozenbeek J , Schneider A , Srinivasan V , Stevanović A , Strahwald B , Syed Abdul S , Varaidzo Machiri S , van der Linden S , Voegeli C , Wardle C , Wegwarth O , White BK , Willie E , Yau B , Purnat TD . JMIR Infodemiology 2023 3 e44207 BACKGROUND: An infodemic is excess information, including false or misleading information, that spreads in digital and physical environments during a public health emergency. The COVID-19 pandemic has been accompanied by an unprecedented global infodemic that has led to confusion about the benefits of medical and public health interventions, with substantial impact on risk-taking and health-seeking behaviors, eroding trust in health authorities and compromising the effectiveness of public health responses and policies. Standardized measures are needed to quantify the harmful impacts of the infodemic in a systematic and methodologically robust manner, as well as harmonizing highly divergent approaches currently explored for this purpose. This can serve as a foundation for a systematic, evidence-based approach to monitoring, identifying, and mitigating future infodemic harms in emergency preparedness and prevention. OBJECTIVE: In this paper, we summarize the Fifth World Health Organization (WHO) Infodemic Management Conference structure, proceedings, outcomes, and proposed actions seeking to identify the interdisciplinary approaches and frameworks needed to enable the measurement of the burden of infodemics. METHODS: An iterative human-centered design (HCD) approach and concept mapping were used to facilitate focused discussions and allow for the generation of actionable outcomes and recommendations. The discussions included 86 participants representing diverse scientific disciplines and health authorities from 28 countries across all WHO regions, along with observers from civil society and global public health-implementing partners. A thematic map capturing the concepts matching the key contributing factors to the public health burden of infodemics was used throughout the conference to frame and contextualize discussions. Five key areas for immediate action were identified. RESULTS: The 5 key areas for the development of metrics to assess the burden of infodemics and associated interventions included (1) developing standardized definitions and ensuring the adoption thereof; (2) improving the map of concepts influencing the burden of infodemics; (3) conducting a review of evidence, tools, and data sources; (4) setting up a technical working group; and (5) addressing immediate priorities for postpandemic recovery and resilience building. The summary report consolidated group input toward a common vocabulary with standardized terms, concepts, study designs, measures, and tools to estimate the burden of infodemics and the effectiveness of infodemic management interventions. CONCLUSIONS: Standardizing measurement is the basis for documenting the burden of infodemics on health systems and population health during emergencies. Investment is needed into the development of practical, affordable, evidence-based, and systematic methods that are legally and ethically balanced for monitoring infodemics; generating diagnostics, infodemic insights, and recommendations; and developing interventions, action-oriented guidance, policies, support options, mechanisms, and tools for infodemic managers and emergency program managers. |
The future of infodemic surveillance as public health surveillance
Chiou H , Voegeli C , Wilhelm E , Kolis J , Brookmeyer K , Prybylski D . Emerg Infect Dis 2022 28 (13) S121-s128 Public health systems need to be able to detect and respond to infodemics (outbreaks of misinformation, disinformation, information overload, or information voids). Drawing from our experience at the US Centers for Disease Control and Prevention, the COVID-19 State of Vaccine Confidence Insight Reporting System has been created as one of the first public health infodemic surveillance systems. Key functions of infodemic surveillance systems include monitoring the information environment by person, place, and time; identifying infodemic events with digital analytics; conducting offline community-based assessments; and generating timely routine reports. Although specific considerations of several system attributes of infodemic surveillance system must be considered, infodemic surveillance systems share several similarities with traditional public health surveillance systems. Because both information and pathogens are spread more readily in an increasingly hyperconnected world, sustainable and routine systems must be created to ensure that timely interventions can be deployed for both epidemic and infodemic response. |
Period prevalence of rheumatic heart disease and the need for a centralized patient registry in American Samoa, 2016 to 2018
Woodruff RC , Eliapo-Unutoa I , Chiou H , Gayapa M , Noonan S , Podila PSB , Rayle V , Sanchez G , Tulafono R , Van Beneden CA , Ritchey M . J Am Heart Assoc 2021 10 (20) e020424 Background Rheumatic heart disease (RHD) is a severe, chronic complication of acute rheumatic fever, triggered by group A streptococcal pharyngitis. Centralized patient registries are recommended for RHD prevention and control, but none exists in American Samoa. Using existing RHD tracking systems, we estimated RHD period prevalence and the proportion of people with RHD documented in the electronic health record. Methods and Results RHD cases were identified from a centralized electronic health record system, which retrieved clinical encounters with RHD International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) codes, clinical problem lists referencing RHD, and antibiotic prophylaxis administration records; 3 RHD patient tracking spreadsheets; and an all-cause mortality database. RHD cases had ≥1 clinical encounter with RHD ICD-10-CM codes, a diagnostic echocardiogram, or RHD as a cause of death, or were included in RHD patient tracking spreadsheets. Period prevalence per 1000 population among children aged <18 years and adults aged ≥18 years from 2016 to 2018 and the proportion of people with RHD with ≥1 clinical encounter with an RHD ICD-10-CM code were estimated. From 2016 to 2018, RHD was documented in 327 people (57.2%: children aged <18 years). Overall RHD period prevalence was 6.3 cases per 1000 and varied by age (10.0 pediatric cases and 4.3 adult cases per 1000). Only 67% of people with RHD had ≥1 clinical encounter with an RHD ICD-10-CM code. Conclusions RHD remains a serious public health problem in American Samoa, and the existing electronic health record does not include all cases. A centralized patient registry could improve tracking people with RHD to ensure they receive necessary care. |
Enhanced contact investigations for nine early travel-related cases of SARS-CoV-2 in the United States.
Burke RM , Balter S , Barnes E , Barry V , Bartlett K , Beer KD , Benowitz I , Biggs HM , Bruce H , Bryant-Genevier J , Cates J , Chatham-Stephens K , Chea N , Chiou H , Christiansen D , Chu VT , Clark S , Cody SH , Cohen M , Conners EE , Dasari V , Dawson P , DeSalvo T , Donahue M , Dratch A , Duca L , Duchin J , Dyal JW , Feldstein LR , Fenstersheib M , Fischer M , Fisher R , Foo C , Freeman-Ponder B , Fry AM , Gant J , Gautom R , Ghinai I , Gounder P , Grigg CT , Gunzenhauser J , Hall AJ , Han GS , Haupt T , Holshue M , Hunter J , Ibrahim MB , Jacobs MW , Jarashow MC , Joshi K , Kamali T , Kawakami V , Kim M , Kirking HL , Kita-Yarbro A , Klos R , Kobayashi M , Kocharian A , Lang M , Layden J , Leidman E , Lindquist S , Lindstrom S , Link-Gelles R , Marlow M , Mattison CP , McClung N , McPherson TD , Mello L , Midgley CM , Novosad S , Patel MT , Pettrone K , Pillai SK , Pray IW , Reese HE , Rhodes H , Robinson S , Rolfes M , Routh J , Rubin R , Rudman SL , Russell D , Scott S , Shetty V , Smith-Jeffcoat SE , Soda EA , Spitters C , Stierman B , Sunenshine R , Terashita D , Traub E , Vahey GM , Verani JR , Wallace M , Westercamp M , Wortham J , Xie A , Yousaf A , Zahn M . PLoS One 2020 15 (9) e0238342 Coronavirus disease 2019 (COVID-19), the respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was first identified in Wuhan, China and has since become pandemic. In response to the first cases identified in the United States, close contacts of confirmed COVID-19 cases were investigated to enable early identification and isolation of additional cases and to learn more about risk factors for transmission. Close contacts of nine early travel-related cases in the United States were identified and monitored daily for development of symptoms (active monitoring). Selected close contacts (including those with exposures categorized as higher risk) were targeted for collection of additional exposure information and respiratory samples. Respiratory samples were tested for SARS-CoV-2 by real-time reverse transcription polymerase chain reaction at the Centers for Disease Control and Prevention. Four hundred four close contacts were actively monitored in the jurisdictions that managed the travel-related cases. Three hundred thirty-eight of the 404 close contacts provided at least basic exposure information, of whom 159 close contacts had ≥1 set of respiratory samples collected and tested. Across all actively monitored close contacts, two additional symptomatic COVID-19 cases (i.e., secondary cases) were identified; both secondary cases were in spouses of travel-associated case patients. When considering only household members, all of whom had ≥1 respiratory sample tested for SARS-CoV-2, the secondary attack rate (i.e., the number of secondary cases as a proportion of total close contacts) was 13% (95% CI: 4-38%). The results from these contact tracing investigations suggest that household members, especially significant others, of COVID-19 cases are at highest risk of becoming infected. The importance of personal protective equipment for healthcare workers is also underlined. Isolation of persons with COVID-19, in combination with quarantine of exposed close contacts and practice of everyday preventive behaviors, is important to mitigate spread of COVID-19. |
Clinical and virologic characteristics of the first 12 patients with coronavirus disease 2019 (COVID-19) in the United States.
Kujawski SA , Wong KK , Collins JP , Epstein L , Killerby ME , Midgley CM , Abedi GR , Ahmed NS , Almendares O , Alvarez FN , Anderson KN , Balter S , Barry V , Bartlett K , Beer K , Ben-Aderet MA , Benowitz I , Biggs HM , Binder AM , Black SR , Bonin B , Bozio CH , Brown CM , Bruce H , Bryant-Genevier J , Budd A , Buell D , Bystritsky R , Cates J , Charles EM , Chatham-Stephens K , Chea N , Chiou H , Christiansen D , Chu V , Cody S , Cohen M , Conners EE , Curns AT , Dasari V , Dawson P , DeSalvo T , Diaz G , Donahue M , Donovan S , Duca LM , Erickson K , Esona MD , Evans S , Falk J , Feldstein LR , Fenstersheib M , Fischer M , Fisher R , Foo C , Fricchione MJ , Friedman O , Fry A , Galang RR , Garcia MM , Gerber SI , Gerrard G , Ghinai I , Gounder P , Grein J , Grigg C , Gunzenhauser JD , Gutkin GI , Haddix M , Hall AJ , Han GS , Harcourt J , Harriman K , Haupt T , Haynes AK , Holshue M , Hoover C , Hunter JC , Jacobs MW , Jarashow C , Joshi K , Kamali T , Kamili S , Kim L , Kim M , King J , Kirking HL , Kita-Yarbro A , Klos R , Kobayashi M , Kocharian A , Komatsu KK , Koppaka R , Layden JE , Li Y , Lindquist S , Lindstrom S , Link-Gelles R , Lively J , Livingston M , Lo K , Lo J , Lu X , Lynch B , Madoff L , Malapati L , Marks G , Marlow M , Mathisen GE , McClung N , McGovern O , McPherson TD , Mehta M , Meier A , Mello L , Moon SS , Morgan M , Moro RN , Murray J , Murthy R , Novosad S , Oliver SE , O’Shea J , Pacilli M , Paden CR , Pallansch MA , Patel M , Patel S , Pedraza I , Pillai SK , Pindyck T , Pray I , Queen K , Quick N , Reese H , Reporter R , Rha B , Rhodes H , Robinson S , Robinson P , Rolfes MA , Routh JA , Rubin R , Rudman SL , Sakthivel SK , Scott S , Shepherd C , Shetty V , Smith EA , Smith S , Stierman B , Stoecker W , Sunenshine R , Sy-Santos R , Tamin A , Tao Y , Terashita D , Thornburg NJ , Tong S , Traub E , Tural A , Uehara A , Uyeki TM , Vahey G , Verani JR , Villarino E , Wallace M , Wang L , Watson JT , Westercamp M , Whitaker B , Wilkerson S , Woodruff RC , Wortham JM , Wu T , Xie A , Yousaf A , Zahn M , Zhang J . Nat Med 2020 26 (6) 861-868 Data on the detailed clinical progression of COVID-19 in conjunction with epidemiological and virological characteristics are limited. In this case series, we describe the first 12 US patients confirmed to have COVID-19 from 20 January to 5 February 2020, including 4 patients described previously(1-3). Respiratory, stool, serum and urine specimens were submitted for SARS-CoV-2 real-time reverse-transcription polymerase chain reaction (rRT-PCR) testing, viral culture and whole genome sequencing. Median age was 53 years (range: 21-68); 8 patients were male. Common symptoms at illness onset were cough (n = 8) and fever (n = 7). Patients had mild to moderately severe illness; seven were hospitalized and demonstrated clinical or laboratory signs of worsening during the second week of illness. No patients required mechanical ventilation and all recovered. All had SARS-CoV-2 RNA detected in respiratory specimens, typically for 2-3 weeks after illness onset. Lowest real-time PCR with reverse transcription cycle threshold values in the upper respiratory tract were often detected in the first week and SARS-CoV-2 was cultured from early respiratory specimens. These data provide insight into the natural history of SARS-CoV-2. Although infectiousness is unclear, highest viral RNA levels were identified in the first week of illness. Clinicians should anticipate that some patients may worsen in the second week of illness. |
NS2B/NS3 mutations enhance the infectivity of genotype I Japanese encephalitis virus in amplifying hosts.
Fan YC , Liang JJ , Chen JM , Lin JW , Chen YY , Su KH , Lin CC , Tu WC , Chiou MT , Ou SC , Chang GJ , Lin YL , Chiou SS . PLoS Pathog 2019 15 (8) e1007992 ![]() Genotype I (GI) virus has replaced genotype III (GIII) virus as the dominant Japanese encephalitis virus (JEV) in the epidemic area of Asia. The mechanism underlying the genotype replacement remains unclear. Therefore, we focused our current study on investigating the roles of mosquito vector and amplifying host(s) in JEV genotype replacement by comparing the replication ability of GI and GIII viruses. GI and GIII viruses had similar infection rates and replicated to similar viral titers after blood meal feedings in Culex tritaeniorhynchus. However, GI virus yielded a higher viral titer in amplifying host-derived cells, especially at an elevated temperature, and produced an earlier and higher viremia in experimentally inoculated pigs, ducklings, and young chickens. Subsequently we identified the amplification advantage of viral genetic determinants from GI viruses by utilizing chimeric and recombinant JEVs (rJEVs). Compared to the recombinant GIII virus (rGIII virus), we observed that both the recombinant GI virus and the chimeric rJEVs encoding GI virus-derived NS1-3 genes supported higher replication ability in amplifying hosts. The replication advantage of the chimeric rJEVs was lost after introduction of a single substitution from a GIII viral mutation (NS2B-L99V, NS3-S78A, or NS3-D177E). In addition, the gain-of-function assay further elucidated that rGIII virus encoding GI virus NS2B-V99L/NS3-A78S/E177E substitutions re-gained the enhanced replication ability. Thus, we conclude that the replication advantage of GI virus in pigs and poultry is the result of three critical NS2B/NS3 substitutions. This may lead to more efficient transmission of GI virus than GIII virus in the amplifying host-mosquito cycle. |
Effectiveness of a no-cost-to-workers, slip-resistant footwear program for reducing slipping-related injuries in food service workers: a cluster randomized trial
Bell JL , Collins JW , Chiou S . Scand J Work Environ Health 2018 45 (2) 194-202 Objective This study evaluated the effectiveness of a no-cost-to-workers, slip-resistant footwear (SRF) program in preventing workers' compensation injury claims caused by slipping on wet or greasy floors. Methods The study population was a dynamic cohort of food service workers from 226 school districts' kindergarten through 12th grade food service operations. A two-arm cluster randomized controlled study design was implemented, with school districts randomized to the intervention group receiving SRF. Data were analyzed according to the intent-to-treat principle. Logistic regression was used to analyze dichotomous response data (injured based on workers' compensation injury claims data, or not injured, for each month worked). Changes in slipping injury rates from baseline to post-intervention follow-up periods were compared between treatment groups. Results The probability of a slipping injury was reduced significantly in the intervention group, from a baseline measure of 3.54 slipping injuries per 10 000 worker-months to 1.18 slipping injuries per 10 000 worker-months in the follow-up period [adjusted odds ratio (OR adj) 0.33, 95% confidence interval (CI) 0.17-0.63]. In the control group, slipping injuries were 2.01 per 10 000 worker-months in the baseline, and 2.30 per 10 000 worker-months in the follow-up. The interaction between treatment group and time period (baseline or follow-up) indicated that the decline seen in the intervention group was significantly different than the increase seen in the control group (OR adj0.29, 95% CI 0.11-0.74, adjusted for age >55 years). Conclusions This study provides evidence for the effectiveness of a no-cost-to-workers SRF program in reducing slipping-related workers' compensation injury claims in food service workers. |
Genotype I of Japanese encephalitis virus virus-like particles elicit sterilizing immunity against genotype I and III viral challenge in swine
Fan YC , Chen JM , Lin JW , Chen YY , Wu GH , Su KH , Chiou MT , Wu SR , Yin JH , Liao JW , Chang GJ , Chiou SS . Sci Rep 2018 8 (1) 7481 Swine are a critical amplifying host involved in human Japanese encephalitis (JE) outbreaks. Cross-genotypic immunogenicity and sterile protection are important for the current genotype III (GIII) virus-derived vaccines in swine, especially now that emerging genotype I (GI) JE virus (JEV) has replaced GIII virus as the dominant strain. Herein, we aimed to develop a system to generate GI JEV virus-like particles (VLPs) and evaluate the immunogenicity and protection of the GI vaccine candidate in mice and specific pathogen-free swine. A CHO-heparan sulfate-deficient (CHO-HS(-)) cell clone, named 51-10 clone, stably expressing GI-JEV VLP was selected and continually secreted GI VLPs without signs of cell fusion. 51-10 VLPs formed a homogeneously empty-particle morphology and exhibited similar antigenic activity as GI virus. GI VLP-immunized mice showed balanced cross-neutralizing antibody titers against GI to GIV viruses (50% focus-reduction micro-neutralization assay titers 71 to 240) as well as potent protection against GI or GIII virus infection. GI VLP-immunized swine challenged with GI or GIII viruses showed no fever, viremia, or viral RNA in tonsils, lymph nodes, and brains as compared with phosphate buffered saline-immunized swine. We thus conclude GI VLPs can provide sterile protection against GI and GIII viruses in swine. |
Evaluation of postural sway and impact forces during ingress and egress of scissor lifts at elevations
Pan CS , Chiou SS , Kau T , Wimer BM , Ning X , Keane P . Appl Ergon 2017 65 152-162 Workers are at risk when entering (ingress) or exiting (egress) elevated scissor lifts. In this study, we recorded ground impact forces and postural sway from 22 construction workers while they performed ingress and egress between a scissor lift and an adjacent work surface with varying conditions: lift opening designs, horizontal and vertical gaps, and sloped work surfaces. We observed higher peak ground shear forces when using a bar-and-chain opening, with larger horizontal gap, with the lift surface more than 0.2 m below the work surface, and presence of a sloped (26) work surface. Similar trends were observed for postural sway, except that the influence of vertical distance was not significant. To reduce slip/trip/fall risk and postural sway of workers while ingress or egress of an elevated scissor lift, we suggest scissor lifts be equipped with a gate-type opening instead of a bar-and-chain design. We also suggest the lift surface be placed no more than 0.2 m lower than the work surface and the horizontal gap between lift and work surfaces be as small as possible. Selecting a non-sloped surface to ingress or egress a scissor lift is also preferred to reduce risk. |
Effect of boot weight and sole flexibility on gait and physiological responses of firefighters in stepping over obstacles
Chiou SS , Turner N , Zwiener J , Weaver DL , Haskell WE . Hum Factors 2012 54 (3) 373-86 OBJECTIVE: The authors investigated the effect of boot weight and sole flexibility on spatiotemporal gait characteristics and physiological responses of firefighters in negotiating obstacles. BACKGROUND: Falls and overexertion are the leading causes of fire ground injuries and fatalities among firefighters. There have been few in-depth studies conducted to evaluate the risk factors of falls and overexertion associated with firefighter boots. METHOD: For the study, 13 female and 14 male firefighters, while wearing full turnout clothing and randomly assigned boots, walked for 5 min while stepping over obstacles. The independent variables included boot weight, sole flexibility, gender, and task duration. Spatiotemporal measures of foot trajectories and toe clearance were determined. Minute ventilation, oxygen consumption, carbon dioxide production, and heart rate were measured. RESULTS: Increased boot weight was found to significantly reduce trailing toe clearance when crossing the 30-cm obstacle. Significant increases in lateral displacement of the foot were found near the end of the 5-min walk compared with the beginning of the task Increased boot weight significantly increased oxygen consumption. There were significant decreases in oxygen consumption for more flexible soles. CONCLUSION: Firefighters were more likely to trip over obstacles when wearing heavier boots and after walking for a period of time. Boot weight affected metabolic variables (5% to 11% increases per 1-kg increase in boot weight), which were mitigated by sole flexibility (5% to 7% decrease for more flexible soles). APPLICATION: This study provides useful information for firefighters and boot manufacturers in boot selection and design for reducing falls and overexertion. |
Mutation analysis of the cross-reactive epitopes of Japanese encephalitis virus envelope glycoprotein.
Chiou SS , Fan YC , Crill WD , Chang RY , Chang GJ . J Gen Virol 2012 93 1185-92 ![]() Group and serocomplex cross-reactive epitopes have been identified in the envelope (E) protein of several flaviviruses and have proven critical in vaccine and diagnostic antigen development. Here, we performed site-directed mutagenesis across the E gene of a recombinant expression plasmid that encodes the Japanese encephalitis virus (JEV) premembrane (prM) and E proteins and produces JEV virus-like particles (VLPs). Mutations were introduced at I135 and E138 in domain I; W101, G104, G106 and L107 in domain II; and T305, E306, K312, A315, S329, S331, G332 and D389 in domain III. None of the mutant JEV VLPs demonstrated reduced activity to the five JEV type-specific mAbs tested. Substitutions at W101, especially W101G, reduced reactivity dramatically with all of the flavivirus group cross-reactive mAbs. The group and JEV serocomplex cross-reactive mAbs examined recognized five and six different overlapping epitopes, respectively. Among five group cross-reactive epitopes, amino acids located in domains I, II and III were involved in one, five and three epitopes, respectively. Recognition by six JEV serocomplex cross-reactive mAbs was reduced by amino acid substitutions in domains II and III. These results suggest that amino acid residues located in the fusion loop of E domain II are the most critical for recognition by group cross-reactive mAbs, followed by residues of domains III and I. The amino acid residues of both domains II and III of the E protein were shown to be important in the binding of JEV serocomplex cross-reactive mAbs. |
Japanese encephalitis virus genotype replacement, Taiwan, 2009-2010.
Chen YY , Fan YC , Tu WC , Chang RY , Shih CC , Lu IH , Chien MS , Lee WC , Chen TH , Chang GJ , Chiou SS . Emerg Infect Dis 2011 17 (12) 2354-6 ![]() Genotype I of Japanese encephalitis virus first appeared in Taiwan in 2008. Phylogenetic analysis of 37 viruses from pig farms in 2009-2010 classified these viruses into 2 unique subclusters of genotype I viruses and suggested multiple introductions and swift replacement of genotype III by genotype I virus in Taiwan. |
Global distribution of Shigella sonnei clones
Filliol-Toutain I , Chiou CS , Mammina C , Gerner-Smidt P , Thong KL , Phung DC , Pichel M , Ranjbar R , Sow AG , Cooper K , Ribot E , Binsztein N , Liang SY . Emerg Infect Dis 2011 17 (10) 1910-2 To investigate global epidemiology of Shigella sonnei, we performed multilocus variable number tandem repeat analysis of 1,672 isolates obtained since 1943 from 50 countries on 5 continents and the Pacific region. Three major clonal groups were identified; 2 were globally spread. Type 18 and its derivatives have circulated worldwide in recent decades. |
Physiological effects of boot weight and design on men and women firefighters
Turner NL , Chiou S , Zwiener J , Weaver D , Spahr J . J Occup Environ Hyg 2010 7 (8) 477-82 The purpose of this study was to determine the effects of two leather (L1, L2) and two rubber (R1, R2) boots on firefighters' metabolic and respiratory variables during simulated firefighting tasks. Twenty-five men and 25 women, while wearing full turnout clothing, a 10.5-kg backpack, gloves, helmet, and one of four randomly assigned pairs of firefighter boots, walked for 6 min at 3 mph (4.8 km/hr) on a level treadmill while carrying a 9.5-kg hose and climbed a stair ergometer for 6 min at 45 steps per min without the hose. [Abstract truncated.] |
Effects of foot placement on postural stability of construction workers on stilts
Pan CS , Chiou S , Kau TY , Bhattacharya A , Ammons D . Appl Ergon 2009 40 (4) 781-9 Stilts are elevated tools that are frequently used by construction workers to raise workers 18-40 inches above the ground. The objective of this laboratory study was to evaluate the potential loss of postural stability associated with the use of stilts in various foot placements. Twenty construction workers with at least 1 year of experience in the use of stilts participated in this study. One Kistler force platform was used to collect kinetic data. Participants were tested under six-foot-placement conditions. These 6 experimental conditions were statically tested under all combinations of 3 levels of elevation: 0'' (no stilts), 24'' stilt height and 40'' stilt height. SAS mixed procedure was used to evaluate the effect of different experimental conditions. The results of the multivariate analysis of variance (MANOVA) and repeated measures of univariate analyses of variance (ANOVAs) demonstrated that stilt height, foot-placement direction, and foot-placement width all had significant effects on the whole-body postural stability. This study found that the higher the stilts were elevated, the greater the postural instability. A stance position with one foot placed forward of the other foot produced greater postural instability than a position with the feet parallel and directly beneath the body. This study found that placement of the feet parallel and directly beneath the body, with the feet positioned a half shoulder width apart, caused a greater amount of postural sway and instability than one and one-and-half shoulder width. This study also found that construction workers using the stilts could perceive the likely postural instability due to the change in foot placements. |
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