Emergence of New SARS-CoV2 Omicron Variants after the Change of Surveillance and Control Strategy.

In January 2022, there was a global and rapid surge of the Omicron variant of SARS-CoV-2 related to more transmission. This coincided with an increase in the incidence in Asturias, a region where rapid diagnosis and containment measures had limited the circulation of variants. METHODS: From January to June 2022, 34,591 variants were determined by the SNP method. From them, 445 were characterized by the WGS method and classified following pangolin program and phylogenic analysis. RESULTS: The Omicron variant went from being detected in 2438 (78%) samples in the first week of January 2021 to 4074 (98%) in the third week, according to the SNP method. Using the WGS method, 159 BA.1 (35.7%), 256 BA.2 (57.6%), 1 BA.4 (0.2%) and 10 BA.5 (2.2%) Omicron variants were found. Phylogenetic analysis detected that three new sub-clades, BA.2,3.5, BA.2.56 and BF1, were circulating. CONCLUSIONS: The increase in the incidence of SARS-CoV2 caused the circulation of new emerging variants. Viral evolution calls for continuous genomic surveillance.

Lifting COVID-19 mitigation measures in Spain (May-June 2020).

INTRODUCTION: The state of alarm was declared in Spain due to the COVID-19 epidemic on March 14, 2020, and established population confinement measures. The objective is to describe the process of lifting these mitigation measures. METHODS: The Plan for the Transition to a New Normality, approved on April 28, contained four sequential phases with progressive increase in socio-economic activities and population mobility. In parallel, a new strategy for early diagnosis, surveillance and control was implemented. A bilateral decision mechanism was established between the Spanish Government and the autonomous communities (AC), guided by a set of qualitative and quantitative indicators capturing the epidemiological situation and core capacities. The territorial units were established ad-hoc and could be from Basic Health Zones to entire AC. RESULTS: The process run from May 4 to June 21, 2020. AC implemented plans for reinforcement of core capacities. Incidence decreased from a median (50% of territories) of 7.4 per 100,000 in 7 days at the beginning to 2.5 at the end. Median PCR testing increased from 53% to 89% of suspected cases and PCR total capacity from 4.5 to 9.8 per 1000 inhabitants weekly; positivity rate decreased from 3.5% to 1.8%. Median proportion of cases with traced contacts increased from 82% to 100%. CONCLUSION: Systematic data collection, analysis, and interterritorial dialogue allowed adequate process control. The epidemiological situation improved but, mostly, the process entailed a great reinforcement of core response capacities nation-wide, under common criteria. Maintaining and further reinforcing capacities remained crucial for responding to future waves.