Epidemiology of the Zika Virus Outbreak in the Cabo Verde Islands, West Africa

Conclusions With an AR ranging from 42% to 61%, our findings suggest that between ~221,000 to ~329,000 people may have been infected with ZIKV during the recent outbreak in Cabo Verde. Was the viral lineage that caused this large outbreak in Cabo Verde introduced from the Americas or from another African country? A rapid assessment of the global air travel network suggests the presence of similar ecologies and direct air travel connections between the northeast of Brazil and Santiago island where most cases were observed. Given the timing of the epidemic (Figure 1a) and the high number of travellers visiting Cabo Verde from the Americas it seems plausible to speculate that the outbreak was caused by the Asian genotype circulating in the Americas (the country received >7000 travellers from ZIKV infected countries in 2015, including direct flights from Northeast Brazil 15). Moreover, recent ZIKV cases in Africa have also been reported in Angola (1 returning traveller to France and 1 autochthonous case 16) and Guinea-Bissau (3 cases in the Bjagó islands 17). Similar to Cabo Verde, no genetic data is available from Angola or Guinea-Bissau. Our mathematical framework is based on two fundamental assumptions: (i) that the AR among pregnant women is the same as the in general population, and (ii) the risk of MC without prior exposition to ZIKV is negligible. The effect of these assumptions in our AR estimations for Cabo Verde are expected to vary between data sources. Without t...
Source: PLOS Currents Outbreaks - Category: Epidemiology Authors: Source Type: research