key: cord-0879909-8wfv22fb
authors: Butt, Adeel A; Al-Halabi, Anas M; Ghazouani, Hafedh; Rhouma, Mohamed Ben Haj; Ayoub, Houssein H; Masoodi, Naseer A; Borham, Abdelsalam M; Hommos, Ahmed A; Bertollini, Roberto; Chemaitelly, Hiam; Abu Raddad, Laith J; Abou-Samra, Abdul-Badi
title: SARS-CoV-2 infection rates in arriving air Travelers in Qatar
date: 2021-10-08
journal: J Travel Med
DOI: 10.1093/jtm/taab163
sha: 6b4036492641989dd88347a80cdcf976f44f168d
doc_id: 879909
cord_uid: 8wfv22fb

Among 352 174 airline travelers entering Qatar, 8236 (2.34%) tested positive on or within the first seven days of arrival, with 3789 (1.08%) testing positive at the time of arrival and the remaining 4447 (1.26%) testing negative at arrival but positive 1 week later.

In response to the SARS-CoV-2 pandemic and the potential of spread via air travel, many airlines instituted measures to reduce the risk of in-flight transmission. These include mandatory use of face masks, frequent disinfection of the aircraft, encouraging use of hand sanitizers, and pre-flight screening. 1 All arriving travelers underwent a medical evaluation at the airport and underwent a nasopharyngeal swab for RT-PCR for SARS-CoV-2 infection and then placed in quarantine.

Repeat testing was performed one week after arrival and those who tested negative on both occasions were released from quarantine. Those with a positive test were immediately transferred to a designated isolation facility or a hospital depending on the presence and severity of symptoms. The port of last embarkation was confirmed for all arriving travelers at the time of baseline evaluation from the airline's boarding pass. Nationality was determined by the Qatar national identification card used at the immigration to gain entry. We determined the proportion of arriving travelers to Qatar who were SARS-CoV-2 positive by RT-PCR on a nasopharyngeal swab. For those with multiple entries into the country, all visits were included unless they tested positive, at which point they were censored. Based on the incubation period of SARS-CoV-2, it is likely that those testing positive at arrival were exposed to infection before embarkation on the arriving flight. Those testing negative at arrival but positive one week later may have been exposed during or after arrival. Strengths of our study include robust data collection and SARS-CoV-2 testing at the single port of entry into Qatar via Hamad International Airport. All quarantine sites were managed by Hamad Medical Corporation, the single largest provider of healthcare in Qatar, thereby making tracking patients and data collection uniform across all sites. Limitations include lack of data on recent variants of concern and their impact on the local epidemic curve. Particularly, the Delta variant has been associated with higher rates of transmission. However, the Delta variant was in community transmission in Qatar only starting from the end of March, 2021, after the end of the observation period for this study. 7, 8 We did not study clinical outcomes in travelers with a positive test. It is also possible that some travelers may not have strictly adhered to the quarantine measures, particularly among those who were allowed to self-quarantine at home.

Finally, some may have had infection with an incubation period >7 days. 

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The authors are grateful for the leadership and assistance provided by the Ministry of Public