Data from the smartphone app can identify the onset of symptoms in an area about five days before requests for COVID tests spike.<\/div>\n
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Testing for the virus has increased dramatically as the pandemic has worn on, but experts say the current rate in the U.S. \u2014 at least 1.1 million in the week of May 10, according to the U.S. Centers for Disease Control and Prevention \u2014 represents a fraction of what is needed.<\/p>\n
The app is among several strategies being employed worldwide to illuminate the overall COVID picture. The recent rush to develop and distribute antibody or serologic tests, which can tell whether someone has had COVID-19 in the past, is one, as is the examination of sewage for COVID-19 DNA, which can be traced to particular neighborhoods undergoing an outbreak. Understanding the disease\u2019s path through a population is essential to design effective responses and \u2014 in the absence of a vaccine \u2014 to gauge progress toward so-called \u201cherd immunity,\u201d where enough people have been infected that it interferes with the virus\u2019 spread.<\/p>\n
Chan said his collaborators in London have worked with the public health service there and shown that data from the smartphone app can identify the onset of symptoms in an area about five days before requests for COVID tests spike.<\/p>\n
\u201cIt gives people really critical planning time they otherwise wouldn\u2019t have had,\u201d Chan said.<\/p>\n
In the work, published recently in the journal Nature Medicine, researchers used data from about 18,000 participants who had been tested for SARS-CoV-2 to understand which symptoms were most common in those who had tested positive. They found that loss of taste and smell were reported by most of those tested, about 65 percent, and that the most predictive group of symptoms was loss of smell and taste, fatigue, persistent cough, and loss of appetite.<\/p>\n
They then applied their model to more than 800,000 study participants who had not been tested and determined that about 140,000 of them were likely infected with the virus, just over 5 percent of the entire 2.6 million study population. Researchers said the study is limited by the fact that the app volunteers are self-selected and likely don\u2019t represent the general population. They also said the results don\u2019t indicate when loss of smell and taste occur in the illness\u2019 course, though that may become apparent as more results are collected over time.<\/p>\n
Chan said the crowdsourced data includes numerous mild cases \u2014 thought to be about a quarter of those infected overall \u2014 and one of the ways the app may do the most good is by increasing understanding of them.<\/p>\n
\u201cThey are a group most at risk of spreading it because they don\u2019t know they have it,\u201d Chan said.<\/p>\n
Another such group would be those who are completely asymptomatic, and the app data wouldn\u2019t capture them since the information is self-reported. Those numbers would only be discovered through actual testing.<\/p>\n
Future work is focusing on other unanswered questions, such as the impact of COVID on cancer patients and the effect of past infections on developing immunity. Discussions are also ongoing as to how the app can help governments direct limited resources, such as a county deploying testing or contact tracing to places where need is highest. It can also be used by managers of smaller groups \u2014 students at a particular college or workers at a large factory \u2014 to guide decisions about how best to guard students\u2019 and workers\u2019 health as society reopens more fully.<\/p>\n
\u201cI think we\u2019re all very nervous about that [reopening], and this will be an opportunity to see if this kind of crowdsourcing information can help,\u201d Chan said. \u201cUltimately it can be a tool people use at the level of public health to predict whether we can loosen restrictions. The more planning we can do the better.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"This is part of our Coronavirus Update series in which Harvard specialists in epidemiology, infectious disease, economics, politics,…\n","protected":false},"author":1,"featured_media":2435,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"csco_singular_sidebar":"","csco_page_header_type":"","csco_appearance_masonry":"","csco_page_load_nextpost":"","csco_post_video_location":[],"csco_post_video_location_hash":"","csco_post_video_url":"","csco_post_video_bg_start_time":0,"csco_post_video_bg_end_time":0,"footnotes":""},"categories":[32],"tags":[],"class_list":{"0":"post-2434","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-health-care","8":"cs-entry","9":"cs-video-wrap"},"_links":{"self":[{"href":"https:\/\/wellnesscornerstore.com\/wp-json\/wp\/v2\/posts\/2434","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wellnesscornerstore.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wellnesscornerstore.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wellnesscornerstore.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/wellnesscornerstore.com\/wp-json\/wp\/v2\/comments?post=2434"}],"version-history":[{"count":0,"href":"https:\/\/wellnesscornerstore.com\/wp-json\/wp\/v2\/posts\/2434\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/wellnesscornerstore.com\/wp-json\/wp\/v2\/media\/2435"}],"wp:attachment":[{"href":"https:\/\/wellnesscornerstore.com\/wp-json\/wp\/v2\/media?parent=2434"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wellnesscornerstore.com\/wp-json\/wp\/v2\/categories?post=2434"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wellnesscornerstore.com\/wp-json\/wp\/v2\/tags?post=2434"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}