{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,2]],"date-time":"2026-07-02T15:49:39Z","timestamp":1783007379962,"version":"3.54.5"},"update-to":[{"DOI":"10.1371\/journal.ppat.1009413","type":"new_version","label":"New version","source":"publisher","updated":{"date-parts":[[2021,3,23]],"date-time":"2021-03-23T00:00:00Z","timestamp":1616457600000}}],"reference-count":37,"publisher":"Public Library of Science (PLoS)","issue":"3","license":[{"start":{"date-parts":[[2021,3,11]],"date-time":"2021-03-11T00:00:00Z","timestamp":1615420800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Institute of Allergy and Infectious Diseases, National Institutes of Health, US Department of Health and Human Services","award":["HHSN272201400006C"],"award-info":[{"award-number":["HHSN272201400006C"]}]}],"content-domain":{"domain":["www.plospathogens.org"],"crossmark-restriction":false},"short-container-title":["PLoS Pathog"],"abstract":"<jats:p>SARS-CoV-2 virus is transmitted in closed settings to people in contact with COVID-19 patients such as healthcare workers and household contacts. However, household person-to-person transmission studies are limited. Households participating in an ongoing cohort study of influenza incidence and prevalence in rural Egypt were followed. Baseline enrollment was done from August 2015 to March 2017. The study protocol was amended in April 2020 to allow COVID-19 incidence and seroprevalence studies. A total of 290 households including 1598 participants were enrolled and followed from April to October 2020 in four study sites. When a participant showed respiratory illness symptoms, a serum sample and a nasal and an oropharyngeal swab were obtained. Swabs were tested by RT-PCR for SARS-CoV-2 infection. If positive, the subject was followed and swabs collected on days three, six, nine, and 14 after the first swab day and a serum sample obtained on day 14. All subjects residing with the index case were swabbed following the same sampling schedule. Sera were collected from cohort participants in October 2020 to assess seroprevalence. Swabs were tested by RT-PCR. Sera were tested by Microneutralization Assay to measure the neutralizing antibody titer. Incidence of COVID-19, household secondary attack rate, and seroprevalence in the cohort were determined. The incidence of COVID-19 was 6.9% and the household secondary attack rate was 89.8%. Transmission within households occurred within two-days of confirming the index case. Infections were asymptomatic or mild with symptoms resolving within 10 days. The majority developed a neutralizing antibody titer by day 14 post onset. The overall seroprevalence among cohort participants was 34.8%. These results suggest that within-household transmission is high in Egypt. Asymptomatic or mild illness is common. Most infections seroconvert and have a durable neutralizing antibody titer.<\/jats:p>","DOI":"10.1371\/journal.ppat.1009413","type":"journal-article","created":{"date-parts":[[2021,3,11]],"date-time":"2021-03-11T18:53:23Z","timestamp":1615488803000},"page":"e1009413","update-policy":"https:\/\/doi.org\/10.1371\/journal.ppat.corrections_policy","source":"Crossref","is-referenced-by-count":29,"title":["Incidence, household transmission, and neutralizing antibody seroprevalence of Coronavirus Disease 2019 in Egypt: Results of a community-based cohort"],"prefix":"10.1371","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7947-3609","authenticated-orcid":true,"given":"Mokhtar R.","family":"Gomaa","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6181-1072","authenticated-orcid":true,"given":"Amira S.","family":"El Rifay","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7556-9398","authenticated-orcid":true,"given":"Mahmoud","family":"Shehata","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3253-6961","authenticated-orcid":true,"given":"Ahmed","family":"Kandeil","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9130-3079","authenticated-orcid":true,"given":"Mina","family":"Nabil Kamel","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mohamed A.","family":"Marouf","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mohamed","family":"GabAllah","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7051-1389","authenticated-orcid":true,"given":"Ahmed","family":"El Taweel","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0439-3476","authenticated-orcid":true,"given":"Ahmed E.","family":"Kayed","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2256-2816","authenticated-orcid":true,"given":"Omnia","family":"Kutkat","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2159-2511","authenticated-orcid":true,"given":"Yassmin","family":"Moatasim","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1011-5608","authenticated-orcid":true,"given":"Sara H.","family":"Mahmoud","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Noura M.","family":"Abo Shama","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mohamed","family":"El Sayes","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2878-5714","authenticated-orcid":true,"given":"Ahmed","family":"Mostafa","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8798-2240","authenticated-orcid":true,"given":"Rabeh","family":"El-Shesheny","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9585-955X","authenticated-orcid":true,"given":"Pamela P.","family":"McKenzie","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4397-7132","authenticated-orcid":true,"given":"Richard J.","family":"Webby","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5387-1622","authenticated-orcid":true,"given":"Ghazi","family":"Kayali","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mohamed A.","family":"Ali","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2021,3,11]]},"reference":[{"issue":"20","key":"ppat.1009413.ref001","doi-asserted-by":"crossref","first-page":"1967","DOI":"10.1056\/NEJMoa030747","article-title":"Identification of a novel coronavirus in patients with severe acute respiratory syndrome","volume":"348","author":"C Drosten","year":"2003","journal-title":"The New England journal of medicine"},{"issue":"19","key":"ppat.1009413.ref002","doi-asserted-by":"crossref","first-page":"1814","DOI":"10.1056\/NEJMoa1211721","article-title":"Isolation of a novel coronavirus from a man with pneumonia in Saudi Arabia","volume":"367","author":"AM Zaki","year":"2012","journal-title":"The New England journal of medicine"},{"issue":"8","key":"ppat.1009413.ref003","doi-asserted-by":"crossref","first-page":"727","DOI":"10.1056\/NEJMoa2001017","article-title":"A Novel Coronavirus from Patients with Pneumonia in China, 2019.","volume":"382","author":"N Zhu","year":"2020","journal-title":"The New England journal of medicine"},{"key":"ppat.1009413.ref004","unstructured":"WHO. COVID-19 Weekly Epidemiological Update 2021 [12\/2\/2021]. Available from: https:\/\/www.who.int\/docs\/default-source\/coronaviruse\/situation-reports\/20210209_weekly_epi_update_26.pdf?sfvrsn=836a69b9_3&download=true."},{"key":"ppat.1009413.ref005","article-title":"Characteristics of and Important Lessons From the Coronavirus Disease 2019 (COVID-19) Outbreak in China: Summary of a Report of 72314 Cases From the Chinese Center for Disease Control and Prevention.","author":"Z Wu","year":"2020","journal-title":"JAMA"},{"key":"ppat.1009413.ref006","unstructured":"WHO. Coronavirus disease (COVID-19) Situation report\u2014187, 27 July 2020. 2020 [27\u20137\u20132020]. Available from: https:\/\/www.who.int\/emergencies\/diseases\/novel-coronavirus-2019\/situation-reports\/."},{"issue":"16","key":"ppat.1009413.ref007","doi-asserted-by":"crossref","first-page":"1564","DOI":"10.1056\/NEJMc2004973","article-title":"Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1","volume":"382","author":"N van Doremalen","year":"2020","journal-title":"The New England journal of medicine"},{"issue":"4","key":"ppat.1009413.ref008","doi-asserted-by":"crossref","first-page":"502","DOI":"10.1038\/s41591-020-0817-4","article-title":"Characteristics of pediatric SARS-CoV-2 infection and potential evidence for persistent fecal viral shedding","volume":"26","author":"Y Xu","year":"2020","journal-title":"Nat Med"},{"issue":"3","key":"ppat.1009413.ref009","doi-asserted-by":"crossref","first-page":"355","DOI":"10.1093\/aje\/kwm082","article-title":"Estimating variability in the transmission of severe acute respiratory syndrome to household contacts in Hong Kong, China","volume":"166","author":"VE Pitzer","year":"2007","journal-title":"Am J Epidemiol"},{"key":"ppat.1009413.ref010","unstructured":"WHO. Transmission of SARS-CoV-2: implications for infection prevention precautions 2020 [26\/7\/2020]. Available from: https:\/\/www.who.int\/news-room\/commentaries\/detail\/transmission-of-sars-cov-2-implications-for-infection-prevention-precautions."},{"key":"ppat.1009413.ref011","article-title":"Household Transmission of SARS-CoV-2, Zhuhai, China, 2020","author":"J Wu","year":"2020","journal-title":"Clinical infectious diseases: an official publication of the Infectious Diseases Society of America"},{"key":"ppat.1009413.ref012","article-title":"Household transmission of SARS-CoV-2","author":"Z Wang","year":"2020","journal-title":"The Journal of infection"},{"key":"ppat.1009413.ref013","article-title":"The characteristics of household transmission of COVID-19","author":"W Li","year":"2020","journal-title":"Clinical infectious diseases: an official publication of the Infectious Diseases Society of America"},{"issue":"10223","key":"ppat.1009413.ref014","doi-asserted-by":"crossref","first-page":"514","DOI":"10.1016\/S0140-6736(20)30154-9","article-title":"A familial cluster of pneumonia associated with the 2019 novel coronavirus indicating person-to-person transmission: a study of a family cluster.","volume":"395","author":"JF-W Chan","year":"2020","journal-title":"Lancet"},{"issue":"9","key":"ppat.1009413.ref015","doi-asserted-by":"crossref","first-page":"245","DOI":"10.15585\/mmwr.mm6909e1","article-title":"Active Monitoring of Persons Exposed to Patients with Confirmed COVID-19\u2014United States, January-February 2020","volume":"69","author":"RM Burke","year":"2020","journal-title":"MMWR Morbidity and mortality weekly report"},{"key":"ppat.1009413.ref016","article-title":"COVID-19 Testing, Epidemic Features, Hospital Outcomes, and Household Prevalence, New York State-March 2020","author":"ES Rosenberg","year":"2020","journal-title":"Clinical infectious diseases: an official publication of the Infectious Diseases Society of America"},{"key":"ppat.1009413.ref017","article-title":"Household secondary attack rate of COVID-19 and associated determinants in Guangzhou, China: a retrospective cohort study","author":"QL Jing","year":"2020","journal-title":"Lancet Infect Dis"},{"issue":"44","key":"ppat.1009413.ref018","doi-asserted-by":"crossref","first-page":"1631","DOI":"10.15585\/mmwr.mm6944e1","article-title":"Transmission of SARS-COV-2 Infections in Households\u2014Tennessee and Wisconsin, April-September 2020","volume":"69","author":"CG Grijalva","year":"2020","journal-title":"MMWR Morbidity and mortality weekly report"},{"key":"ppat.1009413.ref019","article-title":"Household Transmission of SARS-CoV-2 in the United States","author":"NM Lewis","year":"2020","journal-title":"Clinical infectious diseases: an official publication of the Infectious Diseases Society of America"},{"key":"ppat.1009413.ref020","article-title":"Secondary attack rate of COVID-19 in household contacts in the Winnipeg Health Region, Canada.","author":"K Wilkinson","year":"2020","journal-title":"Can J Public Health"},{"key":"ppat.1009413.ref021","article-title":"The household secondary attack rate of SARS-CoV-2: A rapid review","author":"HF Fung","year":"2020","journal-title":"Clinical infectious diseases: an official publication of the Infectious Diseases Society of America"},{"issue":"5","key":"ppat.1009413.ref022","doi-asserted-by":"crossref","DOI":"10.1136\/bmjgh-2020-002794","article-title":"Reduction of secondary transmission of SARS-CoV-2 in households by face mask use, disinfection and social distancing: a cohort study in Beijing, China.","volume":"5","author":"Y Wang","year":"2020","journal-title":"BMJ Glob Health"},{"issue":"8","key":"ppat.1009413.ref023","doi-asserted-by":"crossref","first-page":"1930","DOI":"10.3201\/eid2608.201016","article-title":"Asymptomatic SARS-CoV-2 Infection in Household Contacts of a Healthcare Provider, Wuhan, China","volume":"26","author":"Y Luo","year":"2020","journal-title":"Emerg Infect Dis"},{"key":"ppat.1009413.ref024","article-title":"Robust neutralizing antibodies to SARS-CoV-2 infection persist for months","author":"A Wajnberg","year":"2020","journal-title":"Science"},{"key":"ppat.1009413.ref025","doi-asserted-by":"crossref","first-page":"69","DOI":"10.11606\/s1518-8787.2020054002643","article-title":"Seroprevalence of anti-SARS-CoV-2 among blood donors in Rio de Janeiro, Brazil.","volume":"54","author":"L Amorim Filho","year":"2020","journal-title":"Rev Saude Publica."},{"key":"ppat.1009413.ref026","article-title":"Population-based surveys of antibodies against SARS-CoV-2 in Southern Brazil.","author":"MF Silveira","year":"2020","journal-title":"Nat Med"},{"key":"ppat.1009413.ref027","article-title":"Seroprevalence of SARS-CoV-2-Specific Antibodies Among Adults in Los Angeles County, California, on April 10\u201311, 2020.","author":"N Sood","year":"2020","journal-title":"JAMA"},{"key":"ppat.1009413.ref028","article-title":"Seroprevalence of Antibodies to SARS-CoV-2 in 10 Sites in the United States, March 23-May 12, 2020.","author":"FP Havers","year":"2020","journal-title":"JAMA Intern Med"},{"key":"ppat.1009413.ref029","article-title":"Seroprevalence of anti-SARS-CoV-2 IgG antibodies in Geneva, Switzerland (SEROCoV-POP): a population-based study.","author":"S Stringhini","year":"2020","journal-title":"Lancet"},{"key":"ppat.1009413.ref030","article-title":"Prevalence of SARS-CoV-2 in Spain (ENE-COVID): a nationwide, population-based seroepidemiological study.","author":"M Pollan","year":"2020","journal-title":"Lancet"},{"key":"ppat.1009413.ref031","article-title":"Magnitude and kinetics of anti-SARS-CoV-2 antibody responses and their relationship to disease severity","author":"KL Lynch","year":"2020","journal-title":"Clinical infectious diseases: an official publication of the Infectious Diseases Society of America"},{"issue":"10227","key":"ppat.1009413.ref032","doi-asserted-by":"crossref","first-page":"e47","DOI":"10.1016\/S0140-6736(20)30462-1","article-title":"Secondary attack rate and superspreading events for SARS-CoV-2","volume":"395","author":"Y Liu","year":"2020","journal-title":"Lancet"},{"key":"ppat.1009413.ref033","article-title":"Household transmissions of SARS-CoV-2 in the time of unprecedented travel lockdown in China.","author":"X Xu","year":"2020","journal-title":"medRxiv."},{"issue":"2","key":"ppat.1009413.ref034","doi-asserted-by":"crossref","first-page":"e74","DOI":"10.2196\/resprot.4331","article-title":"Household Transmission of Zoonotic Influenza Viruses in a Cohort of Egyptian Poultry Growers.","volume":"4","author":"AS El Rifay","year":"2015","journal-title":"JMIR research protocols."},{"issue":"4","key":"ppat.1009413.ref035","doi-asserted-by":"crossref","first-page":"549","DOI":"10.1093\/clinchem\/hvaa029","article-title":"Molecular Diagnosis of a Novel Coronavirus (2019-nCoV) Causing an Outbreak of Pneumonia.","volume":"66","author":"DKW Chu","year":"2020","journal-title":"Clinical chemistry"},{"issue":"3","key":"ppat.1009413.ref036","doi-asserted-by":"crossref","first-page":"2000045","DOI":"10.2807\/1560-7917.ES.2020.25.3.2000045","article-title":"Detection of 2019 novel coronavirus (2019-nCoV) by real-time RT-PCR.","volume":"25","author":"VM Corman","year":"2020","journal-title":"Eurosurveillance."},{"issue":"36","key":"ppat.1009413.ref037","doi-asserted-by":"crossref","first-page":"20574","DOI":"10.2807\/1560-7917.ES2013.18.36.20574","article-title":"Seroepidemiology for MERS coronavirus using microneutralisation and pseudoparticle virus neutralisation assays reveal a high prevalence of antibody in dromedary camels in Egypt, June 2013.","volume":"18","author":"RA Perera","year":"2013","journal-title":"Euro Surveill."}],"updated-by":[{"DOI":"10.1371\/journal.ppat.1009413","type":"new_version","label":"New version","source":"publisher","updated":{"date-parts":[[2021,3,23]],"date-time":"2021-03-23T00:00:00Z","timestamp":1616457600000}}],"container-title":["PLOS Pathogens"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.ppat.1009413","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,3,23]],"date-time":"2021-03-23T18:02:19Z","timestamp":1616522539000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.ppat.1009413"}},"subtitle":[],"editor":[{"given":"Ron A. M.","family":"Fouchier","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2021,3,11]]},"references-count":37,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2021,3,11]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.ppat.1009413","relation":{"new_version":[{"id-type":"doi","id":"10.1371\/journal.ppat.1009413","asserted-by":"object"}]},"ISSN":["1553-7374"],"issn-type":[{"value":"1553-7374","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,3,11]]}}}