Effectiveness of a Precise Control Strategy against the COVID-19 Omicron BA.5 Variant in Macao

Abstract

Background: More than two years into the global, coronavirus disease (COVID-19) constantly changes through mutation. Omicron BA.4 and BA.5 lineages are new, dominating lineages that will develop in the near future. Macao, a Special Administrative Region (SAR) of China, is the first region to have a BA.5 wave without a previous, COVID-19 outbreak. Since the emergence of Omicron BA.5 into the community, the Macao SAR government implemented the precise control strategy and controlled the outbreak within 6 weeks. The aim of this article was to introduce a new control strategy against COVID-19 Omicron BA.5 in Macao and showed its effectiveness. Methods: We analyzed the data, during 18 Jun to 2 Aug 2022, and summarized our experience in implementing a precise control strategy for the Omicron BA.5 outbreak. Results: This wave lasted for 6 weeks. In total, 1821 cases were diagnosed, of which 1177 (64.6%) cases were detected because of contact tracing; 784 (43.0%) cases were detected from a restricted period; and 664 (36.5%) cases were related to the target population from 8 different occupations. Comparing with community, the proportion of case finding increased progressively in the restricted period with time. Conclusion: Our policy successfully contained the COVID-19 Omicron BA.5 outbreak. Our experience could provide a reference for the control strategy against COVID-19 Omicron BA.5 in other regions.