Estimation of COVID-19 burden in Egypt
Authors: Khaled Elmeleegy
Journal: The Lancet Infectious Diseases (2020)

The foundation of any estimation process is the use of independent unbiased samples. However, when attempting to estimate Egypt's burden of coronavirus disease 2019 (COVID-19) by studying exported cases, Ashleigh Tuite and colleagues1Tuite AR Ng V Rees E et al.Estimation of the COVID-19 burden in Egypt through exported case detection.Lancet Infect Dis. 2020; (published online March 26.)https://doi.org/10.1016/S1473-3099(20)30233-4Summary Full Text Full Text PDF Scopus (32) Google Scholar established neither independence nor absence of bias for the cases used in their study. This approach is especially problematic in the light of widespread news of a tourist cruise ship in Egypt exporting COVID-19 across the world through hundreds of tourists who were onboard during the timeframe used by Tuite and colleagues in their Correspondence. Regarding sample independence, the authors used two scenarios to estimate the number of COVID-19 cases in Egypt: one with 14 cases and another assuming dependence between some of these cases and hence reducing the number of cases used to five. For the more conservative scenario, Tuite and colleagues estimated Egypt to have 19 310 cases (95% CI 6270–45 070) at the time. However, they acknowledged the cruise ship situation and revised their estimate to "near 6000 cases". However, no analytical basis for this revision was given. For example, if all five cases considered were related to the cruise ship, this would amount to one single case and lead to a different model with a different estimate and different error margins. Regarding sample bias, if all cases in Tuite and colleagues' analysis were indeed related to the cruise ship, then the sample used would be very biased and thus invalid. Egypt has US$2549 of GDP per capita. Therefore, most Egyptians do not have the disposable income to spend on an upscale Nile cruise. Finally, Tuite and colleagues' most conservative estimate is close to 6000 cases by the end of their analysis (March 6, 2020). From March 6 to the date of publication (March 26), 20 days passed. COVID-19's case-count growth rate has been roughly doubling every 3 days in many countries that have lower population density and are more developed than Egypt.2Our World in DataTotal confirmed cases: how rapidly are they increasing?.https://ourworldindata.org/grapher/covid-confirmed-cases-since-100th-caseDate: 2020Date accessed: March 26, 2020Google Scholar Assuming that the number of cases grows at the same rate of doubling every 3 days, Egypt would have had about 640 000 cases by March 26, a time when the whole world had just 593 300 cases reported.3Coronavirus Resource CenterCOVID-19 dashboard by the Center for Systems Science and Engineering at Johns Hopkins University.https://coronavirus.jhu.edu/mapDate: 2020Date accessed: March 26, 2020Google Scholar That is an extraordinary claim. Extraordinary claims require extraordinary proofs, which I could not find in the analysis by Tuite and colleagues. I declare no competing interests. The opinions expressed in this Correspondence are my own and not necessarily those of my employer. Estimation of the COVID-19 burden in Egypt through exported case detectionIn December, coronavirus disease 2019 (COVID-19) emerged in Wuhan, China, causing a pandemic that continues to spread globally.1 86 countries have reported cases.2 As of March 6, 2020, Egypt has reported three cases of COVID-19; however, at least 14 cases have been exported from Egypt to four countries.3 The burden of infection in Egypt, therefore, might be substantially larger than reported. We estimated the potential burden of COVID-19 in Egypt using the approach of Fraser and colleagues.4 Full-Text PDF Estimation of COVID-19 burden in EgyptTo estimate the burden of coronavirus disease 2019 (COVID-19) in Egypt, Ashleigh R Tuite and colleagues1 used the same model of exported case detection used by Fraser and colleagues for the H1N1 outbreak in Mexico.2 However, Tuite and colleagues neither clarified nor verified the assumptions of this exported case-detection model. First, the authors used data from the UN World Tourism Organization (UNWTO) on the average length of stay in Egypt by tourists (11·6 days), which is not accurate for the following reasons: we contacted UNWTO to verify the most recent estimates, and the average length of stay by tourists in Egypt was 11·6 days in 2018, 7·78 days in 2017, 6·1 days in 2016, 9 days in 2015, and 10 days in 2014, with no estimates available for February, 2020; the UNWTO estimates combine the length of stays of domestic and international tourists, including visitors from several countries other than the USA, Canada, France, and Taiwan; and for Egypt, a country with rapid changes in the political, economic, and tourism fields, it would be inaccurate to confidently consider these incomplete statistical data for the present model of February, 2020. Full-Text PDF Estimation of COVID-19 burden in EgyptI read with interest the Correspondence by Ashleigh Tuite and colleagues,1 and I respectfully disagree with the methods used by the authors and their conclusion. Full-Text PDF Estimation of COVID-19 burden in Egypt – Authors' replyWe thank Mohamed Hassany and colleagues, Ahmed Negida, Tarek Sahmoud, and Khaled Elmeleegy for raising their concerns about our modelling study. We would like to reiterate that the number of confirmed cases of coronavirus disease 2019 (COVID-19) in every country worldwide (Egypt included) is an underestimate of the true burden of illness, regardless of the screening programmes in place. Although we are aware that all modelling studies have limitations, we believe that it is important to rely on multiple sources of information to have a more accurate reflection of the so-called ground truth. Full-Text PDF Estimation of COVID-19 burden in EgyptWe read with interest the Correspondence by Ashleigh Tuite and colleagues.1 We thank them for their interest in estimating the coronavirus disease 2019 (COVID-19) burden in Egypt. However, their model-based calculations used the number of patients known on March 6, and the numbers of patients and deaths are continuously changing. Attempting to reach a more up-to-date estimate of the expected number of patients in Egypt, we used other assumptions according to real-life data. Full-Text PDF