Title: Disentangling seasonal introduction and establishment risk of dengue in Africa
Authors: Poongavanan J, Lourenço J, Tsui JHL, Colizza V, Ramphal Y, Baxter C, Kraemer MOG, Dunaiski M, de Oliveira T, Tegally H.
Journal: medRxiv [Preprint],https://doi.org/10.1101/2024.05.07.24306997: (2024)
Abstract
Background The dengue virus 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.
Methods The risk of dengue introduction into Africa from countries of high incidence 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 potential and population density, which we used, along with travel information in a risk flow model, to estimate the importation risks.
Findings We find that countries in east Africa face higher risk of importation from Asia, whereas for west African countries, larger risk of importation is estimated from South America. Some countries with high risk of importation experience low local transmission potential which likely hampers the chances that importations lead to local establishment and transmission. Conversely, Mauritius, Uganda, Ivory Coast, Senegal, and Kenya are identified as countries susceptible to dengue introductions during periods of persistent transmission suitability.
Interpretation Our work improves the data driven allocation of surveillance resources, in regions of Africa that are at high risk of dengue introductions and establishment. This will be critical in detecting and managing imported cases and can improve local response to dengue outbreaks.
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Citation: Poongavanan J, Lourenço J, Tsui JHL, Colizza V, Ramphal Y, Baxter C, Kraemer MOG, Dunaiski M, de Oliveira T, Tegally H. Disentangling seasonal introduction and establishment risk of dengue in Africa medRxiv [Preprint],https://doi.org/10.1101/2024.05.07.24306997: (2024).