Browsing by Author "Pizarro A."

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    An ultrasound score to predict the presence of papillary thyroid carcinoma. Preliminary report
    (2009) Domínguez J.M.; Baudrand R.; Arteaga E.; Campusano C.; González G.; Mosso L.; Fardella C.; Domínguez J.M.; Baudrand R.; Arteaga E.; Campusano C.; González G.; Mosso L.; Arias T.; Pizarro A.; Gómez M.; Fardella C.; Cruz F.; Torres J.; Solar A.; Cavada G.; NCD Risk Factor Collaboration (NCD-RisC)
    Background: Thyroid nodules are common and associated to a low risk of malignancy. Their clinical assessment usually includes a fine neddle aspiration biopsy (FNAB). Aim: To identify ultrasonographic characteristics associated to papillary thyroid carcinoma (PTC) and generate a score that predicts the risk of PTC. Material and methods: Retrospective review of all fine needle aspiration biopsies of the thyroid performed in a lapse of two years. Biopsies that were conclusive for PTC were selected and compared with an equal amount of randomly selected biopsies that disclosed a benign diagnosis. Results: One hundred twenty two biopsies of a total of 1,498 were conclusive for PTC. Univariate analysis showed associations with PTC for the presence of micro-calcifications (Odds ratio (OR) 49.2: 95% confidence intervals (CI) 18.7-140.9), solid predominance (OR 25.1; 95% CI 6-220), hypoechogenicity (OR 23.5, 95% CI 6.5-122.6), irregular borders (OR 17, 95% CI 7.2-42.9), lymph node involvement (OR 12.3, 95% CI 2.7-112), central vascularization (OR 12.2, 95% CI 4.8-33.3), local invasion and hyperechogenicity (OR 0.2; CI 95% CI 0.03-0.6). Multivariate analysis disclosed microcalcifications (OR 28.1; CI 95% 8.9-89), hypoechogenicity (OR 9.4; 95% CI 1.5-59.5) and irregular borders (OR 4.7; CI 95% 1.5-15) as the variables independently associated with the presence of PTC. The prevalence of PTC in the presence of the three variables was 97.6% (Likelihood ratio (LR) 45) and 5.4% in their absence (LR 0.06). Conclusions: This scale predicts the presence or absence of PTC using simple ultrasound characteristics.
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    Consolidado de recomendaciones del comité asesor de vacunas y estrategias de inmunización-cavei, sobre priorización de vacunación covid-19Consolidated recommendations of the Advisory Committee on Vaccines and Immunization Strategies- on prioritizing COVID-19 vaccination
    (2021) Dabanch J.; Bastías M.; Endeiza M.L.; Díaz E.; Inostroza J.; Cerda J.; Santillana S.; Rodríguez J.; González C.; Rodríguez M.; Pizarro A.; Dabanch J.; Bastías M.; González C.; Endeiza M.L.; Díaz E.; Inostroza J.; Cerda J.; Santillana S.; Rodríguez J.; Rodríguez M.; Pizarro A.; Dabanch J.
    © 2021, Sociedad Chilena de Infectologia. All rights reserved.COVID-19 is a global public health issue due to its epidemic nature that, to date, lacks pharmacological treatment. However, some COVID-19 vaccines have been authorized for emergency use, although the duration of their protection, their ability to interrupt viral transmission, and their efficacy against emerging variants of SARS-CoV-2 are being studied. Chile's SARS-CoV-2 vaccination campaign required design and planning, like any other campaign. This process included the prioritization of risk groups for vaccination given the limited supply of COVID-19 vaccines globally. Throughout 2020, CAVEI issued recommendations on the prioritization of population groups to be vaccinated against SARS-CoV-2 in response to different needs and in accordance with available evidence. These recommendations are consolidated in Table 1 in this report. In summary, it was recommended that healthcare workers, people in long-term residences and essential State personnel be vaccinated in phase 1. In phase 2, persons over 65 years of age and people with comorbidities. In phase 3, essential tasks workers and, lastly, the general population.
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    Effectiveness of homologous and heterologous booster doses for an inactivated SARS-CoV-2 vaccine: a large-scale prospective cohort study
    (Elsevier Ltd, 2022) Jara A.; Gonzalez C.; Pizarro A.; Acevedo J.; Leo K.; Paredes F.; Bralic T.; Vergara V.; Mosso M.; Leon F.; Parot I.; Leighton P.; Suarez P.; Rios J.C.; Garcia-Escorza H.; Araos R.; Undurraga E.A.; Zubizarreta J.R.
    © 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licenseBackground: Several countries have authorised or begun using a booster vaccine dose against COVID-19. Policy makers urgently need evidence of the effectiveness of additional vaccine doses and its clinical spectrum for individuals with complete primary immunisation schedules, particularly in countries where the primary schedule used inactivated SARS-CoV-2 vaccines. Methods: Using individual-level data, we evaluated a prospective, observational, national-level cohort of individuals (aged ≥16 years) affiliated with the Fondo Nacional de Salud insurance programme in Chile, to assess the effectiveness of CoronaVac (Sinovac Biotech), AZD1222 (Oxford-AstraZeneca), or BNT162b2 (Pfizer-BioNTech) vaccine boosters in individuals who had completed a primary immunisation schedule with CoronaVac, compared with unvaccinated individuals. Individuals administered vaccines from Feb 2, 2021, to the prespecified study end date of Nov 10, 2021, were evaluated; we excluded individuals with a probable or confirmed SARS-CoV-2 infection (RT-PCR or antigen test) on or before Feb 2, 2021, and individuals who had received at least one dose of any COVID-19 vaccine before Feb 2, 2021. We estimated the vaccine effectiveness of booster doses against laboratory-confirmed symptomatic COVID-19 (symptomatic COVID-19) cases and COVID-19 outcomes (hospitalisation, admission to the intensive care unit [ICU], and death We used inverse probability-weighted and stratified survival regression models to estimate hazard ratios, accounting for time-varying vaccination status and adjusting for relevant demographic, socioeconomic, and clinical confounders. We estimated the change in hazard from unvaccinated status to vaccinated status associated with the primary immunisation series and a booster vaccine. Findings: 11 174 257 individuals were eligible for this study, among whom 4 127 546 completed a primary immunisation schedule (two doses) with CoronaVac and received a booster dose during the study period. 1 921 340 (46·5%) participants received an AZD1222 booster, 2 019 260 (48·9%) received a BNT162b2 booster, and 186 946 (4·5%) received a homologous booster with CoronaVac. We calculated an adjusted vaccine effectiveness (weighted stratified Cox model) in preventing symptomatic COVID-19 of 78·8% (95% CI 76·8–80·6) for a three-dose schedule with CoronaVac, 96·5% (96·2–96·7) for a BNT162b2 booster, and 93·2% (92·9–93·6) for an AZD1222 booster. The adjusted vaccine effectiveness against COVID-19-related hospitalisation, ICU admission, and death was 86·3% (83·7–88·5), 92·2% (88·7–94·6), and 86·7% (80·5–91·0) for a homologous CoronaVac booster, 96·1% (95·3–96·9), 96·2% (94·6–97·3), and 96·8% (93·9–98·3) for a BNT162b2 booster, and 97·7% (97·3–98·0), 98·9% (98·5–99·2), and 98·1% (97·3–98·6) for an AZD1222 booster. Interpretation: Our results suggest that a homologous or heterologous booster dose for individuals with a complete primary vaccination schedule with CoronaVac provides a high level of protection against COVID-19, including severe disease and death. Heterologous boosters showed higher vaccine effectiveness than a homologous booster for all outcomes, providing additional support for a mix-and-match approach. Funding: Agencia Nacional de Investigación y Desarrollo through the Fondo Nacional de Desarrollo Científico y Tecnológico, Millennium Science Initiative Program, and Fondo de Financiamiento de Centros de Investigación en Áreas Prioritarias.