SARS-COV2 InfectionNCT04470648

COVID-19 Infection at Samusocial in Paris: Descriptive and Serological Survey

An observational study of SARS-COV2 Infection, run by Institut National de la Santé Et de la Recherche Médicale, France at 3 sites in France.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record

Search all trials

Trial summary

Study of COVID-19 seroprevalence in precarious population living in shelters of Samusocial de Paris and in staff working in these centers during COVID-19 epidemic. Read more about this study

Who is it for?: Ages 18 years and olderHealthy volunteers can take part
Conditions the study is for: SARS-COV2 Infection
What is being tested?: blood test for SARS-COV2 serology
How many people: 179 participants
Where: 3 sitesFrance
Study dates: 22 Jul 2020to 22 Aug 2021
Phase: Observational
Are there results?: None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 18 years and older
All sexes
Healthy volunteers accepted
Adult, Older adult

Study population: people hosted and workers at one these 3 centers during the epidemic time (march to may 2020)

Who may be able to join

to have been hosted or working in one the three centers (LHSS Ridder-Plaisance or Saint Michel or Halte femmes) between march and may 2020
to be aged 18 y or more
to be able to give an informed consent

Who cannot join

people who refuse to participate
not being able to give an informed consent
Person subject to a legal protection measure (safeguard of justice, curatorship or guardianship)
Person who does not understand the information provided on how to carry out the research
Obstacle to venous sampling

Trial locations and contacts

3 sites in 1 country.

France3 sites

Haltes pour femmes
Paris, 75004
LHSS Saint-Michel
Paris, 75012
LHSS Ridder-Plaisance
Paris, 75014

Other trials in France

About this study

Study of COVID-19 seroprevalence in precarious population living in shelters of Samusocial de Paris and in staff working in these centers during COVID-19 epidemic.

Read the detailed description

After emergence of a new coronavirus (Severe Acute Respiratory Syndrome Coronavirus 2, SARS-CoV2) responsible for a cluster of respiratory infection at Wuhan, China, on January, 7th 2020, first cases were diagnosed in France in January 24th 2020.

Health care components of Samusocial de Paris (Lits Haltes Soins Santé (LHSS)) were created in 2006. They provide medical care for homeless people and people in social distress not needing an hospitalization. Sometimes there are 3 persons in a bedroom.

In december 2018, a special shelter for isolated women or women in precarious situations opened.

Because of the living conditions in these centers and the difficulty for these populations to respect social distancing and hygiene recommendations.

A first case of COVID-19 was identified on March 8th 2020 in one of these healthcare centers. Other cases were detected in the same center, then in another center on March 16th, then in the dormitory of the women shelter on March 30th.

A recent study showed an important prevalence of SARS-COV2 in residents of a homeless shelter in Boston (36%), most of them were asymptomatic.

Seroprevalence studies are done in general population or in health care workers, but don't include vulnerable people.

It seemed important to us to describe the epidemic in these centers and to study COVID-19 seroprevalence in these particular populations.

Conditions: SARS-COV2 Infection
Being tested: blood test for SARS-COV2 serology
Keywords: Seroprevalence, SARS-COV2, Precarious
Medical subject headings: COVID-19

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

blood test for SARS-COV2 serologyDiagnostic test
each person who will accept to participate will have a bood test for a SARS-COV2 serology

Study groups in NCT04470648
Study group	Role	What they receive
hosted in the center and HCWs at the epidemic period		people hosted in the health care or in the women center and health care workers working in one these centers during the epidemic time. People with initial positive SARS-COV2 serology will have a second blood test to mesure atibodies kinetic Receives: Diagnostic Test: blood test for SARS-COV2 serology

What is being measured

The primary outcome is the main question the study is designed to answer.

SARS-COV-2 seroprevalence in 3 centers for homeless and people in social distress
Primary objective is to evaluate SARS-COV2 seroprevalence in people hosted and health care workers of 3 centers of Samusocial de Paris where COVID19 epidemics occured
Measured: 6 months

Secondary outcomes (5)

Morbidity rate
Measure of morbidity in the participating population in the 3 centers
Measured: 6 months
Covid-19 related death rate in the 3 centers from March to May 2020
Number of deaths related to Covid-19 during the epidemic in the 3 centers
Measured: 6 months
Ratio of negative serology rate and positive serology rate in the 3 centers
Measured: 6 months
Ratio of SARS-COV2 seroprevalence obtained in these centers to the estimated seroprevalence in the Ile de France region
Measured: 6 months
kinetics of SARS-COV2 antibodies in people with initial positive serology
2 blood tests 4 and 8 months afetr the first one
Measured: 10 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

22 Jul 202022 Aug 2021

First posted14 Jul 2020
Study start22 Jul 2020
Primary completion8 Apr 2021
Study completion22 Aug 2021

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Publications (9)Papers the sponsor has linked to this study.
Other trials for SARS-COV2 InfectionStudies of the same condition, open and under way.
More trials run by Institut National de la Santé Et de la Recherche Médicale, FranceThe sponsor's other registered studies.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Observational
Observational model: Other
Time perspective: Prospective
Enrolment: 179 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT04470648
Sponsor's protocol ID: C20-50
Status last verified: Feb 2023
First submitted: 12 Jul 2020
Last updated: 26 Jan 2026
Results posted: No
Data monitoring committee: No
FDA-regulated drug: No
FDA-regulated device: No

Publications

Bernard Stoecklin S, Rolland P, Silue Y, Mailles A, Campese C, Simondon A, Mechain M, Meurice L, Nguyen M, Bassi C, Yamani E, Behillil S, Ismael S, Nguyen D, Malvy D, Lescure FX, Georges S, Lazarus C, Tabai A, Stempfelet M, Enouf V, Coignard B, Levy-Bruhl D; Investigation team. First cases of coronavirus disease 2019 (COVID-19) in France: surveillance, investigations and control measures, January 2020. Euro Surveill. 2020 Feb;25(6):2000094. doi: 10.2807/1560-7917.ES.2020.25.6.2000094.
PubMed 32070465
Lescure FX, Bouadma L, Nguyen D, Parisey M, Wicky PH, Behillil S, Gaymard A, Bouscambert-Duchamp M, Donati F, Le Hingrat Q, Enouf V, Houhou-Fidouh N, Valette M, Mailles A, Lucet JC, Mentre F, Duval X, Descamps D, Malvy D, Timsit JF, Lina B, van-der-Werf S, Yazdanpanah Y. Clinical and virological data of the first cases of COVID-19 in Europe: a case series. Lancet Infect Dis. 2020 Jun;20(6):697-706. doi: 10.1016/S1473-3099(20)30200-0. Epub 2020 Mar 27.
PubMed 32224310
Deslandes A, Berti V, Tandjaoui-Lambotte Y, Alloui C, Carbonnelle E, Zahar JR, Brichler S, Cohen Y. SARS-CoV-2 was already spreading in France in late December 2019. Int J Antimicrob Agents. 2020 Jun;55(6):106006. doi: 10.1016/j.ijantimicag.2020.106006. Epub 2020 May 3.
PubMed 32371096
Zhu N, Zhang D, Wang W, Li X, Yang B, Song J, Zhao X, Huang B, Shi W, Lu R, Niu P, Zhan F, Ma X, Wang D, Xu W, Wu G, Gao GF, Tan W; China Novel Coronavirus Investigating and Research Team. A Novel Coronavirus from Patients with Pneumonia in China, 2019. N Engl J Med. 2020 Feb 20;382(8):727-733. doi: 10.1056/NEJMoa2001017. Epub 2020 Jan 24.
PubMed 31978945
Backer JA, Klinkenberg D, Wallinga J. Incubation period of 2019 novel coronavirus (2019-nCoV) infections among travellers from Wuhan, China, 20-28 January 2020. Euro Surveill. 2020 Feb;25(5):2000062. doi: 10.2807/1560-7917.ES.2020.25.5.2000062.
PubMed 32046819
Li Q, Guan X, Wu P, Wang X, Zhou L, Tong Y, Ren R, Leung KSM, Lau EHY, Wong JY, Xing X, Xiang N, Wu Y, Li C, Chen Q, Li D, Liu T, Zhao J, Liu M, Tu W, Chen C, Jin L, Yang R, Wang Q, Zhou S, Wang R, Liu H, Luo Y, Liu Y, Shao G, Li H, Tao Z, Yang Y, Deng Z, Liu B, Ma Z, Zhang Y, Shi G, Lam TTY, Wu JT, Gao GF, Cowling BJ, Yang B, Leung GM, Feng Z. Early Transmission Dynamics in Wuhan, China, of Novel Coronavirus-Infected Pneumonia. N Engl J Med. 2020 Mar 26;382(13):1199-1207. doi: 10.1056/NEJMoa2001316. Epub 2020 Jan 29.
PubMed 31995857
Guan WJ, Ni ZY, Hu Y, Liang WH, Ou CQ, He JX, Liu L, Shan H, Lei CL, Hui DSC, Du B, Li LJ, Zeng G, Yuen KY, Chen RC, Tang CL, Wang T, Chen PY, Xiang J, Li SY, Wang JL, Liang ZJ, Peng YX, Wei L, Liu Y, Hu YH, Peng P, Wang JM, Liu JY, Chen Z, Li G, Zheng ZJ, Qiu SQ, Luo J, Ye CJ, Zhu SY, Zhong NS; China Medical Treatment Expert Group for Covid-19. Clinical Characteristics of Coronavirus Disease 2019 in China. N Engl J Med. 2020 Apr 30;382(18):1708-1720. doi: 10.1056/NEJMoa2002032. Epub 2020 Feb 28.
PubMed 32109013
Baggett TP, Keyes H, Sporn N, Gaeta JM. Prevalence of SARS-CoV-2 Infection in Residents of a Large Homeless Shelter in Boston. JAMA. 2020 Jun 2;323(21):2191-2192. doi: 10.1001/jama.2020.6887.
PubMed 32338732
Husain M, Rachline A, Cousien A, Rolland S, Rouzaud C, Ferre VM, Gomez MV, Le Teurnier M, Wicky-Thisse M, Descamps D, Yazdanpanah Y, Charpentier C, Pasquet-Cadre A. Impact of the COVID-19 pandemic on the homeless: results from a retrospective closed cohort in France (March-May 2020). Clin Microbiol Infect. 2021 Oct;27(10):1520.e1-1520.e5. doi: 10.1016/j.cmi.2021.05.039. Epub 2021 Jun 7.
PubMed 34111590

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

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All SARS-COV2 Infection trials

Study at a glance

From the registry record, last updated by the sponsor on 26 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: COVID-19 Infection at Samusocial in Paris: Descriptive and Serological Survey
ClinicalTrials.gov ID: NCT04470648
Acronym / sponsor ID: C20-50
Conditions: SARS-COV2 Infection
Keywords: Seroprevalence, SARS-COV2, Precarious
Study type: Observational
Recruitment status: Completed
Enrolment: 179 participants (actual)
Lead sponsor: Institut National de la Santé Et de la Recherche Médicale, FranceOther government
Collaborators: Samusocial de Paris, Assistance Publique - Hôpitaux de Paris
Study start: 22 Jul 2020 (actual)
Primary completion: 8 Apr 2021 (actual)
Study completion: 22 Aug 2021 (actual)
First posted: 14 Jul 2020 (actual)
Results: Not posted in the source record

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Study of COVID-19 seroprevalence in precarious population living in shelters of Samusocial de Paris and in staff working in these centers during COVID-19 epidemic.

Detailed description

In december 2018, a special shelter for isolated women or women in precarious situations opened.

Because of the living conditions in these centers and the difficulty for these populations to respect social distancing and hygiene recommendations.

A recent study showed an important prevalence of SARS-COV2 in residents of a homeless shelter in Boston (36%), most of them were asymptomatic.

Seroprevalence studies are done in general population or in health care workers, but don't include vulnerable people.

It seemed important to us to describe the epidemic in these centers and to study COVID-19 seroprevalence in these particular populations.

Study design

Observational model: Other
Time perspective: Prospective
Number of arms: 1

Arm	Type	Receives
hosted in the center and HCWs at the epidemic period	–	Diagnostic Test: blood test for SARS-COV2 serologypeople hosted in the health care or in the women center and health care workers working in one these centers during the epidemic time. People with initial positive SARS-COV2 serology will have a second blood test to mesure atibodies kinetic

Who may qualify

Ages: 18 years and older
Sex: All
Healthy volunteers: Accepted
Age groups: Adult, Older adult
Study population: people hosted and workers at one these 3 centers during the epidemic time (march to may 2020)

Key inclusion criteria (3 listed)

to have been hosted or working in one the three centers (LHSS Ridder-Plaisance or Saint Michel or Halte femmes) between march and may 2020
to be aged 18 y or more
to be able to give an informed consent

Key exclusion criteria (5 listed)

people who refuse to participate
not being able to give an informed consent
Person subject to a legal protection measure (safeguard of justice, curatorship or guardianship)
Person who does not understand the information provided on how to carry out the research
Obstacle to venous sampling

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
blood test for SARS-COV2 serologyeach person who will accept to participate will have a bood test for a SARS-COV2 serology	Diagnostic test	hosted in the center and HCWs at the epidemic period

Primary outcome

SARS-COV-2 seroprevalence in 3 centers for homeless and people in social distress
Time frame: 6 months
Primary objective is to evaluate SARS-COV2 seroprevalence in people hosted and health care workers of 3 centers of Samusocial de Paris where COVID19 epidemics occured

5 secondary outcomes

Morbidity rate
Time frame: 6 months
Covid-19 related death rate in the 3 centers from March to May 2020
Time frame: 6 months
Ratio of negative serology rate and positive serology rate in the 3 centers
Time frame: 6 months
Ratio of SARS-COV2 seroprevalence obtained in these centers to the estimated seroprevalence in the Ile de France region
Time frame: 6 months
kinetics of SARS-COV2 antibodies in people with initial positive serology
Time frame: 10 months

Results and safety

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 26 Jan 2026.
Background: PubMed 32070465Bernard Stoecklin S, Rolland P, Silue Y, Mailles A, Campese C, Simondon A, Mechain M, Meurice L, Nguyen M, Bassi C, Yamani E, Behillil S, Ismael S, Nguyen D, Malvy D, Lescure FX, Georges S, Lazarus C, Tabai A, Stempfelet M, Enouf V, Coignard B, Levy-Bruhl D; Investigation team. First cases of coronavirus disease 2019 (COVID-19) in France: surveillance, investigations and control measures, January 2020. Euro Surveill. 2020 Feb;25(6):2000094. doi: 10.2807/1560-7917.ES.2020.25.6.2000094.
Background: PubMed 32224310Lescure FX, Bouadma L, Nguyen D, Parisey M, Wicky PH, Behillil S, Gaymard A, Bouscambert-Duchamp M, Donati F, Le Hingrat Q, Enouf V, Houhou-Fidouh N, Valette M, Mailles A, Lucet JC, Mentre F, Duval X, Descamps D, Malvy D, Timsit JF, Lina B, van-der-Werf S, Yazdanpanah Y. Clinical and virological data of the first cases of COVID-19 in Europe: a case series. Lancet Infect Dis. 2020 Jun;20(6):697-706. doi: 10.1016/S1473-3099(20)30200-0. Epub 2020 Mar 27.
Background: PubMed 32371096Deslandes A, Berti V, Tandjaoui-Lambotte Y, Alloui C, Carbonnelle E, Zahar JR, Brichler S, Cohen Y. SARS-CoV-2 was already spreading in France in late December 2019. Int J Antimicrob Agents. 2020 Jun;55(6):106006. doi: 10.1016/j.ijantimicag.2020.106006. Epub 2020 May 3.
Background: PubMed 31978945Zhu N, Zhang D, Wang W, Li X, Yang B, Song J, Zhao X, Huang B, Shi W, Lu R, Niu P, Zhan F, Ma X, Wang D, Xu W, Wu G, Gao GF, Tan W; China Novel Coronavirus Investigating and Research Team. A Novel Coronavirus from Patients with Pneumonia in China, 2019. N Engl J Med. 2020 Feb 20;382(8):727-733. doi: 10.1056/NEJMoa2001017. Epub 2020 Jan 24.
Background: PubMed 32046819Backer JA, Klinkenberg D, Wallinga J. Incubation period of 2019 novel coronavirus (2019-nCoV) infections among travellers from Wuhan, China, 20-28 January 2020. Euro Surveill. 2020 Feb;25(5):2000062. doi: 10.2807/1560-7917.ES.2020.25.5.2000062.
Background: PubMed 31995857Li Q, Guan X, Wu P, Wang X, Zhou L, Tong Y, Ren R, Leung KSM, Lau EHY, Wong JY, Xing X, Xiang N, Wu Y, Li C, Chen Q, Li D, Liu T, Zhao J, Liu M, Tu W, Chen C, Jin L, Yang R, Wang Q, Zhou S, Wang R, Liu H, Luo Y, Liu Y, Shao G, Li H, Tao Z, Yang Y, Deng Z, Liu B, Ma Z, Zhang Y, Shi G, Lam TTY, Wu JT, Gao GF, Cowling BJ, Yang B, Leung GM, Feng Z. Early Transmission Dynamics in Wuhan, China, of Novel Coronavirus-Infected Pneumonia. N Engl J Med. 2020 Mar 26;382(13):1199-1207. doi: 10.1056/NEJMoa2001316. Epub 2020 Jan 29.
Background: PubMed 32109013Guan WJ, Ni ZY, Hu Y, Liang WH, Ou CQ, He JX, Liu L, Shan H, Lei CL, Hui DSC, Du B, Li LJ, Zeng G, Yuen KY, Chen RC, Tang CL, Wang T, Chen PY, Xiang J, Li SY, Wang JL, Liang ZJ, Peng YX, Wei L, Liu Y, Hu YH, Peng P, Wang JM, Liu JY, Chen Z, Li G, Zheng ZJ, Qiu SQ, Luo J, Ye CJ, Zhu SY, Zhong NS; China Medical Treatment Expert Group for Covid-19. Clinical Characteristics of Coronavirus Disease 2019 in China. N Engl J Med. 2020 Apr 30;382(18):1708-1720. doi: 10.1056/NEJMoa2002032. Epub 2020 Feb 28.
Background: PubMed 32338732Baggett TP, Keyes H, Sporn N, Gaeta JM. Prevalence of SARS-CoV-2 Infection in Residents of a Large Homeless Shelter in Boston. JAMA. 2020 Jun 2;323(21):2191-2192. doi: 10.1001/jama.2020.6887.
Results publication: PubMed 34111590Husain M, Rachline A, Cousien A, Rolland S, Rouzaud C, Ferre VM, Gomez MV, Le Teurnier M, Wicky-Thisse M, Descamps D, Yazdanpanah Y, Charpentier C, Pasquet-Cadre A. Impact of the COVID-19 pandemic on the homeless: results from a retrospective closed cohort in France (March-May 2020). Clin Microbiol Infect. 2021 Oct;27(10):1520.e1-1520.e5. doi: 10.1016/j.cmi.2021.05.039. Epub 2021 Jun 7.

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Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

Yazdan Yazdanpanah, MD PHD principal investigator

Assistance Publique - Hôpitaux de Paris

3 sites in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

An observational study of SARS-COV2 Infection, run by Institut National de la Santé Et de la Recherche Médicale, France at 3 sites in France.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 26 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 3 sites in France. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

SARS-COV-2 seroprevalence in 3 centers for homeless and people in social distress (time frame: 6 months). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04470648, which also lists 9 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 26 Jan 2026.