Coronavirus disease 2019

Coro­n­avirus dis­ease 2019

COVID-19 is a con­ta­gious dis­ease caused by the coro­n­avirus SARS-CoV-2. In Jan­u­ary 2020, the dis­ease spread world­wide, result­ing in the COVID-19 pan­dem­ic.

The symp­toms of COVID?19 can vary but often include fever,[7] fatigue, cough, breath­ing dif­fi­cul­ties, loss of smell, and loss of taste.[8][9][10] Symp­toms may begin one to four­teen days after expo­sure to the virus. At least a third of peo­ple who are infect­ed do not devel­op notice­able symptoms.[11][12] Of those who devel­op symp­toms notice­able enough to be clas­si­fied as patients, most (81%) devel­op mild to mod­er­ate symp­toms (up to mild pneu­mo­nia), while 14% devel­op severe symp­toms (dys­p­nea, hypox­ia, or more than 50% lung involve­ment on imag­ing), and 5% devel­op crit­i­cal symp­toms (res­pi­ra­to­ry fail­ure, shock, or mul­ti­or­gan dysfunction).[13] Old­er peo­ple have a high­er risk of devel­op­ing severe symp­toms. Some com­pli­ca­tions result in death. Some peo­ple con­tin­ue to expe­ri­ence a range of effects (long COVID) for months or years after infec­tion, and dam­age to organs has been observed.[14] Mul­ti-year stud­ies on the long-term effects are ongoing.[15]

COVID?19 trans­mis­sion occurs when infec­tious par­ti­cles are breathed in or come into con­tact with the eyes, nose, or mouth. The risk is high­est when peo­ple are in close prox­im­i­ty, but small air­borne par­ti­cles con­tain­ing the virus can remain sus­pend­ed in the air and trav­el over longer dis­tances, par­tic­u­lar­ly indoors. Trans­mis­sion can also occur when peo­ple touch their eyes, nose, or mouth after touch­ing sur­faces or objects that have been con­t­a­m­i­nat­ed by the virus. Peo­ple remain con­ta­gious for up to 20 days and can spread the virus even if they do not devel­op symptoms.[16]

Test­ing meth­ods for COVID-19 to detect the virus’s nucle­ic acid include real-time reverse tran­scrip­tion poly­merase chain reac­tion (RT?PCR),[17][18] tran­scrip­tion-medi­at­ed amplification,[17][18][19] and reverse tran­scrip­tion loop-medi­at­ed isother­mal ampli­fi­ca­tion (RT?LAMP)[17][18] from a nasopha­ryn­geal swab.[20]

Sev­er­al COVID-19 vac­cines have been approved and dis­trib­uted in var­i­ous coun­tries, many of which have ini­ti­at­ed mass vac­ci­na­tion cam­paigns. Oth­er pre­ven­tive mea­sures include phys­i­cal or social dis­tanc­ing, quar­an­ti­ning, ven­ti­la­tion of indoor spaces, use of face masks or cov­er­ings in pub­lic, cov­er­ing coughs and sneezes, hand wash­ing, and keep­ing unwashed hands away from the face. While drugs have been devel­oped to inhib­it the virus, the pri­ma­ry treat­ment is still symp­to­matic, man­ag­ing the dis­ease through sup­port­ive care, iso­la­tion, and exper­i­men­tal mea­sures.