SARS-CoV-2 Infection Is at Herd Immunity in the Majority Segment of the Population of Qatar
Mohamed H. Al‐Thani, Elmoubasher Farag, Roberto Bertollini, Hamad Eid Al‐Romaihi, Sami Abdeen, Ashraf Abdelkarim, Faisal Daraan, Ahmed Ismail, Nahid Mostafa, Mohamed Sahl, Jinan Suliman, Elias Tayar, Hasan Ali Kasem, Meynard J. A. Agsalog, Bassam K. Akkarathodiyil, Ayat A. Alkhalaf, Mohamed Morhaf M. H. Alakshar, Abdulsalam Ali A. H. Al-Qahtani, Monther H. A. Al-Shedifat, Anas Ansari, Ahmad Ali Ataalla, Sandeep Chougule, Abhilash K. K. V. Gopinathan, Feroz J. Poolakundan, Sanjay U. Ranbhise, Saed M. A. Saefan, Mohamed M. Thaivalappil, Abubacker S. Thoyalil, Inayath M. Umar, Zaina Al Kanaani, Abdullatif Al Khal, Einas Al‐Kuwari, Adeel A. Butt, Peter Coyle, Andrew Jeremijenko, Anvar Hassan Kaleeckal, Ali Nizar Latif, Riyazuddin Mohammad Shaik, Hanan F. Abdul Rahim, Hadi M. Yassine, Gheyath K. Nasrallah, Mohamed Ghaith Al‐Kuwari, Odette Chaghoury, Hiam Chemaitelly, Laith J. Abu‐Raddad, Craft and Manual Workers Seroprevalence Study Group, Shafeer T Aerattel, Firoj Ansari, Bennet J Babu, Ali O Bakari, Fazil K Basheer, Muhammed J Cherikkal, Muhammed R Chonari, Ahmad S. Darwish, Arvin Dela Cruz, Verlili Z Dela Cruz, Mark W Del Carmen, Richie P Deomampo, Sanu Gopi, Delfin J R O Hortaleza, R.L. Joseph, Veerankutty Kadar, Abdul Kareem A Kalathil, Bigil C Kandi, Mohammed M T Kaniyankandi, Kamarudheen Karimparukuzhiyil, Deelip G Kurane, Manu Kurungott, Jommel R C Lumibao, Walid Mahmoud, Reyaz A Malik, Jan A Maxino, Nabeel T Moosakutty, Hameed N Nawabjahn, Ryan E Orio, Mohamed Osman, Muhammad H Ottappilakkool, Vijayakumar Pattakunninmel, Nissar P Peedika, Suhail T Puthiyaveettil, Ajith Raghavan, Renjee Ramachandran, Adil S Sainudheen, Kannan Sassendran, John M M Soosai, Harris P Sseri, Deepu Vallapil, Patrick J S Venzuela, Rana A M Abdoon, Hind Shakir Ahmed, Ayah M A Mahmoud, Omnia O E Gismelkhalig, Farid Shihata, Khaled Ali, Fraih A A F Alsallama
Abstract
BACKGROUND: Qatar experienced a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemic that disproportionately affected the craft and manual worker (CMW) population, who comprise 60% of the total population. This study aimed to assess ever and/or current infection prevalence in this population. METHODS: A cross-sectional population-based survey was conducted during July 26 to September 09, 2020, to assess both anti-SARS-CoV-2 positivity through serological testing and current infection positivity through polymerase chain reaction (PCR) testing. Associations with antibody and PCR positivity were identified through regression analyses. RESULTS: The study included 2641 participants, 69.3% of whom were <40 years of age. Anti-SARS-CoV-2 positivity was 55.3% (95% CI, 53.3%-57.3%) and was significantly associated with nationality, geographic location, educational attainment, occupation, and previous infection diagnosis. PCR positivity was 11.3% (95% CI, 9.9%-12.8%) and was significantly associated with nationality, geographic location, occupation, contact with an infected person, and reporting 2 or more symptoms. Infection positivity (antibody and/or PCR positive) was 60.6% (95% CI, 58.6%-62.5%). The proportion of antibody-positive CMWs who had a prior SARS-CoV-2 diagnosis was 9.3% (95% CI, 7.9%-11.0%). Only seven infections were ever severe, and only 1 was ever critical-an infection severity rate of 0.5% (95% CI, 0.2%-1.0%). CONCLUSIONS: Six in every 10 CMWs in Qatar have been infected, suggestive of reaching the herd immunity threshold. Infection severity was low, with only 1 in every 200 infections progressing to be severe or critical. Only 1 in every 10 infections had been previously diagnosed, which is suggestive of mostly asymptomatic or mild infections.