SARS-CoV-2 Delta-variant breakthrough infections in nursing home residents at midterm after Comirnaty® COVID-19 vaccination.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta variant breakthrough infections in nursing home residents following vaccination with Comirnaty® COVID-19 vaccine were characterized. In total, 201 participants (median age, 87 years; range, 64-100; 133 female) from two nursing homes in the Valencian community (Spain) were included. SARS-CoV-2-Spike (S) antibody responses were determined by a lateral flow immunocromatography (LFIC) assay and by quantitative electrochemiluminescent assay in LFIC-negative participants. SARS-CoV-2-S-IFNγ T cells were enumerated by flow cytometry in 10 participants. Nasopharyngeal SARS-CoV-2 RNA loads were quantified by real-time polymerase chain reaction assays. Vaccine breakthrough COVID-19 due to the Delta variant occurred in 39 residents (median age, 87 years; range, 69-96; 31 female) at a median of 6.5 months after vaccination (nine requiring hospitalization). Breakthrough infections occurred at a higher rate (p < 0.0001) in residents who had not been previously infected with SARS-CoV-2 (naïve) (33/108; 18%) than in those with prior diagnosis of SARS-CoV-2 infection (experienced) (6/93; 6.4%), and were more likely (p < 0.0001) to develop in residents who tested negative by LFIC (20/49) at 3 months after vaccination as compared to their LFIC-positive counterparts (19/142). Among LFIC-negative residents, a trend towards lower plasma anti-RBD antibody levels was noticed in those developing breakthrough infection (p = 0.16). SARS-CoV-2 RNA loads in nasopharyngeal specimens were lower in SARS-CoV-2-experienced residents (p < 0.001) and in those testing positive by LFIC (p = 0.13). The frequency of SARS-CoV-2-S-reactive T cells at 3 months was similar in LFIC-negative residents with (n = 7) or without (n = 3) breakthrough infection. Prior history of SARS-CoV-2 infection and detection of S-reactive antibodies by LFIC at 3 months is associated with a lower risk of Delta-variant breakthrough infection in nursing home residents at midterm after Comirnaty® COVID-19 vaccination.

[Brote de la COVID-19 en una residencia en ancianos correctamente vacunados. Influencia de la inmunidad híbrida en la carga viral, el riesgo de infección y el riesgo de progresión de la enfermedad]. / COVID-19 outbreak in a properly vaccinated nursing home. Influence of hybrid immunity on viral load, risk of infection and risk of disease progression.

OBJECTIVE: This study addressed a COVID-19 outbreak in a nursing home, where the residents were vaccinated with two doses of Comirnaty® and thirty of them had previously had the infection. Outbreaks in closed communities are opportunities to study the entire clinical spectrum of the disease and, as in this case, the effect of hybrid immunity on transmission, infection progression and viral load. METHODS: A descriptive and retrospective cohort study in the resident population was carried out. Attack rates were calculated for one of four stages of the disease: infection, symptomatic infection, hospitalization, and death. Relative risks (RR) were then estimated using simple and multivariate Poisson regression for each of these stages. RESULTS: The attack rate was 59% (56/95). The clinical spectrum was the same in both sexes. There was a notable protective effect of hybrid immunity against transmission (67%). In terms of progression, those with hybrid immunity had a lower risk of symptomatic infection. Nasopharyngeal viral load was significantly lower in individuals with hybrid immunity and asymptomatic individuals, supporting the idea of lower transmissibility in this group. Age was identified as a risk factor for disease progression. Molecular analysis identified the Delta B.1.617.2 variant in the patients and an air sample, supporting aerosol transmission in closed, poorly ventilated environments. CONCLUSIONS: This study provides a comprehensive view of an outbreak in a vaccinated nursing home, highlighting the importance of hybrid immunity. The results support the individual consideration of previous infection history when assessing the risk of COVID-19, contributing to the understanding of the evolution of the pandemic in the future.

OBJECTIVE: Este estudio abordó un brote de la COVID-19 en una residencia de ancianos, donde los residentes estaban vacunados con dos dosis de Comirnaty® y treinta de ellos habían pasado anteriormente la infección. Los brotes en colectivos cerrados son oportunidades para estudiar todo el espectro clínico de la enfermedad y, como en este caso, el efecto de la inmunidad híbrida sobre la transmisión, la progresión de la infección y la carga viral. METHODS: Se realizó un estudio descriptivo y de cohortes retrospectivo en la población de residentes. Se calcularon las tasas de ataque para uno de cuatro estadios de la enfermedad: infección, infección sintomática, hospitalización y defunción. Después se estimaron los riesgos relativos (RR) mediante regresión de Poisson simple y multivariante para cada uno de esos estadios. RESULTS: La tasa de ataque fue del 59% (56/95). El espectro clínico fue igual en ambos sexos. Hubo un notable efecto protector de la inmunidad híbrida contra la transmisión (67%). En términos de progresión, aquellos con inmunidad híbrida presentaron un riesgo menor de infección sintomática. La carga viral nasofaríngea fue significativamente menor en individuos con inmunidad híbrida y asintomáticos, respaldando la idea de una menor transmisibilidad en este grupo. La edad se identificó como un factor de riesgo para la progresión de la enfermedad. El análisis molecular identificó la variante Delta B.1.617.2 en los pacientes y una muestra de aire, lo que respaldó la transmisión por aerosol en entornos cerrados y mal ventilados. CONCLUSIONS: Este estudio proporciona una visión integral de un brote en una residencia de ancianos vacunados, destacando la importancia de la inmunidad híbrida. Los resultados respaldan la consideración individual de la historia de infección previa al evaluar el riesgo de la COVID-19, contribuyendo a la comprensión de la evolución de la pandemia en el futuro.

[Impact of the pandemic on various infectious diseases with different epidemiological patterns of seasonality, transmission and age]. / Impacto de la pandemia en varias enfermedades infecciosas con patrones epidemiológicos distintos de estacionalidad, transmisión y edad.

OBJECTIVE: The COVID-19 pandemic has had a strong impact on other infectious diseases. The aim of this paper was to analyze the epidemiological changes that occurred during the pandemic in eight infectious diseases with different epidemiological patterns: influenza, respiratory syncytial virus, rotavirus, pneumococcus, Campylobacter, non-typhoid Salmonella, gonorrhea and herpes zoster. METHODS: From the Microbiological Surveillance Network, the time series of cases was traced from January 2017 to March 2023. Three periods were distinguished: reference, pandemic and beginning of the post-pandemic. The distribution by age and sex in these periods was analyzed. Incidence rates and rate ratios (RR) were calculated. These RRs and their 95% confidence intervals were estimated overall and by year of age in children under five years of age. RESULTS: Statistically significant differences were found in the impact that the pandemic had on each of these diseases. Some, after a period of epidemic silence, have revealed an intense post-pandemic rebound. The post-pandemic global RT increased for influenza (2.4), RSV (1.9) and gonorrhea (3.1); rotavirus recovered its pre-pandemic level (1.07); and pneumococcus (0.84), Campylobacter (0.83) and Salmonella (0.60) decreased. In children under 5 years of age, the patterns were specific and heterogeneous for each disease. CONCLUSIONS: The impact of the pandemic is very different in these diseases. Pediatric and respiratory-transmitted seasonal viral infections are the ones that are most affected, but with different patterns of recovery to normality. Gastrointestinal bacterial infections suffer fewer variations, except for rotavirus. Gonorrhea do not interrupt its increasing trend seen in the pre-pandemic. Shingles show a slight post-pandemic increase. Several diseases with different epidemiological patterns have been studied for a sufficient period to observe how the acute phase of the pandemic emerges.

OBJECTIVE: La pandemia de la COVID-19 ha tenido un fuerte impacto sobre otras enfermedades infecciosas. El objetivo de este trabajo fue analizar los cambios epidemiológicos acaecidos durante la pandemia en ocho enfermedades infecciosas con patrones epidemiológicos distintos: la gripe; virus respiratorio sincitial; rotavirus; neumococo; Campylobacter; Salmonella no tifoidea; gonococia; herpes zóster. METHODS: A partir de la Red de Vigilancia Microbiológica, se trazó la serie temporal de casos desde enero de 2017 a marzo de 2023. Se distinguieron tres periodos: prepandemia (referencia), pandemia e inicio de la pospandemia. Se analizó la distribución por edad y sexo en esos periodos. Se calcularon las tasas de incidencia y las razones de tasas (RT). Se estimaron esas RT globales y sus intervalos de confianza al 95% por cada año de edad en menores de cinco años. RESULTS: Se encontraron diferencias estadísticamente significativas en el impacto que la pandemia tuvo en cada una de esas enfermedades. Algunas, tras un periodo de silencio epidémico, revelaron un repunte intenso pospandémico. Incrementaron la RT global postpandémica la gripe (2,4), VRS (1,9) y gonococia (3,1); recuperó su nivel prepandémico el rotavirus (1,07); y disminuyeron el neumococo (0,84), Campylobacter (0,83) y Salmonella (0,60). En menores de cinco años, los patrones fueron específicos y heterogéneos para cada enfermedad. CONCLUSIONS: El impacto de la pandemia es muy diferente en estas enfermedades. Las infecciones víricas estacionales pediátricas y de transmisión respiratoria son las que más se ven afectadas, pero con patrones de recuperación de la normalidad distintos. Las infecciones bacterianas gastrointestinales sufren menos variaciones, salvo el rotavirus. La gonococia no interrumpe su tendencia al aumento avistada ya en la prepandemia. El herpes zóster muestra un ligero incremento pospandémico. Se han estudiado varias enfermedades con distinto patrón epidemiológico durante un periodo suficiente para observar cómo se produce la salida de la fase aguda de la pandemia.

Cycle Threshold Values of SARS-CoV-2 RT-PCR during Outbreaks in Nursing Homes: A Retrospective Cohort Study.

Backgound/Objectives: Cycle threshold (Ct) values of SARS-CoV-2 real-time reverse transcriptase-polymerase chain reaction (RT-PCR) tests are associated with infectivity and viral load, and they could be an aid in forecasting the evolution of SARS-CoV-2 outbreaks. The objective was to know the Ct values related to the incidence and reinfection of SARS-CoV-2 in successive outbreaks, which took place in nursing homes in Castellon (Spain) during 2020-2022, and to test its usefulness as an instrument of epidemic surveillance in nursing homes. METHODS: a retrospective cohort design with Poisson regression and multinomial logistic regression were used. RESULTS: We studied four nursing home SARS-CoV-2 outbreaks, and the average infection rate, reinfection rate, and case fatality were 72.7%, 19.9%, and 5.5%, respectively; 98.9% of residents were vaccinated with three doses of a mRNA SARS-CoV-2 vaccine. Ct values for first infections and reinfections were 27.1 ± 6.6 and 31.9 ± 5.4 (p = 0.000). Considering Ct values ≥ 30 versus <30, residents with reinfections had Ct values higher than residents with a first infection, an adjusted relative risk of 1.66 (95% Confidence interval 1.10-2.51). A sensitivity analysis confirmed these results. CONCLUSIONS: Reinfection and SARS-CoV-2 vaccination (hybrid immunity) could protect against severe disease better than vaccination alone. High Ct values suggest lower transmission and severity. Its value can be useful for surveillance and forecasting future SARS-CoV-2 epidemics.

Incidence, Hospitalization, Mortality and Risk Factors of COVID-19 in Long-Term Care Residential Homes for Patients with Chronic Mental Illness.

Long-term care residential homes (LTCRH) for patients with chronic mental illness have suffered the enormous impact of COVID-19. This study aimed to estimate incidence, hospitalization, mortality, and risk factors of COVID-19 to prevent future epidemics. From March 2020 to January 2021 and before vaccination anti-SARS-CoV-2 begins, cumulate incidence rate (CIR), hospitalization rate (HR), mortality rate (MR), and risk factors of COVID-19 in the 11 LTCRH of two Health Departments of Castellon (Spain) were studied by epidemiological surveillance and an ecological design. Laboratory tests confirmed COVID-19 cases, and multilevel Poisson regression models were employed. All LTCRH participated and comprised 346 residents and 482 staff. Residents had a mean age of 47 years, 40% women, and suffered 75 cases of COVID-19 (CIR = 21.7%), five hospitalizations (HR = 1.4%), and two deaths (MR = 0.6%) with 2.5% fatality-case. Staff suffered 74 cases of the disease (CIR = 15.4%), one hospitalization (HR = 0.2%), and no deaths were reported. Risk factors associated with COVID-19 incidence in residents were private ownership, severe disability, residents be younger, CIR in municipalities where LTCRH was located, CIR in staff, and older age of the facilities. Conclusion: COVID-19 incidence could be prevented by improving infection control in residents and staff and modernizing facilities with increased public ownership.

Incidence, Mortality, and Risk Factors of COVID-19 in Nursing Homes.

During the period from March 2020 to January 2021, we performed an analysis of incidence, mortality, and risk factors of COVID-19 in nursing homes (NHs) in two health departments (HDs) of Castellon (Spain) 2021 through epidemiological surveillance and an ecological design. Laboratory-confirmed COVID-19 cases, cumulative incidence rate (CIR), and mortality rate (MR) of 27 NHs were collected. Information of residents, staff, and facilities was obtained by questionnaire. Multilevel Poisson regression models were applied. All NHs in the HDs participated with 2229 residents (median: 83 years old, 67.3% women) and 1666 staff. Among residents, 815 cases (CIR: 34.8 per 100) and 202 deaths (MR: 8.7 per 100, case fatality 21.0%) were reported and, among staff, 296 cases (CIR: 19.2 per 100) without deaths. Residents' CIR and MR increased with staff CIR, age of the building, residents/staff ratios, occupancy rate, and crowding index; CIR increased with private NH ownership, large NH size, large urban area, and the percentage of women residents; and MR was associated with residents' severe disabilities. In conclusion, several risk factors of COVID-19 incidence and mortality can be prevented by improving infection and quality controls, ameliorating residents/staff ratios, improving structural facilities, and increasing NH public ownership to avoid new outbreaks.

Impacto de la pandemia en varias enfermedades infecciosas con patrones epidemiológicos distintos de estacionalidad, transmisión y edad / mpact of the pandemic on various infectious diseases with different epidemiological patterns of seasonality, transmission and age

Fundamentos: la pandemia de la covid-19 ha tenido un fuerte impacto sobre otras enfermedades infecciosas. El objetivo de este trabajo fue analizar los cambios epidemiológicos acaecidos durante la pandemia en ocho enfermedades infecciosas con patrones epidemiológicos distintos: la gripe; virus respiratorio sincitial; rotavirus; neumococo; campylobacter; salmonella no tifoidea; gonococia; herpes zóster.métodos: a partir de la red de vigilancia microbiológica, se trazó la serie temporal de casos desde enero de 2017 a marzo de 2023. Se distinguieron tres periodos: prepandemia (referencia), pandemia e inicio de la pospandemia. Se analizó la distribución por edad y sexo en esos periodos. Se calcularon las tasas de incidencia y las razones de tasas (rt). Se estimaron esas rt globales y sus intervalos de confianza al 95% por cada año de edad en menores de cinco años. Resultados: se encontraron diferencias estadísticamente significativas en el impacto que la pandemia tuvo en cada una de esas enfermedades. Algunas, tras un periodo de silencio epidémico, revelaron un repunte intenso pospandémico. Incrementaron la rt global postpandémica la gripe (2,4), vrs (1,9) y gonococia (3,1); recuperó su nivel prepandémico el rotavirus (1,07); y disminuyeron el neumococo (0,84), campylobacter (0,83) y salmonella (0,60). En menores de cinco años, los patrones fueron específicos y hete-rogéneos para cada enfermedad.conclusiones: el impacto de la pandemia es muy diferente en estas enfermedades. Las infecciones víricas estacionales pediá-tricas y de transmisión respiratoria son las que más se ven afectadas, pero con patrones de recuperación de la normalidad distintos. Las infecciones bacterianas gastrointestinales sufren menos variaciones, salvo el rotavirus. La gonococia no interrumpe su tendencia al aumento avistada ya en la prepandemia. El herpes zóster muestra un ligero incremento pospandémico. Se han estudiado varias enfermedades con distinto patrón epidemiológico durante un periodo suficiente para observar cómo se produce la salida de la fase aguda de la pandemia.(AU)

Background: the covid-19 pandemic has had a strong impact on other infectious diseases. The aim of this paper was to analyze the epidemiological changes that occurred during the pandemic in eight infectious diseases with different epidemiological patterns: influenza, respiratory syncytial virus, rotavirus, pneumococcus, campylobacter, non-typhoid salmonella, gonorrhea and herpes zoster.methods: from the microbiological surveillance network, the time series of cases was traced from january 2017 to march 2023. Three periods were distinguished: reference, pandemic and beginning of the post-pandemic. The distribution by age and sex in these periods was analyzed. Incidence rates and rate ratios (rr) were calculated. These rrs and their 95% confidence intervals were estimated overall and by year of age in children under five years of age. Results: statistically significant differences were found in the impact that the pandemic had on each of these diseases. Some, after a period of epidemic silence, have revealed an intense post-pandemic rebound. The post-pandemic global rt increased for influenza (2.4), rsv (1.9) and gonorrhea (3.1); rotavirus recovered its pre-pandemic level (1.07); and pneumococcus (0.84), campylobacter (0.83) and salmonella (0.60) decreased. In children under 5 years of age, the patterns were specific and heterogeneous for each disease.conclusions: the impact of the pandemic is very different in these diseases. Pediatric and respiratory-transmitted seasonal viral infections are the ones that are most affected, but with different patterns of recovery to normality. Gastrointestinal bacterial infections suffer fewer variations, except for rotavirus. Gonorrhea do not interrupt its increasing trend seen in the pre-pandemic. Shingles show a slight post-pandemic increase. Several diseases with different epidemiological patterns have been studied for a sufficient period to observe how the acute phase of the pandemic emerges.(AU)