LitCovid-sentences  

PMC:7269710 / 1596-27677 JSONTXT 12 Projects

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Id Subject Object Predicate Lexical cue
T21 0-12 Sentence denotes Introduction
T22 13-651 Sentence denotes On Dec 31, 2019, a cluster of viral pneumonia cases, subsequently identified as coronavirus disease 2019 (COVID-19), was reported in Wuhan, China.1 Subsequent reports suggested that community transmission had occurred in Wuhan and Hubei province, leading to the lockdown of Wuhan on Jan 23, 2020, and subsequently other cities in Hubei province, to control COVID-19 spread.2, 3 WHO declared a public health emergency of international concern on Jan 30, 2020.4 As of March 6, 2020, 98 192 confirmed cases and 3380 deaths were reported globally, including 17 481 cases and 335 deaths from 88 regions or countries outside of mainland China.5
T23 652-856 Sentence denotes Singapore, a city-state in southeast Asia, developed case-definitions, laboratory tests, and enhanced surveillance to detect affected individuals with COVID-19 early, to enable containment of the disease.
T24 857-1040 Sentence denotes Singapore confirmed its first imported case of COVID-19 from Wuhan on Jan 23, 2020.6 With the lockdown of Wuhan, inbound flights from Wuhan to Singapore had ceased since Jan 23, 2020.
T25 1041-1191 Sentence denotes As of Feb 22, 2020, 89 people in Singapore were confirmed to have COVID-19, and the first 18 affected individuals all reported recent travel to Wuhan.
T26 1192-1340 Sentence denotes Singapore identified several local clusters of COVID-19, with the first three linked to a tour group from China, a company conference, and a church.
T27 1341-1425 Sentence denotes To contain the spread of COVID-19, several pertinent questions need to be addressed.
T28 1426-1462 Sentence denotes What is the infectiousness of cases?
T29 1463-1546 Sentence denotes What are the settings and activities beyond family clusters where spread can occur?
T30 1547-1620 Sentence denotes What measures should be taken to improve surveillance and case-detection?
T31 1621-1661 Sentence denotes What measures can reduce disease spread?
T32 1662-2051 Sentence denotes To answer these questions, we report data for the first three clusters of COVID-19 cases in Singapore, the epidemiological and clinical investigations done to ascertain disease characteristics and exposure types, and summary statistics to characterise the incubation period of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the serial interval between transmission pairs.
T33 2052-2180 Sentence denotes Our findings will be important for countries and cities to calibrate detection and response efforts during the ongoing epidemic.
T34 2182-2189 Sentence denotes Methods
T35 2191-2203 Sentence denotes Study design
T36 2204-2355 Sentence denotes Since Jan 2, 2020, the Ministry of Health in Singapore has been refining local case-definitions for people suspected of having COVID-19 (appendix p 4).
T37 2356-2725 Sentence denotes Doctors are required by law to notify the Ministry of Health of cases of COVID-19.7 Further, Singapore implemented enhanced surveillance on Jan 31, 2020, to test for COVID-19 among patients in intensive care units and people who died of unknown cause, all people with pneumonia in hospitals, and individuals with influenza-like illness in sentinel primary-care clinics.
T38 2726-2856 Sentence denotes Hospital-based doctors also have permission to test patients who they view with suspicion for clinical or epidemiological reasons.
T39 2857-3014 Sentence denotes A confirmed case of COVID-19 is defined as an individual with a respiratory sample positive for SARS-CoV-2, using a laboratory-based PCR test (appendix p 1).
T40 3015-3114 Sentence denotes Phylogenetic analysis is done of available viral genomic sequences to ascertain genetic clustering.
T41 3115-3134 Sentence denotes Research in context
T42 3135-3161 Sentence denotes Evidence before this study
T43 3162-3302 Sentence denotes We searched PubMed up to Feb 15, 2020 for reports published in English with no date limitations using the keywords “COVID-19” and “cluster”.
T44 3303-3395 Sentence denotes A family cluster of coronavirus disease 2019 (COVID-19) was reported in Shenzhen, Guangdong.
T45 3396-3524 Sentence denotes Transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has also been reported among co-workers in Germany.
T46 3525-3550 Sentence denotes Added value of this study
T47 3551-3661 Sentence denotes We analysed three clusters of COVID-19 in Singapore to assess interactions and possible modes of transmission.
T48 3662-3761 Sentence denotes Our findings show that SARS-CoV-2 is transmissible in community settings beyond household clusters.
T49 3762-3915 Sentence denotes Importation and limited local transmission of SARS-CoV-2 could have occurred before the lockdown of Wuhan and China's institution of travel restrictions.
T50 3916-3958 Sentence denotes Implications of all the available evidence
T51 3959-4213 Sentence denotes Countries should focus on enhancing detection and containment of local clusters of COVID-19, through surveillance of individuals with general pneumonia or influenza-like illnesses, and of people who have been in contact with unwell travellers from China.
T52 4214-4409 Sentence denotes It is also important for countries to do active case-finding among close contacts of affected individuals, including contacts with mild symptoms, to contain clusters and stop them from spreading.
T53 4410-4545 Sentence denotes The Ministry of Health in Singapore identified the first three clusters of COVID-19 cases on Feb 3, 2020, Feb 5, 2020, and Feb 8, 2020.
T54 4546-4733 Sentence denotes All epidemiological investigations and outbreak containment measures were implemented under the Infectious Diseases Act,7 which provides for use of data for analysis to control outbreaks.
T55 4735-4764 Sentence denotes Epidemiological investigation
T56 4765-4966 Sentence denotes We interviewed people with confirmed COVID-19 to obtain data for demographic characteristics, clinical symptoms, and activity patterns, from 14 days preceding symptom onset until isolation in hospital.
T57 4967-5153 Sentence denotes We initiated contact tracing to identify close contacts (ie, people who spend a prolonged time within 2 m of a confirmed case) and other contacts who had some interactions with the case.
T58 5154-5292 Sentence denotes We asked people with confirmed COVID-19 about possible contact with confirmed cases reported overseas in the 14 days before symptom onset.
T59 5293-5491 Sentence denotes We used open source information from other countries (including government websites), news aggregators (eg, ProMed), and media reports to identify secondary transmissions in the respective clusters.
T60 5492-5585 Sentence denotes For each cluster, we investigated the implicated setting to ascertain potential interactions.
T61 5586-5710 Sentence denotes We reviewed activity maps of other confirmed cases in Singapore to identify potential epidemiological links to each cluster.
T62 5711-5892 Sentence denotes We placed close contacts under quarantine for 14 days from last exposure to the individual with confirmed COVID-19, either at home or at designated government quarantine facilities.
T63 5893-6070 Sentence denotes We monitored their health status daily; people who developed symptoms were conveyed in dedicated ambulances to hospital for isolation and testing as part of active case-finding.
T64 6071-6239 Sentence denotes We video-called individuals who were quarantined at home three times a day to verify their location; quarantine violators were tagged with a continuous tracking device.
T65 6240-6408 Sentence denotes We placed other contacts (depending on risk stratification) on phone surveillance or advised them to self-monitor and visit a primary-care clinic if they became unwell.
T66 6410-6429 Sentence denotes Clinical management
T67 6430-6526 Sentence denotes We isolated people with confirmed COVID-19 in individual negative-pressure rooms with anterooms.
T68 6527-6681 Sentence denotes We did blood investigations including a complete blood count, renal and liver function tests, and amounts of C-reactive protein and lactate dehydrogenase.
T69 6682-6803 Sentence denotes Treatment was mainly supportive; we started some patients on oral lopinavir (400 mg) with ritonavir (100 mg) twice daily.
T70 6804-6989 Sentence denotes We obtained clinical data for chronic medical illnesses, physical examinations, laboratory and radiological results, and clinical progression and outcome from inpatient medical records.
T71 6991-7028 Sentence denotes Analysis of disease transmission data
T72 7029-7174 Sentence denotes We reported the median (IQR) incubation period, defined as the duration between estimated dates of infection and reported symptom onset, using R.
T73 7175-7265 Sentence denotes We reported the serial interval range between transmission pairs in the household cluster.
T74 7266-7450 Sentence denotes We also calculated the probable number of transmissions arising from each confirmed case of COVID-19 by assuming that there was one unknown primary case for each of the three clusters.
T75 7452-7478 Sentence denotes Role of the funding source
T76 7479-7510 Sentence denotes This study received no funding.
T77 7511-7650 Sentence denotes The corresponding authors had full access to all data in the study and had final responsibility for the decision to submit for publication.
T78 7652-7659 Sentence denotes Results
T79 7661-7688 Sentence denotes Confirmed cases of COVID-19
T80 7689-7909 Sentence denotes 36 individuals were confirmed to have COVID-19, and these people were related to three local clusters, referred to as A (containing 11 people), B (consisting of 20 individuals), and C (comprising five people; figure 1 ).
T81 7910-8105 Sentence denotes Of these affected individuals, 17 tested positive for SARS-CoV-2 in Singapore, of whom only two (both from cluster C) had recent travel history to China 14 days before onset of symptoms (table ).
T82 8106-8242 Sentence denotes Two people from cluster A and 17 from cluster B were reported by the health authorities of countries where they resided or travelled to.
T83 8243-8321 Sentence denotes Figure 1 Timing of events and cases in three clusters of COVID-19 in Singapore
T84 8322-8440 Sentence denotes Age and sex are shown for each case (left panels), with other pertinent information (eg, relationship or nationality).
T85 8441-8535 Sentence denotes Timeline of events (right panels); onset dates of symptomatic cases are shown, when available.
T86 8536-8570 Sentence denotes COVID-19=coronavirus disease 2019.
T87 8571-8695 Sentence denotes Table Demographic, clinical, and radiological characteristics of individuals who tested positive for SARS-CoV-2 in Singapore
T88 8696-8714 Sentence denotes Individuals (n=17)
T89 8715-8737 Sentence denotes Age (years) 40 (36–51)
T90 8738-8744 Sentence denotes Gender
T91 8745-8757 Sentence denotes Male 7 (41%)
T92 8758-8773 Sentence denotes Female 10 (59%)
T93 8774-8787 Sentence denotes Ethnic origin
T94 8788-8804 Sentence denotes Chinese 16 (94%)
T95 8805-8817 Sentence denotes Other 1 (6%)
T96 8818-8829 Sentence denotes Nationality
T97 8830-8850 Sentence denotes Singaporean 13 (76%)
T98 8851-8866 Sentence denotes Chinese 3 (18%)
T99 8867-8884 Sentence denotes Indonesian 1 (6%)
T100 8885-8892 Sentence denotes Cluster
T101 8893-8945 Sentence denotes A (tourist group from China and shopworkers) 9 (53%)
T102 8946-8976 Sentence denotes B (company conference) 3 (18%)
T103 8977-8995 Sentence denotes C (church) 5 (29%)
T104 8996-9011 Sentence denotes Chronic illness
T105 9012-9024 Sentence denotes Yes* 3 (18%)
T106 9025-9036 Sentence denotes No 14 (82%)
T107 9037-9068 Sentence denotes Travel to China in past 14 days
T108 9069-9080 Sentence denotes Yes 2 (12%)
T109 9081-9092 Sentence denotes No 15 (88%)
T110 9093-9101 Sentence denotes Symptoms
T111 9102-9116 Sentence denotes Fever 15 (88%)
T112 9117-9131 Sentence denotes Cough 14 (82%)
T113 9132-9151 Sentence denotes Sore throat 8 (47%)
T114 9152-9179 Sentence denotes Shortness of breath 6 (35%)
T115 9180-9195 Sentence denotes Myalgia 5 (29%)
T116 9196-9213 Sentence denotes Diarrhoea 4 (24%)
T117 9214-9232 Sentence denotes Chest pain 3 (18%)
T118 9233-9250 Sentence denotes Runny nose 1 (6%)
T119 9251-9276 Sentence denotes Nausea or vomiting 1 (6%)
T120 9277-9317 Sentence denotes Chest radiography findings on admission†
T121 9318-9333 Sentence denotes Present 8 (53%)
T122 9334-9348 Sentence denotes Absent 7 (47%)
T123 9349-9414 Sentence denotes Interval between symptom onset and hospitalisation (days) 4 (3–9)
T124 9415-9446 Sentence denotes Data are median (IQR) or n (%).
T125 9447-9506 Sentence denotes SARS-CoV-2=severe acute respiratory syndrome coronavirus 2.
T126 9507-9585 Sentence denotes * Allergic rhinitis (n=1), hypertension (n=1), and cervical spondylosis (n=1).
T127 9586-9622 Sentence denotes † Data available for 15 individuals.
T128 9624-9633 Sentence denotes Cluster A
T129 9634-9784 Sentence denotes The Ministry of Health in Singapore was alerted to two individuals with locally acquired COVID-19 on Feb 3, 2020 (AC1 and AC2; figure 1 upper panels).
T130 9785-9935 Sentence denotes They did not fit the case-definition for suspected COVID-19 but were tested because they reported frequent occupational contact with Chinese tourists.
T131 9936-10295 Sentence denotes These two people were later identified to be linked epidemiologically to two other affected individuals (AGX1 and AGX2), a father and daughter reported by official and media websites in Guangxi, China,8, 9, 10 to be Chinese tourists who travelled to Singapore on Jan 22, 2020, and who visited several tourist sites on Jan 22–23, 2020, as part of a tour group.
T132 10296-10491 Sentence denotes AGX1 and AGX2 subsequently departed for Malaysia before re-entry into Singapore for their flight to Guangxi on Jan 27, 2020, and they developed symptoms on Jan 28, 2020, after arrival in Guangxi.
T133 10492-10743 Sentence denotes Details of the tour participants and the itinerary, obtained through the Singapore-based tour guide for the Singapore tour segment (AT1, who also tested positive for SARS-CoV-2) corroborated with details for AGX1 and AGX2 reported by Guangxi websites.
T134 10744-10855 Sentence denotes Of 20 tourists in the tour group from Guangxi, five or six were reported by AT1 to be coughing during the tour.
T135 10856-11124 Sentence denotes To the best of our knowledge, only AGX1 and AGX2 had laboratory-confirmed COVID-19 (positive PCR for SARS-CoV-2).8 However, in view of the reported respiratory symptoms among tour group participants, it is possible that other tour group members were the primary cases.
T136 11125-11305 Sentence denotes Among the places visited by the tour group in Singapore were a complementary health products shop and a jewellery shop; both shops are patronised frequently by Chinese tour groups.
T137 11306-11443 Sentence denotes The visits to the complementary health products shop lasted approximately 30 min, and the visit to the jewellery shop lasted roughly 1 h.
T138 11444-11606 Sentence denotes Four assistants in the complementary health products shop (AC1, AC2, AC3, and AC4) and one assistant in the jewellery shop (AJ1) were identified to have COVID-19.
T139 11607-11692 Sentence denotes All five shop assistants were at work on the day the tour group from Guangxi visited.
T140 11693-11864 Sentence denotes AC1, AC2, AC3, and AC4 reported that they would assist customers to apply samples of medicinal oil on their bodies, and handwashing was not usually done between customers.
T141 11865-12003 Sentence denotes Three secondary transmission cases were identified in the household of AC1 (AH1, AH2, and AH3), none of whom were contacts of other cases.
T142 12004-12261 Sentence denotes For the cases who were confirmed on or before Feb 5, 2020, 179 close contacts who were in Singapore and contactable were placed under quarantine, of whom two close contacts (AC3 and AC4) subsequently reported to be unwell and tested positive for SARS-CoV-2.
T143 12262-12312 Sentence denotes An additional six close contacts were quarantined.
T144 12313-12535 Sentence denotes For active surveillance, 16 shop assistants at the complementary health products shop and the sole remaining uninfected household member of AC1, who were all asymptomatic, were tested and none were positive for SARS-CoV-2.
T145 12536-12725 Sentence denotes Viral genomic sequences were available for four cases (AH1, AH2, AH3, and AT1) and phylogenetic analysis confirmed their linkage, as suggested by the epidemiological data (appendix pp 2–3).
T146 12727-12736 Sentence denotes Cluster B
T147 12737-13070 Sentence denotes On Feb 4, 2020, Malaysia confirmed a case of COVID-19 in an individual (B1) who had recent travel history to Singapore on Jan 16–23, 2020, for a company conference (a closed business meeting for employees from company branches globally), which was attended by at least 111 participants from 19 different countries on Jan 20–22, 2020.
T148 13071-13159 Sentence denotes 17 attendees at the conference were from mainland China and at least one was from Wuhan.
T149 13160-13336 Sentence denotes Subsequently, six participants at the conference who had no recent travel history to China (B2, B3, B4, B5, B6, and B7) tested positive for SARS-CoV-2 (figure 1 middle panels).
T150 13337-13521 Sentence denotes Two affected individuals from Singapore were identified through contact tracing of participants after notification from the Malaysian International Health Regulation (IHR) focal point.
T151 13522-13695 Sentence denotes The conference programme included business presentations, workshops, breakout discussions, a welcome reception and meals, team-building games, and a Singapore city bus tour.
T152 13696-13840 Sentence denotes Seating arrangements (where available) for the conference, and interviews with affected individuals, indicated close interactions between cases.
T153 13841-14020 Sentence denotes Two groups (B1 and B3, and B4 and B7) were seated at the same tables for a 3-h Chinese banquet-style dinner on Jan 20, 2020, with three and two attendees from China, respectively.
T154 14021-14230 Sentence denotes Four cases (B1, B3, B4, and B5) were in a 4-h breakout session on Jan 21, 2020, with 41 other participants, including ten from China, of whom three had dined with B1 and B3 or B4 and B7 at the Chinese banquet.
T155 14231-14300 Sentence denotes Furthermore, the team-building games entailed close physical contact.
T156 14301-14429 Sentence denotes With initial news of B1, 15 conference participants remaining in Singapore were contacted to find out about their health status.
T157 14430-14596 Sentence denotes Four people reported being unwell with fever, respiratory symptoms, or both and were tested for SARS-CoV-2; two individuals (B4 and B5) tested positive for the virus.
T158 14597-14742 Sentence denotes The third local case (B6) was identified via activity mapping to have attended the conference and had subsequent interactions with company staff.
T159 14743-14791 Sentence denotes 153 close contacts were placed under quarantine.
T160 14792-14915 Sentence denotes Hotel staff were told to monitor their health status, and none reported being unwell during the conference or subsequently.
T161 14916-15029 Sentence denotes 13 secondary cases of COVID-19 were reported among family members of B1 in Malaysia and contacts of B7 in France.
T162 15031-15040 Sentence denotes Cluster C
T163 15041-15239 Sentence denotes The Ministry of Health in Singapore identified two people from Singapore (C3 and C4), with no recent travel history to China, who tested positive for SARS-CoV-2 from enhanced pneumonia surveillance.
T164 15240-15330 Sentence denotes Activity mapping showed that both individuals had visited the same church on Jan 19, 2020.
T165 15331-15377 Sentence denotes C5 was identified through active case-finding.
T166 15378-15488 Sentence denotes Two other people with COVID-19 were subsequently linked to this cluster (C1 and C2, who are husband and wife).
T167 15489-15582 Sentence denotes These individuals were Chinese nationals from Wuhan who arrived in Singapore on Jan 19, 2020.
T168 15583-15667 Sentence denotes Re-interviews with C1 and C2 found they had also visited the church on the same day.
T169 15668-15750 Sentence denotes All five people were asymptomatic during the church visit (figure 1 lower panels).
T170 15751-16005 Sentence denotes The church is an independent church that occasionally receives a few visitors from China at the Mandarin service conducted every Sunday.11 Although C1 and C2 were not church members, they attended the 2-h morning service when they travelled to Singapore.
T171 16006-16092 Sentence denotes They left immediately after the service and did not report having lunch at the church.
T172 16093-16275 Sentence denotes Based on closed-circuit camera findings, C5 occupied the same seat as did cases C1 and C2 at the prayer meeting after the morning service, but they did not recall meeting each other.
T173 16276-16390 Sentence denotes Among the 227 regular church members, 191 members were contacted, of whom 142 attended the church on Jan 19, 2020.
T174 16391-16511 Sentence denotes Of these people, only two had travel history to Guangdong, China, 14 days before Jan 19, 2020; both reported being well.
T175 16512-16604 Sentence denotes Six were unwell and referred for further management and none tested positive for SARS-CoV-2.
T176 16605-16652 Sentence denotes 93 close contacts were placed under quarantine.
T177 16653-16744 Sentence denotes No additional cases linked to any of the three clusters were identified as of Feb 14, 2020.
T178 16746-16783 Sentence denotes Analysis of disease transmission data
T179 16784-17027 Sentence denotes Although we were unable to identify the primary case or cases in each cluster with certainty, in cluster A, the cases in the two shops and the tour guide had inter-related interactions with the Guangxi tour group in which two cases were found.
T180 17028-17152 Sentence denotes Exposures of the shop assistants were assumed to occur on Jan 23, 2020, and the tour guide on Jan 22, 2020, or Jan 23, 2020.
T181 17153-17293 Sentence denotes In cluster C, the only overlap in activities was on Jan 19, 2020, when all five cases visited the church and exposures most likely occurred.
T182 17294-17408 Sentence denotes For cluster B, we used information on reported activities to infer most likely infection times within the meeting.
T183 17409-17543 Sentence denotes Excluding the household cluster, we had information on both estimated infection time and reported date of symptom onset for 19 people.
T184 17544-17592 Sentence denotes The incubation periods are plotted in figure 2 .
T185 17593-17643 Sentence denotes The median incubation period was 4 days (IQR 3–6).
T186 17644-17882 Sentence denotes Without accounting for potential tertiary transmission within the household (infected by a case who was not the primary case), the serial interval for the three transmission pairs in the household cluster ranged between 3 days and 8 days.
T187 17883-17955 Sentence denotes Figure 2 Incubation periods for cases with known probable exposure times
T188 17956-18004 Sentence denotes Median (IQR) time to onset was 4 days (IQR 3–6).
T189 18005-18220 Sentence denotes Assuming one unknown primary case seeded the outbreaks in each cluster, we noted that 31% of transmission pairs were associated with one individual (B7), and 32 observed cases had no onward transmission (figure 3 ).
T190 18221-18286 Sentence denotes Figure 3 Probable secondary cases arising from each COVID-19 case
T191 18287-18321 Sentence denotes COVID-19=coronavirus disease 2019.
T192 18323-18340 Sentence denotes Clinical findings
T193 18341-18491 Sentence denotes Of 17 locally confirmed cases, fever and cough were the two most common symptoms, reported in 15 (88%) and 14 (82%) individuals, respectively (table).
T194 18492-18602 Sentence denotes One case, a 6-month old male infant, was asymptomatic until one spike of fever 2 days into hospital admission.
T195 18603-18768 Sentence denotes Pulmonary opacities were reported on chest radiography at admission in eight (53%) individuals, and developed over the course of admission in four additional people.
T196 18769-18924 Sentence denotes Lymphopenia (<1·1 × 109 cells per L) was seen in six people and thrombocytopenia (<150 × 109 cells per L) in four individuals over the course of admission.
T197 18925-18999 Sentence denotes Median time from symptom onset to hospital admission was 4 days (IQR 3–9).
T198 19000-19112 Sentence denotes The clinical course was uncomplicated for most individuals, with resolution of symptoms over the first few days.
T199 19113-19254 Sentence denotes Hospital admission was prolonged because of persistently positive SARS-CoV-2 PCR from nasopharyngeal swab testing (median 6 days, range 3–9).
T200 19255-19407 Sentence denotes One individual needed supplemental oxygen via nasal prongs and another two developed acute respiratory distress requiring intubation and intensive care.
T201 19408-19485 Sentence denotes Four individuals received experimental treatment of lopinavir with ritonavir.
T202 19486-19554 Sentence denotes No deaths were recorded in these three clusters as of March 7, 2020.
T203 19556-19566 Sentence denotes Discussion
T204 19567-19644 Sentence denotes We report three clusters showing local transmission of COVID-19 in Singapore.
T205 19645-19818 Sentence denotes The three clusters involved a Chinese tour group, company conference, and a church and show the transmissibility of COVID-19 in community settings beyond household clusters.
T206 19819-20055 Sentence denotes A household cluster was previously reported in Shenzhen, Guangdong, China.12 These findings have implications for public-health measures and outbreak investigations that other countries might consider to detect and contain transmission.
T207 20056-20188 Sentence denotes The first indication of human-to-human transmission in Singapore was detected 11 days after confirmation of the first imported case.
T208 20189-20302 Sentence denotes China imposed a lockdown of Wuhan on Jan 23, 2020, and suspended all outgoing tour groups beginning Jan 27, 2020.
T209 20303-20482 Sentence denotes Despite these measures, local clusters were subsequently identified in Singapore, with probable links to travellers from China before the measures to curb travel were implemented.
T210 20483-20642 Sentence denotes Although the primary case or cases in all three clusters cannot be conclusively identified, they are postulated to be tourists or business visitors from China.
T211 20643-20954 Sentence denotes The tour group implicated in cluster A originated from Guangxi at a time when relatively few cases had been reported in that region of China.13 Temperature screening for inbound travellers on flights from Wuhan was implemented in Singapore on Jan 3, 2020, and expanded to all flights from China on Jan 22, 2020.
T212 20955-21120 Sentence denotes Nonetheless, it is unlikely that these primary cases could be identified by temperature screening, because there was no indication that they were febrile on arrival.
T213 21121-21383 Sentence denotes Therefore, it is important that countries, particularly those with a high travel volume from China, enhance their surveillance system to identify local cases, not merely among people with a travel history to China because cases could be present in the community.
T214 21384-21648 Sentence denotes The local cases in cluster C were identified through enhanced pneumonia surveillance of people who had no history of travel to China, whereas the initial cases in cluster A were identified because of heightened suspicion by health-care workers, leading to testing.
T215 21649-21971 Sentence denotes Among the first 84 confirmed cases in Singapore, ten were detected by enhanced pneumonia surveillance and testing of patients in intensive care units, and another eight affected individuals were detected based on doctors' discretion to test patients whom they viewed with suspicion for clinical or epidemiological reasons.
T216 21972-22185 Sentence denotes Such surveillance systems are, therefore, important to identify cases in the community who would be missed if the focus were only on travellers, and they have enabled prompt investigation and containment measures.
T217 22186-22448 Sentence denotes Furthermore, with swift response in contact tracing and quarantine of close contacts, two close contacts developed symptoms and were confirmed to be infected with SARS-CoV-2 during their period of quarantine, ensuring no further onward transmission of the virus.
T218 22449-22770 Sentence denotes Only two of 425 close contacts identified by contact tracing developed COVID-19 (ie, most cases identified in the clusters did not transmit the SARS-CoV-2 virus to their close contacts), raising the hypothesis that a few spreading events can result in clusters of transmission, whereas for most cases, transmission ended.
T219 22771-22832 Sentence denotes The ease of international travel makes containment difficult.
T220 22833-23086 Sentence denotes Cluster B was identified because of sharing of case data in Malaysia through the IHR focal point, and Singapore shared information on attendees at the company conference to respective IHR focal points where participants at the conference had originated.
T221 23087-23285 Sentence denotes This work led to early identification of cases globally and highlights the importance of international cooperation and sharing of information under IHR to aid in active case-finding and containment.
T222 23286-23393 Sentence denotes The cases of COVID-19 in these three clusters are probably attributable to close or prolonged interactions.
T223 23394-23508 Sentence denotes Direct physical contact was reported between shop assistants and tourists at the health products shop (cluster A).
T224 23509-23786 Sentence denotes Handshaking and physical contact during team-building activities and sharing of meals were reported among participants of the business meeting (cluster B).14 Therefore, direct transmission could be possible by contact or indirect transmission (eg, via fomites and shared food).
T225 23787-24038 Sentence denotes We have shown environmental contamination of common-touch surfaces in the isolation room of a confirmed case.15 This finding highlights the importance of emphasising personal and hand hygiene as a key public-health message that countries should adopt.
T226 24039-24118 Sentence denotes Recall bias could affect the accuracy of symptom-onset dates reported by cases.
T227 24119-24300 Sentence denotes In cluster A, the date of onset of symptoms for AC2 was uncertain because the individual only sought primary-care treatment on Jan 30, 2020, 7 days after reported onset of symptoms.
T228 24301-24331 Sentence denotes Other exposures are plausible.
T229 24332-24597 Sentence denotes AC2 reported having symptoms on the day of the tour group's arrival, and we could postulate that AC2 acquired infection from other tourists before Jan 23, 2020, and seeded infections among colleagues, the tour guide, and the two people from Guangxi on Jan 23, 2020.
T230 24598-24725 Sentence denotes However, case AJ1 had no interactions with AC2, unless AC2 acquired infection serendipitously at a similar time, independently.
T231 24726-24952 Sentence denotes Similarly, in cluster C, C1 did not report symptoms until 5 days and C2 until 3 days, after attending church, and this difference could be attributable to recall bias of symptom-onset dates, particularly if symptoms were mild.
T232 24953-25109 Sentence denotes Other study limitations include the small sample size used to ascertain the incubation period, because primary cases could not be identified with certainty.
T233 25110-25259 Sentence denotes Moreover, symptom-onset dates and the movement of and exposure history of cases detected overseas were either based on media reports or were unknown.
T234 25260-25601 Sentence denotes Based on symptom-onset dates of 17 local cases, the median incubation period (4 days) corroborates other published findings.16, 17 Although there is interest on asymptomatic transmission, we are unable to address this point in our study, and further studies should be done to better understand disease transmissibility of asymptomatic cases.
T235 25602-25959 Sentence denotes In conclusion, as importation and local transmission could have occurred in other countries before the lockdown of Wuhan and institution of travel restrictions by China, local clusters outside China can be expected and efforts should be focused on surveillance for locally acquired cases and containment efforts to prevent widespread community transmission.
T236 25960-26081 Sentence denotes It is important for countries to do active case-finding among close contacts of cases to prevent clusters from spreading.