What does a positive pcr test result look like

February 27, 2020

JAMA. 2020;323(15):1502-1503. doi:10.1001/jama.2020.2783

  • In the News

    Coronavirus Outbreak—an Evolving Global Health Emergency

    Joan Stephenson, PhD

  • In the News

    FDA Warns Coronavirus Outbreak May Disrupt Supply of Critical Medical Products

    Joan Stephenson, PhD

  • Viewpoint

    Coronavirus Infections—More Than Just the Common Cold

    Catharine I. Paules, MD; Hilary D. Marston, MD, MPH; Anthony S. Fauci, MD

  • Viewpoint

    The 2019 Novel Coronavirus and Challenges for Global Health Governance

    Alexandra L. Phelan, SJD, LLM; Rebecca Katz, PhD, MPH; Lawrence O. Gostin, JD

  • Medical News & Perspectives

    Discussing the ABCs of Health Security—Antibiotic Resistance, Biothreats, and Coronavirus

    Angel N. Desai, MD, MPH

  • Original Investigation

    Clinical Characteristics of Patients With 2019 Novel Coronavirus (2019-nCoV)–Infected Pneumonia in Wuhan, China

    Dawei Wang, MD; Bo Hu, MD; Chang Hu, MD; Fangfang Zhu, MD; Xing Liu, MD; Jing Zhang, MD; Binbin Wang, MD; Hui Xiang, MD; Zhenshun Cheng, MD; Yong Xiong, MD; Yan Zhao, MD; Yirong Li, MD; Xinghuan Wang, MD; Zhiyong Peng, MD

  • Research Letter

    Clinical Characteristics of Patients With Novel Coronavirus (2019-nCoV) Infection Hospitalized in Beijing, China

    De Chang, MD, PhD; Minggui Lin, MD; Lai Wei, MD; Lixin Xie, MD; Guangfa Zhu, MD; Charles S. Dela Cruz, MD, PhD; Lokesh Sharma, PhD

  • Viewpoint

    2019 Novel Coronavirus—Important Information for Clinicians

    Carlos del Rio, MD; Preeti N. Malani, MD, MSJ

  • Viewpoint

    Preparation for Possible Sustained Transmission of 2019 Novel Coronavirus

    David L. Swerdlow, MD; Lyn Finelli, DrPH, MS

  • Viewpoint

    US Emergency Legal Responses to Novel Coronavirus—Balancing Public Health and Civil Liberties

    Lawrence O. Gostin, JD; James G. Hodge Jr, JD, LLM

  • Research Letter

    Novel Coronavirus Infection in Hospitalized Infants Under 1 Year of Age in China

    Min Wei, MD; Jingping Yuan, MD, PhD; Yu Liu, PhD; Tao Fu, PhD; Xue Yu, MS; Zhi-Jiang Zhang, MD, PhD

  • Viewpoint

    Preparing for the Most Critically Ill Patients With COVID-19: The Potential Role of ECMO

    Graeme MacLaren, MSc; Dale Fisher, MBBS; Daniel Brodie, MD

  • Viewpoint

    COVID-19 in Singapore—Experience and Critical Issues That Require Attention and Action

    John E. L. Wong, MBBS; Yee Sin Leo, MBBS, MPH; Chorh Chuan Tan, MBBS, PhD

  • Viewpoint

    The Coronavirus Disease 2019 (COVID-19) Outbreak in China—Summary of a China CDC Report

    Zunyou Wu, MD, PhD; Jennifer M. McGoogan, PhD

  • Research Letter

    Presumed Asymptomatic Carrier Transmission of COVID-19

    Yan Bai, MD; Lingsheng Yao, MD; Tao Wei, MD; Fei Tian, MD; Dong-Yan Jin, PhD; Lijuan Chen, PhD; Meiyun Wang, MD, PhD

  • Viewpoint

    COVID-19—New Insights on a Rapidly Changing Epidemic

    Carlos del Rio, MD; Preeti N. Malani, MD, MSJ

  • Viewpoint

    Response to COVID-19 in Taiwan: Big Data Analytics, New Technology, and Proactive Testing

    C. Jason Wang, MD, PhD; Chun Y. Ng, MBA, MPH; Robert H. Brook, MD, ScD

  • Viewpoint

    Priorities for the US Health Community Responding to COVID-19

    Amesh A. Adalja, MD; Eric Toner, MD; Thomas V. Inglesby, MD

  • Original Investigation

    Epidemiologic Features and Clinical Course of Patients Infected With SARS-CoV-2 in Singapore

    Barnaby Edward Young, MB, BChir; Sean Wei Xiang Ong, MBBS; Shirin Kalimuddin, MPH; Jenny G. Low, MPH; Seow Yen Tan, MBBS; Jiashen Loh, MBBS; Oon-Tek Ng, MPH; Kalisvar Marimuthu, MBBS; Li Wei Ang, Msc; Tze Minn Mak, PhD; Sok Kiang Lau, PhD; Danielle E. Anderson, PhD; Kian Sing Chan, MBBS; Thean Yen Tan, MBBCh; Tong Yong Ng, MBBS; Lin Cui, PhD; Zubaidah Said, MSc; Lalitha Kurupatham, MPH; Mark I-Cheng Chen, PhD; Monica Chan, BMBS; Shawn Vasoo, MBBS; Lin-Fa Wang, PhD; Boon Huan Tan, PhD; Raymond Tzer Pin Lin, MBBS; Vernon Jian Ming Lee, PhD; Yee-Sin Leo, MPH; David Chien Lye, MBBS; for the Singapore 2019 Novel Coronavirus Outbreak Research Team

  • Viewpoint

    Supporting the Health Care Workforce During the COVID-19 Global Epidemic

    James G. Adams, MD; Ron M. Walls, MD

  • Viewpoint

    From Containment to Mitigation of COVID-19 in the US

    Stephen M. Parodi, MD; Vincent X. Liu, MD, MSc

  • JAMA Insights

    Care for Critically Ill Patients With COVID-19

    Srinivas Murthy, MD, CM, MHSc; Charles D. Gomersall, MBBS; Robert A. Fowler, MD, CM, MSc

  • Viewpoint

    Critical Care and the COVID-19 Outbreak in Italy: Early Experience and Forecast

    Giacomo Grasselli, MD; Antonio Pesenti, MD; Maurizio Cecconi, MD

  • Viewpoint

    Managing COVID-19 in Low- and Middle-Income Countries

    Joost Hopman, MD, PhD, DTMH; Benedetta Allegranzi, MD, DTMH; Shaheen Mehtar, MBBS, MD (Lon)

  • Research Letter

    Detection of SARS-CoV-2 in Different Types of Clinical Specimens

    Wenling Wang, PhD; Yanli Xu, MD; Ruqin Gao, MD; Roujian Lu, MPH; Kai Han, BS; Guizhen Wu, MD; Wenjie Tan, MD, PhD

  • JAMA Patient Page

    Testing Individuals for COVID-19

    Joseph Hadaya, MD; Max Schumm, MD; Edward H. Livingston, MD

  • Viewpoint

    Medicaid’s Response to COVID-19: Securing the Safety Net and Protecting Public Health

    Chethan Bachireddy, MD, MSc; Christopher Chen, MD, MBA; Mohammad Dar, MD

  • Viewpoint

    Interpreting Diagnostic Tests for SARS-CoV-2

    Nandini Sethuraman, MD; Sundararaj Stanleyraj Jeremiah, MD; Akihide Ryo, MD, PhD

  • Research Letter

    Change in Saliva RT-PCR Sensitivity Over the Course of SARS-CoV-2 Infection

    Zion Congrave-Wilson, MS; Yesun Lee, PhD; Jaycee Jumarang, MD; Stephanie Perez, BS; Jeffrey M. Bender, MD; Jennifer Dien Bard, PhD; Pia S. Pannaraj, MD, MPH

Audio Clinical Review (33:17)

Audio Author Interview (32:44)

Previous studies on coronavirus disease 2019 (COVID-19) mainly focused on epidemiological, clinical, and radiological features of patients with confirmed infection.1-4 Little attention has been paid to the follow-up of recovered patients.

One hospitalized patient and 3 patients (all medical personnel) quarantined at home with COVID-19 were treated at Zhongnan Hospital of Wuhan University, Wuhan, China, from January 1, 2020, to February 15, 2020, and evaluated with real-time reverse transcriptase–polymerase chain reaction (RT-PCR) tests for COVID-19 nucleic acid to determine if they could return to work. All the following criteria5 had to be met for hospital discharge or discontinuation of quarantine: (1) normal temperature lasting longer than 3 days, (2) resolved respiratory symptoms, (3) substantially improved acute exudative lesions on chest computed tomography (CT) images, and (4) 2 consecutively negative RT-PCR test results separated by at least 1 day.

The RT-PCR tests were performed on throat swabs following a previously described method.1 The RT-PCR test kits (BioGerm) were recommended by the Chinese Center for Disease Control and Prevention. The same technician and brand of test kit was used for all RT-PCR testing reported; both internal controls and negative controls were routinely performed with each batch of tests.

Demographic information, laboratory findings, and radiological features were collected from electronic medical records. After recovery, patients and their families were contacted directly, and patients were asked to visit the hospital to collect throat swabs for the RT-PCR tests.

This study was approved by the Zhongnan Hospital of Wuhan University institutional review board and the need for informed consent was waived.

All 4 patients were exposed to the novel 2019 coronavirus through work as medical professionals. Two were male and the age range was 30 to 36 years. Among 3 of the patients, fever, cough, or both occurred at onset. One patient was initially asymptomatic and underwent thin-section CT due to exposure to infected patients. All patients had positive RT-PCR test results and CT imaging showed ground-glass opacification or mixed ground-glass opacification and consolidation. The severity of disease was mild to moderate.

Antiviral treatment (75 mg of oseltamivir taken orally every 12 hours) was provided for the 4 patients. For 3 of the patients, all clinical symptoms and CT imaging abnormalities had resolved. The CT imaging for the fourth patient showed delicate patches of ground-glass opacity. All 4 patients had 2 consecutive negative RT-PCR test results. The time from symptom onset to recovery ranged from 12 to 32 days.

After hospital discharge or discontinuation of quarantine, the patients were asked to continue the quarantine protocol at home for 5 days. The RT-PCR tests were repeated 5 to 13 days later and all were positive. All patients had 3 repeat RT-PCR tests performed over the next 4 to 5 days and all were positive. An additional RT-PCR test was performed using a kit from a different manufacturer and the results were also positive for all patients. The patients continued to be asymptomatic by clinician examination and chest CT findings showed no change from previous images. They did not report contact with any person with respiratory symptoms. No family member was infected.

Four patients with COVID-19 who met criteria for hospital discharge or discontinuation of quarantine in China (absence of clinical symptoms and radiological abnormalities and 2 negative RT-PCR test results) had positive RT-PCR test results 5 to 13 days later. These findings suggest that at least a proportion of recovered patients still may be virus carriers. Although no family members were infected, all reported patients were medical professionals and took special care during home quarantine. Current criteria for hospital discharge or discontinuation of quarantine and continued patient management may need to be reevaluated. Although false-negative RT-PCR test results could have occurred as suggested by a previous study,6 2 consecutively negative RT-PCR test results plus evidence from clinical characteristics and chest CT findings suggested that the 4 patients qualified for hospital discharge or discontinuation of quarantine.

The study was limited to a small number of patients with mild or moderate infection. Further studies should follow up patients who are not health care professionals and who have more severe infection after hospital discharge or discontinuation of quarantine. Longitudinal studies on a larger cohort would help to understand the prognosis of the disease.

Corresponding Authors: Haibo Xu, MD, PhD, Department of Radiology (), and Yirong Li, MD, PhD, Department of Laboratory Medicine (), Zhongnan Hospital of Wuhan University, Donghu Road, Wuchang District, Wuhan City 430071, Hubei Province, China.

Published Online: February 27, 2020. doi:10.1001/jama.2020.2783

Author Contributions: Drs H. Xu and Li had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. Drs Lan and D. Xu contributed equally to the study. Drs H. Xu and Li contributed equally as senior authors.

Concept and design: Lan, D. Xu, Xia, Wang, H. Xu.

Acquisition, analysis, or interpretation of data: Lan, Ye, Wang, Li.

Drafting of the manuscript: Lan, D. Xu, Ye, H. Xu.

Critical revision of the manuscript for important intellectual content: Xia, Wang, Li.

Statistical analysis: D. Xu, H. Xu.

Supervision: Li.

Conflict of Interest Disclosures: None reported.

Funding/Support: This study was supported by grant 81771819 from the National Natural Science Foundation of China and grant 2017YFC0108803 from the National Key Research and Development Plan of China.

Role of the Funder/Sponsor: The study funders/sponsors had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

1.

Wang  D , Hu  B , Hu  C ,  et al.  Clinical characteristics of 138 hospitalized patients with 2019 novel coronavirus–infected pneumonia in Wuhan, China.   JAMA. Published online February 7, 2020. doi:10.1001/jama.2020.1585PubMedGoogle Scholar

3.

Wei  M , Yuan  J , Liu  Y , Fu  T , Yu  X , Zhang  ZJ .  Novel coronavirus infection in hospitalized infants under 1 year of age in China.   JAMA. Published online February 14, 2020. doi:10.1001/jama.2020.2131PubMedGoogle Scholar

6.

Xie  X , Zhong  Z , Zhao  W , Zheng  C , Wang  F , Liu  J .  Chest CT for typical 2019-nCoV pneumonia: relationship to negative RT-PCR testing.   Radiology. Published online February 12, 2020. 2020;200343. doi:10.1148/radiol.2020200343PubMedGoogle Scholar

What is a positive PCR result?

Positive results: You have tested positive for Sars-CoV-2, the virus causing COVID-19.

How do you read a positive Covid test?

If your COVID-19 test was positive, this means that the test did detect the presence of COVID-19 in your nasal secretions. This result would suggest that you are currently infected with COVID-19. If you had a positive COVID-19 test, please self-isolate at home as much as possible according to CDC instructions.

What does a positive test look like?

Two lines – even faint lines – indicate the test is positive. The test has failed and should be retaken.

How long does a PCR test say positive?

This 90 day period is from the initial onset of symptoms or, if asymptomatic when tested, their positive test result. The previous policy to continue LFD testing following a positive PCR result was because although very unlikely, it is possible to be re- infected within 90 days.