{"id":10013,"date":"2020-06-09T10:25:14","date_gmt":"2020-06-09T08:25:14","guid":{"rendered":"http:\/\/ayamm.org\/?p=10013"},"modified":"2020-06-09T10:25:17","modified_gmt":"2020-06-09T08:25:17","slug":"as-many-as-80-percent-of-people-with-covid-19-arent-aware-they-have-the-virus","status":"publish","type":"post","link":"https:\/\/ayamm.org\/en\/as-many-as-80-percent-of-people-with-covid-19-arent-aware-they-have-the-virus\/","title":{"rendered":"As Many as 80 Percent of People with COVID-19 Aren\u2019t Aware They Have the Virus"},"content":{"rendered":"\n<ul><li><strong>Researchers say anywhere from 25 percent to 80 percent of people with COVID-19 are unaware they have the virus.<\/strong><\/li><li><strong>This allows the novel coronavirus to spread more rapidly throughout a community.<\/strong><\/li><li><strong>Experts say these carriers without symptoms make it even more important for people to wear face masks in public.<\/strong><\/li><\/ul>\n\n\n\n<p><em>All data and statistics are based on publicly available data at the time of publication. Some information may be out of date.&nbsp;Visit our&nbsp;<a rel=\"noreferrer noopener\" target=\"_blank\" href=\"https:\/\/www.healthline.com\/coronavirus\">coronavirus hub<\/a>&nbsp;and follow our&nbsp;<a rel=\"noreferrer noopener\" target=\"_blank\" href=\"https:\/\/www.healthline.com\/health-news\/coronavirus-live-updates\">live updates page<\/a>&nbsp;for the most recent information on the COVID-19 outbreak.<\/em><\/p>\n\n\n\n<p>There may be a lot of people walking around who have&nbsp;<a href=\"https:\/\/www.healthline.com\/health-news\/coronavirus-live-updates\">COVID-19<\/a>&nbsp;but have no idea they are spreading the virus.<\/p>\n\n\n\n<p>The first word of this possibility came in early April from the Centers for Disease Control and Prevention (CDC) director, Dr. Robert Redfield, in an&nbsp;<a href=\"https:\/\/www.npr.org\/sections\/health-shots\/2020\/03\/31\/824155179\/cdc-director-on-models-for-the-months-to-come-this-virus-is-going-to-be-with-us\" target=\"_blank\" rel=\"noreferrer noopener\">interview<\/a>&nbsp;with National Public Radio affiliate WABE.<\/p>\n\n\n\n<p>\u201cOne of the [pieces of] information that we have confirmed now is that a significant number of individuals that are infected actually remain asymptomatic. That may be as many as 25 percent,\u201d Redfield said.<\/p>\n\n\n\n<p>Then a few days later, researchers in Iceland&nbsp;<a href=\"https:\/\/www.cnn.com\/2020\/04\/01\/europe\/iceland-testing-coronavirus-intl\/index.html\" target=\"_blank\" rel=\"noreferrer noopener\">reported<\/a>&nbsp;that 50 percent of their novel coronavirus cases who tested positive had no symptoms. The testing had been conducted by deCODE, a subsidiary of the U.S. Biotech company Amgen.<\/p>\n\n\n\n<p>In another&nbsp;<a href=\"https:\/\/www.cdc.gov\/mmwr\/volumes\/69\/wr\/mm6914e1.htm?s-cid=mm6914e1_e&amp;deliveryName=USCDC_921-DM24694\" target=\"_blank\" rel=\"noreferrer noopener\">reportTrusted Source<\/a>, the CDC stated that researchers in Singapore identified seven clusters of cases in which presymptomatic transmission is the most likely explanation for the occurrence of secondary cases.<\/p>\n\n\n\n<p>That report was backed up by a&nbsp;<a href=\"https:\/\/www.nature.com\/articles\/s41591-020-0869-5\" target=\"_blank\" rel=\"noreferrer noopener\">studyTrusted Source<\/a>&nbsp;published in mid-April that concluded that people with no symptoms are the source of 44 percent of diagnosed COVID-19 cases.<\/p>\n\n\n\n<p>In addition, a&nbsp;<a href=\"https:\/\/www.nature.com\/articles\/s41591-020-0869-5\" target=\"_blank\" rel=\"noreferrer noopener\">studyTrusted Source<\/a>&nbsp;published about the same time reported that people might be most contagious during the period before they have symptoms.<\/p>\n\n\n\n<p>Then, in late April, it was&nbsp;<a href=\"https:\/\/www.sfchronicle.com\/health\/article\/San-Jose-woman-who-died-Feb-6-showed-no-symptoms-15222877.php\" target=\"_blank\" rel=\"noreferrer noopener\">reported<\/a>&nbsp;that the first known person to die from COVID-19 in the United States before she died of a heart attack on February 6 at her home in Northern California.<\/p>\n\n\n\n<p>Finally, two studies published in late May indicated that a high percentage of people with COVID-19 could be without symptoms.<\/p>\n\n\n\n<p>In&nbsp;<a href=\"https:\/\/thorax.bmj.com\/content\/early\/2020\/05\/27\/thoraxjnl-2020-215091\" target=\"_blank\" rel=\"noreferrer noopener\">one study<\/a>, researchers reported that 104 of 128 people (81 percent) on a cruise ship who tested positive the novel coronavirus were asymptomatic.<\/p>\n\n\n\n<p>In&nbsp;<a href=\"https:\/\/jamanetwork.com\/journals\/jamanetworkopen\/fullarticle\/2766237?utm_source=For_The_Media&amp;utm_medium=referral&amp;utm_campaign=ftm_links&amp;utm_term=052720\" target=\"_blank\" rel=\"noreferrer noopener\">another studyTrusted Source<\/a>, researchers reported that 42 percent of people who tested positive for COVID-19 were without symptoms.<\/p>\n\n\n\n<p>\u201cOf those of us that get symptomatic, it appears that we\u2019re shedding significant virus in our oropharyngeal compartment, probably up to 48 hours before we show symptoms,\u201d Redfield said. \u201cThis helps explain how rapidly this virus continues to spread across the country because we have asymptomatic transmitters.\u201d<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><a>How transmission works<\/a><\/h2>\n\n\n\n<p>\u201cIt isn\u2019t a strange idea with respiratory viruses that such an inadvertent transmission could take place,\u201d said&nbsp;<a href=\"https:\/\/www.vumc.org\/health-policy\/person\/william-schaffner-md\" target=\"_blank\" rel=\"noreferrer noopener\">Dr. William Schaffner<\/a>, an infectious disease expert from Vanderbilt University Medical Center in Tennessee.<\/p>\n\n\n\n<p>\u201cIt\u2019s to the virus\u2019 benefit because if you have seemingly healthy people moving around spreading the virus, that maximizes the transmission,\u201d he told Healthline. \u201cOnce you get sick, you tend to restrict your encounters with others.\u201d<\/p>\n\n\n\n<p>To demonstrate how fast the virus transmission works among people who may be unwittingly infecting others,&nbsp;<a href=\"https:\/\/www.mmc.edu\/about\/administration\/james_hildreth_bio.html\" target=\"_blank\" rel=\"noreferrer noopener\">Dr. James Hildreth<\/a>, president and chief executive officer of Meharry Medical College and an infectious disease expert, illustrated the spread in a&nbsp;<a href=\"https:\/\/www.youtube.com\/watch?v=cDycxfTEBXs&amp;feature=youtu.be\" target=\"_blank\" rel=\"noreferrer noopener\">public service announcement<\/a>.<\/p>\n\n\n\n<p>He said people who study virus spread assign viruses basic reproductive spread numbers.<\/p>\n\n\n\n<p>\u201cOne that comes to mind is measles. Measles is one of the most contagious viruses we\u2019ve ever known and its number is somewhere between 12 and 18,\u201d Hildreth told Healthline.<\/p>\n\n\n\n<p>\u201cBy comparison, the COVID-19 virus, it\u2019s basic reproductive number appears to be about 4. What that means is that each person who is infected by the virus has the potential to spread it to four other persons in a susceptible population,\u201d he explained.<\/p>\n\n\n\n<p>\u201cIf you do the math, the number of people infected would double every 6 days or so. But the actual data in some parts of the country is the virus is doubling every 3 days,\u201d Hildreth added.<\/p>\n\n\n\n<p>He noted that this novel coronavirus that began in December in a market in Wuhan, China, has infected 1.4 million people in 4 months.<\/p>\n\n\n\n<p>\u201cWhen you\u2019re dealing with a virus like that, everything we can do to break the chain of transmission is exceedingly important because there are people who are spreading the virus and are not aware of it,\u201d he said.<\/p>\n\n\n\n<figure><iframe width=\"728\" height=\"90\"><\/iframe><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\"><a>This makes masks more important<\/a><\/h2>\n\n\n\n<p>After first telling the public there was no need for anyone to wear a mask unless you were sick or coughing, the CDC did an about-face in early April.<\/p>\n\n\n\n<p>Now, the agency is&nbsp;<a href=\"https:\/\/www.healthline.com\/health-news\/face-masks-importance-battle-with-covid19\">recommending<\/a>&nbsp;people wear a face covering if they go to a public place.<\/p>\n\n\n\n<p>They\u2019ve posted&nbsp;<a href=\"https:\/\/www.cdc.gov\/coronavirus\/2019-ncov\/prevent-getting-sick\/diy-cloth-face-coverings.html\" target=\"_blank\" rel=\"noreferrer noopener\">instructionsTrusted Source<\/a>&nbsp;on how to properly wear a cloth mask.<\/p>\n\n\n\n<p>But does a cloth mask work?<\/p>\n\n\n\n<p>\u201cIt actually works in both directions,\u201d said Schaffner. \u201cBut we\u2019re more sure that masks inhibit the spread out rather than the acquisition in.\u201d<\/p>\n\n\n\n<p>Why the CDC reversal?<\/p>\n\n\n\n<p>\u201cTwo reasons. One is very practical. Early on, they didn\u2019t want there to be a run on masks and respirators by the general public, siphoning them off from the healthcare environment. That was a very real concern,\u201d Schaffner said.<\/p>\n\n\n\n<p>\u201cThe second thing is the appreciation of presymptomatic transmission has become more evident over time,\u201d he added. \u201cIt takes a little bit of time for those discussions to go on and for everyone to agree to ask the American public to do something that is culturally alien.\u201d<\/p>\n\n\n\n<p>And Schaffner believes the masks have a psychological benefit at a time when very little seems in our control.<\/p>\n\n\n\n<p>\u201cPutting on a mask is something I can do to help protect me and it will help protect my family. It makes people feel good to do something,\u201d he said. \u201cAnd when you see others wearing a mask, it builds a sense of community.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Researchers say anywhere from 25 percent to 80 percent of people with COVID-19 are unaware they have the virus. This allows the novel coronavirus to spread<span class=\"excerpt-hellip\"> [\u2026]<\/span><\/p>\n","protected":false},"author":7,"featured_media":10014,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[112],"tags":[],"_links":{"self":[{"href":"https:\/\/ayamm.org\/en\/wp-json\/wp\/v2\/posts\/10013"}],"collection":[{"href":"https:\/\/ayamm.org\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ayamm.org\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ayamm.org\/en\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/ayamm.org\/en\/wp-json\/wp\/v2\/comments?post=10013"}],"version-history":[{"count":1,"href":"https:\/\/ayamm.org\/en\/wp-json\/wp\/v2\/posts\/10013\/revisions"}],"predecessor-version":[{"id":10016,"href":"https:\/\/ayamm.org\/en\/wp-json\/wp\/v2\/posts\/10013\/revisions\/10016"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ayamm.org\/en\/wp-json\/wp\/v2\/media\/10014"}],"wp:attachment":[{"href":"https:\/\/ayamm.org\/en\/wp-json\/wp\/v2\/media?parent=10013"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ayamm.org\/en\/wp-json\/wp\/v2\/categories?post=10013"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ayamm.org\/en\/wp-json\/wp\/v2\/tags?post=10013"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}