Seroprevalence, spatial distribution, and social determinants of SARS-CoV-2 in three urban centers of Chile.

BACKGROUND: Seroprevalence studies provide an accurate measure of SARS-CoV-2 spread and the presence of asymptomatic cases. They also provide information on the uneven impact of the pandemic, pointing out vulnerable groups to prioritize which is particularly relevant in unequal societies. However, due to their high cost, they provide limited evidence of spatial spread of the pandemic specially in unequal societies. Our objective was to estimate the prevalence of SARS-CoV-2 antibodies in Chile and model its spatial risk distribution. METHODS: During Oct-Nov 2020, we conducted a population-based serosurvey in Santiago, Talca, and Coquimbo-La Serena (2493 individuals). We explored the individual association between positive results and socio-economic and health-related variables by logistic regression for complex surveys. Then, using an Empirical Bayesian Kriging model, we estimated the infection risk spatial distribution using individual and census information, and compared these results with official records. RESULTS: Seroprevalence was 10.4% (95% CI 7.8-13.7%), ranging from 2% (Talca) to 11% (Santiago), almost three times the number officially reported. Approximately 36% of these were asymptomatic, reaching 82% below 15 years old. Seroprevalence was associated with the city of residence, previous COVID-19 diagnosis, contact with confirmed cases (especially at household), and foreign nationality. The spatial model accurately interpolated the distribution of disease risk within the cities finding significant differences in the predicted probabilities of SARS-CoV-2 infection by census zone (IQR 2.5-15.0%), related to population density and education. CONCLUSIONS: Our results underscore the transmission heterogeneity of SARS-CoV-2 within and across three urban centers of Chile. Socio-economic factors and the outcomes of this seroprevalence study enable us to identify priority areas for intervention. Our methodological approach and results can help guide the design of interdisciplinary strategies for urban contexts, not only for SARS-CoV-2 but also for other communicable diseases.

Factors influencing neutralizing antibody response to the original SARS-CoV-2 virus and the Omicron variant in a high vaccination coverage country, a population-based study.

The study compared immunity to the original SARS-CoV-2 virus (Wuhan) and the Omicron variant using neutralizing antibodies (NAbs), that provide a good approximation of protective immunity. The results might help determine immunization strategies. DESIGN AND METHODS: Unlike previous studies, we analyzed NAbs in a random sample of 110 IgG positive sera from individuals who participated in a population-based seroprevalence transversal study, carried out in May 2022 in two Chilean cities, a country with high vaccination coverage. RESULTS: Our findings indicate that 98.2% of individuals had NAbs against Wuhan, 65.5% against Omicron, and 32.7% tested positive for Wuhan but not Omicron. Factors influencing protective immunity included a prior natural infection and the number of vaccines received. NAbs titers against the original virus were high, demonstrating vaccine effectiveness in the population. However, the level of antibodies decreased when measuring NAbs against Omicron, particularly among older individuals, indicating a decline in vaccine protection. Previous COVID-19 episodes acted as a natural booster, increasing NAbs titers against both virus strains. CONCLUSIONS: Protective immunity against the original Wuhan SARS-CoV-2 virus is reduced when compared to Omicron variant. Updating vaccine to target emerging variants and continued monitoring of effectiveness at the population level are necessary.

Seroprevalence of Natural and Acquired Immunity against the SARS-CoV-2 Virus in a Population Cohort from Two Chilean Cities, 2020-2022.

BACKGROUND: Chile has achieved the highest coverage for vaccines against the SARS-CoV-2 virus worldwide. OBJECTIVE: To assess the progression of immunity (natural and acquired by vaccine) in a cohort from two Chilean cities. METHODS: Individuals (n = 386) who participated in three phases of population-based serial prevalence studies were included (2020-2021 and 2022). Presence of SARS-CoV-2 antibodies was measured in serum. Data including time of vaccination and type of vaccine received were analysed with descriptive statistics. RESULTS: Seroprevalence was 3.6% in the first round and increased to 96.9% in the second and 98.7% in the third. In the third round, 75% of individuals who had received the basal full scheme were seropositive at 180 days or more since their last dose; 98% of individuals who received one booster dose were seropositive at 180 days or more, and 100% participants who received two boosters were seropositive, regardless of time since their last dose. Participants receiving mRNA vaccines had higher seroprevalence rates over time. CONCLUSIONS: The high vaccination coverage in Chile enabled the population to maintain high levels of antibodies. Vaccination boosters are essential to maintain immunity over time, which also depends on the type of vaccine administered.

Immunization and SARS-CoV-2 Antibody Seroprevalence in a Country with High Vaccination Coverage: Lessons from Chile.

Chile is among the most successful nations worldwide in terms of its COVID-19 vaccine rollout. By 31 December 2021, 84.1% of the population was fully vaccinated, and 56.1% received booster doses using different COVID-19 vaccines. In this context, we aimed to estimate the prevalence of anti-SARS-CoV-2 antibodies following the infection and vaccination campaign. Using a three-stage stratified sampling, we performed a population-based cross-sectional serosurvey based on a representative sample of three Chilean cities. Selected participants were blood-sampled on-site and answered a short COVID-19 and vaccination history questionnaire using Wantai SARS-CoV-2 Ab ELISA to determine seroprevalence. We recruited 2198 individuals aged 7-93 between 5 October and 25 November 2021; 2132 individuals received COVID-19 vaccinations (97%), 67 (3.1%) received one dose, 2065 (93.9%) received two doses, and 936 received the booster jab (42.6%). Antibody seroprevalence reached 97.3%, ranging from 40.9% among those not vaccinated to 99.8% in those with booster doses (OR = 674.6, 154.8-2938.5). SARS-CoV-2 antibodies were associated with vaccination, previous COVID-19 diagnosis, age group, and city of residence. In contrast, we found no significant differences in the type of vaccine used, education, nationality, or type of health insurance. We found a seroprevalence close to 100%, primarily due to the successful vaccination program, which strongly emphasizes universal access.

SARS-CoV-2 Neutralizing Antibodies in Chile after a Vaccination Campaign with Five Different Schemes.

Using levels of neutralizing antibodies (nAbs), we evaluate the successful Chilean SARS-CoV-2 vaccine campaign, which combines different vaccine technologies and heterologous boosters. From a population-based study performed in November 2021, we randomly selected 120 seropositive individuals, organized into six groups of positive samples (20 subjects each) according to natural infection history and the five most frequent vaccination schemes. We conclude that the booster dose, regardless of vaccine technology or natural infection, and mRNA vaccines significantly improve nAbs response.

[Adaptation and validation of the Spanish version of Child Perception Questionnaire CPQ-Spn11-14 in a Chilean community population]. / Adaptación y validación al español del cuestionario de percepción infantil CPQ-Esp11-14 en población comunitaria chilena.

BACKGROUND: In order to validly measure the oral health related quality of life in school age children it is necessary to adapt and validate the CPQ 11-14 for Spanish language. To confirm the four domains of CPQ-Esp 11-14 for the full and abbreviated version of 16 and 8 items. METHODS: The instrument was translated into Spanish and culturally adapted. It was administered to 288 12 year-old children attending public schools. Dental caries experience was measure with the DMFT index. The conceptual structure of the scales was assessed by the AFC. It was also evaluated: internal consistency with Cronbach 's alpha, test- retest temporal stability with intraclass correlation coeficient, and concurrent validity with correlation of score CPQ-Esp 11-14 with caries experience. RESULTS: The five measures used to confirm the structure of the factors on the version of 37 items showed values outside the range of the model fit. Version 16 and 8 items obtained indicators within values indicating the model fit. The internal consistency of full scale and versions 16 and 8 items were measured with Cronbach Alpha wich was higher than 0.6. All versions had intraclass correlation coefficient above 0.81, except for functional limitations of the subscale version a of 16 items. The Rho Spearman correlation was significant between CAOD and the score the questionnaire, except for oral symptoms and full version b version of 16 items. CONCLUSIONS: The hypothetical factor structure was confirmed by the CFA for 16 and 8 items versions. The information contained in abbreviated items allows measuring oral health related quality of life in Chilean children.

Patient satisfaction and quality of emergency dental care in chilean public health services

The provision of dental care services, related to the quality requirements of health policies and patient satisfaction rates, increasingly requires the creation of qualitative indicators, instruments and criteria based on specific objectives, to validate the quality of the services provided. objective: the aim of this study is to determine the main dimensions of the dentist-patient relationship associated with patient satisfaction in a clinical context, with emphasis on the needs and expectations of patients themselves. method: a sample of 88 adults who attend primary care units at public emergency services in the central area of Chile were studied using a qualitative approach based on the social psychology of health and on grounded theory. from these, categories emerged that identify processes, attitudes and behaviors that define the assessment of care providers based on their practices. results: in an interactional context characterized by the patient's expectation regarding the provision of care and anxiety due to potential pain, two already recognized main axes emerged, namely: the capacity to generate trust through interpersonal and communicative good treatment strategies, and the capacity or technical skills of the professional care provider. conclusion: this study proposes a protocol of good care practices, which takes into account the needs and expectations of patients regarding the role of the dentist.

Adaptación y validación al español del cuestionario de percepción infantil CPQ-Esp11-14 en población comunitaria chilena / Adaptation and validation of the spanish versión of child perception questionnaire CPQ-Spn11-14 in a chilean community population

Fundamentos. Con el fin de medir de forma válida la calidad de vida relacionada con la salud oral en escolares, el objetivo de este trabajo fue adaptar y validar el CPQ11-14 al español y confirmar los cuatro dominios de CPQ-Esp11-14 en su versión completa y abreviada de 16 y 8 ítems. Métodos. El instrumento fue traducido y adaptado al español, posteriormente fue administrado a 288 jóvenes de 12 años que asisten a escuelas públicas. Se realizó un examen bucodental para medir historia de caries con el índice CAOD. Se evaluó la estructura conceptual de las escalas con el análisis factorial y se evaluó la consistencia interna con Alpha de Crombach, estabilidad temporal test-retest con Coeficiente de correlación intraclase y la validez concurrente con la correlación del puntaje del CPQ-Esp11-14 con la historia de caries. Resultados: Las cinco medidas usadas para confirmar la estructura de los factores de la versión de 37 ítems mostraron valores fuera del rango de ajuste del modelo. La versión de 16 y 8 ítems presentó los indicadores dentro de valores que indican ajuste del modelo. La consistencia interna de la escala completa y versiones de 16 y 8 ítems medida con Alpha de Crombach fue mayor a 0,6. Todas las versiones tuvieron coeficiente de correlación intraclase superior a 0,81, excepto en subescala limitaciones funcionales de la versión a de 16 ítems. La correlación Rho de Spearman fue significativa entre CAOD y puntaje del cuestionario, excepto para síntomas orales de la versión total y la versión a y b de la escala de 16 ítems. Conclusiones: la estructura hipotética de los factores fue confirmada por el AFC para las versiones de 16 y 8 ítems. La información que contiene los ítems de las versiones abreviadas permite medir la calidad de vida relativa a la salud en niños chilenos (AU)

Background: In order to validly measure the oral health related quality of life in school age children it is necessary to adapt and validate the CPQ 11-14 for Spanish language. To confirm the four domains of CPQ-Esp 11-14 for the full and abbreviated version of 16 and 8 items. Methods: The instrument was translated into Spanish and culturally adapted. It was administered to 288 12 year-old children attending public schools. Dental caries experience was measure with the DMFT index. The conceptual structure of the scales was assessed by the AFC. It was also evaluated: internal consistency with Cronbach ‘s alpha, test- retest temporal stability with intraclass correlation coeficient, and concurrent validity with correlation of score CPQ-Esp 11-14 with caries experience. Results: The five measures used to confirm the structure of the factors on the version of 37 items showed values outside the range of the model fit. Version 16 and 8 items obtained indicators within values indicating the model fit. The internal consistency of full scale and versions 16 and 8 items were measured with Cronbach Alpha wich was higher than 0.6. All versions had intraclass correlation coefficient above 0.81, except for functional limitations of the subscale version a of 16 items. The Rho Spearman correlation was significant between CAOD and the score the questionnaire, except for oral symptoms and full version b version of 16 items. Conclusions: The hypothetical factor structure was confirmed by the CFA for 16 and 8 items versions. The information contained in abbreviated items allows measuring oral health related quality of life in Chilean children (AU)

Salud Oral en Adultos Mayores Postrados / Oral Health in Homebound Elderly Adults

La población de adultos mayores ha aumentado en los últimos años y se hace imprescindible determinar su estado de salud oral con el objetivo de orientar la atención de salud con base científica epidemiológica para brindarles una mejor calidad de vida. El objetivo de este trabajo fue evaluar el estado de la salud oral de los pacientes adultos mayores postrados. Se realizó un estudio descriptivo de corte transversal no probabilístico. Los datos fueron obtenidos del universo de pacientes inscritos en el programa de Atención Domiciliaria del Paciente Postrado de un centro de atención primaria. La tasa de respuesta obtenida fue 90%. El sexo predominante fue femenino; la media de edad fue 80 años; 60,9% sólo tuvo acceso a la educación primaria. La prevalencia de caries fue 100% y COPD de 25,6. El 40,6% se encontraba completamente edentulo y el 54,7% era portador de prótesis dental. El 32,8% presentaba restos radiculares. El 64,7% era capaz de cepillar sus dientes por sí mismo. El 79,4% consideraba tener una pobre salud oral. El cuidador resultó ser la hija, de aproximadamente 53 años, con nivel educacional bajo. Los adultos mayores son un grupo con gran daño odontológico, con escasos dientes remanentes y deficientes prácticas de higiene oral. Son cuidados por familiares con bajo nivel educacional.

The elderly population is on an increase and it is important for us to know the status of their oral health in order to direct our attention to epidemiological aspects on a scientific basis to provide a better quality of life. The purpose of this study was to evaluate the status of oral health of the homebound elderly. A Cross sectional study was conducted using a non-probability sampling method. The data was collected from bedridden patients enrolled in a Patient Home Care in a Primary Care Center. The response rate obtained was 90%. The majority of patients were female; their average age was 80. Only 60.9% of those surveyed had access to primary education. The prevalence of caries was 100% and the DMFT index was 25.6; 40.6% were edentulous and 54.7% had dentures. The 32.8% had root fragments; 82.8% were able to brush their teeth by themselves. 79.4% were observed to have poor oral health. In almost all cases, the caretaker was a daughter around 53 years of age, with low education level. The group surveyed had significant dental damage, had only a few remaining teeth and observed poor oral hygiene practices. Their care was also almost exclusively in the hands of family members who had a low education level.