LitCovid-sentences  

PMC:7029452 / 1304-25251 JSONTXT 11 Projects

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Id Subject Object Predicate Lexical cue
T12 0-10 Sentence denotes Background
T13 11-228 Sentence denotes A novel coronavirus (severe acute respiratory syndrome coronavirus 2, SARS-CoV-2) causing a cluster of respiratory infections (coronavirus disease 2019, COVID-19) in Wuhan, China, was identified on 7 January 2020 [1].
T14 229-397 Sentence denotes Twenty-seven patients with pneumonia had initially been reported, with an epidemiological link to a live animal market that was closed and disinfected on 1 January [1].
T15 398-574 Sentence denotes From 20 January, the number of notifications of cases rose dramatically, and as at 12 February 2020, 45,179 cases of SARS-CoV-2 have been confirmed, including 1,116 deaths [2].
T16 575-767 Sentence denotes Most of the cases (n = 44,665) were reported in 31 provinces and autonomous regions of China and 514 cases were reported in 25 other countries in Asia, Australia, Europe and North America [2].
T17 768-851 Sentence denotes To date, the primary source of infection remains unknown and could still be active.
T18 852-1008 Sentence denotes Human-to-human transmission was observed early after the emergence of this new virus in China and abroad, including family clusters and healthcare settings.
T19 1009-1095 Sentence denotes The current outbreak dynamics strongly indicate sustained human-to-human transmission.
T20 1096-1185 Sentence denotes Strengthened surveillance of COVID-19 cases was implemented in France on 10 January 2020.
T21 1186-1353 Sentence denotes The objective of the surveillance is to identify imported cases early and to prevent secondary transmission whether in the community or among healthcare workers (HCW).
T22 1354-1521 Sentence denotes Investigations are carried out among contacts immediately upon illness onset and a follow-up procedure is initiated according to the evaluated level of infection risk.
T23 1522-1742 Sentence denotes Here we describe the real-time implementation of this surveillance scheme for the first three imported cases of COVID-19 identified in France, who were confirmed on 24 January 2020 in persons with a recent stay in Wuhan.
T24 1743-1797 Sentence denotes Two cases were diagnosed in Paris and one in Bordeaux.
T25 1798-1925 Sentence denotes We present data until 12 February on the follow-up of the cases’ contacts initiated immediately upon confirmation of infection.
T26 1927-1934 Sentence denotes Methods
T27 1936-1962 Sentence denotes French surveillance system
T28 1963-2273 Sentence denotes In France, according to the COVID-19 surveillance protocol, physicians suspecting a COVID-19 case have to contact immediately either the emergency hotline (SAMU-Centre 15), if the patient is seeking medical attention from a general practitioner, or a referring infectious diseases specialist at hospital level.
T29 2274-2387 Sentence denotes Together, they evaluate whether the patient matches the case definition criteria for a possible case (see below).
T30 2388-2741 Sentence denotes If they do, the case has to be reported immediately through a 24/7 available phone line to the Regional Health Agency (Agence régionale de santé, ARS), which informs without delay the hospital infection control teams involved in the management of the patient, the French Public Health Agency (Santé publique France, SpFrance) and the Ministry of Health.
T31 2742-3063 Sentence denotes A standardised investigation form collecting socio-demographical information, clinical details and history of exposure (history of travel to or residence in Wuhan, China or contact with a confirmed case) is completed for each possible case at regional level, in collaboration between the clinicians, the ARS and SpFrance.
T32 3064-3148 Sentence denotes Data are entered into the secure web-based application Voozanoo (Epiconcept, Paris).
T33 3149-3401 Sentence denotes Possible cases have to be hospitalised, isolated and cared for in one of the 38 French referral hospitals designated by the Ministry of Health, according to the guidelines for the management of patients with Middle East respiratory syndrome (MERS) [3].
T34 3402-3741 Sentence denotes For each possible case, respiratory samples from the upper respiratory tract (nasopharyngeal swabs or aspirates) and when possible from the lower respiratory tract (bronchoalveolar lavage fluid, when indicated, or induced sputum) are collected and sent to one of the laboratories accredited to perform SARS-CoV-2-specific real-time RT-PCR.
T35 3742-3897 Sentence denotes Until 27 January, only the National Reference Centre for respiratory viruses (Institut Pasteur, Paris) was able to test for the presence of the SARS-CoV-2.
T36 3899-3914 Sentence denotes Case definition
T37 3915-4305 Sentence denotes From 17 to 29 January 2020, a possible case was defined either as a patient with a severe acute lower respiratory infection requiring admission to hospital and with a history of travel to or residence in Wuhan, China in the 14 days before symptom onset, or a patient with an acute respiratory illness whatever the severity and with a history of at-risk exposure, mainly to a confirmed case.
T38 4306-4450 Sentence denotes A confirmed case was defined as a possible case with a positive SARS-CoV-2 RT-PCR on respiratory samples, performed by an accredited laboratory.
T39 4451-4652 Sentence denotes Testing relied on the real-time RT-PCR procedure developed by the Charité [4] as well as on the use of real-time RT-PCR specific for the RdRp gene (four targets) designed at Institut Pasteur (RdRp-IP).
T40 4653-4726 Sentence denotes The case definition was first set up on 10 January and adapted over time.
T41 4727-4869 Sentence denotes The detailed case definition used for the cases presented here as well as the most up-to-date case definition are available in the Supplement.
T42 4871-4902 Sentence denotes Contact and co-exposure tracing
T43 4903-5026 Sentence denotes Co-exposed persons are defined as people who shared the same risks of exposure as a possible or confirmed case of COVID-19.
T44 5027-5108 Sentence denotes Contact and co-exposure identification is done for all identified possible cases.
T45 5109-5183 Sentence denotes Contacts are traced from the date of onset of clinical symptoms in a case.
T46 5184-5333 Sentence denotes If the diagnosis of SARS-CoV-2 infection is confirmed in the index case, active surveillance of contacts/co-exposed persons is initiated immediately.
T47 5334-5458 Sentence denotes Three levels of risk of infection are defined for contacts/co-exposed persons of a possible/confirmed COVID-19 case (Table).
T48 5459-5579 Sentence denotes Co-exposed persons of a confirmed case are followed-up according to the same procedure as a moderate-/high-risk contact.
T49 5580-5718 Sentence denotes The follow-up procedure for the contacts/co-exposed persons differs according to the evaluation of the level of risk of infection (Table).
T50 5719-5835 Sentence denotes Table Definition of a contact and follow-up procedure by level of risk of infection, COVID-19, France, January 2020
T51 5836-5905 Sentence denotes Level of risk of infection Contact definition Follow-up procedure
T52 5906-6171 Sentence denotes Negligible risk Person who had short (< 15 min) contact with a confirmed case in public settings such as in public transportation, restaurants and shops; healthcare personnel who treated a confirmed case while wearing appropriate PPE without any breach identified.
T53 6173-6224 Sentence denotes Neither identification nor information of contacts.
T54 6225-6490 Sentence denotes Low risk Person who had a close (within 1 m) but short (< 15 min) contact with a confirmed case, or a distant (> 1 m) but prolonged contact in public settings, or any contact in private settings that does not match with the moderate/high risk of exposure criteria.
T55 6492-6589 Sentence denotes Contacts are asked to measure their body temperature twice a day and check for clinical symptoms.
T56 6590-6844 Sentence denotes In case of occurrence of symptoms like fever, cough or dyspnoea, contacts are asked to wear a surgical mask, isolate themselves and immediately contact the emergency hotline (SAMU-centre 15) indicating that they are contacts of a confirmed COVID-19 case.
T57 6845-7233 Sentence denotes Moderate/high risk Person who had prolonged (> 15 min) direct face-to-face contact within 1 m with a confirmed case, shared the same hospital room, lived in the same household or shared any leisure or professional activity in close proximity with a confirmed case, or travelled together with a COVID-19 case in any kind of conveyance, without appropriate individual protection equipment.
T58 7234-7345 Sentence denotes Healthcare personnel who treated a confirmed case without wearing appropriate PPE or with an identified breach.
T59 7347-7607 Sentence denotes In addition to the above, contacts are asked to stay at home during a 14-day period after their last contact with the confirmed case while symptomatic and to avoid contacts with the other persons living in the same household (or at least wear a surgical mask).
T60 7608-7791 Sentence denotes The follow-up consists of an active follow-up through daily calls from the regional follow-up team organised by the Regional Health Agency in collaboration with Santé publique France.
T61 7792-7863 Sentence denotes COVID-19: coronavirus disease 2019; PPE: personal protective equipment.
T62 7864-8047 Sentence denotes During the initial implementation phase of the procedure, owing to the limited number of contacts involved, it was decided to also implement an active follow-up for low risk contacts.
T63 8048-8258 Sentence denotes Patients are interviewed by the clinicians, with the help of a translator if needed, who recover relevant information on their contacts since onset of clinical symptoms and the nature and intensity of exposure.
T64 8259-8436 Sentence denotes The involved regional health agencies work closely with the regional entities of Santé publique France (cellules régionales) in order to implement contact tracing and follow-up.
T65 8437-8554 Sentence denotes Santé publique France coordinates the surveillance at national level in liaison with the national Health Authorities.
T66 8556-8573 Sentence denotes Ethical statement
T67 8574-8813 Sentence denotes The investigations were carried out in accordance with the General Data Protection Regulation (Regulation (EU) 2016/679 and Directive 95/46/EC) and the French data protection law (Law 78–17 on 06/01/1978 and Décret 2019–536 on 29/05/2019).
T68 8814-8961 Sentence denotes Informed consent to disclosure of information relevant to this publication was obtained from the three patients confirmed with 2019-nCoV infection.
T69 8963-8970 Sentence denotes Results
T70 8972-8996 Sentence denotes Detected confirmed cases
T71 8997-9189 Sentence denotes Between 10 January and 24 January (period until confirmation of the first cases in France), nine possible cases were identified in France; among them, three cases were confirmed with COVID-19.
T72 9190-9245 Sentence denotes Case 1 was a 48-year-old male patient living in France.
T73 9246-9414 Sentence denotes He was travelling for professional reasons in China in various cities including Wuhan when he experienced his first symptoms (fever, headaches and cough) on 16 January.
T74 9415-9521 Sentence denotes He flew back to Bordeaux, France on 22 January via Shanghai, Qingdao and Paris Charles de Gaulle airports.
T75 9522-9568 Sentence denotes He reported wearing a mask during the flights.
T76 9569-9830 Sentence denotes He sought medical attention from a general practitioner on 23 January, where he was suspected of COVID-19, and was subsequently transferred to the regional referring hospital in Bordeaux, isolated and sampled for laboratory confirmation of SARS-CoV-2 infection.
T77 9831-9911 Sentence denotes Infection was confirmed on 24 January by the National Reference Centre (Figure).
T78 9912-10132 Sentence denotes Case 1 tested positive only for the E gene target when using the Charité procedure [4] and was positive for all four RdRp-IP targets with threshold cycles (Ct) in good agreement with those obtained for the E gene target.
T79 10133-10257 Sentence denotes Figure Timeline of travel, onset of illness and close contacts of confirmed cases of COVID-19, France, January 2020 (n = 3)
T80 10258-10360 Sentence denotes ED: emergency department; GP: general practitioner; ICU: intensive care unit; ID: infectious diseases.
T81 10361-10512 Sentence denotes The patient arrived in Wuhan on 13 January, did not report any visit to markets, exposure to live animals or contact with sick persons during his stay.
T82 10513-10650 Sentence denotes No detailed information is available about the circumstances of exposure, apart from a visit to family members and friends on 15 January.
T83 10651-10765 Sentence denotes Case 2 was a 31-year-old Chinese male tourist who had left Wuhan on 18 January and arrived in Paris on 19 January.
T84 10766-10842 Sentence denotes He developed fever, chills, fatigue, conjunctivitis and cough on 19 January.
T85 10843-10917 Sentence denotes Case 3 was a 30-year-old Chinese female tourist who travelled with Case 2.
T86 10918-10979 Sentence denotes She developed fever, chills, fatigue and cough on 23 January.
T87 10980-11231 Sentence denotes On 24 January, they were advised by the Chinese embassy to seek medical attention at the national hotline (SAMU-centre 15) and were immediately transferred to a regional referring hospital, isolated and sampled for laboratory confirmation of COVID-19.
T88 11232-11345 Sentence denotes Infection with SARS-CoV-2 was confirmed on 24 January for both of them by the National Reference Centre (Figure).
T89 11346-11587 Sentence denotes Cases 2 and 3 were positive by RT-PCR for all targets of the Charité procedure [4] (RdRp Pan Sarbeco and 2019-nCov probes; E; N) as well for the four RdRp-IP targets with Ct values in good agreement with those obtained for the E gene target.
T90 11588-11715 Sentence denotes The condition of the male patient deteriorated on 29 January and he was admitted to the intensive care unit (ICU) the same day.
T91 11716-11841 Sentence denotes He stayed 72 h in the ICU for non-invasive oxygen therapy and was transferred back to infectious diseases ward on 31 January.
T92 11842-11992 Sentence denotes Neither of the two cases reported any visit to markets, exposure to live animals or contact with sick persons during the 14 days before symptom onset.
T93 11993-12094 Sentence denotes Both visited a hospital in Wuhan on 16 January for an unrelated medical condition in Case 3 (Figure).
T94 12095-12174 Sentence denotes As at 12 February, Case 1 was afebrile and symptomatic with a persistent cough.
T95 12175-12268 Sentence denotes Cases 2 and 3 were not symptomatic any more and were discharged from hospital on 12 February.
T96 12269-12496 Sentence denotes As soon as the infection with SARS-CoV-2 was confirmed for the three cases on 24 January, this information was immediately released through a press conference held by the French Minister of Health and the Chief Medical Officer.
T97 12497-12631 Sentence denotes Daily public communication on the state of the investigations around the cases was subsequently implemented by the Ministry of Health.
T98 12632-12685 Sentence denotes Daily updates were also published on the SpF website.
T99 12686-12935 Sentence denotes The three cases were notified to the European Commission via the Early Warning and Response System (EWRS) on 26 January, and to the European Center for Disease Prevention and Control (ECDC) via the European Surveillance System (TESSy) on 28 January.
T100 12937-12970 Sentence denotes Contact and co-exposition tracing
T101 12971-13018 Sentence denotes No co-exposed person was identified for Case 1.
T102 13019-13293 Sentence denotes Two contacts were evaluated at low risk of infection, the taxi driver who drove the case from the airport to his home (30-min drive) and the general practitioner who took care of the patient before wearing appropriate personal protection equipment (3-min non-close contact).
T103 13294-13363 Sentence denotes Seventeen contacts were evaluated at moderate/high risk of infection.
T104 13364-13523 Sentence denotes Four of them shared the same waiting room in the general practitioner’s office while Case 1 was coughing, seated ca 1–1.5 m away from the case during 5–30 min.
T105 13524-13660 Sentence denotes The other 13 contacts were the persons sitting in the two seats around Case 1 in the Shanghai–Paris and Paris–Bordeaux flights (Figure).
T106 13661-14002 Sentence denotes They were considered at moderate risk of exposure despite the fact that Case 1 reported wearing a mask during the whole flight; this was based on the length of one of the flights (> 6 h) and the fact that it was unclear whether or not Case 1 removed his mask during short periods (e.g. meals) and kept the same mask during the whole flights.
T107 14003-14158 Sentence denotes None of the contacts of the Shanghai–Paris flight were French nationals and their contact tracing was referred to their home countries’ health authorities.
T108 14159-14570 Sentence denotes All other identified contacts were evaluated at negligible risk of infection because the contacts were short and/or distant in public settings and did not imply face-to-face conversations or because appropriate personal protective equipment (PPE) was worn by the healthcare personnel who took care of the patient, including those involved in the transfer from the general practitioner to the referring hospital.
T109 14571-14750 Sentence denotes Cases 2 and 3 stayed together and shared the same activities during their stay in Paris, and therefore shared the same contacts from 23 January (date of illness onset for Case 3).
T110 14751-14979 Sentence denotes Three contacts were evaluated at low risk of infection: the two owners of the apartment rented by the couple and a department store employee with whom Case 2 reported a distant (> 1 m) contact during around 20 min on 22 January.
T111 14980-15115 Sentence denotes The apartment owner’s child who visited Cases 2 and 3 and was hugged by them was evaluated at moderate/high risk of infection (Figure).
T112 15116-15413 Sentence denotes All other identified contacts were evaluated at negligible risk of infection, as contacts were short and distant in public settings such as department stores and did not imply face-to-face conversations or because appropriate PPE was worn by the healthcare personnel who took care of the patients.
T113 15414-15509 Sentence denotes Follow-up of the identified contacts was initiated according to the COVID-19 procedure (Table).
T114 15510-15622 Sentence denotes As at 2 February, two contacts have been classified as possible cases since the implementation of the follow-up:
T115 15623-15920 Sentence denotes A person sitting two seats away from Case 1 during the Paris–Bordeaux flight, and therefore identified as a moderate/high risk contact, developed respiratory symptoms on 27 January and was classified as a possible case on 31 January and was subsequently excluded following negative RT-PCR results.
T116 15921-15976 Sentence denotes Infection with SARS-CoV-2 was excluded on the same day.
T117 15977-16132 Sentence denotes A radiology assistant who took care of both Cases 2 and 3 developed respiratory symptoms on 30 January and was classified as a possible case on 2 February.
T118 16133-16260 Sentence denotes This person had been classified as at negligible risk of exposure, because she wore appropriate PPE during the whole procedure.
T119 16261-16314 Sentence denotes Infection with SARS-CoV-2 was excluded on 2 February.
T120 16315-16361 Sentence denotes Follow-up of the contacts ended on 6 February.
T121 16362-16436 Sentence denotes No identified contact of the three cases has been confirmed with COVID-19.
T122 16438-16448 Sentence denotes Discussion
T123 16449-16590 Sentence denotes Specific COVID-19 surveillance has been in place in France since 10 January 2020, 3 days after the identification of the SARS-CoV-2 in China.
T124 16591-16715 Sentence denotes The first three imported cases of COVID-19 in France, the first ones in Europe, were diagnosed 14 days later, on 24 January.
T125 16716-17134 Sentence denotes Rapid and effective collaboration between the clinicians (general practitioners attending the cases, emergency hotline clinicians (SAMU-centre 15) and infectious diseases specialists), the National Reference Centre and the regional and national health authorities has played a crucial role in the system’s capacity to quickly detect, isolate and investigate those cases in order to implement adequate control measures.
T126 17135-17485 Sentence denotes The surveillance system as well as the control measures were adapted from those implemented during past emerging infections that occurred after 2003 (severe acute respiratory syndrome (SARS), MERS, influenza A(H1N1)pdm09, Ebolavirus disease), and all involved parties were already familiar with the system, which probably favoured its responsiveness.
T127 17486-17723 Sentence denotes The case definition of a possible case in use on 24 January was slightly adapted from the one provided by the World Health Organization (WHO), based on an epidemiological link to Wuhan, China and a severe lower acute respiratory disease.
T128 17724-17936 Sentence denotes It is noteworthy that the first nine possible cases identified in France, including the three confirmed cases described here, displayed mild respiratory symptoms with no sign of severity at the time of diagnosis.
T129 17937-18074 Sentence denotes Increasing evidence suggests that mild clinical symptoms could be more frequent in cases of COVID-19 than with SARS-CoV and MERS-CoV [5].
T130 18075-18149 Sentence denotes Therefore, the case definition in effect on 24 January lacked sensitivity.
T131 18150-18362 Sentence denotes This was counter-balanced by a tendency from the infectious diseases specialists in charge of classification of suspected cases to privilege the exposure to Wuhan over the clinical presentation in their decision.
T132 18363-18503 Sentence denotes However, we cannot exclude that some COVID-19 cases remained undetected in France because of the lack of sensitivity of our case definition.
T133 18504-18670 Sentence denotes The clinical criteria were expanded on 4 February to include any lower acute respiratory disease and the epidemiological criterion was extended to the whole of China.
T134 18671-18809 Sentence denotes At that time, the French laboratory capacities were reinforced from one to five laboratories able to perform the diagnostics for COVID-19.
T135 18810-18912 Sentence denotes Further extension to all 38 referring hospital laboratories is expected by early to mid-February 2020.
T136 18913-19138 Sentence denotes Santé publique France will deploy in early February the outbreak investigation tool developed by the WHO (Go.Data [6]) in order to facilitate case data management and contact tracing at the national and local level in France.
T137 19139-19340 Sentence denotes Contact and co-exposure identification of the three confirmed cases had been initiated as soon as they were classified as possible cases, which facilitated investigations upon confirmation of COVID-19.
T138 19341-19590 Sentence denotes Confirmation of the diagnosis was made in the evening of 24 January and the investigation to retrieve as exhaustively as possible contacts and co-exposed individuals and evaluate their level of risk of transmission was started immediately overnight.
T139 19591-19717 Sentence denotes Complete transparency of the investigations was ensured through daily press conferences held by the French health authorities.
T140 19718-19959 Sentence denotes Although the follow-up procedure for the contacts/co-exposed persons used in France slightly differ from the ECDC and WHO guidelines [7,8], which were not available at the time of this investigation, it relies on the same general principles.
T141 19960-20159 Sentence denotes Contact tracing of the passengers seated near Case 1 during the two flights Shanghai–Paris and Paris–Bordeaux was adapted from the ECDC guidelines for infectious diseases transmitted on aircraft [9].
T142 20160-20342 Sentence denotes Even though Case 1 was wearing a face mask during those flights, we could not exclude breaches and subsequent risk of transmission to the persons sitting in the two seats around him.
T143 20343-20630 Sentence denotes Because of the current uncertainties about the capacity of SARS-CoV-2 to easily spread from human to human, the decision to consider a contact as close if the case–contact distance was between 1 m and 2 m was made on a case-by-case basis, depending on the type and length of interaction.
T144 20631-20823 Sentence denotes Through the extensive interviews made with the cases and their high compliance to cooperate to the investigation, we believe that the contacts most at risk have been satisfactorily identified.
T145 20824-20929 Sentence denotes All of them could be rapidly contacted and informed about measures to be taken, which they all agreed to.
T146 20930-21348 Sentence denotes However, some contacts were either impossible to trace back (e.g. co-travellers on public transportation) or evaluated as at negligible risk of exposure because of short and/or distant contacts (e.g. restaurant, contacts with cashiers while running errands, visiting museums), although accidental events carrying the risk of transmission on such occasions, such as an episode of cough of sneezing, cannot be ruled out.
T147 21349-21428 Sentence denotes Moreover, the contact tracing was limited to the period after onset of illness.
T148 21429-21653 Sentence denotes However, should the transmission of SARS-CoV-2 occur during the asymptomatic phase, we cannot exclude that secondary transmission events initiated from the three confirmed cases remained undetected during the investigations.
T149 21654-21748 Sentence denotes Case 3 developed symptoms 4 days after her husband and 5 days after the couple had left Wuhan.
T150 21749-21837 Sentence denotes The incubation period of SARS-CoV-2 is currently estimated at around 3–7 days [5,10,11].
T151 21838-21934 Sentence denotes Therefore, she may have acquired the infection from her husband, although this cannot be proved.
T152 21935-22285 Sentence denotes The active surveillance of close contacts of confirmed COVID-19 cases and the implementation of control measures, including home quarantine for those evaluated at moderate/high risk of exposure, decrease the risk of human-to-human transmission originating from imported cases and subsequently delay propagation of the virus in the general population.
T153 22286-22370 Sentence denotes This allows our healthcare system to prepare for any further spread of the epidemic.
T154 22371-22513 Sentence denotes Besides, the epidemiological and clinical data collected about the confirmed cases and their contacts will increase our knowledge of COVID-19.
T155 22514-22722 Sentence denotes The rapid and collaborative management of the first imported COVID-19 cases in France highlights the fact that the French healthcare system is adequately prepared to respond to such emerging diseases threats.
T156 22723-22820 Sentence denotes However, this surveillance system is extremely time-consuming and requires considerable manpower.
T157 22821-22991 Sentence denotes The data available on 12 February strongly suggest that human-to-human transmission of SARS-CoV-2 is frequent, with the reproduction number estimated at 2 to 3 [5,10-14].
T158 22992-23137 Sentence denotes Twenty-five countries have already reported imported cases from China, and several of them have described autochthonous transmission events [15].
T159 23138-23279 Sentence denotes In the case of further spread of SARS-CoV-2 worldwide, it would soon become impossible to detect all imported cases and trace their contacts.
T160 23280-23409 Sentence denotes Especially the occurrence of large clusters in the same region would strongly impact on the local health authorities’ capacities.
T161 23410-23539 Sentence denotes The surveillance objectives would then need to evolve from containing the epidemic to mitigating its medical and societal impact.
T162 23540-23714 Sentence denotes As at 12 February, the contacts of the three first confirmed cases of COVID-19 in France have been followed up for the whole 14 days follow-up time after the cases isolation.
T163 23715-23797 Sentence denotes No secondary transmission event has been detected so far despite active follow-up.
T164 23798-23947 Sentence denotes Given the first estimations of the SARS-CoV-2 incubation period, the probability of secondary cases originating from those three cases is negligible.