Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 185
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
N Engl J Med ; 386(19): 1804-1816, 2022 05 12.
Artículo en Inglés | MEDLINE | ID: mdl-35263534

RESUMEN

BACKGROUND: Waning of vaccine protection against coronavirus disease 2019 (Covid-19) and the emergence of the omicron (or B.1.1.529) variant of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have led to expedited efforts to scale up booster vaccination. Protection conferred by booster doses of the BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna) vaccines in Qatar, as compared with protection conferred by the two-dose primary series, is unclear. METHODS: We conducted two matched retrospective cohort studies to assess the effectiveness of booster vaccination, as compared with that of a two-dose primary series alone, against symptomatic SARS-CoV-2 infection and Covid-19-related hospitalization and death during a large wave of omicron infections from December 19, 2021, through January 26, 2022. The association of booster status with infection was estimated with the use of Cox proportional-hazards regression models. RESULTS: In a population of 2,239,193 persons who had received at least two doses of BNT162b2 or mRNA-1273 vaccine, those who had also received a booster were matched with persons who had not received a booster. Among the BNT162b2-vaccinated persons, the cumulative incidence of symptomatic omicron infection was 2.4% (95% confidence interval [CI], 2.3 to 2.5) in the booster cohort and 4.5% (95% CI, 4.3 to 4.6) in the nonbooster cohort after 35 days of follow-up. Booster effectiveness against symptomatic omicron infection, as compared with that of the primary series, was 49.4% (95% CI, 47.1 to 51.6). Booster effectiveness against Covid-19-related hospitalization and death due to omicron infection, as compared with the primary series, was 76.5% (95% CI, 55.9 to 87.5). BNT162b2 booster effectiveness against symptomatic infection with the delta (or B.1.617.2) variant, as compared with the primary series, was 86.1% (95% CI, 67.3 to 94.1). Among the mRNA-1273-vaccinated persons, the cumulative incidence of symptomatic omicron infection was 1.0% (95% CI, 0.9 to 1.2) in the booster cohort and 1.9% (95% CI, 1.8 to 2.1) in the nonbooster cohort after 35 days; booster effectiveness against symptomatic omicron infection, as compared with the primary series, was 47.3% (95% CI, 40.7 to 53.3). Few severe Covid-19 cases were noted in the mRNA-1273-vaccinated cohorts. CONCLUSIONS: The messenger RNA (mRNA) boosters were highly effective against symptomatic delta infection, but they were less effective against symptomatic omicron infection. However, with both variants, mRNA boosters led to strong protection against Covid-19-related hospitalization and death. (Funded by Weill Cornell Medicine-Qatar and others.).


Asunto(s)
Vacuna nCoV-2019 mRNA-1273/inmunología , Vacuna BNT162/inmunología , COVID-19 , COVID-19/epidemiología , COVID-19/inmunología , COVID-19/prevención & control , Vacunas contra la COVID-19 , Estudios de Cohortes , Humanos , Inmunización Secundaria , Inmunogenicidad Vacunal , Qatar/epidemiología , ARN Mensajero , Estudios Retrospectivos , SARS-CoV-2 , Eficacia de las Vacunas , Vacunas Sintéticas , Vacunas de ARNm
2.
N Engl J Med ; 387(1): 21-34, 2022 07 07.
Artículo en Inglés | MEDLINE | ID: mdl-35704396

RESUMEN

BACKGROUND: The protection conferred by natural immunity, vaccination, and both against symptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection with the BA.1 or BA.2 sublineages of the omicron (B.1.1.529) variant is unclear. METHODS: We conducted a national, matched, test-negative, case-control study in Qatar from December 23, 2021, through February 21, 2022, to evaluate the effectiveness of vaccination with BNT162b2 (Pfizer-BioNTech) or mRNA-1273 (Moderna), natural immunity due to previous infection with variants other than omicron, and hybrid immunity (previous infection and vaccination) against symptomatic omicron infection and against severe, critical, or fatal coronavirus disease 2019 (Covid-19). RESULTS: The effectiveness of previous infection alone against symptomatic BA.2 infection was 46.1% (95% confidence interval [CI], 39.5 to 51.9). The effectiveness of vaccination with two doses of BNT162b2 and no previous infection was negligible (-1.1%; 95% CI, -7.1 to 4.6), but nearly all persons had received their second dose more than 6 months earlier. The effectiveness of three doses of BNT162b2 and no previous infection was 52.2% (95% CI, 48.1 to 55.9). The effectiveness of previous infection and two doses of BNT162b2 was 55.1% (95% CI, 50.9 to 58.9), and the effectiveness of previous infection and three doses of BNT162b2 was 77.3% (95% CI, 72.4 to 81.4). Previous infection alone, BNT162b2 vaccination alone, and hybrid immunity all showed strong effectiveness (>70%) against severe, critical, or fatal Covid-19 due to BA.2 infection. Similar results were observed in analyses of effectiveness against BA.1 infection and of vaccination with mRNA-1273. CONCLUSIONS: No discernable differences in protection against symptomatic BA.1 and BA.2 infection were seen with previous infection, vaccination, and hybrid immunity. Vaccination enhanced protection among persons who had had a previous infection. Hybrid immunity resulting from previous infection and recent booster vaccination conferred the strongest protection. (Funded by Weill Cornell Medicine-Qatar and others.).


Asunto(s)
Vacuna nCoV-2019 mRNA-1273 , Vacuna BNT162 , COVID-19 , Inmunidad Innata , Inmunización , SARS-CoV-2 , Vacuna nCoV-2019 mRNA-1273/inmunología , Vacuna nCoV-2019 mRNA-1273/uso terapéutico , Vacuna BNT162/inmunología , Vacuna BNT162/uso terapéutico , COVID-19/inmunología , COVID-19/prevención & control , COVID-19/virología , Estudios de Casos y Controles , Humanos , Inmunidad Innata/inmunología , Inmunización Secundaria , Recurrencia , SARS-CoV-2/inmunología , Vacunación
3.
N Engl J Med ; 387(20): 1865-1876, 2022 11 17.
Artículo en Inglés | MEDLINE | ID: mdl-36322837

RESUMEN

BACKGROUND: The BNT162b2 vaccine against coronavirus disease 2019 (Covid-19) has been authorized for use in children 5 to 11 years of age and adolescents 12 to 17 years of age but in different antigen doses. METHODS: We assessed the real-world effectiveness of the BNT162b2 vaccine against infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among children and adolescents in Qatar. To compare the incidence of SARS-CoV-2 infection in the national cohort of vaccinated participants with the incidence in the national cohort of unvaccinated participants, we conducted three matched, retrospective, target-trial, cohort studies - one assessing data obtained from children 5 to 11 years of age after the B.1.1.529 (omicron) variant became prevalent and two assessing data from adolescents 12 to 17 years of age before the emergence of the omicron variant (pre-omicron study) and after the omicron variant became prevalent. Associations were estimated with the use of Cox proportional-hazards regression models. RESULTS: Among children, the overall effectiveness of the 10-µg primary vaccine series against infection with the omicron variant was 25.7% (95% confidence interval [CI], 10.0 to 38.6). Effectiveness was highest (49.6%; 95% CI, 28.5 to 64.5) right after receipt of the second dose but waned rapidly thereafter and was negligible after 3 months. Effectiveness was 46.3% (95% CI, 21.5 to 63.3) among children 5 to 7 years of age and 16.6% (95% CI, -4.2 to 33.2) among those 8 to 11 years of age. Among adolescents, the overall effectiveness of the 30-µg primary vaccine series against infection with the omicron variant was 30.6% (95% CI, 26.9 to 34.1), but many adolescents had been vaccinated months earlier. Effectiveness waned over time since receipt of the second dose. Effectiveness was 35.6% (95% CI, 31.2 to 39.6) among adolescents 12 to 14 years of age and 20.9% (95% CI, 13.8 to 27.4) among those 15 to 17 years of age. In the pre-omicron study, the overall effectiveness of the 30-µg primary vaccine series against SARS-CoV-2 infection among adolescents was 87.6% (95% CI, 84.0 to 90.4) and waned relatively slowly after receipt of the second dose. CONCLUSIONS: Vaccination in children was associated with modest, rapidly waning protection against omicron infection. Vaccination in adolescents was associated with stronger, more durable protection, perhaps because of the larger antigen dose. (Funded by Weill Cornell Medicine-Qatar and others.).


Asunto(s)
Vacuna BNT162 , COVID-19 , Eficacia de las Vacunas , Adolescente , Niño , Humanos , Vacuna BNT162/administración & dosificación , Vacuna BNT162/uso terapéutico , COVID-19/epidemiología , COVID-19/prevención & control , Vacunas contra la COVID-19/administración & dosificación , Vacunas contra la COVID-19/uso terapéutico , Qatar/epidemiología , Estudios Retrospectivos , SARS-CoV-2 , Preescolar , Eficacia de las Vacunas/estadística & datos numéricos
4.
N Engl J Med ; 385(24): e83, 2021 12 09.
Artículo en Inglés | MEDLINE | ID: mdl-34614327

RESUMEN

BACKGROUND: Waning of vaccine protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or coronavirus disease 2019 (Covid-19) is a concern. The persistence of BNT162b2 (Pfizer-BioNTech) vaccine effectiveness against infection and disease in Qatar, where the B.1.351 (or beta) and B.1.617.2 (or delta) variants have dominated incidence and polymerase-chain-reaction testing is done on a mass scale, is unclear. METHODS: We used a matched test-negative, case-control study design to estimate vaccine effectiveness against any SARS-CoV-2 infection and against any severe, critical, or fatal case of Covid-19, from January 1 to September 5, 2021. RESULTS: Estimated BNT162b2 effectiveness against any SARS-CoV-2 infection was negligible in the first 2 weeks after the first dose. It increased to 36.8% (95% confidence interval [CI], 33.2 to 40.2) in the third week after the first dose and reached its peak at 77.5% (95% CI, 76.4 to 78.6) in the first month after the second dose. Effectiveness declined gradually thereafter, with the decline accelerating after the fourth month to reach approximately 20% in months 5 through 7 after the second dose. Effectiveness against symptomatic infection was higher than effectiveness against asymptomatic infection but waned similarly. Variant-specific effectiveness waned in the same pattern. Effectiveness against any severe, critical, or fatal case of Covid-19 increased rapidly to 66.1% (95% CI, 56.8 to 73.5) by the third week after the first dose and reached 96% or higher in the first 2 months after the second dose; effectiveness persisted at approximately this level for 6 months. CONCLUSIONS: BNT162b2-induced protection against SARS-CoV-2 infection appeared to wane rapidly following its peak after the second dose, but protection against hospitalization and death persisted at a robust level for 6 months after the second dose. (Funded by Weill Cornell Medicine-Qatar and others.).


Asunto(s)
Vacuna BNT162/inmunología , COVID-19/prevención & control , Inmunogenicidad Vacunal , Eficacia de las Vacunas , Vacuna nCoV-2019 mRNA-1273 , Adulto , Anciano , COVID-19/epidemiología , COVID-19/inmunología , COVID-19/mortalidad , Vacunas contra la COVID-19 , Estudios de Casos y Controles , Femenino , Humanos , Inmunización Secundaria , Masculino , Persona de Mediana Edad , Qatar/epidemiología , Factores de Tiempo , Adulto Joven
5.
Am J Epidemiol ; 2023 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-38061757

RESUMEN

The COVID-19 pandemic has highlighted the need to use infection testing databases to rapidly estimate effectiveness of prior infection in preventing reinfection ($P{E}_S$) by novel SARS-CoV-2 variants. Mathematical modeling was used to demonstrate a theoretical foundation for applicability of the test-negative, case-control study design to derive $P{E}_S$. Apart from the very early phase of an epidemic, the difference between the test-negative estimate for $P{E}_S$ and true value of $P{E}_S$ was minimal and became negligible as the epidemic progressed. The test-negative design provided robust estimation of $P{E}_S$ and its waning. Assuming that only 25% of prior infections are documented, misclassification of prior infection status underestimated $P{E}_S$, but the underestimate was considerable only when >50% of the population was ever infected. Misclassification of latent infection, misclassification of current active infection, and scale-up of vaccination all resulted in negligible bias in estimated $P{E}_S$. The test-negative design was applied to national-level testing data in Qatar to estimate $P{E}_S$ for SARS-CoV-2. $P{E}_S$ against SARS-CoV-2 Alpha and Beta variants was estimated at 97.0% (95% CI: 93.6-98.6) and 85.5% (95% CI: 82.4-88.1), respectively. These estimates were validated using a cohort study design. The test-negative design offers a feasible, robust method to estimate protection from prior infection in preventing reinfection.

6.
Virol J ; 20(1): 188, 2023 08 22.
Artículo en Inglés | MEDLINE | ID: mdl-37608372

RESUMEN

BACKGROUND: Limited data exists on herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) infections in migrant populations. This study investigated HSV-1 and HSV-2 seroprevalences and associations among craft and manual workers (CMWs) in Qatar who constitute 60% of Qatar's population. METHODS: A national population-based cross-sectional seroprevalence survey was conducted on the CMW population, all men, between July 26 and September 9, 2020. 2,612 sera were tested for anti-HSV-1 IgG antibodies using HerpeSelect 1 ELISA IgG kits and for anti-HSV-2 IgG antibodies using HerpeSelect 2 ELISA IgG kits (Focus Diagnostics, USA). Univariable and multivariable logistic regression analyses were conducted to identify associations with HSV-1 and HSV-2 infections. RESULTS: Serological testing identified 2,171 sera as positive, 403 as negative, and 38 as equivocal for HSV-1 antibodies, and 300 sera as positive, 2,250 as negative, and 62 as equivocal for HSV-2 antibodies. HSV-1 and HSV-2 seroprevalences among CMWs were estimated at 84.2% (95% CI 82.8-85.6%) and 11.4% (95% CI 10.1-12.6%), respectively. HSV-1 infection was associated with nationality, educational attainment, and occupation. HSV-2 infection was associated with age, nationality, and educational attainment. CONCLUSIONS: Over 80% of CMWs are infected with HSV-1 and over 10% are infected with HSV-2. The findings highlight the need for sexual health programs to tackle sexually transmitted infections among the CMW population.


Asunto(s)
Herpes Simple , Herpesvirus Humano 1 , Migrantes , Masculino , Humanos , Qatar/epidemiología , Estudios Transversales , Estudios Seroepidemiológicos , Herpes Simple/epidemiología , Herpesvirus Humano 2 , Anticuerpos Antivirales , Inmunoglobulina G
7.
Pain Med ; 24(8): 985-992, 2023 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-36944266

RESUMEN

OBJECTIVE: Movement-evoked pain (MeP) may predispose the geriatric chronic low back pain (LBP) population to health decline. As there are differing operational definitions for MeP, the question remains as to whether these different definitions have similar associations with health outcomes in older adults with chronic LBP. DESIGN: Cross-sectional analysis of an observational study. SETTING: Clinical research laboratory. SUBJECTS: 226 older adults with chronic LBP. METHODS: This secondary analysis used baseline data from a prospective cohort study (n = 250). LBP intensity was collected before and after the repeated chair rise test, stair climbing test, and 6-minute walk test; MeP change scores (ie, sum of pretest pain subtracted from posttest pain) and aggregated posttest pain (ie, sum of posttest pain) variables were calculated. LBP-related disability and self-efficacy were measured by the Quebec Back Pain Disability Scale (QBPDS) and Low Back Activity Confidence Scale (LOBACS), respectively. Physical function was measured with the Health ABC Performance Battery. Robust regression with HC3 standard errors was used to evaluate adjusted associations between both MeP variables and disability, self-efficacy, and physical function. RESULTS: Greater aggregated posttest MeP was independently associated with worse disability (b = 0.593, t = 2.913, P = .004), self-efficacy (b = -0.870, t = -3.110, P = .002), and physical function (b = -0.017, t = -2.007, P = .039). MeP change scores were not associated with any outcome (all P > .050). CONCLUSIONS: Aggregate posttest MeP was linked to poorer health outcomes in older adults with chronic LBP, but MeP change scores were not. Future studies should consider that the construct validity of MeP paradigms partially depends on the chosen operational definition.


Asunto(s)
Dolor Crónico , Dolor de la Región Lumbar , Humanos , Anciano , Dolor de la Región Lumbar/complicaciones , Estudios Prospectivos , Estudios Transversales , Caminata , Dimensión del Dolor , Evaluación de la Discapacidad
8.
Clin Infect Dis ; 75(1): e361-e367, 2022 08 24.
Artículo en Inglés | MEDLINE | ID: mdl-35404391

RESUMEN

SHORT SUMMARY: Severe acute respiratory syndrome coronavirus 2 infection from the Omicron variant in children/adolescents is less severe than infection from the Delta variant. Those 6 to <18 years also have less severe disease than those <6 years old. BACKGROUND: There are limited data assessing coronavirus 2019 (COVID-19) disease severity in children/adolescents infected with the Omicron variant. METHODS: We identified children and adolescents <18 years of age with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection with Delta and propensity score-matched controls with Omicron variant infection from the National COVID-19 Database in Qatar. Primary outcome was disease severity, determined by hospital admission, admission to the intensive care unit (ICU), or mechanical ventilation within 14 days of diagnosis, or death within 28 days. RESULTS: Among 1735 cases with Delta variant infection between 1 June and 6 November 2021, and 32 635 cases with Omicron variant infection between 1 January and 15 January 2022, who did not have prior infection and were not vaccinated, we identified 985 propensity score-matched pairs. Among those who were Delta infected, 84.2% had mild, 15.7% had moderate, and 0.1% had severe/critical disease. Among those who were Omicron infected, 97.8% had mild, 2.2% had moderate, and none had severe/critical disease (P < .001). Omicron variant infection (vs Delta) was associated with significantly lower odds of moderate or severe/critical disease (adjusted odds ratio [AOR], 0.12; 95% confidence interval [CI], .07-.18). Those aged 6-11 and 12 to <18 years had lower odds of developing moderate or severe/critical disease compared with those younger than age 6 years (aOR, 0.47; 95% CI, .33-.66 for 6-11 year olds; aOR, 0.45; 95% CI, .21-.94 for 12 to <18 year olds). CONCLUSIONS: Omicron variant infection in children/adolescents is associated with less severe disease than Delta variant infection as measured by hospitalization rates and need for ICU care or mechanical ventilation. Those 6 to <18 years of age also have less severe disease than those <6 years old.


Asunto(s)
COVID-19 , Adolescente , Niño , Humanos , Respiración Artificial , SARS-CoV-2 , Índice de Severidad de la Enfermedad
9.
Clin Infect Dis ; 75(1): e1188-e1191, 2022 08 24.
Artículo en Inglés | MEDLINE | ID: mdl-34657152

RESUMEN

Beta (B.1.351)-variant coronavirus disease 2019 (COVID-19) disease was investigated in Qatar. Compared with the Alpha (B.1.1.7) variant, odds (95% confidence interval) of progressing to severe disease, critical disease, and COVID-19-related death were 1.24-fold (1.11-1.39), 1.49-fold (1.13-1.97), and 1.57-fold (1.03-2.43) higher, respectively, for the Beta variant.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética
10.
Arch Phys Med Rehabil ; 103(3): 473-480.e1, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34547273

RESUMEN

OBJECTIVE: To investigate if clinically observable aberrant lumbopelvic movements are associated with physical function at 12-month follow-up in older adults with chronic low back pain (CLBP), both directly and indirectly through baseline physical function. DESIGN: Secondary analysis of a yearlong prospective cohort study. SETTING: Clinical Research Laboratory. PARTICIPANTS: Community-dwelling older adults with CLBP (N=250). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Data from 239 participants were analyzed. Participants were screened at baseline for aberrant lumbopelvic movements during active trunk flexion; total observable aberrant movements were recorded and summed (range 0-4). Latent constructs of physical function were developed from an array of perception-based and performance-based outcome measures at baseline and 12 months, respectively. Structural Equation Modeling was used to assess the direct effect of baseline aberrant movement score on the latent construct of 12-month physical function, and its indirect effect through baseline physical function. RESULTS: Aberrant movements were present in most participants (64.7%) and had a significant negative total effect on 12-month physical function (γ= -0.278, P<.001). Aberrant movement score's direct effect and indirect effect, through baseline functioning, were significantly negatively associated with physical function at 12-months, after adjusting for covariates (γ=-0.068, P=.038; γ= -0.210, P<.001, respectively). CONCLUSIONS: Aberrant lumbopelvic movements are associated with decreased physical function at 12-month follow-up in older adults with CLBP, independent of baseline physical function and covariates. Future studies should evaluate if screening for aberrant movements may inform prognostic and interventional efforts in this patient population.


Asunto(s)
Dolor de la Región Lumbar , Anciano , Humanos , Vida Independiente , Movimiento , Estudios Prospectivos , Rango del Movimiento Articular
11.
Clin Infect Dis ; 73(7): e1830-e1840, 2021 10 05.
Artículo en Inglés | MEDLINE | ID: mdl-33315061

RESUMEN

BACKGROUND: Risk of reinfection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unknown. We assessed the risk and incidence rate of documented SARS-CoV-2 reinfection in a cohort of laboratory-confirmed cases in Qatar. METHODS: All SARS-CoV-2 laboratory-confirmed cases with at least 1 polymerase chain reaction-positive swab that was ≥45 days after a first positive swab were individually investigated for evidence of reinfection. Viral genome sequencing of the paired first positive and reinfection viral specimens was conducted to confirm reinfection. RESULTS: Out of 133 266 laboratory-confirmed SARS-CoV-2 cases, 243 persons (0.18%) had at least 1 subsequent positive swab ≥45 days after the first positive swab. Of these, 54 cases (22.2%) had strong or good evidence for reinfection. Median time between the first swab and reinfection swab was 64.5 days (range, 45-129). Twenty-three of the 54 cases (42.6%) were diagnosed at a health facility, suggesting presence of symptoms, while 31 (57.4%) were identified incidentally through random testing campaigns/surveys or contact tracing. Only 1 person was hospitalized at the time of reinfection but was discharged the next day. No deaths were recorded. Viral genome sequencing confirmed 4 reinfections of 12 cases with available genetic evidence. Reinfection risk was estimated at 0.02% (95% confidence interval [CI], .01%-.02%), and reinfection incidence rate was 0.36 (95% CI, .28-.47) per 10 000 person-weeks. CONCLUSIONS: SARS-CoV-2 reinfection can occur but is a rare phenomenon suggestive of protective immunity against reinfection that lasts for at least a few months post primary infection.


Asunto(s)
COVID-19 , SARS-CoV-2 , Trazado de Contacto , Humanos , Incidencia , Reinfección
12.
Emerg Infect Dis ; 27(5): 1343-1352, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33900174

RESUMEN

We investigated what proportion of the population acquired severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and whether the herd immunity threshold has been reached in 10 communities in Qatar. The study included 4,970 participants during June 21-September 9, 2020. Antibodies against SARS-CoV-2 were detected by using an electrochemiluminescence immunoassay. Seropositivity ranged from 54.9% (95% CI 50.2%-59.4%) to 83.8% (95% CI 79.1%-87.7%) across communities and showed a pooled mean of 66.1% (95% CI 61.5%-70.6%). A range of other epidemiologic measures indicated that active infection is rare, with limited if any sustainable infection transmission for clusters to occur. Only 5 infections were ever severe and 1 was critical in these young communities; infection severity rate of 0.2% (95% CI 0.1%-0.4%). Specific communities in Qatar have or nearly reached herd immunity for SARS-CoV-2 infection: 65%-70% of the population has been infected.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , Inmunidad Colectiva , Qatar/epidemiología
13.
PLoS Med ; 18(12): e1003879, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34914711

RESUMEN

BACKGROUND: The epidemiology of the SARS-CoV-2 B.1.1.7 (or Alpha) variant is insufficiently understood. This study's objective was to describe the introduction and expansion of this variant in Qatar and to estimate the efficacy of natural infection against reinfection with this variant. METHODS AND FINDINGS: Reinfections with the B.1.1.7 variant and variants of unknown status were investigated in a national cohort of 158,608 individuals with prior PCR-confirmed infections and a national cohort of 42,848 antibody-positive individuals. Infections with B.1.1.7 and variants of unknown status were also investigated in a national comparator cohort of 132,701 antibody-negative individuals. B.1.1.7 was first identified in Qatar on 25 December 2020. Sudden, large B.1.1.7 epidemic expansion was observed starting on 18 January 2021, triggering the onset of epidemic's second wave, 7 months after the first wave. B.1.1.7 was about 60% more infectious than the original (wild-type) circulating variants. Among persons with a prior PCR-confirmed infection, the efficacy of natural infection against reinfection was estimated to be 97.5% (95% CI: 95.7% to 98.6%) for B.1.1.7 and 92.2% (95% CI: 90.6% to 93.5%) for variants of unknown status. Among antibody-positive persons, the efficacy of natural infection against reinfection was estimated to be 97.0% (95% CI: 92.5% to 98.7%) for B.1.1.7 and 94.2% (95% CI: 91.8% to 96.0%) for variants of unknown status. A main limitation of this study is assessment of reinfections based on documented PCR-confirmed reinfections, but other reinfections could have occurred and gone undocumented. CONCLUSIONS: In this study, we observed that introduction of B.1.1.7 into a naïve population can create a major epidemic wave, but natural immunity in those previously infected was strongly associated with limited incidence of reinfection by B.1.1.7 or other variants.


Asunto(s)
COVID-19/epidemiología , COVID-19/virología , Reinfección/epidemiología , Reinfección/virología , SARS-CoV-2 , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Número Básico de Reproducción , Niño , Femenino , Humanos , Inmunidad Innata , Masculino , Persona de Mediana Edad , Modelos Teóricos , Reacción en Cadena de la Polimerasa , Qatar/epidemiología , Estudios Retrospectivos , Factores de Tiempo , Adulto Joven
15.
J Med Virol ; 93(3): 1678-1686, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-32965715

RESUMEN

BACKGROUND: The role of convalescent plasma therapy for patients with coronavirus disease 2019 (COVID-19) is unclear. METHODS: We retrospectively compared outcomes in a cohort of critical COVID-19 patients who received standard care (SC Group) and those who, in addition, received convalescent plasma (CP Group). RESULTS: In total, 40 patients were included in each group. The median patient age was 53.5 years (interquartile range [IQR] 42-60.5), and the majority of patients required invasive ventilation (69, 86.2%). Plasma was harvested from donors after a median of 37 days (IQR 31-46) from the first positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction (PCR) result and 26 days (IQR 21-32) after documented viral clearance; it was administered after a median of 10 days (IQR 9-10) from the onset of symptoms and 2.5 days (IQR 2-4) from admission to intensive care unit. The primary endpoint of improvement in respiratory support status within 28 days was achieved in 26 patients (65%) in the SC Group and 31 patients (77.5%) in the CP Group (p = .32). The 28-day all-cause mortality (12.5% vs. 2.5%; p = .22) and viral clearance (65% vs. 55%; p = .49) were not significantly different between the two groups. Convalescent plasma was not significantly associated with the primary endpoint (adjusted hazard ratio 0.87; 95% confidence interval 0.51-1.49; p = .62). Adverse events were balanced between the two study groups. CONCLUSION: In severe COVID-19, convalescent plasma therapy was not associated with clinical benefits. Randomized trials are required to confirm our findings.


Asunto(s)
COVID-19/terapia , Plasma/inmunología , Adulto , COVID-19/inmunología , Femenino , Humanos , Inmunización Pasiva/métodos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , SARS-CoV-2/inmunología , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Sueroterapia para COVID-19
16.
BMC Gastroenterol ; 21(1): 266, 2021 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-34130641

RESUMEN

BACKGROUND: The rapid growth of Qatar in the last two decades has attracted a large influx of immigrant workers who mostly come from HEV-hyperendemic countries. Thus, we aim to investigate the prevalence of HEV among acute non-A-C hepatitis patients in Qatar; and to evaluate the performance of four dominant commercial serological assays for HEV diagnosis. METHODS: 259 patients with non-A-C hepatitis were tested using the Wantai HEV-IgM, HEV-IgG, HEV-Ag ELISA kits, and the MP Biomedical HEV-Total Ab ELISA kit. ALT levels were tested and HEV RNA (viral loads) was performed using Taqman AmpliCube HEV RT-PCR kit (Mikrogen, Neuried, Germany). The performance of each kit was assessed according to the RT-PCR results. RESULTS: HEV-RNA was detected in 23.1% of the samples. Most of these HEV-RNA-positive cases belonged to non-Qatari residents from the Indian subcontinent; India, Pakistan, etc. HEV-Ag, HEV-IgM, HEV-IgG, HEV-Total Ab were detected in 5.56%, 8.65%, 32.1%, and 34.2% of all tested samples, respectively. Elevated ALT levels were highly correlated with the HEV-Ag, HEV-IgM, HEV-RNA but not with the HEV-IgG and HEV-Total Ab. Although HEV-Ag was very specific (100%), yet its sensitivity was poor (36.7%). HEV-IgM demonstrated the best second marker for diagnosis of acute HEV after RT-PCR as jugged by the overall performance parameters: specificity (96.2%), sensitivity (71.4%), PPV (83.3%), NPP (92.7%), agreement with RT-PCR (91.0%), and Kappa-value (0.71). CONCLUSION: Our study demonstrated a high prevalence of HEV virus in Qatar, mostly among immigrants from the Indian subcontinent. The HEV-IgM represents the best marker for detecting the acute HEV infection, where RT-PCR cannot be performed.


Asunto(s)
Virus de la Hepatitis E , Hepatitis E , Alemania , Hepatitis E/diagnóstico , Hepatitis E/epidemiología , Virus de la Hepatitis E/genética , Humanos , Inmunoglobulina G , Inmunoglobulina M , India , Pakistán , Prevalencia , Qatar/epidemiología , ARN Viral , Sensibilidad y Especificidad
17.
Pain Med ; 22(6): 1353-1359, 2021 06 04.
Artículo en Inglés | MEDLINE | ID: mdl-33585935

RESUMEN

OBJECTIVES: There is considerable overlap in risk profiles between chronic low back pain with radiculopathy (CLBPR) and cardiovascular health among older adults; obesity and smoking are related to both conditions and may largely drive the potential relationship. We sought to explore the impact of CLBPR on cardiovascular health outcomes, independent of body mass index (BMI) and current smoking status. METHODS: Age- and sex-matched older adults (60-85 years of age) with (n = 21) and without (n = 21) CLBPR were recruited. Current smokers were excluded. Blood samples were collected to measure cholesterol levels and pro-inflammatory markers (i.e., C-reactive protein and interleukin-6). Vascular endothelial function, a marker of cardiovascular health, was evaluated by measuring brachial artery flow-mediated dilation (FMD). General linear models with multifactorial designs were evaluated; group membership, BMI, education, and their respective two-way interaction terms were included as independent variables. RESULTS: Older adults with CLBPR had significantly higher BMIs (P = 0.004) and lower educational levels (P = 0.013) than did those without pain. There was a significant group-by-education interaction effect (P = 0.049) for endothelial function. Older adults without pain who were highly educated had higher FMD values, indicating better endothelial function (9.2%), whereas the following combinations all had lower FMD values: no pain plus low education, CLBPR plus high education, and CLBPR plus low education (5.9%, 6.1%, and 6.6%, respectively). CONCLUSIONS: Among older adults, CLBPR is linked with worse endothelial function, regardless of educational level and independent of BMI and smoking. These findings suggest that older adults with CLBPR may be at a higher risk of cardiovascular disease.


Asunto(s)
Enfermedades Cardiovasculares , Dolor de la Región Lumbar , Anciano , Biomarcadores , Arteria Braquial , Enfermedades Cardiovasculares/diagnóstico , Enfermedades Cardiovasculares/epidemiología , Humanos , Pierna , Dolor de la Región Lumbar/epidemiología , Vasodilatación
18.
Arch Phys Med Rehabil ; 102(3): 532-542, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33263286

RESUMEN

The purpose of this Special Communication is to discuss the rationale and design of the Movement Matters Activity Program for Stroke (MMAP) and explore implementation successes and challenges in home health and outpatient therapy practices across the stroke belt state of North Carolina. MMAP is an interventional component of the Comprehensive Postacute Stroke Services Study, a randomized multicenter pragmatic trial of stroke transitional care. MMAP was designed to maximize survivor health, recovery, and functional independence in the community and to promote evidence-based rehabilitative care. MMAP provided training, tools, and resources to enable rehabilitation providers to (1) prescribe physical activity and exercise according to evidence-based guidelines and programs, (2) match service setting and parameters with survivor function and benefit coverage, and (3) align treatment with quality metric reporting to demonstrate value-based care. MMAP implementation strategies were aligned with the Expert Recommendations for Implementing Change project, and MMAP site champion and facilitator survey feedback were thematically organized into the Consolidated Framework for Implementation Research domains. MMAP implementation was challenging, required modification and was affected by provider- and system-level factors. Program and study participation were limited and affected by practice priorities, productivity standards, and stroke patient volume. Sites with successful implementation appeared to have empowered MMAP champions in vertically integrated systems that embraced innovation. Findings from this broad evaluation can serve as a road map for the design and implementation of other comprehensive, complex interventions that aim to bridge the currently disconnected realms of acute care, postacute care, and community resources.


Asunto(s)
Ejercicio Físico , Promoción de la Salud , Evaluación de Programas y Proyectos de Salud , Rehabilitación de Accidente Cerebrovascular/métodos , Atención Subaguda , Cuidado de Transición , Humanos , North Carolina , Recuperación de la Función
19.
BMC Public Health ; 21(1): 2070, 2021 11 11.
Artículo en Inglés | MEDLINE | ID: mdl-34763694

RESUMEN

BACKGROUND: There is controversy regarding the role of in-person attendance in schools and transmission of the SARS-CoV-2 pandemic. Several studies have demonstrated no increase in transmission, while some have reported large outbreaks with in-person attendance. We determined the incidence and risk factors for SARS-CoV-2 infection among school staff after one school term. METHODS: Nasopharyngeal swabs (NPS) for SARS-CoV-2 RT-PCR and blood for SARS-CoV-2 antibody testing were obtained from staff at a large international school in Qatar at the beginning of the 2020-2021 school year and repeated at the end of the first term. RESULTS: A total of 376 staff provided samples for testing. At the beginning of the 2020-2021 school year, the PCR positivity for SARS-CoV-2 was 13%, while seropositivity was 30.1%. A majority of those who tested positive either by PCR or serologically, were non-teaching staff. At the end of the first school term four months later, only 3.5% of the initially antibody-negative staff had seroconverted. In multivariable logistic regression analysis, male gender (OR 11.48, 95%CI 4.77-27.64), non-teaching job category (OR 3.09, 95%CI 1.10-8.64), contact with a confirmed case (OR 20.81, 95%CI 2.90-149.18), and presence of symptoms in the preceding 2 weeks [1-2 symptoms OR 4.82, 95%CI 1.79-12.94); ≥3 symptoms OR 42.30, 95%CI 3.76-476.43) independently predicted SARS-CoV-2 infection in school staff before school starting. CONCLUSION: Male gender, non-teaching job, presence of symptoms, and exposure to a confirmed case were associated with higher risk of infection. These data can help policymakers in determining the optimal strategy for school reopening.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , Masculino , Pandemias , Reacción en Cadena de la Polimerasa , Instituciones Académicas
20.
Br J Sports Med ; 55(19): 1092-1098, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33589470

RESUMEN

OBJECTIVES: The risk of viral transmission associated with contact sports such as football (soccer) during the COVID-19 pandemic is unknown. The aim of this study was to describe the infective and immune status of professional football players, team staff and league officials over a truncated football season resumed at the height of the COVID-19 pandemic in a country with high infection rates and to investigate the clinical symptoms related to COVID-19 infection in professional football players. METHODS: Prospective cohort study of 1337 football players, staff and officials during a truncated football season (9 weeks) with a tailored infection control programme based on preventive measures and regular SARS-CoV-2 PCR swab testing (every 3-5 days) combined with serology testing for immunity (every 4 weeks). Clinical symptoms in positive participants were recorded using a 26-item, Likert-Scale-based scoring system. RESULTS: During the study period, 85 subjects returned positive (cycle threshold (cT) ≤30) or reactive (30

Asunto(s)
Prueba de COVID-19 , COVID-19/diagnóstico , COVID-19/transmisión , Control de Enfermedades Transmisibles , Salud de la Familia , Fútbol/estadística & datos numéricos , Interacción Social , Adulto , COVID-19/inmunología , COVID-19/prevención & control , Portador Sano , Humanos , Pandemias , Estudios Prospectivos , Qatar/epidemiología , SARS-CoV-2/aislamiento & purificación
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA