View source for COVID-19 diagnostic study of choice

__NOTOC__
'''For COVID-19 frequently asked inpatient questions, click [[COVID-19 frequently asked inpatient questions|here]]'''<br>
'''For COVID-19 frequently asked outpatient questions, click [[COVID-19 frequently asked outpatient questions|here]]'''<br>
{{COVID-19}}
{{CMG}} ; {{AE}} {{sab}} {{MSJ}}

==Overview==
The [[diagnostic]] study of choice for COVID-19 illness is the [[Nucleic acid amplification test]] (NAAT) by a reverse transcriptase-polymerase chain reaction (RT-PCR). The RT-PCR is performed in symptomatic patients and individuals with high-risk exposure. There is no need to perform additional tests in situations with positive NAAT. The diagnostic criteria for suspected and confirmed cases of [[coronavirus]] disease 2019 ([[COVID-19]]) are also tabulated in the section below.

==Diagnostic Study of Choice==
===Study of Choice===
*The Nucleic acid amplification test by the reverse transcriptase-[[polymerase chain reaction]] (RT-PCR) is the gold standard test for detecting [[coronavirus]] illness. These tests are highly specific for detecting [[coronavirus]] illness.<ref name="pmid32269100">{{cite journal| author=Nalla AK, Casto AM, Huang MW, Perchetti GA, Sampoleo R, Shrestha L | display-authors=etal| title=Comparative Performance of SARS-CoV-2 Detection Assays Using Seven Different Primer-Probe Sets and One Assay Kit. | journal=J Clin Microbiol | year= 2020 | volume= 58 | issue= 6 | pages=  | pmid=32269100 | doi=10.1128/JCM.00557-20 | pmc=7269385 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=32269100  }} </ref>

===Diagnostic Results===
*The NAAT detects viral gene sequence specific for [[coronavirus]]. The genes detected by NAAT include [[nucleocapsid]](N), [[Viral envelope|envelope]](E), spike(S), and [[RNA dependent RNA polymerase]] (RdRP) in the open reading frame. <ref name="pmid32245835">{{cite journal| author=Tang YW, Schmitz JE, Persing DH, Stratton CW| title=Laboratory Diagnosis of COVID-19: Current Issues and Challenges. | journal=J Clin Microbiol | year= 2020 | volume= 58 | issue= 6 | pages=  | pmid=32245835 | doi=10.1128/JCM.00512-20 | pmc=7269383 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=32245835  }} </ref>
*The turnaround time for these tests is variable depending upon the specific testing kit and laboratory performing it.<ref name="pmid32350048">{{cite journal| author=Lieberman JA, Pepper G, Naccache SN, Huang ML, Jerome KR, Greninger AL| title=Comparison of Commercially Available and Laboratory Developed Assays for in vitro Detection of SARS-CoV-2 in Clinical Laboratories. | journal=J Clin Microbiol | year= 2020 | volume=  | issue=  | pages=  | pmid=32350048 | doi=10.1128/JCM.00821-20 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=32350048  }} </ref>
*The diagnosis of [[coronavirus]] illness requires detection of at least two genes specific for SAR Cov-2 by RT-[[Polymerase chain reaction|PCR]]. In the United States, the Center for disease control and prevention recommends testing for two [[nucleocapsid]] proteins N1 and N2.<ref name="pmid32004427">{{cite journal| author=Holshue ML, DeBolt C, Lindquist S, Lofy KH, Wiesman J, Bruce H | display-authors=etal| title=First Case of 2019 Novel Coronavirus in the United States. | journal=N Engl J Med | year= 2020 | volume= 382 | issue= 10 | pages= 929-936 | pmid=32004427 | doi=10.1056/NEJMoa2001191 | pmc=7092802 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=32004427  }} </ref>
*World Health Organization recommends two-step gene testing by NAAT for diagnosis of [[coronavirus]] illness. The first step is screening for [[coronavirus]] illness with [[Viral envelope|Envelope]](E) gene assay followed by a confirmatory test with [[RNA dependent RNA polymerase]] (RdRP) gene assay.<ref name="pmid31992387">{{cite journal| author=Corman VM, Landt O, Kaiser M, Molenkamp R, Meijer A, Chu DK | display-authors=etal| title=Detection of 2019 novel coronavirus (2019-nCoV) by real-time RT-PCR. | journal=Euro Surveill | year= 2020 | volume= 25 | issue= 3 | pages=  | pmid=31992387 | doi=10.2807/1560-7917.ES.2020.25.3.2000045 | pmc=6988269 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=31992387  }} </ref>
*The RdRp/Hel gene assay has the highest sensitivity and specificity for the diagnosis of [[coronavirus]] illness in comparison with spike and [[nucleocapsid]] genes. It has the lowest limit of detection in vitro.<ref name="pmid32132196">{{cite journal| author=Chan JF, Yip CC, To KK, Tang TH, Wong SC, Leung KH | display-authors=etal| title=Improved Molecular Diagnosis of COVID-19 by the Novel, Highly Sensitive and Specific COVID-19-RdRp/Hel Real-Time Reverse Transcription-PCR Assay Validated In Vitro and with Clinical Specimens. | journal=J Clin Microbiol | year= 2020 | volume= 58 | issue= 5 | pages=  | pmid=32132196 | doi=10.1128/JCM.00310-20 | pmc=7180250 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=32132196  }} </ref>
*The NAAT can have false-negative results. The false-negative results can depend upon a number of factors related to sample, course of illness, genetic mutations in the [[virus]].<ref name="pmid32342927">{{cite journal| author=Zainol Rashid Z, Othman SN, Abdul Samat MN, Ali UK, Wong KK| title=Diagnostic performance of COVID-19 serology assays. | journal=Malays J Pathol | year= 2020 | volume= 42 | issue= 1 | pages= 13-21 | pmid=32342927 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=32342927  }} </ref> An adequate sample should be taken with proper technique and transported and stored at an optimum temperature from the testing area to laboratory.
*The sampling time on the day of illness is important as the viral load is low in the early and convalescence stages of infection. The RT-[[Polymerase chain reaction|PCR]] is positive one to two days before the onset of symptoms till 7 to 12 days in moderate cases and up to two weeks in severe patients.<ref name="pmid32342927">{{cite journal| author=Zainol Rashid Z, Othman SN, Abdul Samat MN, Ali UK, Wong KK| title=Diagnostic performance of COVID-19 serology assays. | journal=Malays J Pathol | year= 2020 | volume= 42 | issue= 1 | pages= 13-21 | pmid=32342927 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=32342927  }} </ref> A study was done in a hospital in China where 51 [[coronavirus]] suspected patients had RT-[[Polymerase chain reaction|PCR]] tests and chest CT scans. 36 patients had positive first RT-[[Polymerase chain reaction|PCR]] tests. 15 patients had negative tests with CT scan findings were highly suggestive of viral [[pneumonia]]. Serial testing by RT-[[Polymerase chain reaction|PCR]] was positive in these [[patient]]<nowiki/>s.<ref name="FangZhang2020">{{cite journal|last1=Fang|first1=Yicheng|last2=Zhang|first2=Huangqi|last3=Xie|first3=Jicheng|last4=Lin|first4=Minjie|last5=Ying|first5=Lingjun|last6=Pang|first6=Peipei|last7=Ji|first7=Wenbin|title=Sensitivity of Chest CT for COVID-19: Comparison to                     RT-PCR|journal=Radiology|year=2020|pages=200432|issn=0033-8419|doi=10.1148/radiol.2020200432}}</ref>
*The type of sample is an important factor. In patients with dry [[cough]] nasopharyngeal swabs should be preferred over oropharyngeal swabs.<ref name="pmid32221523">{{cite journal| author=Yu F, Yan L, Wang N, Yang S, Wang L, Tang Y | display-authors=etal| title=Quantitative Detection and Viral Load Analysis of SARS-CoV-2 in Infected Patients. | journal=Clin Infect Dis | year= 2020 | volume=  | issue=  | pages=  | pmid=32221523 | doi=10.1093/cid/ciaa345 | pmc=7184442 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=32221523  }} </ref> The lower respiratory tract samples have high viral load and positive detection rates compared to upper respiratory tract samples. A study was done in China which compared the positive detection rates in different specimens from 205 symptomatic patients. The study showed a 93% positive rate in [[bronchoalveolar lavage]] fluids specimens, 72 % in [[sputum]], 63 % in nasal, and 32 % in the pharyngeal swab.<ref name="pmid32159775">{{cite journal| author=Wang W, Xu Y, Gao R, Lu R, Han K, Wu G | display-authors=etal| title=Detection of SARS-CoV-2 in Different Types of Clinical Specimens. | journal=JAMA | year= 2020 | volume=  | issue=  | pages=  | pmid=32159775 | doi=10.1001/jama.2020.3786 | pmc=7066521 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=32159775  }} </ref>

===The comparison of chest CT scan and RT-PCR===
*There are research studies that compared the [[Accuracy and precision|accuracy]], [[Sensitivity (tests)|sensitivity]], and [[Specificity (tests)|specificity]] of chest CT scans with RT-[[Polymerase chain reaction|PCR]] in diagnosing [[coronavirus]] illness.
*The RT-[[Polymerase chain reaction|PCR]] test is the reference standard for the comparison.
*A retrospective study was performed by Ai et al. in 1049 suspected patients at the largest [[hospital]] in Wuhan, China. <ref name="pmid32101510">{{cite journal| author=Ai T, Yang Z, Hou H, Zhan C, Chen C, Lv W | display-authors=etal| title=Correlation of Chest CT and RT-PCR Testing in Coronavirus Disease 2019 (COVID-19) in China: A Report of 1014 Cases. | journal=Radiology | year= 2020 | volume=  | issue=  | pages= 200642 | pmid=32101510 | doi=10.1148/radiol.2020200642 | pmc=7233399 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=32101510  }} </ref> Gietema et al. did a prospective study on 193 symptomatic [[patient]]<nowiki/>s in a [[hospital]] in Netherland.<ref name="pmid32645053">{{cite journal| author=Gietema HA, Zelis N, Nobel JM, Lambriks LJG, van Alphen LB, Oude Lashof AML | display-authors=etal| title=CT in relation to RT-PCR in diagnosing COVID-19 in The Netherlands: A prospective study. | journal=PLoS One | year= 2020 | volume= 15 | issue= 7 | pages= e0235844 | pmid=32645053 | doi=10.1371/journal.pone.0235844 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=32645053  }} </ref> The results from both these studies are tabulated below:
{| class="wikitable"
|+
!Author!! Total number of patients !! Sensitivity % (95 % CI) !! Specificity % (95% CI) !! Positive predictive value % (95% CI) !! Negative predictive value % (95% CI)
|-
!Ai et al
|1049 || 89.2(80.4-94.9) || 68.2(58.6-76.7) || 67.9(61.4-73.7) || 89.3(81.6-94)
|-
!Gietema et al
|193 || 97(95-98) || 25(22-30) || 65(62-68) || 83(76-89)
|}
*Both studies showed high [[Sensitivity (tests)|sensitivity]] of chest CT scans in diagnosing [[coronavirus]] illness.
*The RT-[[Polymerase chain reaction|PCR]] has a low positive rate. The [[Sensitivity (tests)|sensitivity]] of chest CT scan is overestimated, and [[Specificity (tests)|specificity]] is underestimated by using RT-[[Polymerase chain reaction|PCR]] as a reference test.<ref name="pmid32101510">{{cite journal| author=Ai T, Yang Z, Hou H, Zhan C, Chen C, Lv W | display-authors=etal| title=Correlation of Chest CT and RT-PCR Testing in Coronavirus Disease 2019 (COVID-19) in China: A Report of 1014 Cases. | journal=Radiology | year= 2020 | volume=  | issue=  | pages= 200642 | pmid=32101510 | doi=10.1148/radiol.2020200642 | pmc=7233399 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=32101510  }} </ref>
*In the early course of the illness, both the RT-[[Polymerase chain reaction|PCR]] and Chest CT scans can have false-negative results.<ref name="pmid32049601 10.1148/radiol.2020200463">{{cite journal| author=Xie X, Zhong Z, Zhao W, Zheng C, Wang F, Liu J| title=Chest CT for Typical 2019-nCoV Pneumonia: Relationship to Negative RT-PCR Testing. | journal=Radiology | year= 2020 | volume=  | issue=  | pages= 200343 | pmid=32049601 10.1148/radiol.2020200463 | doi=10.1148/radiol.2020200343 | pmc=7233363 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=32049601  }} </ref> Serial RT-[[Polymerase chain reaction|PCR]] tests should be performed in patients with clinical symptoms suggestive of [[coronavirus]] illness.
*The chest CT scan can have positive findings in other respiratory illnesses including viral [[pneumonia]].<ref name="pmid32645053">{{cite journal| author=Gietema HA, Zelis N, Nobel JM, Lambriks LJG, van Alphen LB, Oude Lashof AML | display-authors=etal| title=CT in relation to RT-PCR in diagnosing COVID-19 in The Netherlands: A prospective study. | journal=PLoS One | year= 2020 | volume= 15 | issue= 7 | pages= e0235844 | pmid=32645053 | doi=10.1371/journal.pone.0235844 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=32645053  }} </ref>

===The Comparison of Serological Assays with RT-PCR===
[[Image:COVID-19 - Dx testing.png|left|500px]]



*The serological assays detect titers of [[antibodies]] against two structural proteins on SARS Cov-2. The proteins are S proteins from spike and N proteins from helical [[nucleocapsid]] of [[coronavirus]].<ref name="pmid19342289">{{cite journal| author=Chan CM, Tse H, Wong SS, Woo PC, Lau SK, Chen L | display-authors=etal| title=Examination of seroprevalence of coronavirus HKU1 infection with S protein-based ELISA and neutralization assay against viral spike pseudotyped virus. | journal=J Clin Virol | year= 2009 | volume= 45 | issue= 1 | pages= 54-60 | pmid=19342289 | doi=10.1016/j.jcv.2009.02.011 | pmc=7108224 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=19342289  }} </ref><ref name="pmid15018127">{{cite journal| author=Chan-Yeung M, Xu RH| title=SARS: epidemiology. | journal=Respirology | year= 2003 | volume= 8 Suppl | issue=  | pages= S9-14 | pmid=15018127 | doi=10.1046/j.1440-1843.2003.00518.x | pmc=7169193 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15018127  }} </ref><ref name="pmid32113505">{{cite journal| author=Liu Y, Eggo RM, Kucharski AJ| title=Secondary attack rate and superspreading events for SARS-CoV-2. | journal=Lancet | year= 2020 | volume= 395 | issue= 10227 | pages= e47 | pmid=32113505 | doi=10.1016/S0140-6736(20)30462-1 | pmc=7158947 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=32113505  }} </ref>Both these proteins are highly antigenic and elevated titers of [[antibodies]] are produced on exposure to it. [[Immunoglobulin M|IgM]], [[Immunoglobulin G|IgG]] or both [[antibodies]] levels are measured by rapid lateral flow assays in [[serum]], [[Blood plasma|plasma]], or whole [[blood]] samples.<ref name="pmid32104917">{{cite journal| author=Li Z, Yi Y, Luo X, Xiong N, Liu Y, Li S | display-authors=etal| title=Development and clinical application of a rapid IgM-IgG combined antibody test for SARS-CoV-2 infection diagnosis. | journal=J Med Virol | year= 2020 | volume=  | issue=  | pages=  | pmid=32104917 | doi=10.1002/jmv.25727 | pmc=7228300 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=32104917  }} </ref>
*The [[Immunoglobulin M|IgM]] and [[Immunoglobulin G|IgG]] [[antibodies]] rise in the later course of the illness.
** [[Immunoglobulin M|IgM]] [[antibodies]] titers rise first with a median duration of detection of 5 days after the onset of symptoms followed by a rise in [[Immunoglobulin G|IgG]] [[antibodies]] titer. 
** The median time for the detection of [[Immunoglobulin G|IgG]] [[antibodies]] titers is 2 weeks after the onset of symptoms.<ref name="pmid32198501">{{cite journal| author=Guo L, Ren L, Yang S, Xiao M, Yang F | display-authors=etal| title=Profiling Early Humoral Response to Diagnose Novel Coronavirus Disease (COVID-19). | journal=Clin Infect Dis | year= 2020 | volume=  | issue=  | pages=  | pmid=32198501 | doi=10.1093/cid/ciaa310 | pmc=7184472 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=32198501  }} </ref>
** Sensitivity for [[Immunoglobulin G|IgG]] [[antibodies]] titers is over 90% after three weeks<ref name="pmid32422057">{{cite journal| author=Kucirka LM, Lauer SA, Laeyendecker O, Boon D, Lessler J| title=Variation in False-Negative Rate of Reverse Transcriptase Polymerase Chain Reaction-Based SARS-CoV-2 Tests by Time Since Exposure. | journal=Ann Intern Med | year= 2020 | volume= 173 | issue= 4 | pages= 262-267 | pmid=32422057 | doi=10.7326/M20-1495 | pmc=7240870 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=32422057  }} </ref><ref name="pmid33609075">{{cite journal| author=Zhang JJY, Lee KS, Ong CW, Chan MY, Ang LW, Leo YS | display-authors=etal| title=Diagnostic performance of COVID-19 serological assays during early infection: A systematic review and meta-analysis of 11 516 samples. | journal=Influenza Other Respir Viruses | year= 2021 | volume=  | issue=  | pages=  | pmid=33609075 | doi=10.1111/irv.12841 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=33609075  }} </ref>

*The Serological assays can help detect subclinical, asymptomatic, late, and previous exposure to [[coronavirus]]. The serological assays increase the positive detection rates for detecting SARS Cov-2 when performed in conjunction with RT-[[Polymerase chain reaction|PCR]] compared to [[Polymerase chain reaction|PCR]] alone in suspected individuals. The positive detection rate of RT-[[Polymerase chain reaction|PCR]] with [[Immunoglobulin M|IgM]] assay was 98.6% compared to 51.9% with [[Polymerase chain reaction|PCR]] alone.<ref name="pmid32198501">{{cite journal| author=Guo L, Ren L, Yang S, Xiao M, Yang F | display-authors=etal| title=Profiling Early Humoral Response to Diagnose Novel Coronavirus Disease (COVID-19). | journal=Clin Infect Dis | year= 2020 | volume=  | issue=  | pages=  | pmid=32198501 | doi=10.1093/cid/ciaa310 | pmc=7184472 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=32198501  }} </ref>
*There are few advantages of serological assays over the [[Polymerase chain reaction|PCR]]. The serological assays are less expensive, rapid, and easier to perform with less hazard of transmission to the [[virus]] to the health worker collecting the sample. <ref name="pmid32342927">{{cite journal| author=Zainol Rashid Z, Othman SN, Abdul Samat MN, Ali UK, Wong KK| title=Diagnostic performance of COVID-19 serology assays. | journal=Malays J Pathol | year= 2020 | volume= 42 | issue= 1 | pages= 13-21 | pmid=32342927 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=32342927  }} </ref>
*Secondly, the false-negative results due to sample characteristics in RT-[[Polymerase chain reaction|PCR]] are absent in it. The antibodies are uniformly present in [[Blood plasma|plasma]]. <ref name="pmid32198501">{{cite journal| author=Guo L, Ren L, Yang S, Xiao M, Yang F | display-authors=etal| title=Profiling Early Humoral Response to Diagnose Novel Coronavirus Disease (COVID-19). | journal=Clin Infect Dis | year= 2020 | volume=  | issue=  | pages=  | pmid=32198501 | doi=10.1093/cid/ciaa310 | pmc=7184472 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=32198501  }} </ref>

=== Diagnostic Criteria ===
The diagnostic criteria for suspected and confirmed cases of [[coronavirus]] disease 2019 ([[COVID-19]]) is tabulated below:<ref name="ChenZhou2020">{{cite journal|last1=Chen|first1=Nanshan|last2=Zhou|first2=Min|last3=Dong|first3=Xuan|last4=Qu|first4=Jieming|last5=Gong|first5=Fengyun|last6=Han|first6=Yang|last7=Qiu|first7=Yang|last8=Wang|first8=Jingli|last9=Liu|first9=Ying|last10=Wei|first10=Yuan|last11=Xia|first11=Jia'an|last12=Yu|first12=Ting|last13=Zhang|first13=Xinxin|last14=Zhang|first14=Li|title=Epidemiological and clinical characteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study|journal=The Lancet|volume=395|issue=10223|year=2020|pages=507–513|issn=01406736|doi=10.1016/S0140-6736(20)30211-7}}</ref><ref>{{Cite web|url=http://www.nhc.gov.cn/xcs/zhengcwj/202002/de2d62a5711c41ef9b2c4b6f4d1f2136.shtml|title=C.N.H. Commission
Notice on prevention and control of pneumonia in children and pregnant women with new coronavirus infection
China National Health Commission, Beijing (2020)
(in Chinese)|last=|first=|date=|website=|archive-url=|archive-date=|dead-url=|access-date=}}</ref><ref>{{Cite web|url=http://kns.cnki.net.ezp-prod1.hul.harvard.edu/kcms/detail/42.1293.r.20200130.1803.002.html.|title=Technology, M.e.g.o.T.h.a.t.T.M.C.o.H.U.o.S.a. A rapid guideline for the diagnosis and treatment of pneumonia with new coronavirus infection (Third edition).|last=|first=|date=|website=|archive-url=|archive-date=|dead-url=|access-date=}}</ref><ref>{{Cite web|url=https://mp.weixin.qq.com/s/d7btF9g1wMhNgFnHy5vY1Q|title=Union Hospital
T.M.C., Huazhong University of Science and Technology., Wuhan union hospital manage the 2019 new coronavirus infection strategies and instructions
(in Chinese)|last=|first=|date=|website=|archive-url=|archive-date=|dead-url=|access-date=}}</ref><ref name="pmid32023681">{{cite journal |vauthors= |title=[Diagnosis and clinical management of 2019 novel coronavirus infection: an operational recommendation of Peking Union Medical College Hospital (V2.0)] |language=Chinese |journal=Zhonghua Nei Ke Za Zhi |volume=59 |issue=3 |pages=186–188 |date=February 2020 |pmid=32023681 |doi=10.3760/cma.j.issn.0578-1426.2020.03.003 |url=}}</ref><ref>{{Cite web|url=https://www.who.int/publications-detail/clinical-management-of-severe-acute-respiratory-infection-when-novel-coronavirus-(ncov)-infection-is-suspected|title=Clinical management of severe acute respiratory infection when novel coronavirus (nCoV) infection is suspected|last=|first=|date=|website=|archive-url=|archive-date=|dead-url=|access-date=}}</ref>
{| class="wikitable"
|+
!Case
!Diagnostic Criteria
|-
!Suspected Case
|Anyone with a history of [[epidemiology]] and any two of the clinical manifestations or anyone without [[Epidemiology|epidemiological]] history and three of the clinical manifestations is considered to be a suspected case:
'''1) Epidemiological history:'''

* Within 14 days before the disease onset, there is a travel history or living history in Wuhan or other areas with local cases
* Within 14 days before the disease onset, there is contact with patients who had a fever or [[respiratory]] symptoms from Wuhan or other areas with local cases
* Clustering of patients or contact with patients infected with the [[SARS-CoV-2]]


'''2) Clinical manifestations:'''

*[[Fever]] and/or respiratory symptoms
*With the above-mentioned imaging characteristics of [[pneumonia]]
*The total number of [[leukocytes]] in the early stage of the disease is normal or decreased, or the lymphocyte count is decreased
|-
!Confirmed Case
|Any suspected case with one of the following pathogenic features is reclassified as a confirmed case:

* Positive results of [[SARS-CoV-2]] [[Nucleic acid|nucleic acids]] by real-time reverse-transcriptase polymerase-chain-reaction ([[Reverse transcription polymerase chain reaction|RT]]-[[Polymerase chain reaction|PCR]]) of respiratory or blood specimens
*[[DNA]] highly [[Homology (biology)|homologous]] to [[SARS-CoV-2]] by genetic sequencing of viral [[genes]] in respiratory or blood specimens<br />
|}

== Ongoing diagnostic Trials ==

* A researcher at Israel’s Ben-Gurion University of the Negev (BGU) has developed a test that identifies those carrying the COVID-19 virus in less than a minute. And it is both affordable and works with greater than 90% accuracy to boot<ref>{{Cite web|url=https://www.bioworld.com/articles/435285-Israels-ben-Gurion-university-develops-one-minute-coronavirus-test.html|title=|last=|first=|date=|website=|archive-url=|archive-date=|dead-url=|access-date=}}</ref>

====Antibody response====
* Most recovering from #[[COVID-19|COVID19]] do not have high levels of neutralizing [[antibodies]] BUT [[antibodies]] to the receptor binding domain (RBD) of the spike protein with potent antiviral activity were found in all individuals tested & may be tx target<ref name="RobbianiGaebler2020">{{cite journal|last1=Robbiani|first1=Davide F.|last2=Gaebler|first2=Christian|last3=Muecksch|first3=Frauke|last4=Lorenzi|first4=Julio C. C.|last5=Wang|first5=Zijun|last6=Cho|first6=Alice|last7=Agudelo|first7=Marianna|last8=Barnes|first8=Christopher O.|last9=Gazumyan|first9=Anna|last10=Finkin|first10=Shlomo|last11=Hägglöf|first11=Thomas|last12=Oliveira|first12=Thiago Y.|last13=Viant|first13=Charlotte|last14=Hurley|first14=Arlene|last15=Hoffmann|first15=Hans-Heinrich|last16=Millard|first16=Katrina G.|last17=Kost|first17=Rhonda G.|last18=Cipolla|first18=Melissa|last19=Gordon|first19=Kristie|last20=Bianchini|first20=Filippo|last21=Chen|first21=Spencer T.|last22=Ramos|first22=Victor|last23=Patel|first23=Roshni|last24=Dizon|first24=Juan|last25=Shimeliovich|first25=Irina|last26=Mendoza|first26=Pilar|last27=Hartweger|first27=Harald|last28=Nogueira|first28=Lilian|last29=Pack|first29=Maggi|last30=Horowitz|first30=Jill|last31=Schmidt|first31=Fabian|last32=Weisblum|first32=Yiska|last33=Michailidis|first33=Eleftherios|last34=Ashbrook|first34=Alison W.|last35=Waltari|first35=Eric|last36=Pak|first36=John E.|last37=Huey-Tubman|first37=Kathryn E.|last38=Koranda|first38=Nicholas|last39=Hoffman|first39=Pauline R.|last40=West|first40=Anthony P.|last41=Rice|first41=Charles M.|last42=Hatziioannou|first42=Theodora|last43=Bjorkman|first43=Pamela J.|last44=Bieniasz|first44=Paul D.|last45=Caskey|first45=Marina|last46=Nussenzweig|first46=Michel C.|title=Convergent antibody responses to SARS-CoV-2 in convalescent individuals|journal=Nature|year=2020|issn=0028-0836|doi=10.1038/s41586-020-2456-9}}</ref>
*8 weeks after hospital discharge, 40% of asymptomatic patients have no antibodies, and 12.9% of those who were symptomatic had no #COVID19 antibodies<ref name="LongTang2020">{{cite journal|last1=Long|first1=Quan-Xin|last2=Tang|first2=Xiao-Jun|last3=Shi|first3=Qiu-Lin|last4=Li|first4=Qin|last5=Deng|first5=Hai-Jun|last6=Yuan|first6=Jun|last7=Hu|first7=Jie-Li|last8=Xu|first8=Wei|last9=Zhang|first9=Yong|last10=Lv|first10=Fa-Jin|last11=Su|first11=Kun|last12=Zhang|first12=Fan|last13=Gong|first13=Jiang|last14=Wu|first14=Bo|last15=Liu|first15=Xia-Mao|last16=Li|first16=Jin-Jing|last17=Qiu|first17=Jing-Fu|last18=Chen|first18=Juan|last19=Huang|first19=Ai-Long|title=Clinical and immunological assessment of asymptomatic SARS-CoV-2 infections|journal=Nature Medicine|year=2020|issn=1078-8956|doi=10.1038/s41591-020-0965-6}}</ref>

==References==
{{reflist|2}}