A Cluster of Novel Coronavirus Disease 2019 Infections Indicating Person-to-Person Transmission Among Casual Contacts From Social Gatherings: An Outbreak Case-Contact Investigation

Abstract Background Severe acute respiratory syndrome coronavirus 2, the pathogen causing novel coronavirus disease of 2019 (COVID-19), efficiently spreads from person to person in close contact settings. Transmission among casual contacts in settings such as during social gatherings is not well understood. Methods We report several transmission events to both close and casual contacts from a cluster of 7 COVID-19 cases occurring from mid-January to early February 2020. A total of 539 social and family contacts of the index patient’s, including members of a 2-day wedding and a family party, were contacted and screened through epidemiologic surveys. The clinical progression of all cases is described. Results We estimate the secondary attack rate among close contacts to be 29% (2 of 7) and for the casual contacts to be 0.6% (3 of 473). The incubation period of our case cluster was 4–12 days (median, 7 days). Conclusions Transmission efficiency among close contacts was higher than among casual contacts; however, transmission from second-generation cases may help spread the virus during the incubation period.

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Epidemiology and contact tracing assessment of COVID-19 and potential risk of transmission at different exposure settings: A prospective cohort study

10.21203/rs.3.rs-442709/v1 ◽

2021 ◽

Author(s):

Abu Shadat M Noman ◽

Mohammed Rezaul Karim ◽

ASM Zahed ◽

ATM Rezaul Karim ◽

Syed S Islam

Keyword(s):

Risk Ratio ◽

Attack Rate ◽

Close Contact ◽

Household Contact ◽

Control Measures ◽

Effective Control ◽

Secondary Contact ◽

Epidemiological Characteristics ◽

Index Cases ◽

Close Contacts

Abstract Background: Transmission risk of coronavirus disease 2019 (COVID-19) to close contacts and at different exposure settings are yet to be fully understood for the evaluation of effective control measures. Methods: We traced 1171 close contact cases who were linked to 291 index cases between July 3, 2020 and September 3, 2020. Clinical and epidemiological characteristics of all index cases, close contacts, and secondary contact cases were collected and analyzed the secondary attack rate and risk of transmission at different exposure settings. Results: Median age of 291 index cases were 43.0 years (range 18.5-82.3) including 213 male and 78 females. Among all 1171 close contact cases, 39(3.3%) cases were identified as secondary infected cases. Among 39 secondary cases, 33(84.62%) cases were symptomatic and 3 (7.69%) cases were asymptomatic. Of the 33 symptomatic cases, 31(86.1%) male and 5(13.9%) female. Of these 36 symptomatic cases, 24(66.7%) cases between age 20-59 and remaining 12(33.3%) cases were age 60 and over. Of the 36 symptomatic cases, 11(30.6%) cases were identified as severe, 19(52.8%) as moderate and 6(16.7%) as mild. The overall secondary clinical attack rate was 3.07% (95% CI 2.49-3.64). The attack rate was higher among those aged between 50 to 69 years and shows higher risk of transmission than age below 50 years. The attack rate was higher among household contact (6.17%(95%CI 4.7-7.6; risk ratio 2.44[95%CI1.5-3.4]), and lower in hospital facility (2.29%,95%CI0.58-3.40; [risk ratio 0.91,95%CI 0.17-1.9]), funeral ceremony (2.53%,95%CI 0.32-4.73), work places (3.95%,95% CI2.5-5.42 [risk ratio 1.56,95%CI 0.63-2.5]), family contacts (3.87%,95%CI 2.4-5.3; risk ratio 1.53,95%CI 0.61-2.45]). Conclusions: Among all exposure settings analyzed, household contact exposure setting remained the highest transmission probability and risk of transmission of COVID-19 with the increase of age and disease severity.

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Epidemiological analysis of 67 local COVID-19 clusters in Sichuan Province, China

10.21203/rs.3.rs-26119/v1 ◽

2020 ◽

Author(s):

Suling Mao ◽

Ting Huang ◽

Heng Yuan ◽

Min Li ◽

Xiaomei Huang ◽

...

Keyword(s):

Incubation Period ◽

Attack Rate ◽

Clinical Symptoms ◽

Close Contact ◽

Sichuan Province ◽

Information Support ◽

Protective Effects ◽

Systemic Symptoms ◽

And Control ◽

Epidemiological Characteristics

Abstract Background This study was intended to investigate the epidemiological characteristics of COVID-19 clusters and the severity distribution of clinical symptoms of involved cases in Sichuan Province, so as to provide information support for the development and adjustment of strategies for the prevention and control of local clusters.Methods The epidemiological characteristics of 67 local clusters of COVID-19 cases in Sichuan Province reported as of March 17, 2020 were described and analyzed. Information about all COVID-19 clusters and involved cases was acquired from the China Information System for Disease Control and Prevention and analyzed with the epidemiological investigation results taken into account.Results The clusters were temporally and regionally concentrated. Clusters caused by imported cases from Wuhan and other provinces except Wuhan accounted for 73.13%; familial clusters accounted for 68.66%; the average attack rate was 8.54%, and the average secondary attack rate was 6.11%; the median incubation period was 8.5 d;a total of 28 cases met the criteria for incubation period determination, and in the 28 cases, the incubation period was > 14 d in 21.43% (6/28). a total of 226 confirmed cases were reported in the 67 clusters. Ten cases were exposed before the confirmed cases they contacted with developed clinical symptoms, and the possibility of exposure to other infection sources was ruled out; two clusters were caused by asymptomatic carriers; confirmed cases mainly presented with fever, respiratory and systemic symptoms; a gradual decline in the severity of clinical symptoms was noted with the increase of the case generation.Conclusions Population movement and gathering restrictions and strict close contact management measures will significantly contribute to the identification and control of cases. Transmission during the incubation period and asymptomatic infections have been noted. Studies on the pathogenicity and transmissibility in these populations and on COVID-19 antibody levels and protective effects in healthy people and cases are required.

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Incubation Period of Severe Acute Respiratory Syndrome Novel Coronavirus 2 that Causes Coronavirus Disease 2019: A Systematic Review and Meta-Analysis

Current Therapeutic Research ◽

10.1016/j.curtheres.2020.100607 ◽

2020 ◽

Vol 93 ◽

pp. 100607 ◽

Cited By ~ 1

Author(s):

Gizachew Tadesse Wassie ◽

Abebaw Gedef Azene ◽

Getasew Mulat Bantie ◽

Getenet Dessie ◽

Abiba Mihret Aragaw

Keyword(s):

Systematic Review ◽

Severe Acute Respiratory Syndrome ◽

Incubation Period ◽

Meta Analysis ◽

Novel Coronavirus

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COVID-19 vaccination for patients with primary immunodeficiency

LymphoSign Journal ◽

10.14785/lymphosign-2021-0020 ◽

2021 ◽

Author(s):

Chaim M Roifman ◽

Linda Vong

Keyword(s):

Severe Acute Respiratory Syndrome ◽

Hand Hygiene ◽

Immune Responses ◽

Primary Immunodeficiency ◽

Close Contact ◽

Herd Immunity ◽

Severe Illness ◽

Third Wave ◽

Novel Coronavirus ◽

Spread Of Infection

The worldwide tally of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, causing novel coronavirus disease 2019 (COVID-19), currently approaches 149.7 million (as of April 30, 2021). Canada’s cases amount to 1,211,083 confirmed infections and 24,169 deaths. In the midst of the pandemic and a third wave of infections, programs aimed at widespread vaccination against COVID-19 remain an essential stop-gap to slow the spread of infection and help achieve protective herd immunity. Patients with primary immunodeficiency (PID) have impaired immune responses and may be at greater risk of severe illness due to COVID-19, thus, are strongly recommended to avoid interactions with those outside of their immediate household “bubble”, practice hand hygiene, and wear masks when spending time outside or in enclosed spaces where close contact with other people cannot be avoided. With the ongoing rollout of COVID-19 vaccinations, we provide here recommendations for patients with PID. It is important to note that individuals who are immunocompromised should always consult their immunologist for additional considerations/contraindications when reviewing their suitability for vaccination.

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Clinical Outcomes in 55 Patients With Severe Acute Respiratory Syndrome Coronavirus 2 Who Were Asymptomatic at Hospital Admission in Shenzhen, China

The Journal of Infectious Diseases ◽

10.1093/infdis/jiaa119 ◽

2020 ◽

Vol 221 (11) ◽

pp. 1770-1774 ◽

Cited By ~ 115

Author(s):

Yanrong Wang ◽

Yingxia Liu ◽

Lei Liu ◽

Xianfeng Wang ◽

Nijuan Luo ◽

...

Keyword(s):

Nucleic Acid ◽

Young People ◽

Severe Acute Respiratory Syndrome ◽

Hospital Admission ◽

Clinical Outcomes ◽

Close Contact ◽

Nucleic Acid Testing ◽

Pharyngeal Swab ◽

Asymptomatic Carriers ◽

Novel Coronavirus

Abstract An epidemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has spread unexpectedly in Wuhan, Hubei Province, China, since December 2019. There are few reports about asymptomatic contacts of infected patients identified as positive for SARS-CoV-2 through screening. We studied the epidemiological and clinical outcomes in 55 asymptomatic carriers who were laboratory confirmed to be positive for SARS-CoV-2 through nucleic acid testing of pharyngeal swab samples. The asymptomatic carriers seldom occurred among young people (aged 18–29 years) who had close contact with infected family members. In the majority of patients, the outcome was mild or ordinary 2019 novel coronavirus disease during hospitalization.

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Epidemiological analysis of 67 local COVID-19 clusters in Sichuan Province, China

BMC Public Health ◽

10.1186/s12889-020-09606-4 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Suling Mao ◽

Ting Huang ◽

Heng Yuan ◽

Min Li ◽

Xiaomei Huang ◽

...

Keyword(s):

Incubation Period ◽

Attack Rate ◽

Clinical Symptoms ◽

Close Contact ◽

Sichuan Province ◽

Information Support ◽

Protective Effects ◽

Systemic Symptoms ◽

And Control ◽

Epidemiological Characteristics

Abstract Background This study was intended to investigate the epidemiological characteristics of COVID-19 clusters and the severity distribution of clinical symptoms of involved cases in Sichuan Province, so as to provide information support for the development and adjustment of strategies for the prevention and control of local clusters. Methods The epidemiological characteristics of 67 local clusters of COVID-19 cases in Sichuan Province reported as of March 17, 2020 were described and analyzed. Information about all COVID-19 clusters and involved cases was acquired from the China Information System for Disease Control and Prevention and analyzed with the epidemiological investigation results taken into account. Results The clusters were temporally and regionally concentrated. Clusters caused by imported cases from other provinces accounted for 73.13%; familial clusters accounted for 68.66%; the average attack rate was 8.54%, and the average secondary attack rate was 6.11%; the median incubation period was 8.5 d; a total of 28 cases met the criteria for incubation period determination, and in the 28 cases, the incubation period was > 14 d in 21.43% (6/28). a total of 226 confirmed cases were reported in the 67 clusters. Ten cases were exposed before the confirmed cases they contacted with developed clinical symptoms, and the possibility of exposure to other infection sources was ruled out; two clusters were caused by asymptomatic carriers; confirmed cases mainly presented with fever, respiratory and systemic symptoms; a gradual decline in the severity of clinical symptoms was noted with the increase of the case generation. Conclusions Population movement and gathering restrictions and strict close contact management measures will significantly contribute to the identification and control of cases. Transmission during the incubation period and asymptomatic infections have been noted. Studies on the pathogenicity and transmissibility in these populations and on COVID-19 antibody levels and protective effects in healthy people and cases are required.

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Transmission Risk of SARS-CoV-2 Among Close Contacts- Results of Case- Contact Tracing

10.21203/rs.3.rs-29844/v1 ◽

2020 ◽

Author(s):

Haimei Jia ◽

Minhong CHen ◽

Hanwei Wang ◽

Chenping Guan ◽

Yangwei Chen ◽

...

Keyword(s):

Virus Disease ◽

Close Contact ◽

Secondary Infection ◽

Transmission Risk ◽

Contact Tracing ◽

Anal Swab ◽

Novel Coronavirus ◽

Asymptomatic Case ◽

Epidemiological Characteristics ◽

Close Contacts

Abstract Background: The ongoing outbreak of corona virus Disease-19 (COVID-19) is rapid escalation and global spread.The epidemiological characteristics and particularly its ability to spread in the human population of COVID-19 were uncertainty. We analyzed infection of 2019 novel coronavirus pneumonia (COVID-19) and close contacts in Fuzhou, Fujian Province, and to understand the risk of infection and morbidity in different exposure mode. Methods: We investigated cases and their close contacts by face-to –face or telephone interview and conducted laboratory test on nasopharyngeal or oropharyngeal swabs or anal swab for evidence of COVID-19 infection. Information on cases including the epidemiology, expose and laboratory were collected. Results: There were 72 patients of COVID-19 and 1 asymptomatic case were confirmed in Fuzhou. A total of 1159 close contacts were traced, the secondary infection rate (SIR) was 2.07% (24/1159), the median of interval was 12 days (rang 2-21 days). In the relationship between close contact and cases, the SIR of old people under care were the highest (28.57% ) than family members (5.52%), medical staff (3.23%), relatives (2.41%) and colleagues / classmates (1.67%), respectively( 2＝534.38， P＜0.00 ). Among the contact ways, the SIR of Nursing (nursing home) were the highest (28.57% ) than medical care (3.23%), family gathering (2.82%), same building (1.77%) and short talk or handle affairs (1.55%),respectively. The median of incubation period was 5days (rang1-12days). Conclusions: The COVID-19 has highly contagious. Timely and strict quarantine should be conducted for close contacts to reduce the possibility of community communication.

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Letter to Editor COVID-19 outbreak and medical waste: Challenge in hand

International Journal of Public Health Science (IJPHS) ◽

10.11591/ijphs.v9i3.20523 ◽

2020 ◽

Vol 9 (3) ◽

pp. 153

Author(s):

Hassan Musa ◽

Taha H. Musa ◽

Idriss H. Musa ◽

Olayinka Oderinde

Keyword(s):

Severe Acute Respiratory Syndrome ◽

Close Contact ◽

Medical Waste ◽

The World ◽

Novel Coronavirus ◽

Health Experts

The ongoing pandemic of novel coronavirus disease, COVID19, which first reported in Wuhan, China, inDecember 2019, [1] and caused by severe acute respiratory syndrome coronavirus 2 (SARSCoV2) has resulted to more than 6,881,352 confirmed cases in the world, and 399,895 global deaths, as reported in 8:36am CEST, 8 June 2020. [2] It has been reported that the primary spread of COVID-19 via human transmission is during close contact, most often through small droplets spread by coughing, sneezing, and talking. [3] Researchers and health experts have discovered that wearing of appropriate face masks can significantly reduce the transmission up to the 75%.

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A Family Cluster of Severe Acute Respiratory Syndrome Coronavirus 2 Infections

10.21203/rs.3.rs-16921/v1 ◽

2020 ◽

Cited By ~ 1

Author(s):

Xuesong Gao ◽

Zheng Yuan ◽

Di Yang ◽

Hongjie Li ◽

Yijin Zhang ◽

...

Keyword(s):

Severe Acute Respiratory Syndrome ◽

Clinical Symptoms ◽

Close Contact ◽

Hubei Province ◽

Adverse Outcomes ◽

Family Cluster ◽

High Flow Oxygen ◽

Novel Coronavirus ◽

Epidemiological Characteristics ◽

Beijing China

Abstract Background In December 2019, the outbreak of 2019 novel coronavirus disease (COVID-19) began in Wuhan, Hubei Province, China. The disease has rapidly spread from Wuhan to other provinces and other countries. Clinical and epidemiological knowledge is limited. We aimed to describe the clinical and epidemiological characteristics of a family cluster of COVID-19 in Beijing.Methods We reported a family cluster of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cases in Beijing, China. We obtained and analyzed clinical and epidemiologic data from these patients. Throat swab samples were tested for SARS-CoV-2 using real-time reverse transcriptase-polymerase chain reaction assays.Results This family comprised three laboratory confirmed cases with clinical symptoms. All three patients had close contact with a relative from Wuhan, Hubei Province. Chest computerized tomography revealed ground-glass opacities and consolidation. Patient 1 was finally intubated and mechanical ventilated. Patient 2 received high-flow oxygen therapy. The clinical condition of Patient 3 has resolved.Conclusion SARS-CoV-2 infections tend to clusters. Advanced age and comorbidities are associated with adverse outcomes. Physicians should be aware of contact history so that infected patients can be identified promptly and further spreading prevented.

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Characterizing COVID-19 Transmission: Incubation Period, Reproduction Rate, and Multiple-Generation Spreading

Frontiers in Physics ◽

10.3389/fphy.2020.589963 ◽

2021 ◽

Vol 8 ◽

Author(s):

Lin Zhang ◽

Jiahua Zhu ◽

Xuyuan Wang ◽

Juan Yang ◽

Xiao Fan Liu ◽

...

Keyword(s):

Incubation Period ◽

Disease Transmission ◽

Transmission Rate ◽

Close Contact ◽

Mainland China ◽

Reproduction Rate ◽

Prevention Measures ◽

Multiple Generation ◽

Log Normal ◽

Close Contacts

Understanding the transmission process is crucial for the prevention and mitigation of COVID-19 spread. This paper contributes to the COVID-19 knowledge by analyzing the incubation period, the transmission rate from close contact to infection, and the properties of multiple-generation transmission. The data regarding these parameters are extracted from a detailed line-list database of 9,120 cases reported in mainland China from January 15 to February 29, 2020. The incubation period of COVID-19 has a mean, median, and mode of 7.83, 7, and 5 days, and, in 12.5% of cases, more than 14 days. The number of close contacts for these cases during the incubation period and a few days before hospitalization follows a log-normal distribution, which may lead to super-spreading events. The disease transmission rate from close contact roughly decreases in line with the number of close contacts with median 0.13. The average secondary cases are 2.10, 1.35, and 2.2 for the first, second, and third generations conditioned on at least one offspring. However, the ratio of no further spread in the 2nd, 3rd, and 4th generations are 26.2, 93.9, and 90.7%, respectively. Moreover, the conditioned reproduction number in the second generation is geometrically distributed. Our findings suggest that, in order to effectively control the pandemic, prevention measures, such as social distancing, wearing masks, and isolating from close contacts, would be the most important and least costly measures.

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