Association between Exposure to PM 2·5 and the Date-Based Secondary Attack Rate of COVID-19 in Guangzhou, China: A Retrospective Cohort Study

2021 ◽  
Author(s):  
Mao Wang ◽  
Qinlong Jing ◽  
Ai-Li Jiang ◽  
Meng Meng Ma ◽  
Bi-Ling Wen ◽  
...  
Keyword(s):  
Cohort Study ◽  
Retrospective Cohort Study ◽  
Attack Rate ◽  
Retrospective Cohort

scholarly journals Transmission of SARS-CoV-2 from Children and Adolescents

2020 ◽  
Author(s):  
Victoria T. Chu ◽  
Anna R. Yousaf ◽  
Karen Chang ◽  
Noah G. Schwartz ◽  
Clinton J. McDaniel ◽  
...  
Keyword(s):  
Public Health ◽  
Cohort Study ◽  
Confidence Interval ◽  
Children And Adolescents ◽  
Retrospective Cohort Study ◽  
Attack Rate ◽  
Retrospective Cohort ◽  
Mitigation Strategies ◽  
Household Contacts ◽  
Council Of State

AbstractA better understanding of SARS-CoV-2 transmission from children and adolescents is crucial for informing public health mitigation strategies. We conducted a retrospective cohort study among household contacts of primary cases defined as children and adolescents aged 7⍰19 years with laboratory evidence of SARS-CoV-2 infection acquired during an overnight camp outbreak. Among household contacts, we defined secondary cases using the Council of State and Territorial Epidemiologists definition. Among 526 household contacts of 224 primary cases, 48 secondary cases were identified, corresponding to a secondary attack rate of 9% (95% confidence interval [CI], 7%–12%). Our findings show that children and adolescents can transmit SARS-CoV-2 to adult contacts and other children in a household setting.

scholarly journals Secondary attack rate of COVID-19 among contacts and risk factors, Tamil Nadu, March–May 2020: a retrospective cohort study

BMJ Open ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. e051491
Author(s):  
Kolandaswamy Karumanagoundar ◽  
Mohankumar Raju ◽  
Manickam Ponnaiah ◽  
Prabhdeep Kaur ◽  
Vidhya viswanathan ◽  
...  
Keyword(s):  
Cohort Study ◽  
Retrospective Cohort Study ◽  
Attack Rate ◽  
Retrospective Cohort ◽  
Tamil Nadu ◽  
Significant Proportion ◽  
Primary Case ◽  
Factors Associated ◽  
Household Contacts ◽  
Increased Risk

ObjectiveTo describe the characteristics of contacts of patients with COVID-19 case in terms of time, place and person, to calculate the secondary attack rate (SAR) and factors associated with COVID-19 infection among contacts.DesignA retrospective cohort studySetting and participantsContacts of cases identified by the health department from 14 March 2020to 30 May 2020, in 9 of 38 administrative districts of Tamil Nadu. Significant proportion of cases attended a religious congregation.Outcome measureAttack rate among the contacts and factors associated with COVID-19 positivity.ResultsWe listed 15 702 contacts of 931 primary cases. Of the contacts, 89% (n: 14 002) were tested for COVID-19. The overall SAR was 4% (599/14 002), with higher among the household contacts (13%) than the community contacts (1%). SAR among the contacts of primary cases with congregation exposure were 5 times higher than the contacts of non-congregation primary cases (10% vs 2%). Being a household contact of a primary case with congregation exposure had a fourfold increased risk of getting COVID-19 (relative risk (RR): 16.4; 95% CI: 13 to 20) than contact of primary case without congregation exposure. Among the symptomatic primary cases, household contacts of congregation primaries had higher RR than household contacts of other cases ((RR: 25.3; 95% CI: 10.2 to 63) vs (RR: 14.6; 95% CI: 5.7 to 37.7)). Among asymptomatic primary case, RR was increased among household contacts (RR: 16.5; 95% CI: 13.2 to 20.7) of congregation primaries compared with others.ConclusionOur study showed an increase in disease transmission among household contacts than community contacts. Also, symptomatic primary cases and primary cases with exposure to the congregation had more secondary cases than others.

scholarly journals Household secondary attack rate of COVID-19 and associated determinants in Guangzhou, China: a retrospective cohort study

2020 ◽  
Vol 20 (10) ◽  
pp. 1141-1150 ◽  
Author(s):  
Qin-Long Jing ◽  
Ming-Jin Liu ◽  
Zhou-Bin Zhang ◽  
Li-Qun Fang ◽  
Jun Yuan ◽  
...  
Keyword(s):  
Cohort Study ◽  
Retrospective Cohort Study ◽  
Attack Rate ◽  
Retrospective Cohort

scholarly journals A whirlpool associated outbreak of Pontiac fever at a hotel in Northern Sweden

2001 ◽  
Vol 126 (2) ◽  
pp. 241-247 ◽  
Author(s):  
H. M. GÖTZ ◽  
A. TEGNELL ◽  
B. DE JONG ◽  
K. A. BROHOLM ◽  
M. KUUSI ◽  
...  
Keyword(s):  
Risk Factor ◽  
Cohort Study ◽  
Retrospective Cohort Study ◽  
Attack Rate ◽  
Retrospective Cohort ◽  
Environmental Sampling ◽  
Epidemiological Investigation ◽  
Northern Sweden ◽  
Pontiac Fever ◽  
Legionella Micdadei

In April 1999, an outbreak of Pontiac fever occurred at a hotel in Northern Sweden. A retrospective cohort study to find the source and define the extent of the outbreak was carried out among 530 Swedish and Norwegian guests. Twenty-nine epidemiological cases (8 % of 378 responders) aged 21–57 years were identified. Antibodies against Legionella micdadei were detected in 17 of 27 tested cases and 3 other symptomatic persons. Visiting the whirlpool area was identified as the sole risk factor (RR 86; 95 % CI 21–352) and infected cases were confined to visitors to this area over three successive days. The attack rate was 71 % (27/38) and 24 cases (83 %) used the whirlpool. Environmental sampling was negative for Legionella sp. But epidemiological investigation strongly suggests that the whirlpool was the source of the outbreak. The possibility of serious legionella infections underlines the importance of strict maintenance practices to maintain hygiene of whirlpools.

scholarly journals The proof of the pudding is in the eating: an outbreak of emetic syndrome after a kindergarten excursion, Berlin, Germany, December 2007

2011 ◽  
Vol 16 (15) ◽  
Author(s):  
G O Kamga Wambo ◽  
F Burckhardt ◽  
C Frank ◽  
P Hiller ◽  
H Wichmann-Schauer ◽  
...  
Keyword(s):  
Cohort Study ◽  
Relative Risk ◽  
Retrospective Cohort Study ◽  
Attack Rate ◽  
Retrospective Cohort ◽  
Food Poisoning ◽  
Sensu Stricto ◽  
Kindergarten Children ◽  
Food Handling ◽  
Epidemiological Characteristics

An outbreak of food poisoning (emetic syndrome) occurred in three kindergartens (A, B and C) in Berlin, Germany, on 3 December 2007 after an excursion during which food was served. We conducted a retrospective cohort study among the kindergarten children and personnel who participated in the trip. The overall attack rate among the 155 participants was 30%. It was 31% among the 137 children (aged two to six years) and 17% among adults (n=18). The consumption of rice pudding was significantly associated with disease. Among those who ate rice pudding, the attack rate was 36%, compared with 0% for non-eaters (relative risk: infinite, p<0.001, aetiological fraction: 100%), but differed significantly between kindergartens A (43%), B (61%) and C (3%), probably because groups were served from different pots. Bacillus cereus sensu stricto was identified from one vomit sample. The clinical and epidemiological characteristics suggest that B. cereus emetic toxin (cereulide) was the causative agent, although it could not be proven in the single vomit isolate. Inadequate food handling most probably led to the outbreak. Single-portion ready-to-eat rice pudding was recommended for subsequent excursions and no further cases of food poisoning occurred.

scholarly journals Role of Secondary Attack Rate in The Surge of COVID 19 Cases: A Comparative Retrospective Cohort Study between First Wave and Second Wave of COVID 19

2021 ◽  
Vol 001 (02) ◽  
Author(s):  
Jayendrakumar Patel ◽  
Shalin Parikh ◽  
Rakesh Patel ◽  
Shwetaben Patel ◽  
Ronak Patel ◽  
...  
Keyword(s):  
Cohort Study ◽  
Social Interaction ◽  
Social Interactions ◽  
Retrospective Cohort Study ◽  
Attack Rate ◽  
Retrospective Cohort ◽  
Age Group ◽  
Incidence Proportion ◽  
Household Members ◽  
Second Wave

India had the worst conditions during the second wave, and yet, the cause of the enormous spike in COVID-19 cases in a short time span remains unexplained. We aimed to decipher the cause of the enormous spike in COVID-19 cases in the second wave in India. A comparative retrospective cohort study was conducted between the first wave and the second wave. An individual primary case was interviewed using the "COVID-19 transmission questionaries sheet" to trace the total number of primary cases and age-wise unrestricted social interaction and secondary cases. Between January-2021 and May-2021, 1587 unrestricted social interactions were traced with 437 primary cases for the second wave. While for the first wave, 436 unrestricted social interactions were traced with 112 primary cases between January-2020 and December-2020. In the second wave, 36.8% of primary cases developed 334 secondary cases, while 25.0% of primary cases developed 82 secondary cases in the first wave. The secondary attack rate rose 2.5-fold in the age group >50years, and rose ~86% in the age group <10years, while it remained stable in the age group 10-50years. The overall 58% increment in secondary attack rate in the second wave indicates changes in the pattern of unrestricted social interaction amongst household members. This was further supported by the incidence proportion rate that surprisingly rose to ~39% in households of two- and three members in the second wave, while it was negligible in the first wave. Changes in the pattern of unrestricted social interaction among household members and a high affinity of the delta variant virus for infecting people in the age groups of <10 years and >50 years escalated the secondary attack rate and incidence proportion rate that led to the unprecedented surge of COVID-19 cases in the second wave.

scholarly journals Two doses of the mRNA BNT162b2 vaccine reduce severe outcomes, viral load and secondary attack rate: evidence from a SARS-CoV-2 Alpha outbreak in a nursing home, Osnabrueck, Germany, January-March 2021

2021 ◽  
Author(s):  
Emily Dorothee Meyer ◽  
Mirco Sandfort ◽  
Jennifer K Bender ◽  
Dorothea Matysiak-Klose ◽  
Achim Doerre ◽  
...  
Keyword(s):  
Cohort Study ◽  
Nursing Home ◽  
Viral Load ◽  
Confidence Interval ◽  
Retrospective Cohort Study ◽  
Attack Rate ◽  
Retrospective Cohort ◽  
Vaccine Effectiveness ◽  
Pharmaceutical Interventions

A SARS-CoV-2 Alpha outbreak was detected in a nursing home after residents and staff had completed vaccination with BNT162b. In a retrospective cohort study, we estimated an age-adjusted vaccine effectiveness of 88% [95% confidence interval (95%CI) 41-98%] against hospitalization/death. Ct values at diagnosis were higher with longer intervals since the second vaccination [>21 vs. ≤21 days: 4.82 cycles, 95%CI: 0.06-9.58]. Secondary attack rates were 67% lower in households of vaccinated [2/9 (22.2%)] than unvaccinated infected staff [12/18 (66.7%); p=0.046]. Vaccination reduced the risk of severe outcomes, Ct values and transmission, but not fully. Non-pharmaceutical interventions remain important for vaccinated individuals.

Tu1788 CLINICAL CHARACTERISTICS AND TREATMENT DIFFERENCES BETWEEN YOUNGER AND OLDER ONSET MICROSCOPIC COLITIS: A MULTICENTER RETROSPECTIVE COHORT STUDY

2020 ◽  
Vol 158 (6) ◽  
pp. S-1161
Author(s):  
Amrit K. Kamboj ◽  
Amandeep Gujral ◽  
Elida Voth ◽  
Daniel Penrice ◽  
Jessica McGoldrick ◽  
...  
Keyword(s):  
Cohort Study ◽  
Retrospective Cohort Study ◽  
Retrospective Cohort ◽  
Clinical Characteristics ◽  
Microscopic Colitis
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