Fan Lingyu, Shi Wenzhong, Pei Qing, Zhang Anshu
Department of Land Surveying and Geo-Informatics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China.
Otto Poon Charitable Foundation Smart Cities Research Institute, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China.
BMC Public Health. 2025 Jul 23;25(1):2526. doi: 10.1186/s12889-025-23686-0.
The COVID-19 pandemic has exposed the vulnerabilities of lower-income countries due to limited healthcare infrastructure and socioeconomic constraints, highlighting the need for effective containment measures that minimize socioeconomic costs and prepare for future pandemics alike, which are expected to become more frequent. Although prior studies have examined various strategies in these regions, a significant gap remains in quantitative research on affordable measures to combat the highly transmissible SARS-CoV-2 Omicron variant, which greatly challenges effective measures for previous strains. Studies on targeted containment measures for Omicron have dramatically declined even in higher-income regions, and their findings could be much less applicable in lower-income regions due to substantial socioeconomic disparities.
This study addresses this gap by focusing on South Africa. A spatial Susceptible-Exposed-Infected-Recovered (SEIR) model was developed to simulate the virus spread during the country's first Omicron wave from November 2021 to April 2022, integrating multisource statistics to overcome the typical scarcity of inter-city mobility data in lower-income countries. Three affordable containment measures were examined: (1) restricting inter-city mobility in epicenter provinces, while allowing nationwide intra-city movement for livelihood activities; (2) home isolation for positive cases, alongside quarantine for co-residents, accounting for high rates of asymptomatic cases, underreporting, and delays of self-isolation; and (3) prioritizing booster vaccinations for high-risk healthcare workers.
The findings indicate that restricting inter-city mobility in the epicenter Gauteng, which only accounted for 3.6% of national mobility, could reduce national infections by 15.0%. Quarantining households with positive cases could reduce infections by 10.9%, despite the high rates of asymptomatic cases and presymptomatic transmission. Prioritizing booster vaccinations was also effective when healthcare workers had a much higher infection risk than others. Meanwhile, these measures incurred minimal socioeconomic costs compared to earlier pandemic strategies. Additionally, the spatial variation of containment measure effectiveness suggests that timely implementation of these measures before the infection rate escalates is critical for ensuring their effectiveness.
This research provides essential insights for lower-income countries to manage current and future pandemics within their economic and healthcare constraints, especially regarding targeted mobility restriction, quarantine, prioritized vaccination, and timing of containment measures.
由于医疗基础设施有限和社会经济限制，新冠疫情暴露了低收入国家的脆弱性，凸显了采取有效防控措施的必要性，这些措施要将社会经济成本降至最低，并为未来预计会更频繁出现的类似疫情做好准备。尽管先前的研究考察了这些地区的各种策略，但在对抗高传染性的新冠病毒奥密克戎变种的经济适用措施的定量研究方面仍存在重大差距，该变种给针对先前毒株的有效措施带来了巨大挑战。即使在高收入地区，关于奥密克戎的针对性防控措施的研究也大幅减少，而且由于巨大的社会经济差异，其研究结果在低收入地区的适用性可能更低。
本研究聚焦于南非以填补这一空白。开发了一个空间易感-暴露-感染-康复（SEIR）模型，以模拟该国在2021年11月至2022年4月的首次奥密克戎疫情浪潮期间的病毒传播情况，整合多源统计数据以克服低收入国家典型的城市间流动数据稀缺问题。研究了三种经济适用的防控措施：（1）限制疫情中心省份的城市间流动，同时允许全国范围内为维持生计活动的市内流动；（2）对阳性病例进行居家隔离，同时对同住者进行检疫，考虑到无症状病例比例高、漏报以及自我隔离延迟的情况；（3）优先为高风险医护人员接种加强针。
研究结果表明，限制疫情中心豪登省（该省仅占全国流动量的3.6%）的城市间流动可使全国感染人数减少15.0%。对阳性病例家庭进行检疫可使感染人数减少10.9%，尽管无症状病例比例高且存在症状前传播。当医护人员的感染风险远高于其他人时，优先接种加强针也很有效。与此同时，与早期的疫情防控策略相比，这些措施产生的社会经济成本极低。此外，防控措施有效性的空间差异表明，在感染率上升之前及时实施这些措施对于确保其有效性至关重要。
本研究为低收入国家在其经济和医疗限制范围内管理当前及未来疫情提供了重要见解，特别是在针对性流动限制、检疫、优先接种疫苗以及防控措施的时机方面。
