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1.
Nature ; 590(7846): 468-472, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33505020

RESUMEN

Neutralizing antibody function provides a foundation for the efficacy of vaccines and therapies1-3. Here, using a robust in vitro Ebola virus (EBOV) pseudo-particle infection assay and a well-defined set of solid-phase assays, we describe a wide spectrum of antibody responses in a cohort of healthy survivors of the Sierra Leone EBOV outbreak of 2013-2016. Pseudo-particle virus-neutralizing antibodies correlated with total anti-EBOV reactivity and neutralizing antibodies against live EBOV. Variant EBOV glycoproteins (1995 and 2014 strains) were similarly neutralized. During longitudinal follow-up, antibody responses fluctuated in a 'decay-stimulation-decay' pattern that suggests de novo restimulation by EBOV antigens after recovery. A pharmacodynamic model of antibody reactivity identified a decay half-life of 77-100 days and a doubling time of 46-86 days in a high proportion of survivors. The highest antibody reactivity was observed around 200 days after an individual had recovered. The model suggests that EBOV antibody reactivity declines over 0.5-2 years after recovery. In a high proportion of healthy survivors, antibody responses undergo rapid restimulation. Vigilant follow-up of survivors and possible elective de novo antigenic stimulation by vaccine immunization should be considered in order to prevent EBOV viral recrudescence in recovering individuals and thereby to mitigate the potential risk of reseeding an outbreak.


Asunto(s)
Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Convalecencia , Ebolavirus/inmunología , Fiebre Hemorrágica Ebola/inmunología , Sobrevivientes , Adolescente , Adulto , África Occidental/epidemiología , Anticuerpos Neutralizantes/sangre , Anticuerpos Neutralizantes/inmunología , Estudios de Cohortes , Femenino , Semivida , Fiebre Hemorrágica Ebola/sangre , Fiebre Hemorrágica Ebola/epidemiología , Fiebre Hemorrágica Ebola/prevención & control , Humanos , Masculino , Persona de Mediana Edad , Pruebas de Neutralización , Factores de Tiempo , Viremia/sangre , Viremia/inmunología , Adulto Joven
2.
J Infect Dis ; 226(1): 70-82, 2022 08 12.
Artículo en Inglés | MEDLINE | ID: mdl-33119755

RESUMEN

BACKGROUND: The extent of human infections with avian influenza A(H7N9) virus, including mild and asymptomatic infections, is uncertain. METHODS: We performed a systematic review and meta-analysis of serosurveys for avian influenza A(H7N9) virus infections in humans published during 2013-2020. Three seropositive definitions were assessed to estimate pooled seroprevalence, seroconversion rate, and seroincidence by types of exposures. We applied a scoring system to assess the quality of included studies. RESULTS: Of 31 included studies, pooled seroprevalence of A(H7N9) virus antibodies from all participants was 0.02%, with poultry workers, close contacts, and general populations having seroprevalence of 0.1%, 0.2%, and 0.02%, respectively, based on the World Health Organization (WHO)-recommended definition. Although most infections were asymptomatic, evidence of infection was highest in poultry workers (5% seroconversion, 19.1% seroincidence per 100 person-years). Use of different virus clades did not significantly affect seroprevalence estimates. Most serological studies were of low to moderate quality and did not follow standardized seroepidemiological protocols or WHO-recommended laboratory methods. CONCLUSIONS: Human infections with avian influenza A(H7N9) virus have been uncommon, especially for general populations. Workers with occupational exposures to poultry and close contacts of A(H7N9) human cases had low risks of infection.


Asunto(s)
Subtipo H7N9 del Virus de la Influenza A , Gripe Aviar , Gripe Humana , Animales , Aves , China , Humanos , Gripe Aviar/epidemiología , Aves de Corral , Estudios Seroepidemiológicos
3.
Emerg Infect Dis ; 28(8): 1559-1568, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35876478

RESUMEN

Ribavirin has been used widely to treat Lassa fever in West Africa since the 1980s. However, few studies have systematically appraised the evidence for its use. We conducted a systematic review of published and unpublished literature retrieved from electronic databases and gray literature from inception to March 8, 2022. We identified 13 studies of the comparative effectiveness of ribavirin versus no ribavirin treatment on mortality outcomes, including unpublished data from a study in Sierra Leone provided through a US Freedom of Information Act request. Although ribavirin was associated with decreased mortality rates, results of these studies were at critical or serious risk for bias when appraised using the ROBINS-I tool. Important risks for bias related to lack of control for confounders, immortal time bias, and missing outcome data. Robust evidence supporting the use of ribavirin in Lassa fever is lacking. Well-conducted clinical trials to elucidate the effectiveness of ribavirin for Lassa fever are needed.


Asunto(s)
Fiebre de Lassa , África Occidental , Humanos , Fiebre de Lassa/tratamiento farmacológico , Fiebre de Lassa/epidemiología , Virus Lassa/genética , Ribavirina/uso terapéutico , Sierra Leona
4.
Thorax ; 77(6): 606-615, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-34810237

RESUMEN

PURPOSE: To prospectively validate two risk scores to predict mortality (4C Mortality) and in-hospital deterioration (4C Deterioration) among adults hospitalised with COVID-19. METHODS: Prospective observational cohort study of adults (age ≥18 years) with confirmed or highly suspected COVID-19 recruited into the International Severe Acute Respiratory and emerging Infections Consortium (ISARIC) WHO Clinical Characterisation Protocol UK (CCP-UK) study in 306 hospitals across England, Scotland and Wales. Patients were recruited between 27 August 2020 and 17 February 2021, with at least 4 weeks follow-up before final data extraction. The main outcome measures were discrimination and calibration of models for in-hospital deterioration (defined as any requirement of ventilatory support or critical care, or death) and mortality, incorporating predefined subgroups. RESULTS: 76 588 participants were included, of whom 27 352 (37.4%) deteriorated and 12 581 (17.4%) died. Both the 4C Mortality (0.78 (0.77 to 0.78)) and 4C Deterioration scores (pooled C-statistic 0.76 (95% CI 0.75 to 0.77)) demonstrated consistent discrimination across all nine National Health Service regions, with similar performance metrics to the original validation cohorts. Calibration remained stable (4C Mortality: pooled slope 1.09, pooled calibration-in-the-large 0.12; 4C Deterioration: 1.00, -0.04), with no need for temporal recalibration during the second UK pandemic wave of hospital admissions. CONCLUSION: Both 4C risk stratification models demonstrate consistent performance to predict clinical deterioration and mortality in a large prospective second wave validation cohort of UK patients. Despite recent advances in the treatment and management of adults hospitalised with COVID-19, both scores can continue to inform clinical decision making. TRIAL REGISTRATION NUMBER: ISRCTN66726260.


Asunto(s)
COVID-19 , Adolescente , Adulto , COVID-19/terapia , Mortalidad Hospitalaria , Humanos , Estudios Observacionales como Asunto , Pronóstico , SARS-CoV-2 , Medicina Estatal , Organización Mundial de la Salud
5.
BMC Med ; 20(1): 425, 2022 11 07.
Artículo en Inglés | MEDLINE | ID: mdl-36345005

RESUMEN

BACKGROUND: The COVID-19 pandemic has highlighted the importance of evidence-based clinical decision-making. Clinical management guidelines (CMGs) may help reduce morbidity and mortality by improving the quality of clinical decisions. This systematic review aims to evaluate the availability, inclusivity, and quality of pandemic influenza CMGs, to identify gaps that can be addressed to strengthen pandemic preparedness in this area. METHODS: Ovid Medline, Ovid Embase, TRIP (Turning Research Into Practice), and Guideline Central were searched systematically from January 2008 to 23rd June 2022, complemented by a grey literature search till 16th June 2022. Pandemic influenza CMGs including supportive care or empirical treatment recommendations were included. Two reviewers independently extracted data from the included studies and assessed their quality using AGREE II (Appraisal of Guidelines for Research & Evaluation). The findings are presented narratively. RESULTS: Forty-eight CMGs were included. They were produced in high- (42%, 20/48), upper-middle- (40%, 19/48), and lower-middle (8%, 4/48) income countries, or by international organisations (10%, 5/48). Most CMGs (81%, 39/48) were over 5 years old. Guidelines included treatment recommendations for children (75%, 36/48), pregnant women (54%, 26/48), people with immunosuppression (33%, 16/48), and older adults (29%, 14/48). Many CMGs were of low quality (median overall score: 3 out of 7 (range 1-7). All recommended oseltamivir; recommendations for other neuraminidase inhibitors and supportive care were limited and at times contradictory. Only 56% (27/48) and 27% (13/48) addressed oxygen and fluid therapy, respectively. CONCLUSIONS: Our data highlights the limited availability of up-to-date pandemic influenza CMGs globally. Of those identified, many were limited in scope and quality and several lacked recommendations for specific at-risk populations. Recommendations on supportive care, the mainstay of treatment, were limited and heterogeneous. The most recent guideline highlighted that the evidence-base to support antiviral treatment recommendations is still limited. There is an urgent need for trials into treatment and supportive care strategies including for different risk populations. New evidence should be incorporated into globally accessible guidelines, to benefit patient outcomes. A 'living guideline' framework is recommended and further research into guideline implementation in different resourced settings, particularly low- and middle-income countries.


Asunto(s)
COVID-19 , Gripe Humana , Niño , Femenino , Humanos , Embarazo , Anciano , Preescolar , Pandemias , Gripe Humana/tratamiento farmacológico , Gripe Humana/epidemiología , Oseltamivir , Antivirales/uso terapéutico
6.
Lancet ; 395(10236): 1569-1578, 2020 05 16.
Artículo en Inglés | MEDLINE | ID: mdl-32423584

RESUMEN

BACKGROUND: No specific antiviral drug has been proven effective for treatment of patients with severe coronavirus disease 2019 (COVID-19). Remdesivir (GS-5734), a nucleoside analogue prodrug, has inhibitory effects on pathogenic animal and human coronaviruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in vitro, and inhibits Middle East respiratory syndrome coronavirus, SARS-CoV-1, and SARS-CoV-2 replication in animal models. METHODS: We did a randomised, double-blind, placebo-controlled, multicentre trial at ten hospitals in Hubei, China. Eligible patients were adults (aged ≥18 years) admitted to hospital with laboratory-confirmed SARS-CoV-2 infection, with an interval from symptom onset to enrolment of 12 days or less, oxygen saturation of 94% or less on room air or a ratio of arterial oxygen partial pressure to fractional inspired oxygen of 300 mm Hg or less, and radiologically confirmed pneumonia. Patients were randomly assigned in a 2:1 ratio to intravenous remdesivir (200 mg on day 1 followed by 100 mg on days 2-10 in single daily infusions) or the same volume of placebo infusions for 10 days. Patients were permitted concomitant use of lopinavir-ritonavir, interferons, and corticosteroids. The primary endpoint was time to clinical improvement up to day 28, defined as the time (in days) from randomisation to the point of a decline of two levels on a six-point ordinal scale of clinical status (from 1=discharged to 6=death) or discharged alive from hospital, whichever came first. Primary analysis was done in the intention-to-treat (ITT) population and safety analysis was done in all patients who started their assigned treatment. This trial is registered with ClinicalTrials.gov, NCT04257656. FINDINGS: Between Feb 6, 2020, and March 12, 2020, 237 patients were enrolled and randomly assigned to a treatment group (158 to remdesivir and 79 to placebo); one patient in the placebo group who withdrew after randomisation was not included in the ITT population. Remdesivir use was not associated with a difference in time to clinical improvement (hazard ratio 1·23 [95% CI 0·87-1·75]). Although not statistically significant, patients receiving remdesivir had a numerically faster time to clinical improvement than those receiving placebo among patients with symptom duration of 10 days or less (hazard ratio 1·52 [0·95-2·43]). Adverse events were reported in 102 (66%) of 155 remdesivir recipients versus 50 (64%) of 78 placebo recipients. Remdesivir was stopped early because of adverse events in 18 (12%) patients versus four (5%) patients who stopped placebo early. INTERPRETATION: In this study of adult patients admitted to hospital for severe COVID-19, remdesivir was not associated with statistically significant clinical benefits. However, the numerical reduction in time to clinical improvement in those treated earlier requires confirmation in larger studies. FUNDING: Chinese Academy of Medical Sciences Emergency Project of COVID-19, National Key Research and Development Program of China, the Beijing Science and Technology Project.


Asunto(s)
Adenosina Monofosfato/análogos & derivados , Alanina/análogos & derivados , Antivirales/uso terapéutico , Infecciones por Coronavirus/tratamiento farmacológico , Neumonía Viral/tratamiento farmacológico , Adenosina Monofosfato/efectos adversos , Adenosina Monofosfato/uso terapéutico , Anciano , Alanina/efectos adversos , Alanina/uso terapéutico , Antivirales/efectos adversos , Betacoronavirus , COVID-19 , China , Método Doble Ciego , Femenino , Humanos , Infusiones Intravenosas , Masculino , Persona de Mediana Edad , Resultados Negativos , Pandemias , SARS-CoV-2 , Tratamiento Farmacológico de COVID-19
7.
BMC Med Ethics ; 22(1): 106, 2021 07 28.
Artículo en Inglés | MEDLINE | ID: mdl-34320970

RESUMEN

Over recent years, the research community has been increasingly using preprint servers to share manuscripts that are not yet peer-reviewed. Even if it enables quick dissemination of research findings, this practice raises several challenges in publication ethics and integrity. In particular, preprints have become an important source of information for stakeholders interested in COVID19 research developments, including traditional media, social media, and policy makers. Despite caveats about their nature, many users can still confuse pre-prints with peer-reviewed manuscripts. If unconfirmed but already widely shared first-draft results later prove wrong or misinterpreted, it can be very difficult to "unlearn" what we thought was true. Complexity further increases if unconfirmed findings have been used to inform guidelines. To help achieve a balance between early access to research findings and its negative consequences, we formulated five recommendations: (a) consensus should be sought on a term clearer than 'pre-print', such as 'Unrefereed manuscript', "Manuscript awaiting peer review" or ''Non-reviewed manuscript"; (b) Caveats about unrefereed manuscripts should be prominent on their first page, and each page should include a red watermark stating 'Caution-Not Peer Reviewed'; (c) pre-print authors should certify that their manuscript will be submitted to a peer-review journal, and should regularly update the manuscript status; (d) high level consultations should be convened, to formulate clear principles and policies for the publication and dissemination of non-peer reviewed research results; (e) in the longer term, an international initiative to certify servers that comply with good practices could be envisaged.


Asunto(s)
COVID-19 , Medios de Comunicación Sociales , Humanos , Revisión de la Investigación por Pares , SARS-CoV-2
8.
JAMA ; 326(6): 499-518, 2021 08 10.
Artículo en Inglés | MEDLINE | ID: mdl-34228774

RESUMEN

Importance: Clinical trials assessing the efficacy of IL-6 antagonists in patients hospitalized for COVID-19 have variously reported benefit, no effect, and harm. Objective: To estimate the association between administration of IL-6 antagonists compared with usual care or placebo and 28-day all-cause mortality and other outcomes. Data Sources: Trials were identified through systematic searches of electronic databases between October 2020 and January 2021. Searches were not restricted by trial status or language. Additional trials were identified through contact with experts. Study Selection: Eligible trials randomly assigned patients hospitalized for COVID-19 to a group in whom IL-6 antagonists were administered and to a group in whom neither IL-6 antagonists nor any other immunomodulators except corticosteroids were administered. Among 72 potentially eligible trials, 27 (37.5%) met study selection criteria. Data Extraction and Synthesis: In this prospective meta-analysis, risk of bias was assessed using the Cochrane Risk of Bias Assessment Tool. Inconsistency among trial results was assessed using the I2 statistic. The primary analysis was an inverse variance-weighted fixed-effects meta-analysis of odds ratios (ORs) for 28-day all-cause mortality. Main Outcomes and Measures: The primary outcome measure was all-cause mortality at 28 days after randomization. There were 9 secondary outcomes including progression to invasive mechanical ventilation or death and risk of secondary infection by 28 days. Results: A total of 10 930 patients (median age, 61 years [range of medians, 52-68 years]; 3560 [33%] were women) participating in 27 trials were included. By 28 days, there were 1407 deaths among 6449 patients randomized to IL-6 antagonists and 1158 deaths among 4481 patients randomized to usual care or placebo (summary OR, 0.86 [95% CI, 0.79-0.95]; P = .003 based on a fixed-effects meta-analysis). This corresponds to an absolute mortality risk of 22% for IL-6 antagonists compared with an assumed mortality risk of 25% for usual care or placebo. The corresponding summary ORs were 0.83 (95% CI, 0.74-0.92; P < .001) for tocilizumab and 1.08 (95% CI, 0.86-1.36; P = .52) for sarilumab. The summary ORs for the association with mortality compared with usual care or placebo in those receiving corticosteroids were 0.77 (95% CI, 0.68-0.87) for tocilizumab and 0.92 (95% CI, 0.61-1.38) for sarilumab. The ORs for the association with progression to invasive mechanical ventilation or death, compared with usual care or placebo, were 0.77 (95% CI, 0.70-0.85) for all IL-6 antagonists, 0.74 (95% CI, 0.66-0.82) for tocilizumab, and 1.00 (95% CI, 0.74-1.34) for sarilumab. Secondary infections by 28 days occurred in 21.9% of patients treated with IL-6 antagonists vs 17.6% of patients treated with usual care or placebo (OR accounting for trial sample sizes, 0.99; 95% CI, 0.85-1.16). Conclusions and Relevance: In this prospective meta-analysis of clinical trials of patients hospitalized for COVID-19, administration of IL-6 antagonists, compared with usual care or placebo, was associated with lower 28-day all-cause mortality. Trial Registration: PROSPERO Identifier: CRD42021230155.


Asunto(s)
Anticuerpos Monoclonales Humanizados/uso terapéutico , Tratamiento Farmacológico de COVID-19 , Interleucina-6/antagonistas & inhibidores , Anciano , COVID-19/complicaciones , COVID-19/mortalidad , COVID-19/terapia , Causas de Muerte , Coinfección , Progresión de la Enfermedad , Quimioterapia Combinada , Femenino , Glucocorticoides/uso terapéutico , Hospitalización , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Ensayos Clínicos Controlados Aleatorios como Asunto , Respiración Artificial
9.
Clin Infect Dis ; 70(4): 696-697, 2020 02 03.
Artículo en Inglés | MEDLINE | ID: mdl-31406989

RESUMEN

The Ebola virus disease outbreak in west Africa has prompted significant progress in responding to the clinical needs of patients affected by emerging infectious disease outbreaks. Among the noteworthy successes of vaccine trials, and the commendable efforts to implement clinical treatment trials during Ebola outbreaks, we should also focus on strengthening the collection and curation of epidemiological and observational data that can improve the conception and design of clinical research.


Asunto(s)
Epidemias , Fiebre Hemorrágica Ebola , África Occidental/epidemiología , Brotes de Enfermedades/prevención & control , Fiebre Hemorrágica Ebola/epidemiología , Fiebre Hemorrágica Ebola/prevención & control , Humanos
10.
BMC Med ; 18(1): 265, 2020 08 21.
Artículo en Inglés | MEDLINE | ID: mdl-32825816

RESUMEN

BACKGROUND: New emerging infections have no known treatment. Assessing potential drugs for safety and efficacy enables clinicians to make evidence-based treatment decisions and contributes to overall outbreak control. However, it is difficult to launch clinical trials in the unpredictable environment of an outbreak. We conducted a bibliometric systematic review for the 2009 influenza pandemic to determine the speed and quality of evidence generation for treatments. This informs approaches to high-quality evidence generation in this and future pandemics. METHODS: We searched PubMed for all clinical data (including clinical trial, observational and case series) describing treatment for patients with influenza A(H1N1)pdm09 and ClinicalTrials.gov for research that aimed to enrol patients with the disease. RESULTS: Thirty-three thousand eight hundred sixty-nine treatment courses for patients hospitalised with A(H1N1)pdm09 were detailed in 160 publications. Most were retrospective observational studies or case series. Five hundred ninety-two patients received treatment (or placebo) as participants in a registered interventional clinical trial with results publicly available. None of these registered trial results was available during the timeframe of the pandemic, and the median date of publication was 213 days after the Public Health Emergency of International Concern ended. CONCLUSION: Patients were frequently treated for pandemic influenza with drugs not registered for this indication, but rarely under circumstances of high-quality data capture. The result was a reliance on use under compassionate circumstances, resulting in continued uncertainty regarding the potential benefits and harms of anti-viral treatment. Rapid scaling of clinical trials is critical for generating a quality evidence base during pandemics.


Asunto(s)
Antivirales/uso terapéutico , Ensayos de Uso Compasivo , Prescripción Inadecuada/prevención & control , Subtipo H1N1 del Virus de la Influenza A , Gripe Humana/tratamiento farmacológico , Uso Fuera de lo Indicado , Betacoronavirus , Bibliometría , COVID-19 , Infecciones por Coronavirus/tratamiento farmacológico , Infecciones por Coronavirus/epidemiología , Análisis Costo-Beneficio , Salud Global , Humanos , Gripe Humana/epidemiología , Pandemias , Neumonía Viral/tratamiento farmacológico , Neumonía Viral/epidemiología , Proyectos de Investigación , SARS-CoV-2 , Resultado del Tratamiento
11.
BMC Med ; 18(1): 377, 2020 12 02.
Artículo en Inglés | MEDLINE | ID: mdl-33261599

RESUMEN

BACKGROUND: Highly pathogenic avian influenza A(H5N1) virus poses a global public health threat given severe and fatal zoonotic infections since 1997 and ongoing A(H5N1) virus circulation among poultry in several countries. A comprehensive assessment of the seroprevalence of A(H5N1) virus antibodies remains a gap and limits understanding of the true risk of A(H5N1) virus infection. METHODS: We conducted a systematic review and meta-analysis of published serosurveys to assess the risk of subclinical and clinically mild A(H5N1) virus infections. We assessed A(H5N1) virus antibody titers and changes in titers among populations with variable exposures to different A(H5N1) viruses. RESULTS: Across studies using the World Health Organization-recommended seropositive definition, the point estimates of the seroprevalence of A(H5N1) virus-specific antibodies were higher in poultry-exposed populations (range 0-0.6%) and persons exposed to both human A(H5N1) cases and infected birds (range 0.4-1.8%) than in close contacts of A(H5N1) cases or the general population (none to very low frequencies). Seroprevalence was higher in persons exposed to A(H5N1) clade 0 virus (1.9%, range 0.7-3.2%) than in participants exposed to other clades of A(H5N1) virus (range 0-0.5%) (p < 0.05). Seroprevalence was higher in poultry-exposed populations (range 0-1.9%) if such studies utilized antigenically similar A(H5N1) virus antigens in assays to A(H5N1) viruses circulating among poultry. CONCLUSIONS: These low seroprevalences suggest that subclinical and clinically mild human A(H5N1) virus infections are uncommon. Standardized serological survey and laboratory methods are needed to fully understand the extent and risk of human A(H5N1) virus infections.


Asunto(s)
Subtipo H5N1 del Virus de la Influenza A/patogenicidad , Gripe Aviar/epidemiología , Gripe Humana/epidemiología , Zoonosis/epidemiología , Animales , Aves , Humanos , Estudios Seroepidemiológicos
12.
Clin Infect Dis ; 68(4): 623-631, 2019 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-29961834

RESUMEN

Background: The 2016-17 epidemic of human infections with avian influenza A(H7N9) virus was alarming, due to the surge in reported cases across a wide geographic area and the emergence of highly-pathogenic A(H7N9) viruses. Our study aimed to assess whether the human-to-human transmission risk of A(H7N9) virus has changed across the 5 waves since 2013. Methods: Data on human cases and clusters of A(H7N9) virus infection were collected from the World Health Organization, open access national and provincial reports, informal online sources, and published literature. We compared the epidemiological characteristics of sporadic and cluster cases, estimated the relative risk (RR) of infection in blood relatives and non-blood relatives, and estimated the bounds on the effective reproductive number (Re) across waves from 2013 through September 2017. Results: We identified 40 human clusters of A(H7N9) virus infection, with a median cluster size of 2 (range 2-3). The overall RR of infection in blood relatives versus non-blood relatives was 1.65 (95% confidence interval [CI]: 0.88, 3.09), and was not significantly different across waves (χ2 = 2.66, P = .617). The upper limit of Re for A(H7N9) virus was 0.12 (95% CI: 0.10, 0.14) and was not significantly different across waves (χ2 = 1.52, P = .822). Conclusions: The small cluster size and low Re suggest that human-to-human transmissibility of A(H7N9) virus has not changed over time and remains limited to date. Continuous assessment of A(H7N9) virus infections and human case clusters is of crucial importance for public health.


Asunto(s)
Número Básico de Reproducción , Transmisión de Enfermedad Infecciosa , Subtipo H7N9 del Virus de la Influenza A/aislamiento & purificación , Gripe Humana/transmisión , Gripe Humana/virología , Adulto , Animales , China/epidemiología , Análisis por Conglomerados , Femenino , Humanos , Gripe Humana/epidemiología , Masculino , Persona de Mediana Edad
13.
N Engl J Med ; 374(1): 33-42, 2016 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-26735992

RESUMEN

BACKGROUND: In the wake of the recent outbreak of Ebola virus disease (EVD) in several African countries, the World Health Organization prioritized the evaluation of treatment with convalescent plasma derived from patients who have recovered from the disease. We evaluated the safety and efficacy of convalescent plasma for the treatment of EVD in Guinea. METHODS: In this nonrandomized, comparative study, 99 patients of various ages (including pregnant women) with confirmed EVD received two consecutive transfusions of 200 to 250 ml of ABO-compatible convalescent plasma, with each unit of plasma obtained from a separate convalescent donor. The transfusions were initiated on the day of diagnosis or up to 2 days later. The level of neutralizing antibodies against Ebola virus in the plasma was unknown at the time of administration. The control group was 418 patients who had been treated at the same center during the previous 5 months. The primary outcome was the risk of death during the period from 3 to 16 days after diagnosis with adjustments for age and the baseline cycle-threshold value on polymerase-chain-reaction assay; patients who had died before day 3 were excluded. The clinically important difference was defined as an absolute reduction in mortality of 20 percentage points in the convalescent-plasma group as compared with the control group. RESULTS: A total of 84 patients who were treated with plasma were included in the primary analysis. At baseline, the convalescent-plasma group had slightly higher cycle-threshold values and a shorter duration of symptoms than did the control group, along with a higher frequency of eye redness and difficulty in swallowing. From day 3 to day 16 after diagnosis, the risk of death was 31% in the convalescent-plasma group and 38% in the control group (risk difference, -7 percentage points; 95% confidence interval [CI], -18 to 4). The difference was reduced after adjustment for age and cycle-threshold value (adjusted risk difference, -3 percentage points; 95% CI, -13 to 8). No serious adverse reactions associated with the use of convalescent plasma were observed. CONCLUSIONS: The transfusion of up to 500 ml of convalescent plasma with unknown levels of neutralizing antibodies in 84 patients with confirmed EVD was not associated with a significant improvement in survival. (Funded by the European Union's Horizon 2020 Research and Innovation Program and others; ClinicalTrials.gov number, NCT02342171.).


Asunto(s)
Transfusión de Componentes Sanguíneos , Fiebre Hemorrágica Ebola/terapia , Plasma , Adolescente , Adulto , Anticuerpos Neutralizantes/sangre , Transfusión de Componentes Sanguíneos/efectos adversos , Niño , Preescolar , Convalecencia , Ebolavirus/inmunología , Femenino , Guinea , Fiebre Hemorrágica Ebola/mortalidad , Humanos , Lactante , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Plasma/inmunología , Embarazo , Adulto Joven
14.
J Virol ; 92(17)2018 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-29925664

RESUMEN

Since 2013, influenza A H7N9 virus has emerged as the most common avian influenza virus subtype causing human infection, and it is associated with a high fatality risk. However, the characteristics of immune memory in patients who have recovered from H7N9 infection are not well understood. We assembled a cohort of 45 H7N9 survivors followed for up to 15 months after infection. Humoral and cellular immune responses were analyzed in sequential samples obtained at 1.5 to 4 months, 6 to 8 months, and 12 to 15 months postinfection. H7N9-specific antibody concentrations declined over time, and protective antibodies persisted longer in severely ill patients admitted to the intensive care unit (ICU) and patients presenting with acute respiratory distress syndrome (ARDS) than in patients with mild disease. Frequencies of virus-specific gamma interferon (IFN-γ)-secreting T cells were lower in critically ill patients requiring ventilation than in patients without ventilation within 4 months after infection. The percentages of H7N9-specific IFN-γ-secreting T cells tended to increase over time in patients ≥60 years or in critically ill patients requiring ventilation. Elevated levels of antigen-specific CD8+ T cells expressing the lung-homing marker CD49a were observed at 6 to 8 months after H7N9 infection compared to those in samples obtained at 1.5 to 4 months. Our findings indicate the prolonged reconstruction and evolution of virus-specific T cell immunity in older or critically ill patients and have implications for T cell-directed immunization strategies.IMPORTANCE Avian influenza A H7N9 virus remains a major threat to public health. However, no previous studies have determined the characteristics and dynamics of virus-specific T cell immune memory in patients who have recovered from H7N9 infection. Our findings showed that establishment of H7N9-specific T cell memory after H7N9 infection was prolonged in older and severely affected patients. Severely ill patients mounted lower T cell responses in the first 4 months after infection, while T cell responses tended to increase over time in older and severely ill patients. Higher levels of antigen-specific CD8+ T cells expressing the lung-homing marker CD49a were detected at 6 to 8 months after infection. Our results indicated a long-term impact of H7N9 infection on virus-specific memory T cells. These findings advance our understanding of the dynamics of virus-specific memory T cell immunity after H7N9 infection, which is relevant to the development of T cell-based universal influenza vaccines.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Memoria Inmunológica , Subtipo H7N9 del Virus de la Influenza A/inmunología , Gripe Humana/inmunología , Subgrupos de Linfocitos T/inmunología , Adulto , Anciano , Anticuerpos Antivirales/sangre , Femenino , Estudios de Seguimiento , Humanos , Interferón gamma/metabolismo , Masculino , Persona de Mediana Edad , Factores de Tiempo
16.
Clin Infect Dis ; 67(11): 1729-1735, 2018 11 13.
Artículo en Inglés | MEDLINE | ID: mdl-29688329

RESUMEN

Background: Hand, foot, and mouth disease (HFMD) represents a substantial disease burden in the Western Pacific region. We investigated the spectrum of causative enteroviruses of HFMD, and evaluated different clinical samples' diagnostic yield for enteroviruses. Methods: We enrolled pediatric patients hospitalized for HFMD among 6 hospitals in Anhua County, Hunan Province, China between October 2013 and September 2016. Throat swabs and stool samples (or rectal swabs) were collected to detect the enterovirus serotypes by real-time reverse-transcription polymerase chain reaction (PCR) or nested PCR. Results: Among the 2836 patients, only 1 developed severe illness. Seventeen serotypes were identified in 2401 patients (85%), with the most frequently detected being CV-A16 (29% [814]), CV-A6 (28% [784]), EV-A71 (17% [491]), CV-A10 (4% [114]), and CV-A4 (2% [53]). Children were younger in CV-A6, CV-A10, and CV-A4 infections (median, 12 months; interquartile range [IQR], 12-24 months) than EV-A71 and CV-A16 infections (median, 24 months; IQR, 12-36 months; P < .05). The predominant enterovirus serotype shifted between CV-A16 and CV-A6 during the 3 years. Stool had a higher diagnostic yield (89%) than rectal (77%) and throat swabs (74%). Detection rates reached 93% when testing stools followed by throat swabs if stools were negative, and 89% when testing rectal swabs followed by throat swabs if rectal swabs were negative. Conclusions: Our results provide a virological benchmark for future surveillance and diagnostics. Continuous comprehensive virological surveillance is essential, especially after implementation of the EV-A71 vaccine in China, to monitor serotype replacement and the vaccine's impact.


Asunto(s)
Infecciones por Enterovirus/virología , Enterovirus/clasificación , Heces/virología , Enfermedad de Boca, Mano y Pie/virología , Faringe/virología , Preescolar , China/epidemiología , Infecciones por Enterovirus/diagnóstico , Infecciones por Enterovirus/epidemiología , Femenino , Enfermedad de Boca, Mano y Pie/diagnóstico , Enfermedad de Boca, Mano y Pie/epidemiología , Hospitalización , Humanos , Lactante , Masculino , ARN Viral/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Serogrupo
17.
BMC Med ; 16(1): 43, 2018 03 19.
Artículo en Inglés | MEDLINE | ID: mdl-29551092

RESUMEN

BACKGROUND: Refugees may have an increased vulnerability to infectious diseases, and the consequences of an outbreak are more severe in a refugee camp. When an outbreak is suspected, access to clinical information is critical for investigators to verify that an outbreak is occurring, to determine the cause and to select interventions to control it. Experience from previous outbreaks suggests that the accuracy and completeness of this information is poor. This study is the first to assess the adequacy of clinical characterisation of acute medical illnesses in refugee camps. The objective is to direct improvements in outbreak identification and management in this vulnerable setting. METHODS: We collected prospective data in 13 refugee camps in Greece. We passively observed consultations where patients presented with syndromes that might warrant inclusion into an existing syndromic surveillance system and then undertook a structured assessment of routine clinical data collection to examine the extent to which key clinical parameters required for an outbreak response were ascertained and then documented. RESULTS: A total of 528 patient consultations were included. The most common presenting condition was an acute respiratory illness. Clinicians often made a comprehensive clinical assessment, especially for common syndromes of respiratory and gastrointestinal conditions, but documented their findings less frequently. For fewer than 5% of patients were a full set of vital signs ascertained and so the severity of patient illnesses was largely unknown. In only 11% of consultations was it verified that a patient who met the case criteria for syndromic surveillance reporting based on an independent assessment was reported into the system. DISCUSSION: Opportunities exist to strengthen clinical data capture and recording in refugee camps, which will produce a better calibrated and directed public health response. CONCLUSION: Information of significant utility for outbreak response is collected at the clinical interface and we recommend improving how this information is recorded and linked into surveillance systems.


Asunto(s)
Enfermedades Transmisibles/etiología , Campos de Refugiados/normas , Refugiados/psicología , Adolescente , Adulto , Anciano , Niño , Preescolar , Enfermedades Transmisibles/epidemiología , Brotes de Enfermedades , Grecia , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Adulto Joven
18.
Ann Intern Med ; 166(10): 725-732, 2017 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-28319995

RESUMEN

Zika virus (ZIKV) infection in pregnancy is associated with adverse fetal outcomes, such as microcephaly and other congenital malformations. No therapeutic options are available to pregnant women with ZIKV infection to prevent these effects. Drug trials in pregnancy raise several scientific, ethical, and logistic challenges, which are compounded further in ZIKV because of limited knowledge of the disease pathophysiology and a product development pipeline in its infancy. We evaluate the major challenges in choosing therapeutics to prevent congenital ZIKV disease and conducting clinical trials of these treatments, with a focus on preventing congenital central nervous system malformations. These challenges must be characterized and planned for now so that clinical trials can progress expediently and effectively in the future.


Asunto(s)
Antivirales/uso terapéutico , Ensayos Clínicos como Asunto , Complicaciones Infecciosas del Embarazo/virología , Infección por el Virus Zika/congénito , Infección por el Virus Zika/prevención & control , Anticuerpos/uso terapéutico , Antivirales/efectos adversos , Antivirales/farmacocinética , Femenino , Humanos , Inmunidad Celular/efectos de los fármacos , Microcefalia/prevención & control , Microcefalia/virología , Placenta/efectos de los fármacos , Embarazo , Complicaciones Infecciosas del Embarazo/tratamiento farmacológico , Complicaciones Infecciosas del Embarazo/metabolismo , Proteínas Proto-Oncogénicas/efectos de los fármacos , Proteínas Tirosina Quinasas Receptoras/efectos de los fármacos , Teratógenos , Replicación Viral/efectos de los fármacos , Infección por el Virus Zika/complicaciones , Tirosina Quinasa del Receptor Axl
19.
Emerg Infect Dis ; 23(11): 1922-1924, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-29048276

RESUMEN

Zika virus RNA is frequently detected in the semen of men after Zika virus infection. To learn more about persistence of viruses in genital fluids, we searched PubMed for relevant articles. We found evidence that 27 viruses, across a broad range of virus families, can be found in human semen.


Asunto(s)
Semen/virología , Virosis/virología , Virus/aislamiento & purificación , Humanos , Masculino , Viremia/virología
20.
PLoS Med ; 13(4): e1001997, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27093560

RESUMEN

BACKGROUND: TKM-130803, a small interfering RNA lipid nanoparticle product, has been developed for the treatment of Ebola virus disease (EVD), but its efficacy and safety in humans has not been evaluated. METHODS AND FINDINGS: In this single-arm phase 2 trial, adults with laboratory-confirmed EVD received 0.3 mg/kg of TKM-130803 by intravenous infusion once daily for up to 7 d. On days when trial enrolment capacity was reached, patients were enrolled into a concurrent observational cohort. The primary outcome was survival to day 14 after admission, excluding patients who died within 48 h of admission. After 14 adults with EVD had received TKM-130803, the pre-specified futility boundary was reached, indicating a probability of survival to day 14 of ≤0.55, and enrolment was stopped. Pre-treatment geometric mean Ebola virus load in the 14 TKM-130803 recipients was 2.24 × 109 RNA copies/ml plasma (95% CI 7.52 × 108, 6.66 × 109). Two of the TKM-130803 recipients died within 48 h of admission and were therefore excluded from the primary outcome analysis. Of the remaining 12 TKM-130803 recipients, nine died and three survived. The probability that a TKM-130803 recipient who survived for 48 h will subsequently survive to day 14 was estimated to be 0.27 (95% CI 0.06, 0.58). TKM-130803 infusions were well tolerated, with 56 doses administered and only one possible infusion-related reaction observed. Three patients were enrolled in the observational cohort, of whom two died. CONCLUSIONS: Administration of TKM-130803 at a dose of 0.3 mg/kg/d by intravenous infusion to adult patients with severe EVD was not shown to improve survival when compared to historic controls. TRIAL REGISTRATION: Pan African Clinical Trials Registry PACTR201501000997429.


Asunto(s)
Antivirales/uso terapéutico , Ebolavirus/genética , Fiebre Hemorrágica Ebola/tratamiento farmacológico , ARN Interferente Pequeño/uso terapéutico , ARN Viral/genética , Tratamiento con ARN de Interferencia/métodos , Adulto , Anciano , Anciano de 80 o más Años , Ebolavirus/patogenicidad , Femenino , Fiebre Hemorrágica Ebola/diagnóstico , Fiebre Hemorrágica Ebola/genética , Fiebre Hemorrágica Ebola/mortalidad , Fiebre Hemorrágica Ebola/virología , Interacciones Huésped-Patógeno , Humanos , Infusiones Intravenosas , Masculino , Persona de Mediana Edad , Nanopartículas , ARN Interferente Pequeño/administración & dosificación , ARN Viral/sangre , Tratamiento con ARN de Interferencia/efectos adversos , Sierra Leona , Análisis de Supervivencia , Factores de Tiempo , Resultado del Tratamiento , Carga Viral/efectos de los fármacos , Carga Viral/genética , Adulto Joven
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