Poongavanan Jenicca, Lourenço José, Tsui Joseph L-H, Colizza Vittoria, Ramphal Yajna, Baxter Cheryl, Kraemer Moritz U G, Dunaiski Marcel, de Oliveira Tulio, Tegally Houriiyah
Centre for Epidemic Response and innovation (CERI), Stellenbosch University, Stellenbosch, South Africa.
BioISI (Biosystems and Integrative Sciences Institute), University of Lisbon, Lisbon, Portugal.
medRxiv. 2024 Oct 29:2024.05.07.24306997. doi: 10.1101/2024.05.07.24306997.
Dengue is a significant global public health concern that poses a threat to Africa. Particularly, African countries are at risk of viral introductions through air travel connectivity with areas of South America and Asia that experience frequent explosive outbreaks. Limited reporting and diagnostic capacity hinder a comprehensive assessment of continent-wide transmission dynamics and deployment of surveillance strategies in Africa. This study aimed to identify African airports at high risk of receiving dengue infected passengers from Asia, Latin America and other African countries with high dengue incidence.
The risk of dengue introduction into Africa from countries of high incidence in Africa, Latin America and within Africa was estimated based on origin-destination air travel flows and epidemic activity at origin. We produced a novel proxy for local dengue epidemic activity using a composite index of theoretical climate-driven transmission suitability and population density, which we used, along with travel information in a risk flow model, to estimate importation risk.
We find that countries in East Africa face higher estimated risk of importation from Asia and other East African countries, whereas for West African countries, larger risk of importation is estimated from within the region. Some countries with high risk of importation experience low local transmission suitability which likely hampers the chances that importations lead to local transmission and establishment. Conversely, Mauritius, Uganda, Ivory Coast, Senegal, and Kenya are identified as countries susceptible to dengue introductions during periods of persistent transmission suitability.
Our work improves data driven allocation of surveillance resources, in regions of Africa that are at high risk of dengue introduction and establishment, including from regional circulation. This will be critical in detecting and managing imported cases and can improve local response to dengue outbreaks.
Rockefeller Foundation, National Institute of Health, EDCTP3 and Horizon Europe Research and Innovation, World Bank Group, Medical Research Foundation, Wellcome Trust, Google.org, Oxford Martin School Pandemic Genomics programme, John Fell Fund.
登革热是一个重大的全球公共卫生问题，对非洲构成威胁。特别是，非洲国家因与南美洲和亚洲地区有航空旅行联系，而这些地区经常爆发大规模疫情，所以面临病毒传入的风险。有限的报告和诊断能力阻碍了对非洲大陆传播动态的全面评估以及监测策略的部署。本研究旨在确定从亚洲、拉丁美洲和其他登革热发病率高的非洲国家接收登革热感染乘客风险高的非洲机场。
根据出发地-目的地航空旅行流量和出发地的疫情活动，估计了登革热从非洲、拉丁美洲高发病率国家以及非洲内部传入非洲的风险。我们使用理论气候驱动的传播适宜性和人口密度的综合指数，制作了一个当地登革热疫情活动的新代理指标，并将其与风险流动模型中的旅行信息一起用于估计输入风险。
我们发现，东非国家面临来自亚洲和其他东非国家的更高估计输入风险，而对于西非国家，估计来自该地区内部的输入风险更大。一些输入风险高的国家当地传播适宜性较低，这可能会降低输入导致本地传播和定殖的可能性。相反，毛里求斯、乌干达、科特迪瓦、塞内加尔和肯尼亚被确定为在持续传播适宜期易受登革热传入的国家。
我们的工作改进了在非洲登革热传入和定殖风险高的地区，包括区域传播地区的数据驱动监测资源分配。这对于检测和管理输入病例至关重要，并可改善当地对登革热疫情的应对。
洛克菲勒基金会、美国国立卫生研究院、EDCTP3和欧洲地平线研究与创新、世界银行集团、医学研究基金会、惠康信托基金会、谷歌.org、牛津马丁学院大流行基因组学计划、约翰·费尔基金。
