School of Public Health, Key Laboratory of Public Health Safety, Ministry of Education, Fudan University, Shanghai, 200032, China.
Division of International Epidemiology and Population Studies, Fogarty International Center, National Institutes of Health, Bethesda, MD, USA.
Infect Dis Poverty. 2024 Feb 29;13(1):21. doi: 10.1186/s40249-024-01189-1.
The 2022-2023 mpox (monkeypox) outbreak has spread rapidly across multiple countries in the non-endemic region, mainly among men who have sex with men (MSM). In this study, we aimed to evaluate mpox's importation risk, border screening effectiveness and the risk of local outbreak in Chinese mainland.
We estimated the risk of mpox importation in Chinese mainland from April 14 to September 11, 2022 using the number of reported mpox cases during this multi-country outbreak from Global.health and the international air-travel data from Official Aviation Guide. We constructed a probabilistic model to simulate the effectiveness of a border screening scenario during the mpox outbreak and a hypothetical scenario with less stringent quarantine requirement. And we further evaluated the mpox outbreak potential given that undetected mpox infections were introduced into men who have sex with men, considering different transmissibility, population immunity and population activity.
We found that the reduced international air-travel volume and stringent border entry policy decreased about 94% and 69% mpox importations respectively. Under the quarantine policy, 15-19% of imported infections would remain undetected. Once a case of mpox is introduced into active MSM population with almost no population immunity, the risk of triggering local transmission is estimated at 42%, and would rise to > 95% with over six cases.
Our study demonstrates that the reduced international air-travel volume and stringent border entry policy during the COVID-19 pandemic reduced mpox importations prominently. However, the risk could be substantially higher with the recovery of air-travel volume to pre-pandemic level. Mpox could emerge as a public health threat for Chinese mainland given its large MSM community.
2022-2023 年猴痘（猴痘）疫情在多个非流行地区迅速蔓延，主要发生在男男性行为者（MSM）中。本研究旨在评估中国大陆猴痘输入风险、边境筛查效果和本地暴发风险。
我们利用全球卫生组织报告的多国强流行期间的猴痘病例数和官方航空指南的国际航空旅行数据，估算了 2022 年 4 月 14 日至 9 月 11 日中国大陆猴痘输入风险。我们构建了一个概率模型，模拟猴痘流行期间的边境筛查情景和检疫要求较低的假设情景的效果。我们还考虑到不同的传染性、人群免疫力和人群活动，评估了将未检出的猴痘感染输入到 MSM 中引发本地暴发的潜力。
我们发现，国际航空旅行量减少和边境入境政策严格分别减少了约 94%和 69%的猴痘输入。在检疫政策下，约 15-19%的输入感染仍未被发现。一旦有一例猴痘病例输入到几乎没有人群免疫力的活跃 MSM 人群中，引发本地传播的风险估计为 42%，如果有超过六例病例，则风险将上升至>95%。
本研究表明，在 COVID-19 大流行期间，国际航空旅行量减少和边境入境政策严格显著减少了猴痘输入。然而，随着航空旅行量恢复到疫情前水平，风险可能会显著增加。鉴于中国大陆庞大的 MSM 人群，猴痘可能会对中国大陆构成公共卫生威胁。
