{"id":9050,"date":"2020-08-14T11:36:43","date_gmt":"2020-08-14T18:36:43","guid":{"rendered":"https:\/\/depts.washington.edu\/pandemicalliance\/?p=9050"},"modified":"2021-04-13T11:37:19","modified_gmt":"2021-04-13T18:37:19","slug":"contact-settings-and-risk-for-transmission-in-3410-close-contacts-of-patients-with-covid-19-in-guangzhou-china-a-prospective-cohort-study","status":"publish","type":"post","link":"https:\/\/depts.washington.edu\/pandemicalliance\/2020\/08\/14\/contact-settings-and-risk-for-transmission-in-3410-close-contacts-of-patients-with-covid-19-in-guangzhou-china-a-prospective-cohort-study\/","title":{"rendered":"Contact Settings and Risk for Transmission in 3410 Close Contacts of Patients With COVID-19 in Guangzhou, China: A Prospective Cohort Study"},"content":{"rendered":"<ul>\n<li data-leveltext=\"\uf0b7\" data-font=\"Symbol\" data-listid=\"44\" data-aria-posinset=\"1\" data-aria-level=\"1\"><span data-contrast=\"auto\">A study of\u00a0<\/span><span data-contrast=\"auto\">SARS-CoV-2 infection among<\/span><span data-contrast=\"auto\">\u00a03,410 close contacts<\/span><span data-contrast=\"auto\">\u00a0of 391 confirmed SARS-CoV-2 cases<\/span><span data-contrast=\"auto\">\u00a0<\/span><span data-contrast=\"auto\">in Guangzhou<\/span><span data-contrast=\"auto\">, China<\/span><span data-contrast=\"auto\">\u00a0found a secondary attack rate of\u00a0<\/span><span data-contrast=\"auto\">4<\/span><span data-contrast=\"auto\">%.\u00a0<\/span><span data-contrast=\"auto\">Close contact was defined as contact without effective protection starting 2 days before\u00a0<\/span><span data-contrast=\"auto\">symptom\u00a0<\/span><span data-contrast=\"auto\">onset or 2 days before testing for asymptomatic cases.\u00a0<\/span><span data-contrast=\"auto\">Eight percent\u00a0<\/span><span data-contrast=\"auto\">of index cases\u00a0<\/span><span data-contrast=\"auto\">were asymptomatic, 16% had mild symptoms, 6<\/span><span data-contrast=\"auto\">9<\/span><span data-contrast=\"auto\">% had moderate symptoms, and 9% had severe<\/span><span data-contrast=\"auto\">\/<\/span><span data-contrast=\"auto\">critical illness.\u00a0<\/span><span data-contrast=\"auto\">Secondary attac<\/span><span data-contrast=\"auto\">k<\/span><span data-contrast=\"auto\">\u00a0rates were highest in\u00a0<\/span><span data-contrast=\"auto\">household\u00a0<\/span><span data-contrast=\"auto\">settings (<\/span><span data-contrast=\"auto\">10%)<\/span><span data-contrast=\"auto\">\u00a0and lower in\u00a0<\/span><span data-contrast=\"auto\">healthcare settings (1%) and on public transportation (0.1<\/span><span data-contrast=\"auto\">%<\/span><span data-contrast=\"auto\">).\u00a0<\/span><span data-ccp-props=\"{&quot;134233279&quot;:true,&quot;201341983&quot;:0,&quot;335559739&quot;:160,&quot;335559740&quot;:259}\">\u00a0<\/span><\/li>\n<li data-leveltext=\"\uf0b7\" data-font=\"Symbol\" data-listid=\"44\" data-aria-posinset=\"2\" data-aria-level=\"1\"><span data-contrast=\"auto\">Secondary attack rate was positively associated with index case severity,\u00a0<\/span><span data-contrast=\"auto\">at\u00a0<\/span><span data-contrast=\"auto\">0.3% for asymptomatic index cases, 3%<\/span><span data-contrast=\"auto\">\u00a0for mild<\/span><span data-contrast=\"auto\">\u00a0<\/span><span data-contrast=\"auto\">cases, 6<\/span><span data-contrast=\"auto\">% for moderate<\/span><span data-contrast=\"auto\">\u00a0cases,\u00a0<\/span><span data-contrast=\"auto\">and 6% for severe or critical\u00a0<\/span><span data-contrast=\"auto\">cases<\/span><span data-contrast=\"auto\">.\u00a0<\/span><span data-contrast=\"auto\">Secondary attack rate was\u00a0<\/span><span data-contrast=\"auto\">also\u00a0<\/span><span data-contrast=\"auto\">far higher for index cases<\/span><span data-contrast=\"auto\">\u00a0<\/span><span data-contrast=\"auto\">with\u00a0<\/span><span data-contrast=\"auto\">a productive cough (<\/span><span data-contrast=\"auto\">1<\/span><span data-contrast=\"auto\">4<\/span><span data-contrast=\"auto\">% versus 3%<\/span><span data-contrast=\"auto\">)<\/span><span data-contrast=\"auto\">.\u00a0<\/span><span data-ccp-props=\"{&quot;134233279&quot;:true,&quot;201341983&quot;:0,&quot;335559739&quot;:160,&quot;335559740&quot;:259}\">\u00a0<\/span><\/li>\n<\/ul>\n<p><i><span data-contrast=\"none\">Luo et al. (Aug 2020). Contact Settings and Risk for Transmission in 3410 Close Contacts of Patients With COVID-19 in Guangzhou, China: A Prospective Cohort Study. Annals of Internal Medicine.\u00a0<\/span><\/i><a href=\"https:\/\/doi.org\/10.7326\/M20-2671\"><span data-contrast=\"none\">https:\/\/doi.org\/10.7326\/M20-2671<\/span><\/a><i><span data-contrast=\"none\">\u00a0<\/span><\/i><i><span data-contrast=\"none\">\u00a0<\/span><\/i><span data-ccp-props=\"{&quot;201341983&quot;:0,&quot;335559685&quot;:720,&quot;335559739&quot;:160,&quot;335559740&quot;:259}\">\u00a0<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>A study of\u00a0SARS-CoV-2 infection among\u00a03,410 close contacts\u00a0of 391 confirmed SARS-CoV-2 cases\u00a0in Guangzhou, China\u00a0found a secondary attack rate of\u00a04%.\u00a0Close contact was defined as contact without effective protection starting 2 days before\u00a0symptom\u00a0onset or 2 days before testing for asymptomatic cases.\u00a0Eight percent\u00a0of index cases\u00a0were asymptomatic, 16% had mild symptoms, 69% had moderate symptoms, and 9% had severe\/critical illness.\u00a0Secondary&#8230;<\/p>\n<div><a class=\"more\" href=\"https:\/\/depts.washington.edu\/pandemicalliance\/2020\/08\/14\/contact-settings-and-risk-for-transmission-in-3410-close-contacts-of-patients-with-covid-19-in-guangzhou-china-a-prospective-cohort-study\/\">Read more<\/a><\/div>\n","protected":false},"author":8,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_links_to":"","_links_to_target":""},"categories":[6],"tags":[],"topic":[21],"class_list":["post-9050","post","type-post","status-publish","format-standard","hentry","category-article-summary","topic-transmission"],"_links":{"self":[{"href":"https:\/\/depts.washington.edu\/pandemicalliance\/wp-json\/wp\/v2\/posts\/9050","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/depts.washington.edu\/pandemicalliance\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/depts.washington.edu\/pandemicalliance\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/depts.washington.edu\/pandemicalliance\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/depts.washington.edu\/pandemicalliance\/wp-json\/wp\/v2\/comments?post=9050"}],"version-history":[{"count":1,"href":"https:\/\/depts.washington.edu\/pandemicalliance\/wp-json\/wp\/v2\/posts\/9050\/revisions"}],"predecessor-version":[{"id":9051,"href":"https:\/\/depts.washington.edu\/pandemicalliance\/wp-json\/wp\/v2\/posts\/9050\/revisions\/9051"}],"wp:attachment":[{"href":"https:\/\/depts.washington.edu\/pandemicalliance\/wp-json\/wp\/v2\/media?parent=9050"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/depts.washington.edu\/pandemicalliance\/wp-json\/wp\/v2\/categories?post=9050"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/depts.washington.edu\/pandemicalliance\/wp-json\/wp\/v2\/tags?post=9050"},{"taxonomy":"topic","embeddable":true,"href":"https:\/\/depts.washington.edu\/pandemicalliance\/wp-json\/wp\/v2\/topic?post=9050"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}