By the time of publication, Egypt had only reported three cases of COVID-19. However, at least 14 cases had been exported from Egypt to four other countries. Therefore, the burden of infection in Egypt must be substantially larger than reported. The authors wanted to estimate the potential burden of COVID-19 in Egypt. They examined two scenarios: (1) all exported cases, considered to be independent (n = 14), and (2) all exported cases minus travellers who visited multiple countries and possibly linked cases (n = 5). In the second scenario, the linked cases included six cases exported to France, all of whom were from the same tour group. Two exported cases to the US, a husband and wife, were also counted as a single case, and five cases exported to Canada were counted as three cases because two cases were linked to a third. In February 2019, 829,370 international air travellers departed from Egypt. The four countries reporting exported cases were ranked eighth (USA), 13th (France), 31st (Canada) and 40th (Taiwan) for travel volumes; together accounting for 5·1% of outbound air travellers from Egypt. The average length of stay in Egypt by tourists is estimated to be 11·6 days and the proportion of air travellers who are tourists rather than residents of Egypt was estimated to be 61%. Residents were assumed to have had a 1-month exposure period. Based on a conservative estimate of the COVID-19 burden (scenario 2), the authors estimated an outbreak size of 19,310 cases in Egypt. If this was expanded to scenario 1 then it would produce a higher estimate of 51,520 cases. However, given reports that several Nile tour operators have COVID-19 infections, these values may overestimate the burden in Egypt if tourists are being preferentially affected. Therefore the actual value is probably closer to the lower end of the confidence interval in the conservative estimate, suggesting 6000 cases. Therefore, Egypt probably has a large burden of COVID-19 cases that are currently unreported.
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