[Effect of the Omicron variant on cumulative incidence of infection and lethality during the sixth wave of the COVID-19 epidemic in Spain]

The COVID-19 pandemic has strained healthcare systems globally. The successive epidemic waves have shown different characteristics. The Omicron variant of SARS-CoV-2 modified the epidemic behavior that previous variants had followed. The aim of this analysis was to determine the epidemiological characteristics of COVID-19 during the sixth epidemic wave and its differences according to the predominance of the Delta or Omicron variants. The epidemiological data corresponding to the sixth wave of the epidemic published by official organizations were analyzed, and the cumulative incidence of infection (CI-I) and case fatality rates (CFR) were calculated, both for Spain as a whole and for the different Autonomous Communities, in the population as a whole and by age groups. The results showed that the CI-I was higher with the Ómicron variant (10.89% vs 0.75% with Delta) while the CFR was higher with the Delta variant (4.2‰ vs 1.3‰ with Ómicron), as well as a higher rate of hospitalization and ICU admission with the Delta variant.

Case-fatality rate of SARS-CoV-2 infection during the third and fifth epidemic waves in Spain: Impact of vaccination

INTRODUCTION

During the first and second epidemic waves in Spain, the SARS-CoV-2 case-fatality rates (CFRs) showed significant differences between Autonomous Communities (ACs). Comparing CFRs in the third and fifth epidemic waves can provide information on the impact of the different vaccination coverages in the ACs.

OBJECTIVE

To evaluate the impact of vaccination on COVID-19 CFRs in the third and fifth epidemic waves in Spain, according to sex, age, and AC.

METHODS

This work is an observational, descriptive study which uses data on COVID-19 infections, deaths, and vaccinees published by the Spanish Ministry of Health and the regional Health Departments of the ACs. The third epidemic wave was defined as the period from 26th December 2020 to 19th April 2021, and the fifth wave, from 19th July to 19th September 2021. The CFRs (deaths per 1000 infected [‰]) were calculated according to sex, age group, and AC. The standardized case-fatality ratio (SCFR) was adjusted for age and sex for each wave. We estimated the correlation between CFRs and their change between the two epidemic waves with the vaccination coverages reached at the beginning of the fifth wave.

RESULTS

The CFR in the fifth wave (5.7‰) was lower than in the third wave (16.5‰). In addition, the CFR in both waves was significantly higher in men than in women, and in older people than in younger ones. A decrease in the CFR between both waves was only observed in those older than 49. A strong direct and positive correlation (R2a=0.8399) was found between vaccination coverage by age group and decrease in CFR between both epidemic waves. Significant differences were seen between ACs in the two waves, as regards both CFRs and SCFRs. When comparing ACs, a direct correlation was observed between vaccination coverage and CFRs in the fifth wave, and also - although weak - between vaccination coverage and decrease in CFR between both waves.

CONCLUSION

The CFR significantly decreased in Spain between the third and the fifth epidemic waves in population aged 50 or older, probably due to the high vaccination coverage in that age group. Differences were observed between CFRs and SCFRs between ACs that are not explained by the differences in vaccination coverage, suggesting the need for further research and evaluation.

Tasas de letalidad por SARS-CoV-2 según Comunidades Autónomas durante la segunda onda epidémica en España

Introducción

En España, los sistemas sanitarios están transferidos a las Comunidades Autónomas (CC.AA.), constituyendo 19 sistemas sanitarios con gestión y recursos diferenciados. Durante la primera onda epidémica de la COVID-19 se objetivaron diferencias en los sistemas de declaración y en las tasas de letalidad (TL) entre las CC.AA. El objetivo de este estudio fue analizar las TL por CC.AA. durante la segunda onda epidémica (del 20 de julio al 25 de diciembre de 2020) y su relación con la prevalencia de la infección.

Material y métodos

Se realizó un estudio observacional descriptivo con la información disponible sobre el número de fallecidos por COVID-19 registrados en el Ministerio de Sanidad, Consejerías de Salud y los Departamentos de Salud Pública de las CC.AA. y según el exceso de mortalidad informado por el Sistema de Monitorización de Mortalidad Diaria (MoMo). La prevalencia de la infección se estimó a partir de las diferencias entre la segunda y cuarta ronda del estudio ENE-COVID y sus intervalos de confianza del 95%. Se calcularon las TL (fallecidos por cada mil infectados) globales, por sexo, grupos de edad (< 65 y ≥ 65 años) y CC.AA. Se calculó la razón estandarizada de letalidad por edad (REL) de las CC.AA. utilizando las TL de España para cada grupo de etario. Estas estimaciones se realizaron con las defunciones declaradas oficialmente (TLo) y el exceso de defunciones estimadas por MoMo (TLMo). Se estimaron las correlaciones entre las prevalencias de infección y las TLo y TLMo, ponderando por población.

Resultados

Para el conjunto de España, la TLo durante la segunda onda epidémica fue del 7,6%, oscilando entre 3,8% de Baleares y 16,4% de Asturias, y la TLMo fue de 10,1%, oscilando entre el 4,8% de Madrid y el 21,7% en Asturias. Se observaron diferencias significativas entre la TLo y la TLMo en Canarias, Castilla la Mancha, Extremadura, Comunidad Valenciana, Andalucía y las Ciudades Autónomas de Ceuta y Melilla. La TLo fue significativamente mayor en hombres (8,2%) que en mujeres (7,1%). Las TLo y TLMo fueron significativamente mayores en el grupo de edad ≥ 65 años (55,4 y 72,2%, respectivamente) que en el grupo < 65 años (0,5 y 1,4%, respectivamente). País Vasco, Aragón, Andalucía y Castilla la Mancha presentaron una REL significativamente superiores a uno. Las correlaciones entre la prevalencia de infección y las TLo fueron inversas.

Conclusiones

La letalidad por COVID-19 durante la segunda onda epidémica en España mejoró respecto a la primera. Los datos disponibles sugieren que la letalidad de la segunda onda en las CC.AA. estaría influida por la elevada letalidad observada en la primera onda en personas con comorbilidades, así como por las limitaciones de los sistemas de detección y notificación de SARS-CoV-2. Las tasas de letalidad fueron mayores en hombres y personas mayores, y variaban significativamente entre CC.AA. Es necesario profundizar en el análisis de las causas de estas diferencias.

[Potentially useful drugs in the treatment of COVID-19 in Primary Care]

The consequences of the SARS-CoV-2 pandemic have exceeded any forecast made. Today we know that the level of severity of the infection in its initial stages will correspond to the evolution and the presence of sequelae in the future. There are no specific treatments that have shown sufficient evidence to allow their recommendation, especially in the mild-moderate stages of the disease. The anti-Covid vaccination is showing clear benefits, both in the prevention of the disease and in its evolution, with the consequent improvement in the numbers of those affected by the pandemic. The use of different drugs used in other indications has been proposed as possible beneficial treatments for COVID-19 that, if used, will be prescribed individually taking into account the characteristics and situation of the patient, the evolutionary phase of the disease as well as well as the limitations of the lack of evidence in its administration.

[Analysis of fatality rates case of SARS-CoV-2 infection in the Autonomous Communities of Spain]

INTRODUCTION

The SARS-CoV-2 pandemic has posed a real challenge to health systems. In Spain, the heterogeneous distribution of the virus infection and the different health strategies have conditioned the morbidity and fatality rate. The aim of this study was to analyse the lethality of the infection by sex and age range in the Autonomous Communities (AC) of Spain.

MATERIAL AND METHODS

To perform the analysis, data were extracted from the Ministry of Health, Regional and Public Health Departments of the different AC. The infected population was estimated from the results of the ENE-COVID19 and the population registered on 1 January 2020 (INE) for the validity of the IgG antibody test with 80% sensitivity and 100% specificity. The case fatality rate (TL) (deaths/1000 estimated infected) by sex and age (<20years, 20-64 and ≥65years) was calculated for each AC. The standardized case fatality ratio (REL) was calculated by the exact method (EPIDAT).

RESULTS

The estimated prevalence of SARS-CoV-2 infection in Spain was 6% (range, 1.4% [Ceuta] -14.1% [Community of Madrid]). The TL in Spain was 9,6/1000, ranged per AC from 1/1000 in Melilla to 26.6/1000 in La Rioja, with no correlation between case fatality and prevalence of infection. The TL was higher in men (10.2/1000, ratio 1.17 with respect to women), except in Cataluña (ratio 0.92), and especially high in those over 64years of age in La Rioja (143.5/1000), Asturias (69.2/1000) and Basque Country (46.6/1000). Overall excess REL was found to be over 30% in La Rioja (2.91; 95%CI: 2.36-3.57), Asturias (1.51; 95%CI: 1.27-1.80), Basque Country (1.42; 95%CI: 1.31-1.54) and Extremadura (1.37; 95%CI: 1.20-1.57) and in those over 64 years in Madrid and the Canary Islands.

CONCLUSIONS

SARs-CoV-2 virus infection has been very unevenly distributed in the different ACs, with notably differences in TL between ACs, particularly high in La Rioja, Asturias and the Basque Country. Is important to study the excess in TL the population over 64years of age in the ACs of Madrid and the Canary Islands.

[COVID-19. History repeats itself and we keep stumbling on the same stone]

La pandemia por COVID-19 ha provocado un desajuste en todos los sistemas de salud. La mayoría de los países habían olvidado cómo comportarse ante una epidemia de estas características sin disponer de los recursos adecuados. Es preciso realizar un balance de todo lo sucedido, instruir a la población y generar un nuevo conocimiento que nos permita afrontar nuevas epidemias.