Genomic surveillance of SARS-CoV-2 positive passengers on flights from China to Italy, December 2022

With numbers of COVID-19 cases having substantially increased at the end of 2022 in China, some countries have started or expanded testing and genomic surveillance of travellers. We report screening results in Italy in late December 2022 of 556 flight passengers in provenance from two Chinese provinces. Among these passengers, 126 (22.7%) tested SARS-CoV-2 positive. Whole genome sequencing of 61 passengers' positive samples revealed Omicron variants, notably sub-lineages BA.5.2.48, BF.7.14 and BQ.1.1, in line with data released from China. Following relaxation since September 2022, of measures related to 'zero-COVID' policies, a substantial increase in coronavirus disease (COVID-19) cases has been observed in China [1,2]. In a preprint article, the cumulative infection attack rate (i.e. the proportion of population who has been infected since 1 November) in Beijing was reported to be 43.1% (95% credible interval (CrI): 25.6-60.9) on 14 December and 75.7% (95% CrI: 60.7-84.4) on 22 December 2022 [3]. In reaction to this situation, a number of countries have recently required passengers on planes from mainland China to have a negative SARS-CoV-2 test, taken shortly pre-departure [4,5]. Moreover, some countries are testing incoming passengers from China for SARS-CoV-2 at arrival and/or are conducting/expanding genomic surveillance of travellers to monitor SARS-CoV-2 variants [4-6]. Here we report the results of screening that was conducted in Italy between 26 December and 29 December 2022 on flight passengers from China arriving at two major airports, namely Fiumicino Leonardo da Vinci airport in Rome and Malpensa airport in Milan.

Automated summary

With an increase in COVID-19 cases at the end of 2022 in China, some countries have started or expanded testing and genomic surveillance of travelers. Screening results in Italy in late December 2022 showed that 22.7% of flight passengers from two Chinese provinces tested positive for SARS-CoV-2. Whole genome sequencing revealed Omicron variants among the positive samples, consistent with data from China.