scholarly journals SARS-CoV-2 Omicron VOC Transmission in Danish Households

2021 ◽  
Author(s):  
Frederik Plesner Lyngse ◽  
Laust Hvas Mortensen ◽  
Matthew J. Denwood ◽  
Lasse Engbo Christiansen ◽  
Camilla Holten Møller ◽  
...  
Keyword(s):  
Strong Evidence ◽  
Attack Rate ◽  
Transmission Dynamics ◽  
Secondary Infections ◽  
Rapid Spread

The Omicron variant of concern (VOC) is a rapidly spreading variant of SARS-CoV-2 that is likely to overtake the previously dominant Delta VOC in many countries by the end of 2021. We estimated the transmission dynamics following the spread of Omicron VOC within Danish households during December 2021. We used data from Danish registers to estimate the household secondary attack rate (SAR). Among 11,937 households (2,225 with the Omicron VOC), we identified 6,397 secondary infections during a 1-7 day follow-up period. The SAR was 31\% and 21\% in households with the Omicron and Delta VOC, respectively. We found an increased transmission for unvaccinated individuals, and a reduced transmission for booster-vaccinated individuals, compared to fully vaccinated individuals. Comparing households infected with the Omicron to Delta VOC, we found an 1.17 (95\%-CI: 0.99-1.38) times higher SAR for unvaccinated, 2.61 times (95\%-CI: 2.34-2.90) higher for fully vaccinated and 3.66 (95\%-CI: 2.65-5.05) times higher for booster-vaccinated individuals, demonstrating strong evidence of immune evasiveness of the Omicron VOC. Our findings confirm that the rapid spread of the Omicron VOC primarily can be ascribed to the immune evasiveness rather than an inherent increase in the basic transmissibility.

Head Louse Feces: Chemical Analysis and Behavioral Activity

2019 ◽  
Author(s):  
F G Galassi ◽  
M I Picollo ◽  
P Gonzalez-Audino
Keyword(s):  
Acetic Acid ◽  
Head Louse ◽  
Skin Irritation ◽  
Human Head ◽  
Behavioral Activity ◽  
Volatile Components ◽  
Head Lice ◽  
Pediculus Humanus ◽  
Secondary Infections

Abstract Human head lice Pediculus humanus capitis (De Geer) (Phthiraptera: Pediculidae) are insect parasites closely associated with humans, feeding on the blood of their hosts and causing them skin irritation and probable secondary infections. Despite being a severe nuisance, very few studies have reported on intraspecific chemical communication in head lice. Here, we evaluated the attractive response of head lice to the volatile compounds and solvent extracts from their feces. We also chemically analyzed the main volatile components of these feces and those of the feces’ extracts. Head lice were attracted to the methanol extract of their feces but not to the hexane or dichloromethane extracts, suggesting the polar nature of bioactive chemicals present in head louse feces. Follow-up chemical identifications, in fact, showed the presence of hypoxanthine, uric acid, and another purine tentatively identified as either guanine or iso-guanine. Additionally, head lice were significantly attracted by volatiles emitted from samples containing feces. The volatiles emanated from feces alone contained 19 identified substances: 2-pentanone, hexanal, heptanal, 3-methyl-3-buten-1-ol, octanal, sulcatone, nonanal, acetic acid, 2-ethyl-1-hexanol, decanal, 1-octanol, butyric acid, 1-nonanol, hexanoic acid, octanoic acid, 2,6-dimethyl-7-octen-2-ol, 2-undecanone, geranylacetone, and hexadecane. The major compounds found were decanal, nonanal, hexanal, and acetic acid, together representing approximately 60% of the identified compounds. This work represents the first chemical evidence of intraspecies communication among head lice. The results support the existence of active substances present in the feces of P. humanus capitis that may be involved in its aggregation behavior.

scholarly journals Revisiting the Natural History of Pulmonary Tuberculosis: A Bayesian Estimation of Natural Recovery and Mortality Rates

2020 ◽  
Author(s):  
Romain Ragonnet ◽  
Jennifer A Flegg ◽  
Samuel L Brilleman ◽  
Edine W Tiemersma ◽  
Yayehirad A Melsew ◽  
...  
Keyword(s):  
Natural History ◽  
Credible Interval ◽  
Mortality Rates ◽  
Previous Systematic Review ◽  
Secondary Infections ◽  
Specific Mortality ◽  
History Of ◽  
Smear Negative ◽  
Related Mortality

Abstract Background Tuberculosis (TB) natural history remains poorly characterized, and new investigations are impossible as it would be unethical to follow up TB patients without treatment. Methods We considered the reports identified in a previous systematic review of studies from the prechemotherapy era, and extracted detailed data on mortality over time. We used a Bayesian framework to estimate the rates of TB-induced mortality and self-cure. A hierarchical model was employed to allow estimates to vary by cohort. Inference was performed separately for smear-positive TB (SP-TB) and smear-negative TB (SN-TB). Results We included 41 cohorts of SP-TB patients and 19 cohorts of pulmonary SN-TB patients in the analysis. The median estimates of the TB-specific mortality rates were 0.389 year−1 (95% credible interval [CrI], .335–.449) and 0.025 year−1 (95% CrI, .017–.035) for SP-TB and SN-TB patients, respectively. The estimates for self-recovery rates were 0.231 year−1 (95% CrI, .177–.288) and 0.130 year−1 (95% CrI, .073–.209) for SP-TB and SN-TB patients, respectively. These rates correspond to average durations of untreated TB of 1.57 years (95% CrI, 1.37–1.81) and 5.35 years (95% CrI, 3.42–8.23) for SP-TB and SN-TB, respectively, when assuming a non-TB-related mortality rate of 0.014 year−1 (ie, a 70-year life expectancy). Conclusions TB-specific mortality rates are around 15 times higher for SP-TB than for SN-TB patients. This difference was underestimated dramatically in previous TB modeling studies, raising concerns about the accuracy of the associated predictions. Despite being less infectious, SN-TB may be responsible for equivalent numbers of secondary infections as SP-TB due to its much longer duration.

scholarly journals Effectiveness of vaccinating household contacts in addition to chemoprophylaxis after a case of meningococcal disease: a systematic review

2008 ◽  
Vol 136 (11) ◽  
pp. 1441-1447 ◽  
Author(s):  
M. R. HOEK ◽  
H. CHRISTENSEN ◽  
W. HELLENBRAND ◽  
P. STEFANOFF ◽  
M. HOWITZ ◽  
...  
Keyword(s):  
Systematic Review ◽  
Meningococcal Disease ◽  
Attack Rate ◽  
Meta Analysis ◽  
Weighted Average ◽  
Inclusion Criteria ◽  
Primary Case ◽  
Household Contacts ◽  
Unpublished Report

SUMMARYWe performed a systematic review to estimate the effectiveness of vaccination, in addition to chemoprophylaxis, in preventing meningococcal disease among household contacts. Medline, EMBASE, EMGM, and EUIBIS were used for data collection. Studies reporting on at least 100 primary cases and on subsequent cases in household settings with follow-up of more than 2 weeks after onset of disease in the primary case were reviewed. A meta-analysis was used to calculate the average attack rate in household contacts given chemoprophylaxis 14–365 days after onset of disease in the primary case. In total, 652 studies were identified, five studies and one unpublished report met the inclusion criteria. The weighted average attack rate was 1·1/1000 household contacts (95% CI 0·7–1·7). This review supports vaccination of household contacts in addition to chemoprophylaxis to reduce the risk of meningococcal disease among household contacts of a case caused by a vaccine-preventable serogroup.

scholarly journals School-based interventions targeting stigma of mental illness: systematic review

2014 ◽  
Vol 38 (4) ◽  
pp. 164-171 ◽  
Author(s):  
Catriona Mellor
Keyword(s):  
Mental Illness ◽  
Young People ◽  
Strong Evidence ◽  
Positive Impact ◽  
School Based ◽  
Programme Design ◽  
Stigma Of Mental Illness ◽  
School Based Interventions ◽  
A Current

Aims and methodTo systematically review the published literature on the effectiveness of classroom-based interventions to tackle the stigma of mental illness in young people, and to identify any consistent elements within successful programmes.ResultsSeventeen studies were included in the analysis. A minority of studies reported a positive impact on stigma or knowledge outcomes at follow-up and there were considerable methodological shortcomings in the studies reviewed. These interventions varied substanitally in content and delivery. It was not possible to use this data to draw out what aspects make a successful intervention. There is currently no strong evidence to support previous conclusions that these types of intervention work for children and adolescents.Clinical implicationsWhen anti-stigma interventions for young people are rolled out in the future, it is important that the programme design and method of delivery have evidence to prove their effectiveness, and that the audience and setting are the most appropriate to target. There is a current lack of strong evidence to inform this.

scholarly journals Transmission dynamics of Ebola virus disease and intervention effectiveness in Sierra Leone

2016 ◽  
Vol 113 (16) ◽  
pp. 4488-4493 ◽  
Author(s):  
Li-Qun Fang ◽  
Yang Yang ◽  
Jia-Fu Jiang ◽  
Hong-Wu Yao ◽  
David Kargbo ◽  
...  
Keyword(s):  
Sierra Leone ◽  
Ebola Virus ◽  
Virus Disease ◽  
Atmospheric Temperature ◽  
Transmission Dynamics ◽  
Ebola Virus Disease ◽  
Transmission Model ◽  
Household Transmission ◽  
Secondary Infections ◽  
The Impact

Sierra Leone is the most severely affected country by an unprecedented outbreak of Ebola virus disease (EVD) in West Africa. Although successfully contained, the transmission dynamics of EVD and the impact of interventions in the country remain unclear. We established a database of confirmed and suspected EVD cases from May 2014 to September 2015 in Sierra Leone and mapped the spatiotemporal distribution of cases at the chiefdom level. A Poisson transmission model revealed that the transmissibility at the chiefdom level, estimated as the average number of secondary infections caused by a patient per week, was reduced by 43% [95% confidence interval (CI): 30%, 52%] after October 2014, when the strategic plan of the United Nations Mission for Emergency Ebola Response was initiated, and by 65% (95% CI: 57%, 71%) after the end of December 2014, when 100% case isolation and safe burials were essentially achieved, both compared with before October 2014. Population density, proximity to Ebola treatment centers, cropland coverage, and atmospheric temperature were associated with EVD transmission. The household secondary attack rate (SAR) was estimated to be 0.059 (95% CI: 0.050, 0.070) for the overall outbreak. The household SAR was reduced by 82%, from 0.093 to 0.017, after the nationwide campaign to achieve 100% case isolation and safe burials had been conducted. This study provides a complete overview of the transmission dynamics of the 2014−2015 EVD outbreak in Sierra Leone at both chiefdom and household levels. The interventions implemented in Sierra Leone seem effective in containing the epidemic, particularly in interrupting household transmission.

scholarly journals Estimation of Dengue Virus IgM Persistence Using Regression Analysis

2011 ◽  
Vol 18 (12) ◽  
pp. 2183-2185 ◽  
Author(s):  
Harry E. Prince ◽  
Jose L. Matud
Keyword(s):  
Regression Analysis ◽  
Dengue Virus ◽  
Primary Infection ◽  
Secondary Infection ◽  
Disease Onset ◽  
Decay Rates ◽  
Point Index ◽  
Infection Group ◽  
Secondary Infections

ABSTRACTDengue virus IgM persistence was estimated using follow-up sera from 98 patients (60 with primary infections and 38 with secondary infections) whose first-specimen IgM index was strongly positive, suggesting recent disease onset. Regression analysis of the follow-up IgM index versus days between samples yielded a trend line that reached the cut-point index (1.10) at 179 days for the primary infection group and 139 days for the secondary infection group. This difference reflected significantly higher first-sample IgM indices in primary infections than in secondary infections rather than differences in IgM decay rates.

scholarly journals TA Treatment of Emetophobia - A Hermeneutic Single-Case Efficacy Design Study – ‘Peter’

2013 ◽  
Vol 4 (2) ◽  
Author(s):  
Colin Kerr
Keyword(s):  
Outcome Measures ◽  
Strong Evidence ◽  
Clinical Characteristics ◽  
Single Case ◽  
White Male ◽  
Male Student ◽  
Case Record ◽  
Literature Reviews ◽  
The Uk

This study reports on theapplication of Hermeneutic Single Case Efficacy Design (HSCED) (Elliott 2002) to a 39 session TA-based psychotherapy intervention with a 19 year old white male student in the UK who was suffering from emetophobia. The author, who was also the researcher, provides literature reviews on emetophobia clinical characteristics,contrasts it with other phobias, and reviews prior research including TA-based approaches to phobias generally. HSCED Methodology is briefly described; quantitative outcome measures are obtained and analysed using GAD-7 (Spritzer et al 2006)and SPQ (Elliott et al 1999), and qualitative measures via a rich case record, session recordings/transcripts, and a 4-month follow-up interview.  Bohart at al’s (2011) 56 criteria for evidence adjudication were used alongside HSCED criteria. There was strong evidence of significant client changes, and that these changes were the result of the therapy.

scholarly journals Characteristics and Transmission Dynamics of COVID-19 in Resident Physicians at a Mexico City Teaching Hospital

2021 ◽  
Vol 2 (3) ◽  
pp. 72-76
Author(s):  
Jessica G. Azcorra-Lopez ◽  
Jesus Reyna-Figueroa ◽  
Eva M. Luna-Rivera ◽  
Berenice Cabañas-Espinosa ◽  
Yamile N. Esquivel-Torruco ◽  
...  
Keyword(s):  
Healthcare Workers ◽  
Infection Prevention ◽  
Case Control Study ◽  
Transmission Dynamics ◽  
Central Tendency ◽  
Resident Physicians ◽  
Significant Difference ◽  
The Mean ◽  
Control Study

Introduction: During the COVID-19 pandemic, hospitals have been busy controlling their spread among healthcare workers, including resident doctors. We seek to characterize and know the transmission dynamics of the SARS-COV-2 infection in the personnel of our hospital. Methodology: 204 resident physicians were followed up, in three parts: Part 1. Training, Part 2. follow-up through the WhatsApp application, Part 3. case-control study; looking for risk factors. The statistical analysis was carried out using measures of central tendency and dispersion, comparison of proportions and rates. As well as the calculation of the odds ratio with a 95% confidence interval; p <0.05 was considered significant. Results: 66 resident physicians were included, 31.8% had a positive result. The mean age was 28.9. The most frequent clinical manifestation was myalgia (66.6%), followed by headache (47%). When comparing with symptomatic resident physicians, with a negative test, there was a significant difference in arthralgia (p = 0.01) and dyspnea (0.05). Noncompliance with training (OR 7.0; 95% CI 2.2-26 and p = 0.000) was significant as a risk factor for infection. Conclusions: Resident physicians must be mostly supervised during infection prevention and containment training.

scholarly journals 375. High Laboratory-confirmed SARS-CoV-2 Attack Rate in Lima Health Care Personnel During August 2020-March 2021 Suggests Role for Improved Infection Control

2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S289-S290
Author(s):  
Matthew Westercamp ◽  
Giselle Soto ◽  
Rachel Smith ◽  
Eduardo Azziz-Baumgartner ◽  
Susan Bollinger ◽  
...  
Keyword(s):  
Attack Rate ◽  
Healthcare Workers ◽  
P Value ◽  
Risk Of Infection ◽  
Vaccine Introduction ◽  
Specimen Collection ◽  
Increased Risk ◽  
Reduction Strategies ◽  
Risk Reduction Strategies

Abstract Background Peru has one of the highest per capita SARS-CoV-2 death rates in Latin America. Healthcare workers (HCW) are a critical workforce during the COVID-19 pandemic but are themselves often at increased risk of infection. We evaluated SARS-CoV-2 attack rate and risk factors among frontline HCWs. Methods We performed a prospective cohort study of HCW serving two acute care hospitals in Lima, Peru from Aug 2020 to Mar 2021. Participants had baseline SARS-CoV-2 serology using the CDC ELISA, active symptom monitoring, and weekly respiratory specimen collection with COVID-19 exposure/risk assessment for 16-weeks regardless of symptoms. Respiratory specimens were tested by real-time reverse transcriptase PCR (rRT-PCR). Results Of 783 eligible, 667 (85%) HCW were enrolled (33% nurse assistants, 29% non-clinical staff, 26% nurses, 7% physicians, and 6% other). At baseline and prior to COVID-19 vaccine introduction, 214 (32.1%; 214/667) were reactive for SARS-CoV-2 antibodies. In total, 72 (10.8%; 72/667) HCWs were found to be rRT-PCR positive during weekly follow-up. Of the rRT-PCR positive HCWs, 37.5% (27/72) did not report symptoms within 1-week of specimen collection. During follow up, HCW without detectable SARS-CoV-2 antibodies at baseline were significantly more likely to be rRT-PCR positive (65/453, 14.3%) compared to those with SARS-CoV-2 antibodies at baseline (4/214, 1.9%) (p-value: &lt; 0.001). Three HCW were both serologically reactive and rRT-PCR positive at baseline. Looking only at HCW without SARS-CoV-2 antibodies, nurse assistants (rRT-PCR positive: 18.6%; 27/141) and non-clinical healthcare workers (16.5%; 21/127) were at greater risk of infection compared to nurses (8.5%; 10/118), physicians (7.9%; 3/38), and other staff (10.3%; 4/29) (RR 1.95;95%CI 1.2,3.3; p-value: 0.01). Conclusion Baseline SARS-CoV-2 prevalence and 16-week cumulative incidence were substantial in this pre-vaccination Peruvian HCW cohort. Almost 40% of new infections occurred in HCW without complaint of symptoms illustrating a limitation of symptom-based HCW screening for COVID-19 prevention. Nurse assistants and non-clinical healthcare workers were at greater risk of infection indicating a role for focused infection prevention and risk reduction strategies for some groups of HCW. Disclosures Fernanda C. Lessa, MD, MPH, Nothing to disclose

scholarly journals A review of COVID-19 transmission dynamics and clinical outcomes on cruise ships worldwide, January to October 2020

2022 ◽  
Vol 27 (1) ◽  
Author(s):  
Kathryn S Willebrand ◽  
Lauren Pischel ◽  
Amyn A Malik ◽  
Samuel M Jenness ◽  
Saad B Omer
Keyword(s):  
Attack Rate ◽  
The United States ◽  
Median Number ◽  
Transmission Dynamics ◽  
Mitigation Measures ◽  
Confined Space ◽  
Susceptible Population ◽  
Comprehensive Review ◽  
Cruise Ships ◽  
Epidemiological Information

Background Cruise ships provide an ideal setting for transmission of SARS-CoV-2, given the socially dense exposure environment. Aim To provide a comprehensive review of COVID-19 outbreaks on cruise ships. Methods PubMed was searched for COVID-19 cases associated with cruise ships between January and October 2020. A list of cruise ships with COVID-19 was cross-referenced with the United States Centers for Disease Control and Prevention’s list of cruise ships associated with a COVID-19 case within 14 days of disembarkation. News articles were also searched for epidemiological information. Narratives of COVID-19 outbreaks on ships with over 100 cases are presented. Results Seventy-nine ships and 104 unique voyages were associated with COVID-19 cases before 1 October 2020. Nineteen ships had more than one voyage with a case of COVID-19. The median number of cases per ship was three (interquartile range (IQR): 1–17.8), with two notable outliers: the Diamond Princess and the Ruby Princess, which had 712 and 907 cases, respectively. The median attack rate for COVID-19 was 0.2% (IQR: 0.03–1.5), although this distribution was right-skewed with a mean attack rate of 3.7%; 25.9% (27/104) of voyages had at least one COVID-19-associated death. Outbreaks involving only crew occurred later than outbreaks involving guests and crew. Conclusions In the absence of mitigation measures, COVID-19 can spread easily on cruise ships in a susceptible population because of the confined space and high-density contact networks. This environment can create superspreader events and facilitate international spread.

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