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1.
Clin Infect Dis ; 2020 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-31960898
2.
MMWR Morb Mortal Wkly Rep ; 69(2): 40-43, 2020 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-31945035

RESUMEN

Multiple genetically distinct influenza B/Victoria lineage viruses have cocirculated in the United States recently, circulating sporadically during the 2018-19 season and more frequently early during the 2019-20 season (1). The beginning of the 2019-20 influenza season in Louisiana was unusually early and intense, with infections primarily caused by influenza B/Victoria lineage viruses. One large pediatric health care facility in New Orleans (facility A) reported 1,268 laboratory-confirmed influenza B virus infections, including 23 hospitalizations from July 31 to November 21, 2019, a time when influenza activity is typically low. During this period, Louisiana also reported one pediatric death associated with influenza B virus infection. An investigation of the influenza B virus infections in Louisiana, including medical and vaccine record abstraction on 198 patients, primarily from facility A, with sporadic cases from other facilities in the state, found that none of the patients had received 2019-20 seasonal influenza vaccine, in part because influenza activity began before influenza vaccination typically occurs. Among 83 influenza B viruses sequenced from 198 patients in Louisiana, 81 (98%) belonged to the recently emerged B/Victoria V1A.3 genetic subclade. Nationally, to date, B/Victoria viruses are the most commonly reported influenza viruses among persons aged <25 years (2). Of the 198 patients in the investigation, 95% were aged <18 years. Although most illnesses were uncomplicated, the number of hospitalizations, clinical complications, and the reported pediatric death in Louisiana serve as a reminder that, even though influenza B viruses are less common than influenza A viruses in most seasons, influenza B virus infection can be severe in children. All persons aged ≥6 months should receive an annual influenza vaccination if they have not already received it (3). Antiviral treatment of influenza is recommended as soon as possible for all hospitalized patients and for outpatients at high risk for influenza complications (including children aged <2 years and persons with underlying medical conditions) (4).


Asunto(s)
Virus de la Influenza B/aislamiento & purificación , Gripe Humana/epidemiología , Gripe Humana/virología , Adolescente , Adulto , Niño , Preescolar , Humanos , Lactante , Vacunas contra la Influenza/administración & dosificación , Gripe Humana/prevención & control , Louisiana/epidemiología , Estaciones del Año , Adulto Joven
4.
Clin Infect Dis ; 2020 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-31905401

RESUMEN

BACKGROUND: Current multivalent influenza vaccine products provide protection against influenza A(H1N1)pdm09, A(H3N2), and B lineage viruses. The 2018-2019 influenza season in the US included prolonged circulation of both A(H1N1)pdm09 viruses well-matched to the vaccine strain, and A(H3N2) viruses the majority of which were mismatched to the vaccine. We estimate the number of vaccine-prevented influenza-associated illnesses, medical visits, hospitalizations, and deaths for the season. METHODS: We used a mathematical model and Monte Carlo algorithm to estimate numbers and 95% uncertainty intervals (UI) of influenza-associated outcomes prevented by vaccination in the US. The model incorporated age-specific estimates of national 2018-2019 influenza vaccine coverage, influenza virus-specific vaccine effectiveness from the US Influenza Vaccine Effectiveness Network, and disease burden estimated from population-based rates of influenza-associated hospitalizations through the Influenza Hospitalization Surveillance Network. RESULTS: Influenza vaccination prevented an estimated 4.4 million (95% UI: 3.4 million-7.1 million) illnesses, 2.3 million (95% UI: 1.8 million-3.8 million) medical visits, 58,000 (95% UI: 30,000-156,000) hospitalizations, and 3,500 (95% UI: 1,000-13,000) deaths due to influenza viruses during the US 2018-2019 influenza season. Vaccination prevented 14% of projected hospitalizations associated with A(H1N1)pdm09 overall and 43% among young children aged 6 months-4 years. CONCLUSIONS: Influenza vaccination averted substantial influenza-associated disease including hospitalizations and deaths in the US, primarily due to effectiveness against A(H1N1)pdm09. Our findings underscore the value of influenza vaccination, highlighting that vaccines measurably decrease illness and associated health care utilization even in a season in which a vaccine component does not match to a circulating virus.

5.
Clin Infect Dis ; 70(2): 357-358, 2020 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-31112216
6.
MMWR Morb Mortal Wkly Rep ; 68(50): 1158-1161, 2019 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-31856148

RESUMEN

The 2017-18 U.S. influenza season was notable for its high severity, with approximately 45 million illnesses and 810,000 influenza-associated hospitalizations throughout the United States (1). The purpose of the investigation reported here was to create a state-level estimate of the number of persons in Utah who became ill with influenza disease during this severe national seasonal influenza epidemic and to create a sustainable system for making timely updates in future influenza seasons. Knowing the extent of influenza-associated illness can help public health officials, policymakers, and clinicians tailor influenza messaging, planning, and responses for seasonal influenza epidemics or during pandemics. Using national methods and existing influenza surveillance and testing data, the influenza burden (number of influenza illnesses, medical visits for influenza, and influenza-associated hospitalizations) in Utah during the 2016-17 and 2017-18 influenza seasons was estimated. During the 2016-17 season, an estimated 265,000 symptomatic illnesses affecting 9% of Utah residents occurred, resulting in 125,000 medically attended illnesses and 2,700 hospitalizations. During the 2017-18 season, an estimated 338,000 symptomatic illnesses affecting 11% of Utah residents occurred, resulting in 160,000 medically attended illnesses and 3,900 hospitalizations. Other state or county health departments could adapt similar methods in their jurisdictions to estimate the burden of influenza locally and support prompt public health activities.


Asunto(s)
Gripe Humana/epidemiología , Adolescente , Adulto , Distribución por Edad , Anciano , Niño , Preescolar , Humanos , Incidencia , Lactante , Recién Nacido , Persona de Mediana Edad , Estaciones del Año , Utah/epidemiología , Adulto Joven
7.
PLoS One ; 14(9): e0221479, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31490961

RESUMEN

BACKGROUND: Despite having influenza vaccination policies and programs, countries in the Americas underutilize seasonal influenza vaccine, in part because of insufficient evidence about severe influenza burden. We aimed to estimate the annual burden of influenza-associated respiratory hospitalizations in the Americas. METHODS: Thirty-five countries in the Americas with national influenza surveillance were invited to provide monthly laboratory data and hospital discharges for respiratory illness (International Classification of Diseases 10th edition J codes 0-99) during 2010-2015. In three age-strata (<5, 5-64, and ≥65 years), we estimated the influenza-associated hospitalizations rate by multiplying the monthly number of respiratory hospitalizations by the monthly proportion of influenza-positive samples and dividing by the census population. We used random effects meta-analyses to pool age-group specific rates and extrapolated to countries that did not contribute data, using pooled rates stratified by age group and country characteristics found to be associated with rates. RESULTS: Sixteen of 35 countries (46%) contributed primary data to the analyses, representing 79% of the America's population. The average pooled rate of influenza-associated respiratory hospitalization was 90/100,000 population (95% confidence interval 61-132) among children aged <5 years, 21/100,000 population (13-32) among persons aged 5-64 years, and 141/100,000 population (95-211) among persons aged ≥65 years. We estimated the average annual number of influenza-associated respiratory hospitalizations in the Americas to be 772,000 (95% credible interval 716,000-829,000). CONCLUSIONS: Influenza-associated respiratory hospitalizations impose a heavy burden on health systems in the Americas. Countries in the Americas should use this information to justify investments in seasonal influenza vaccination-especially among young children and the elderly.

8.
Influenza Other Respir Viruses ; 13(6): 547-555, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31424627

RESUMEN

BACKGROUND: The estimated association of maternal influenza vaccination and birth outcomes may be sensitive to methods used to define preterm birth or small-for-gestational age (SGA). METHODS: In a cohort of pregnant women in Lao People's Democratic Republic, we estimated gestational age from: (a) date of last menstrual period (LMP), (b) any prenatal ultrasound, (c) first trimester ultrasound, (d) Ballard Score at delivery, and (e) an algorithm combining LMP and ultrasound. Infants were classified as SGA at birth using a Canadian, global, and equation-based growth reference. We estimated the association of maternal influenza vaccination and birth outcomes, by influenza activity, using multivariable log-binomial regression and Cox proportional hazards regression with vaccination as a time-varying exposure. RESULTS: The frequency of preterm birth in the cohort varied by method to estimate gestational age, from 5% using Ballard Score to 15% using any ultrasound. Using LMP, any ultrasound, or the algorithm, we found statistically significant reductions in preterm birth among vaccinated women during periods of high influenza activity and statistically significant increases in SGA, using a Canadian growth reference. We did not find statistically significant associations with SGA when using global or equation-based growth references. CONCLUSIONS: The association of maternal influenza vaccination and birth outcomes was most affected by the choice of a growth reference used to define SGA at birth. The association with pre-term birth was present and consistent across multiple statistical approaches. Future studies of birth outcomes, specifically SGA, should carefully consider the potential for bias introduced by measurement choice.

9.
Open Forum Infect Dis ; 6(7)2019 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-31363771

RESUMEN

BACKGROUND: Rates of influenza hospitalizations differ by age, but few data are available regarding differences in laboratory-confirmed rates among adults aged ≥65 years. METHODS: We evaluated age-related differences in influenza-associated hospitalization rates, clinical presentation, and outcomes among 19 760 older adults with laboratory-confirmed influenza at 14 FluSurv-NET sites during the 2011-2012 through 2014-2015 influenza seasons using 10-year age groups. RESULTS: There were large stepwise increases in the population rates of influenza hospitalization with each 10-year increase in age. Rates ranged from 101-417, 209-1264, and 562-2651 per 100 000 persons over 4 influenza seasons in patients aged 65-74 years, 75-84 years, and ≥85 years, respectively. Hospitalization rates among adults aged 75-84 years and ≥85 years were 1.4-3.0 and 2.2-6.4 times greater, respectively, than rates for adults aged 65-74 years. Among patients hospitalized with laboratory-confirmed influenza, there were age-related differences in demographics, medical histories, and symptoms and signs at presentation. Compared to hospitalized patients aged 65-74 years, patients aged ≥85 years had higher odds of pneumonia (aOR, 1.2; 95% CI, 1.0-1.3; P = .01) and in-hospital death or transfer to hospice (aOR, 2.1; 95% CI, 1.7-2.6; P < .01). CONCLUSIONS: Age-related differences in the incidence and severity of influenza hospitalizations among adults aged ≥65 years can inform prevention and treatment efforts, and data should be analyzed and reported using additional age strata.

10.
Clin Infect Dis ; 2019 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-31344229

RESUMEN

BACKGROUND: Vaccination is the best way to prevent influenza; however, greater benefit could be achieved. To help guide research and policy agendas, we aimed to quantify the magnitude of influenza disease that would be prevented through targeted increases in vaccine effectiveness (VE) or coverage. METHODS: For three influenza seasons (2011-12, 2015-16, and 2017-18) we used a mathematical model to estimate the number of prevented influenza-associated illnesses, medically-attended illnesses, and hospitalizations across five age groups. Compared with estimates of prevented illness during each season, given observed VE and coverage, we explored the number of additional outcomes that would be prevented from a 5% absolute increase in VE or coverage or achieving 60% VE or 70% coverage. RESULTS: During the 2017-18 season, compared with the burden already prevented by influenza vaccination, a 5% absolute VE increase would prevent an additional 1,050,000 illnesses and 25,000 hospitalizations (76% among those aged ≥65 years) while achieving 60% VE would prevent an additional 190,000 hospitalizations. A 5% coverage increase would result in 785,000 fewer illnesses (56% among those aged 18-64 years) and 11,000 fewer hospitalizations; reaching 70% would prevent an additional 39,000 hospitalizations. CONCLUSIONS: Small, attainable improvements in effectiveness or coverage of influenza vaccine could lead to substantial additional reductions in influenza burden in the U.S. Improvements in VE would have the greatest impact in reducing hospitalizations in adults aged ≥65 years and coverage improvements would have the largest benefit in reducing illnesses in adults aged 18-49 years.

11.
Clin Infect Dis ; 69(11): 1845-1853, 2019 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-30715278

RESUMEN

BACKGROUND: The severity of the 2017-2018 influenza season in the United States was high, with influenza A(H3N2) viruses predominating. Here, we report influenza vaccine effectiveness (VE) and estimate the number of vaccine-prevented influenza-associated illnesses, medical visits, hospitalizations, and deaths for the 2017-2018 influenza season. METHODS: We used national age-specific estimates of 2017-2018 influenza vaccine coverage and disease burden. We estimated VE against medically attended reverse-transcription polymerase chain reaction-confirmed influenza virus infection in the ambulatory setting using a test-negative design. We used a compartmental model to estimate numbers of influenza-associated outcomes prevented by vaccination. RESULTS: The VE against outpatient, medically attended, laboratory-confirmed influenza was 38% (95% confidence interval [CI], 31%-43%), including 22% (95% CI, 12%-31%) against influenza A(H3N2), 62% (95% CI, 50%-71%) against influenza A(H1N1)pdm09, and 50% (95% CI, 41%-57%) against influenza B. We estimated that influenza vaccination prevented 7.1 million (95% CrI, 5.4 million-9.3 million) illnesses, 3.7 million (95% CrI, 2.8 million-4.9 million) medical visits, 109 000 (95% CrI, 39 000-231 000) hospitalizations, and 8000 (95% credible interval [CrI], 1100-21 000) deaths. Vaccination prevented 10% of expected hospitalizations overall and 41% among young children (6 months-4 years). CONCLUSIONS: Despite 38% VE, influenza vaccination reduced a substantial burden of influenza-associated illness, medical visits, hospitalizations, and deaths in the United States during the 2017-2018 season. Our results demonstrate the benefit of current influenza vaccination and the need for improved vaccines.

12.
Emerg Infect Dis ; 25(5): 1011-1014, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30741630

RESUMEN

In the United States, outbreaks of avian influenza H5 and H7 virus infections in poultry have raised concern about the risk for infections in humans. We reviewed the data collected during 2014-2017 and found no human infections among 4,555 exposed responders who were wearing protection.


Asunto(s)
Virus de la Influenza A , Gripe Aviar/epidemiología , Gripe Aviar/virología , Enfermedades de las Aves de Corral/epidemiología , Enfermedades de las Aves de Corral/virología , Animales , Brotes de Enfermedades , Historia del Siglo XXI , Virus de la Influenza A/clasificación , Gripe Aviar/historia , Aves de Corral , Enfermedades de las Aves de Corral/historia , Vigilancia en Salud Pública , Estados Unidos/epidemiología
13.
Clin Infect Dis ; 68(11): 1798-1806, 2019 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-30204854

RESUMEN

BACKGROUND: In recent influenza seasons, the effectiveness of inactivated influenza vaccines against circulating A(H3N2) virus has been lower than against A(H1N1)pdm09 and B viruses, even when circulating viruses remained antigenically similar to vaccine components. METHODS: During the 2016-2017 influenza season, vaccine effectiveness (VE) across age groups and vaccine types was examined among outpatients with acute respiratory illness at 5 US sites using a test-negative design that compared the odds of vaccination among reverse transcription polymerase chain reaction-confirmed influenza positives and negatives. RESULTS: Among 7083 enrollees, 1342 (19%) tested positive for influenza A(H3N2), 648 (9%) were positive for influenza B (including B/Yamagata, n = 577), and 5040 (71%) were influenza negative. Vaccine effectiveness was 40% (95% confidence interval [CI], 32% to 46%) against any influenza virus, 33% (95% CI, 23% to 41%) against influenza A(H3N2) viruses, and 53% (95% CI, 43% to 61%) against influenza B viruses. CONCLUSIONS: The 2016-2017 influenza vaccines provided moderate protection against any influenza among outpatients but were less protective against influenza A(H3N2) viruses than B viruses. Approaches to improving effectiveness against A(H3N2) viruses are needed.

14.
Vaccine ; 36(48): 7331-7337, 2018 11 19.
Artículo en Inglés | MEDLINE | ID: mdl-30327213

RESUMEN

INTRODUCTION: To evaluate the public health benefit of yearly influenza vaccinations, CDC estimates the number of influenza cases and hospitalizations averted by vaccine. Available input data on cases and vaccinations is aggregated by month and the estimation model is intentionally simple, raising concerns about the accuracy of estimates. METHODS: We created a synthetic dataset with daily counts of influenza cases and vaccinations, calculated "true" averted cases using a reference model applied to the daily data, aggregated the data by month to simulate data that would actually be available, and evaluated the month-level data with seven test methods (including the current method). Methods with averted case estimates closest to the reference model were considered most accurate. To examine their performance under varying conditions, we re-evaluated the test methods when synthetic data parameters (timing of vaccination relative to cases, vaccination coverage, infection rate, and vaccine effectiveness) were varied over wide ranges. Finally, we analyzed real (i.e., collected by surveillance) data from 2010 to 2017 comparing the current method used by CDC with the best-performing test methods. RESULTS: In the synthetic dataset (population 1 million persons, vaccination uptake 55%, seasonal infection risk without vaccination 12%, vaccine effectiveness 48%) the reference model estimated 28,768 averted cases. The current method underestimated averted cases by 9%. The two best test methods estimated averted cases with <1% error. These two methods also worked well when synthetic data parameters were varied over wide ranges (≤6.2% error). With the real data, these two methods estimated numbers of averted cases that are a median 8% higher than the currently-used method. CONCLUSIONS: We identified two methods for estimating numbers of influenza cases averted by vaccine that are more accurate than the currently-used algorithm. These methods will help us to better assess the benefits of influenza vaccination.


Asunto(s)
Programas de Inmunización , Vacunas contra la Influenza/uso terapéutico , Gripe Humana/prevención & control , Cobertura de Vacunación/estadística & datos numéricos , Adolescente , Adulto , Anciano , Niño , Preescolar , Conjuntos de Datos como Asunto , Hospitalización , Humanos , Lactante , Vacunas contra la Influenza/administración & dosificación , Gripe Humana/epidemiología , Persona de Mediana Edad , Salud Pública , Estaciones del Año , Estados Unidos/epidemiología , Adulto Joven
15.
Clin Infect Dis ; 67(4): 493-501, 2018 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-29617951

RESUMEN

Background: During the 2014-2015 US influenza season, 320 cases of non-mumps parotitis (NMP) among residents of 21 states were reported to the Centers for Disease Control and Prevention (CDC). We conducted an epidemiologic and laboratory investigation to determine viral etiologies and clinical features of NMP during this unusually large occurrence. Methods: NMP was defined as acute parotitis or other salivary gland swelling of >2 days duration in a person with a mumps- negative laboratory result. Using a standardized questionnaire, we collected demographic and clinical information. Buccal samples were tested at the CDC for selected viruses, including mumps, influenza, human parainfluenza viruses (HPIVs) 1-4, adenoviruses, cytomegalovirus, Epstein-Barr virus (EBV), herpes simplex viruses (HSVs) 1 and 2, and human herpes viruses (HHVs) 6A and 6B. Results: Among the 320 patients, 65% were male, median age was 14.5 years (range, 0-90), and 67% reported unilateral parotitis. Commonly reported symptoms included sore throat (55%) and fever (48%). Viruses were detected in 210 (71%) of 294 NMP patients with adequate samples for testing, ≥2 viruses were detected in 37 samples, and 248 total virus detections were made among all samples. These included 156 influenza A(H3N2), 42 HHV6B, 32 EBV, 8 HPIV2, 2 HPIV3, 3 adenovirus, 4 HSV-1, and 1 HSV-2. Influenza A(H3N2), HHV6B, and EBV were the most frequently codetected viruses. Conclusions: Our findings suggest that, in addition to mumps, clinicians should consider respiratory viral (influenza) and herpes viral etiologies for parotitis, particularly among patients without epidemiologic links to mumps cases or outbreaks.


Asunto(s)
Gripe Humana/complicaciones , Gripe Humana/epidemiología , Parotiditis/virología , Virus/aislamiento & purificación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Paperas , Parotiditis/epidemiología , Faringitis/virología , Estaciones del Año , Encuestas y Cuestionarios , Estados Unidos/epidemiología , Adulto Joven
16.
Clin Infect Dis ; 67(4): 485-492, 2018 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-29617957

RESUMEN

Background: During the 2014-2015 influenza season in the United States, 256 cases of influenza-associated parotitis were reported from 27 states. We conducted a case-control study and laboratory investigation to further describe this rare clinical manifestation of influenza. Methods: During February 2015-April 2015, we interviewed 50 cases (with parotitis) and 124 ill controls (without parotitis) with laboratory-confirmed influenza; participants resided in 11 states and were matched by age, state, hospital admission status, and specimen collection date. Influenza viruses were characterized using real-time polymerase chain reaction and next-generation sequencing. We compared cases and controls using conditional logistic regression. Specimens from additional reported cases were also analyzed. Results: Cases, 73% of whom were aged <20 years, experienced painful (86%), unilateral (68%) parotitis a median of 4 (range, 0-16) days after onset of systemic or respiratory symptoms. Cases were more likely than controls to be male (76% vs 51%; P = .005). We detected influenza A(H3N2) viruses, genetic group 3C.2a, in 100% (32/32) of case and 92% (105/108) of control specimens sequenced (P = .22). Influenza B and A(H3N2) 3C.3 and 3C.3b genetic group virus infections were detected in specimens from additional cases. Conclusions: Influenza-associated parotitis, as reported here and in prior sporadic case reports, seems to occur primarily with influenza A(H3N2) virus infection. Because of the different clinical and infection control considerations for mumps and influenza virus infections, we recommend clinicians consider influenza in the differential diagnoses among patients with acute parotitis during the influenza season.


Asunto(s)
Gripe Humana/complicaciones , Parotiditis/virología , Adolescente , Adulto , Estudios de Casos y Controles , Niño , Preescolar , Diagnóstico Diferencial , Femenino , Humanos , Lactante , Subtipo H3N2 del Virus de la Influenza A/genética , Subtipo H3N2 del Virus de la Influenza A/aislamiento & purificación , Masculino , Persona de Mediana Edad , Parotiditis/diagnóstico , Parotiditis/epidemiología , Estaciones del Año , Estados Unidos , Adulto Joven
17.
Influenza Other Respir Viruses ; 12(1): 132-137, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29446233

RESUMEN

BACKGROUND: Estimates of influenza disease burden are broadly useful for public health, helping national and local authorities monitor epidemiologic trends, plan and allocate resources, and promote influenza vaccination. Historically, estimates of the burden of seasonal influenza in the United States, focused mainly on influenza-related mortality and hospitalization, were generated every few years. Since the 2010-2011 influenza season, annual US influenza burden estimates have been generated and expanded to include estimates of influenza-related outpatient medical visits and symptomatic illness in the community. METHODS: We used routinely collected surveillance data, outbreak field investigations, and proportions of people seeking health care from survey results to estimate the number of illnesses, medical visits, hospitalizations, and deaths due to influenza during six influenza seasons (2010-2011 through 2015-2016). RESULTS: We estimate that the number of influenza-related illnesses that have occurred during influenza season has ranged from 9.2 million to 35.6 million, including 140 000 to 710 000 influenza-related hospitalizations. DISCUSSION: These annual efforts have strengthened public health communications products and supported timely assessment of the impact of vaccination through estimates of illness and hospitalizations averted. Additionally, annual estimates of influenza burden have highlighted areas where disease surveillance needs improvement to better support public health decision making for seasonal influenza epidemics as well as future pandemics.


Asunto(s)
Gripe Humana/epidemiología , Gripe Humana/prevención & control , Vigilancia de la Población/métodos , Adolescente , Adulto , Anciano , Niño , Preescolar , Costo de Enfermedad , Humanos , Lactante , Vacunas contra la Influenza/administración & dosificación , Vacunas contra la Influenza/inmunología , Persona de Mediana Edad , Estudios Retrospectivos , Estaciones del Año , Estados Unidos/epidemiología , Adulto Joven
18.
J Infect Dis ; 217(7): 1078-1088, 2018 03 13.
Artículo en Inglés | MEDLINE | ID: mdl-29342251

RESUMEN

Background: The kinetics of the antibody response during severe influenza are not well documented. Methods: Critically ill patients infected with 2009 pandemic influenza A(H1N1) virus (A[H1N1]pdm09), confirmed by reverse-transcription polymerase chain reaction analysis or seroconversion (defined as a ≥4-fold rise in titers), during 2009-2011 in Canada were prospectively studied. Antibody titers in serially collected sera were determined using hemagglutinin inhibition (HAI) and microneutralization assays. Average antibody curves were estimated using linear mixed-effects models and compared by patient outcome, age, and corticosteroid treatment. Results: Of 47 patients with A(H1N1)pdm09 virus infection (median age, 47 years), 59% had baseline HAI titers of <40, and 68% had baseline neutralizing titers of <40. Antibody titers rose quickly after symptom onset, and, by day 14, 83% of patients had HAI titers of ≥40, and 80% had neutralizing titers ≥40. Baseline HAI titers were significantly higher in patients who died compared with patients who survived; however, the antibody kinetics were similar by patient outcome and corticosteroid treatment. Geometric mean titers over time in older patients were lower than those in younger patients. Conclusions: Critically ill patients with influenza A(H1N1)pdm09 virus infection had strong HAI and neutralizing antibody responses during their illness. Antibody kinetics differed by age but were not associated with patient outcome.


Asunto(s)
Anticuerpos Antivirales/sangre , Enfermedad Crítica , Subtipo H1N1 del Virus de la Influenza A/inmunología , Gripe Humana/sangre , Gripe Humana/epidemiología , Pandemias , Adolescente , Adulto , Anciano , Canadá/epidemiología , Femenino , Humanos , Gripe Humana/mortalidad , Masculino , Persona de Mediana Edad , Factores de Riesgo , Estaciones del Año , Factores de Tiempo , Adulto Joven
19.
Vaccine ; 35(50): 6967-6976, 2017 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-29100706

RESUMEN

BACKGROUND: Few trials have evaluated influenza vaccine efficacy (VE) in young children, a group particularly vulnerable to influenza complications. We aimed to estimate VE against influenza in children aged <2 years in Bangladesh; a subtropical setting, where influenza circulation can be irregular. METHODS: Children aged 6-23 months were enrolled 1:1 in a parallel, double-blind, randomized controlled trial of trivalent inactivated influenza vaccine (IIV3) versus inactivated polio vaccine (IPV); conducted August 2010-March 2014 in Dhaka, Bangladesh. Children received two pediatric doses of vaccine, one month apart, and were followed for one year for febrile and respiratory illness. Field assistants conducted weekly home-based, active surveillance and ill children were referred to the study clinic for clinical evaluation and nasopharyngeal wash specimen collection. Analysis included all children who received a first vaccine dose and compared yearly incidence of reverse transcription polymerase chain reaction (RT-PCR)-confirmed influenza between trial arms. The VE was estimated as 1-(rate ratio of illness) × 100%, using unadjusted Poisson regression. The trial was registered with ClinicalTrials.gov, number NCT01319955. RESULTS: Across four vaccination rounds, 4081 children were enrolled and randomized, contributing 2576 child-years of observation to the IIV3 arm and 2593 child-years to the IPV arm. Influenza incidence was 10 episodes/100 child-years in the IIV3 arm and 15 episodes/100 child-years in the IPV arm. Overall, the VE was 31% (95% confidence interval 18, 42%) against any RT-PCR-confirmed influenza. The VE varied by season, but was similar by influenza type/subtype and participant age and sex. CONCLUSIONS: Vaccination of young children with IIV3 provided a significant reduction in laboratory-confirmed influenza; however, exploration of additional influenza vaccine strategies, such as adjuvanted vaccines or standard adult vaccine doses, is warranted to find more effective influenza vaccines for young children in low-income countries.


Asunto(s)
Vacunas contra la Influenza/inmunología , Gripe Humana/prevención & control , Bangladesh , Método Doble Ciego , Femenino , Humanos , Lactante , Vacunas contra la Influenza/administración & dosificación , Masculino , Resultado del Tratamiento
20.
BMC Neurol ; 17(1): 110, 2017 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-28606065

RESUMEN

BACKGROUND: HIV-infected persons with detectable cryptococcal antigen (CrAg) in blood have increased morbidity and mortality compared with HIV-infected persons who are CrAg-negative. This study examined neurocognitive function among persons with asymptomatic cryptococcal antigenemia. METHODS: Participants from three prospective HIV cohorts underwent neurocognitive testing at the time of antiretroviral therapy (ART) initiation. Cohorts included persons with cryptococcal meningitis (N = 90), asymptomatic CrAg + (N = 87), and HIV-infected persons without central nervous system infection (N = 125). Z-scores for each neurocognitive test were calculated relative to an HIV-negative Ugandan population with a composite quantitative neurocognitive performance Z-score (QNPZ-8) created from eight tested domains. Neurocognitive function was measured pre-ART for all three cohorts and additionally after 4 weeks of ART (and 6 weeks of pre-emptive fluconazole) treatment among asymptomatic CrAg + participants. RESULTS: Cryptococcal meningitis and asymptomatic CrAg + participants had lower median CD4 counts (17 and 26 cells/µL, respectively) than the HIV-infected control cohort (233 cells/µL) as well as lower Karnofsky performance status (60 and 70 vs. 90, respectively). The composite QNPZ-8 for asymptomatic CrAg + (-1.80 Z-score) fell between the cryptococcal meningitis cohort (-2.22 Z-score, P = 0.02) and HIV-infected controls (-1.36, P = 0.003). After four weeks of ART and six weeks of fluconazole, the asymptomatic CrAg + cohort neurocognitive performance improved (-1.0 Z-score, P < 0.001). CONCLUSION: Significant deficits in neurocognitive function were identified in asymptomatic CrAg + persons with advanced HIV/AIDS even without signs or sequelae of meningitis. Neurocognitive function in this group improves over time after initiation of pre-emptive fluconazole treatment and ART, but short term adherence support may be necessary.


Asunto(s)
Cryptococcus/aislamiento & purificación , Infecciones por VIH/complicaciones , Meningitis Criptocócica/diagnóstico , Adulto , Antígenos Fúngicos/aislamiento & purificación , Estudios de Cohortes , Femenino , Humanos , Masculino , Estudios Prospectivos
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