Seven-day COVID-19 quarantine may be too short: assessing post-quarantine transmission risk in four university cohorts

BackgroundDespite rising rates of vaccination, quarantine remains critical to control SARS-CoV-2 transmission. COVID-19 quarantine length around the world varies in part due to the limited amount of empirical data. ObjectiveTo assess post-quarantine transmission risk for various quarantine lengths. DesignCohort study. SettingFour US universities, September 2020 to February 2021. Participants3,641 students and staff were identified as close contacts to SARS-CoV-2-positive individuals. They entered strict or non-strict quarantine and were tested on average twice per week for SARS-CoV-2. Strict quarantine included designated housing with a private room, private bathroom and meal delivery. Non-strict quarantine potentially included interactions with household members. MeasurementsDates of exposure and last negative and first positive tests during quarantine. ResultsOf the 418 quarantined individuals who eventually converted to positive, 11%, 4.2%, and 1.2% were negative and asymptomatic on days 7, 10 and 14, respectively. The US CDC recently shortened its quarantine guidance from 14 to 7 days based on estimates of 2.3-8.6% post-quarantine transmission risk at day 7, significantly below the 11% risk we report here. Notably, 6% of individuals tested positive after day 7 in strict quarantine, versus 14% in non-strict quarantine. Ongoing exposure during quarantine likely explains the higher rate of COVID-19 in non-strict quarantine. LimitationsQuarantine should be longer for individuals using antigen testing, given antigen testings lower sensitivity than qPCR. Results apply in settings in which SAR-CoV-2 variants do not affect latent period. ConclusionsTo maintain the 5% transmission risk that the CDC used in its guidance, our data suggest that quarantine with qPCR testing 1 day before intended release should extend to 10 days for non-strict quarantine. Funding SourceNone.

Association between keratoconus, ocular allergy, and sleeping behavior.

PURPOSE: To compare the severity and laterality of keratoconus according to allergic rhinitis, scratching and sleeping habits, and manual dexterity. METHODS: Objective assessments regarding allergic rhinitis, eye itching, and slee-ping position among patients with keratoconus (diagnosed based on corneal tomography) were conducted. Diagnostic criteria and classification were based on the Amsler-Krumeich classification. RESULTS: Ocular pruritus was reported by 29 of 34 participants (85.29%). Eighteen participants (62.07%) reported equal scratching of both eyes, six (20.69%) more on the right eye, and five (17.24%) more on the left eye. Comparison of the main sleeping position and the eye with more severe presentation of the disease using Fisher's exact test revealed some correlations (0.567 and 0.568 in the right and left eye, respectively). However, these correlations were not statistically significant. CONCLUSIONS: The association between higher keratometry values and sleeping position appears to be more significant than that reported between keratometry and itching, or manual dexterity.

Association between keratoconus, ocular allergy, and sleeping behavior / Associação entre ceratocone, alergia ocular e comportamento ao dormir

ABSTRACT Purpose: To compare the severity and laterality of keratoconus according to allergic rhinitis, scratching and sleeping habits, and manual dexterity. Methods: Objective assessments regarding allergic rhinitis, eye itching, and slee­ping position among patients with keratoconus (diagnosed based on corneal tomography) were conducted. Diagnostic criteria and classification were based on the Amsler-Krumeich classification. Results: Ocular pruritus was reported by 29 of 34 participants (85.29%). Eighteen participants (62.07%) reported equal scratching of both eyes, six (20.69%) more on the right eye, and five (17.24%) more on the left eye. Comparison of the main sleeping position and the eye with more severe presentation of the disease using Fisher's exact test revealed some correlations (0.567 and 0.568 in the right and left eye, respectively). However, these correlations were not statistically significant. Conclusions: The association between higher keratometry values and sleeping position appears to be more significant than that reported between keratometry and itching, or manual dexterity.

RESUMO Objetivo: Comparar a gravidade e a lateralidade do ceratocone de acordo com a rinite alérgica, os hábitos de coçar e dormir e a destreza manual. Métodos: Foram realizadas questões objetivas sobre rinite alérgica, prurido ocular e posi­ção do sono em pacientes com ceratocone, diagnosticados com base na tomografia corneana. Esses exames foram analisados e classificados de acordo com a classificação de Amsler-Krumeich. Resultados: O prurido ocular foi referido por 29 (85,29%) dos 34 voluntários. Dezoito sujeitos (62,07%) relataram coçar ambos os olhos igualmente, 6 (20,69%) mais no olho direito e 5 (17,24%) mais no olho esquerdo. Comparando-se a posição de dormir principal e o olhos com apresentação mais grave da doença, foi encontrada alguma relação baseada no teste exato de Fisher (0,567 no olho direito e 0,568 no olho esquerdo), embora nenhuma comparação parecesse estatisticamente significante. Conclusões: A associação entre maiores valores de ceratometria e posição do sono parece ser mais importante do que entre ceratometria e prurido ou destreza manual.

Impaired Colonic Contractility and Intestinal Permeability in Symptomatic Uncomplicated Diverticular Disease

Background/Aims@#Impaired intestinal motility seems to play a crucial role in symptomatic uncomplicated diverticular disease (SUDD), although the mechanism is not clear. The aim of the present study is to explore the contractility patterns of colonic smooth muscle strips (MS) and smooth muscle cells (SMCs) and to assess mucosal integrity in SUDD patients. @*Methods@#MS or SMCs were isolated from specimens of human distal colon of 18 patients undergoing surgery for non-obstructive colonic cancer, among them 9 with SUDD. Spontaneous phasic contractions on strips and morpho-functional parameters on cells were evaluated in basal conditions and in response to acetylcholine (ACh). Mucosal integrity of SUDD colonic biopsies was evaluated by the Ussing Chamber system. Immunohistochemical staining for tight junction protein complex and for Toll-like receptor 4 (TLR4) was performed. @*Results@#Colonic MS of SUDD group showed a significant reduced basal tone and ACh-elicited contraction, compared to the control group (9.5 g and 47.0% in the SUDD group; 14.16 g and 69.0% in the control group; P < 0.05). SMCs of SUDD group showed a maximal contractile response to ACh significantly reduced compared to control group (8.8% vs 16.5%, P < 0.05). SUDD patients displayed lower transepithelial electrical resistance and increased paracellular permeability compared to control group. Immunohistochemical expression of TLR4 was not different in both groups, while tight junction protein complex expression was lower in SUDD patients compared to control group patients. @*Conclusion@#It could be hypothesized that in SUDD, in absence of severe inflammation, an increased intestinal mucosal permeability is related to altered colonic motility probably responsible for symptoms genesis.

Impaired Colonic Contractility and Intestinal Permeability in Symptomatic Uncomplicated Diverticular Disease

Background/Aims@#Impaired intestinal motility seems to play a crucial role in symptomatic uncomplicated diverticular disease (SUDD), although the mechanism is not clear. The aim of the present study is to explore the contractility patterns of colonic smooth muscle strips (MS) and smooth muscle cells (SMCs) and to assess mucosal integrity in SUDD patients. @*Methods@#MS or SMCs were isolated from specimens of human distal colon of 18 patients undergoing surgery for non-obstructive colonic cancer, among them 9 with SUDD. Spontaneous phasic contractions on strips and morpho-functional parameters on cells were evaluated in basal conditions and in response to acetylcholine (ACh). Mucosal integrity of SUDD colonic biopsies was evaluated by the Ussing Chamber system. Immunohistochemical staining for tight junction protein complex and for Toll-like receptor 4 (TLR4) was performed. @*Results@#Colonic MS of SUDD group showed a significant reduced basal tone and ACh-elicited contraction, compared to the control group (9.5 g and 47.0% in the SUDD group; 14.16 g and 69.0% in the control group; P < 0.05). SMCs of SUDD group showed a maximal contractile response to ACh significantly reduced compared to control group (8.8% vs 16.5%, P < 0.05). SUDD patients displayed lower transepithelial electrical resistance and increased paracellular permeability compared to control group. Immunohistochemical expression of TLR4 was not different in both groups, while tight junction protein complex expression was lower in SUDD patients compared to control group patients. @*Conclusion@#It could be hypothesized that in SUDD, in absence of severe inflammation, an increased intestinal mucosal permeability is related to altered colonic motility probably responsible for symptoms genesis.