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What if my COVID-19 test is positive?

Text updated on 2020-12-23

You just got a COVID-19 test result and it's positive. Don't panic! In most cases, the symptoms will disappear in a few days. By isolating yourself and telling the people you've been in contact with in the last week, you will limit the spread of the virus.

Whether it is an antigen test or an RT-PCR test, this result indicates that you are infected with the coronavirus and are probably contagious. Here are some tips to limit the spread of the coronavirus and to treat yourself.

Case 1: You have symptoms: fever, difficulty breathing with or without cough, muscle aches, headache, loss of taste, loss of smell, unexplained fatigue, diarrhea, vomiting.

Remain in isolation for 8 days after the onset of symptoms. For non-severe forms of COVID-19, the contagious period begins on average 2-3 days before the onset of symptoms and lasts 7-8 days after the onset of symptoms. Thereafter, the SARS-CoV-2 coronavirus remains detectable in small amounts in the saliva and nasal cavities of some patients until several weeks after the onset of the disease. But it seems that from 9 days after the onset of symptoms, the viral particles of the patients are no longer able to infect cells in culture, suggesting that the virus is no longer contaminating.

Notify people with whom you had close contact during the three days before the onset of symptoms and who may have been infected (see the question What is close contact?). If you took the test when you had symptoms for 2 days, you must add those 2 days and tell everyone you were in contact with during the 5 days before the test. Make a list of people: friends, colleagues, relatives, patients, clients, and warn them so that they in turn can take the necessary precautions to prevent the spread of the epidemic (see question What should I do if I find out that I have recently been in contact with someone who has just tested positive?).

The application Breaking the chain can help you clarify your symptoms and, above all, find and prevent your contacts, without tracing or geolocation.

Case 2: You have no symptoms on the day of the test, but symptoms appear in the following days.

Put yourself in isolation as soon as you get the test results! You have probably been tested during the so-called presymptomatic period before symptoms appear but are already contagious.

The duration of isolation is 8 days from the first day of symptoms. 

Notify the people you have been in contact with 3 days before the onset of symptoms.

Case 3: You have no symptoms, and no symptoms appear within 2-3 days after the test.

Put yourself in isolation as soon as you get the test results! You probably have an asymptomatic form of COVID-19 and you'll never get the symptoms of the disease. Asymptomatic forms account for about 30% to 80% of cases depending on studies, age, sex, whether or not a mask was worn, etc. The evolution of the viral load and the risks of contagiousness of asymptomatic people are still poorly known to this day. In order to take as few risks as possible, it is wise to stay in isolation for a period similar to those who have symptoms, i.e., 8 days after the test.  

If you are tested positive, it means that you have probably been contagious for a few days already. It is difficult to estimate exactly when you were infected and how long you have been contagious. Since RT-PCR and antigenic tests are sensitive to the amount of viral load and positive when the viral load reaches a certain threshold, it can be estimated that you were probably infected between 2 and 8 days before the test. To maximize the chances of stopping the spread of the epidemic, tell people you have been in contact with during the last 6 days before the test.

What is isolation?

Isolation means that you need to isolate yourself in your home to avoid spreading the coronavirus to those around you.

If you live alone, you shouldn't go out of your house and the safest thing to do is to have your groceries delivered so you don't have to go to the stores.

If you don't live alone, you should respect the barrier gestures at home too. The members of your household should breathe as little as possible the same air as you. To do this, you should :

If you absolutely have to get out of your house:

The evolution of the symptoms of COVID-19

COVID-19 can cause symptoms that vary from person to person, ranging from flu-like illness to respiratory distress that can lead to death. In the majority of cases, symptoms disappear within a few days and taking paracetamol (Tylenol) may be sufficient to reduce fever and muscle pain.

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This article compares the interval between the onset of symptoms in 77 pairs of individuals, one of whom has been infected by the other (this is called the serial interval, estimated here at 5 to 6 days) with the mean incubation time of the disease. The authors deduce that individuals carrying the SARS-CoV-2 virus are contagious as early as 2 to 3 days before the onset of the first symptoms and that the peak of contagiousness is between 2 days before and 1 day after the onset of symptoms.

He, X., Lau, E. H., Wu, P., Deng, X., Wang, J., Hao, X., ... & Mo, X. (2020). Temporal dynamics in viral shedding and transmissibility of COVID-19. Nature medicine, 1-4.

A meta-analysis of 5 studies estimates the mean incubation time to be 5.1 days.

He, W., Yi, G. Y., & Zhu, Y. (2020). Estimation of the basic reproduction number, average incubation time, asymptomatic infection rate, and case fatality rate for COVID-19: Meta-analysis and sensitivity analysis. Journal of Medical Virology.

Description of the symptoms of COVID-19.

Yang, P., Wang, X. COVID-19: a new challenge for human beings. Cell Mol Immunol (2020).

Analysis of symptoms in 1,099 patients with COVID-19 in China. Although 90% of patients symptomatic of COVID-19 end up with a fever, it is present in less than 50% of cases at the time of hospital admission. Therefore, it is the mild symptoms that are the most important to detect at the onset of symptoms.

Guan, W. J., Ni, Z. Y., Hu, Y., Liang, W. H., Ou, C. Q., He, J. X., ... & Du, B. (2020). Clinical characteristics of coronavirus disease 2019 in China. New England journal of medicine, 382(18), 1708-1720.

A multicenter cohort study on hospitals in France, Belgium, and Switzerland followed more than 4,000 patients admitted to intensive care units between the end of February and early May, 2020. Mortality (estimated at 90 days) of ICU patients fell steadily from 42% to 25% during this period (Table S5), with an average case-fatality rate of 31%.

Armstrong, R. A., Kane, A. D., & Cook, T. M. (2020). Outcomes from intensive care in patients with COVID-19: a systematic review and meta-analysis of observational studies. Anaesthesia, 75(10), 1340-1349.

This very interesting article studies in detail the dynamics of replication of the SARS-CoV-2 virus in different tissues of infected patients. Among other things, it questions the relationship between the presence of the virus in these tissues and its infectivity, measured as its ability to infect cells in culture. According to the authors, while sputum and nasopharyngeal specimens isolated during the first week of symptoms are highly infectious, those collected 9 or more days after the onset of symptoms are devoid of any infectious properties. Similarly, faecal or urine specimens, although containing viral particles, are not capable of infecting cells in culture, regardless of when they are collected.

Wölfel, R., Corman, V. M., Guggemos, W., Seilmaier, M., Zange, S., Müller, M. A., ... & Hoelscher, M. (2020). Virological assessment of hospitalized patients with COVID-2019. Nature, 581(7809), 465-469.

Study of 100 individuals infected by SARS-CoV-2 identified by RT-PCR, known as index cases and their 2,761 close contacts. A close contact is a person who has been physically close to the index case, without mask for more than 15 minutes. Cases of COVID-19 to contact cases occurred during the presymptomatic period of index cases, before they reported symptoms and within 5 days of symptom onset. No transmission from SARS-CoV-2 occurred more than 6 days after the onset of symptoms.

Cheng, H. Y., Jian, S. W., Liu, D. P., Ng, T. C., Huang, W. T., & Lin, H. H. (2020). Contact tracing assessment of COVID-19 transmission dynamics in Taiwan and risk at different exposure periods before and after symptom onset. JAMA internal medicine.

This study focuses on the study of viral load after the onset of symptoms. It involved 230 people working in a clinic and positive for COVID-19. The viral load of these patients was quantified up to 6 weeks after the onset of symptoms. Only patients with non-severe forms of COVID-19 (which do not require hospitalization) were included in this study. The variable that best explains the dynamics of viral load evolution is the onset of symptoms with a peak viral load during the 2-3 days following the onset of symptoms, which rapidly decreases and becomes very low 10 days later. The distribution of the risk of transmission of SARS-CoV-2 after the onset of symptoms shows that the possibility of transmission is highest in the first 7 days after the onset of symptoms (96.9%) with a peak in the first 4-5 days, and decreases to 2.9% between 7 and 10 days after the onset of symptoms, and to 0.2% between 10 and 14 days.

Shrestha, N. K., Marco Canosa, F., Nowacki, A. S., Procop, G. W., Vogel, S., Fraser, T. G., ... & Gordon, S. M. (2020). Distribution of transmission potential during non-severe COVID-19 illness. Clinical Infectious Diseases.

Study that analyses the evolution over time of the risks of transmission of the SARS-CoV-2 coronavirus after an infection. Quantifying the risk of contagion is an essential factor in controlling the epidemic. This study shows that in symptomatic individuals, the period of transmission of SARS-CoV-2 to other individuals is related to the time of symptom onset (rather than the day the infection occurred), i.e., transmission occurs mainly during the 2-3 days before the onset of symptoms and during the 2-3 days after the onset of symptoms.

Ferretti, L., Ledda, A., Wymant, C., Zhao, L., Ledda, V., & Abeler-Dorner, L. The timing of COVID-19 transmission. MedRxiv, 2020. Publisher: Cold Spring Harbor Laboratory Press eprint: https://www. medrxiv. org/content/early/2020/09/07/2020.09, 4.

Study of 31 people who were asymptomatic at the time of RT-PCR testing but who tested positive for SARS-CoV-2. Of these people, 9 remained asymptomatic, the remaining people became symptomatic during follow-up and therefore had been tested during the presymptomatic period before reporting symptoms. All of these people also had a chest CT scan, which showed 4 of the 9 asymptomatic and 9 of the 22 presymptomatic people had a typical pattern of pneumonia. The evolution over time of the viral load of 14 presymptomatic and 4 asymptomatic persons was quantified. The results show that in this small group of patients, the viral load is lower in the asymptomatic than in the symptomatic, but that the viral load evolution is similar, with a peak and then a decrease.

Zhou, R., Li, F., Chen, F., Liu, H., Zheng, J., Lei, C., & Wu, X. (2020). Viral dynamics in asymptomatic patients with COVID-19. International Journal of Infectious Diseases.

Study of the population of Vo' (Italy) during two phases of nasopharyngeal RT-PCR tests on 2,812 and 2,343 people (respectively, 85.9% and 71.5% of the population). The results show that 42.5% of the SARS-CoV-2 positive population were asymptomatic, i.e., had no symptoms at the time of the test and did not have any symptoms afterwards. The viral load of asymptomatic people is no different from that of symptomatic people.

Lavezzo, E., Franchin, E., Ciavarella, C., Cuomo-Dannenburg, G., Barzon, L., Del Vecchio, C., ... & Abate, D. (2020). Suppression of a SARS-CoV-2 outbreak in the Italian municipality of Vo'. Nature, 584(7821), 425-429.

On a cruise ship, the Greg Mortimer, which was cruising off Antarctica in March, 2020, an individual was reported to have COVID-19 on day eight of the cruise. For 28 days, the boat remained at sea without permission to disembark and the passengers remained isolated from the rest of the world. All passengers wore masks. Of the 217 passengers, 128 were infected with SARS-CoV-2. But only 24 passengers (19%) with SARS-CoV-2 showed symptoms of COVID-19 and only one died. Out of all the other passengers infected with SARS-CoV-2, 104 individuals (81%) were asymptomatic.

Ing, A. J., Cocks, C., & Green, J. P. (2020). COVID-19 in the footsteps of Ernest Shackleton. Thorax.

Meta-analysis of 94 studies of people infected with SARS-CoV-2 but asymptomatic. Depending on the studies, the proportion of asymptomatic individuals varied widely, probably due to methodological biases. This meta-analysis shows that there is a 35% lower risk of being infected by an asymptomatic person (who has no symptoms and will not develop symptoms) than by a symptomatic person.

Buitrago-Garcia, D., Egli-Gany, D., Counotte, M. J., Hossmann, S., Imeri, H., Ipekci, A. M., ... & Low, N. (2020). Occurrence and transmission potential of asymptomatic and presymptomatic SARS-CoV-2 infections: A living systematic review and meta-analysis. PLoS medicine, 17(9), e1003346.

In France, if symptoms worsen or if you have breathing difficulties, call the SAMU by dialling 15.


Further reading

How many people are contagious with COVID around me?

What is the risk of meeting a person COVID in a group, knowing the incidence rate?

What is the risk of dying from this COVID-19 for an infected person?

How long is a person contagious?

How many days after contact should I wait for a COVID test?

Should I get tested before seeing friends and family?

What are the symptoms of COVID-19 ?

What factors increase the risk of dying from COVID-19 ?

Can we catch COVID-19 without direct interaction with a contagious person?