Estimating the latent period of coronavirus disease 2019 (COVID-19)

Incubation Period of COVID-19 From 11545 Patients in Observation Study

10.21203/rs.3.rs-332666/v1 ◽

2021 ◽

Author(s):

Cheng Cheng ◽

Dongdong Zhang ◽

Dejian Dang ◽

Juan Geng ◽

Peiyu Zhu ◽

...

Keyword(s):

Decision Making ◽

Confidence Interval ◽

Incubation Period ◽

Mainland China ◽

Observation Study ◽

Male And Female ◽

Precise Data ◽

Validation Population ◽

Significant Difference ◽

The Mean

Abstract Background The incubation period is a key index of epidemiology in understanding of the spread of infectious diseases and the decision-making of the disease control. However, the incubation period of the emerging COVID-19 is still unclear. Methods Between January 19, 2020 and September 21, 2020, we collected information on 11545 patients in Mainland China outside Hubei. The 218 patients with precise data was validation population. The incubation period was fitted with lognormal model by the coarseDataTools package in R. Results In 11545 patients, the mean incubation period of COVID-19 was 7.1 days (95% Confidence interval [CI], 7.0–7.2). About 5.4% of patients had precise incubation period less than 3 days, 10.2% longer than 14 days, and 2.1% longer than 21 days. There was no statistically significant difference in incubation period between male and female (P = 0.603). It was similar in the 218 patients. The mean accurate incubation period was 6.8 days (6.2–7.4). Of which, 14.7% (32/218) of patients had incubation period less than 3 days, 12.4% (27/218) longer than 14 days, and 0.9% (2/218) longer than 21 days. Conclusions For COVID-19, the mean incubation period is 7.1 days and 10.2% of patients developed disease 14 days after infection, which challenges the current 14-day quarantine strategy.

Download Full-text

Association of host, agent and environment characteristics and the duration of incubation and symptomatic periods of norovirus gastroenteritis

Epidemiology and Infection ◽

10.1017/s0950268814003288 ◽

2014 ◽

Vol 143 (11) ◽

pp. 2308-2314 ◽

Cited By ~ 8

Author(s):

T. DEVASIA ◽

B. LOPMAN ◽

J. LEON ◽

A. HANDEL

Keyword(s):

Confidence Interval ◽

Incubation Period ◽

Environmental Characteristics ◽

Norovirus Gastroenteritis ◽

Incubation Periods ◽

Host Pathogen ◽

The Mean ◽

Reported Data

SUMMARYWe analysed the reported duration of incubation and symptomatic periods of norovirus for a dataset of 1022 outbreaks, 64 of which reported data on the average incubation period and 87 on the average symptomatic period. We found the mean and median incubation periods for norovirus to be 32·8 [95% confidence interval (CI) 30·9–34·6] hours and 33·5 (95% CI 32·0–34·0) hours, respectively. For the symptomatic period we found the mean and median to be 44·2 (95% CI 38·9–50·7) hours and 43·0 (95% CI 36·0–48·0) hours, respectively. We further investigated how these average periods were associated with several reported host, agent and environmental characteristics. We did not find any strong, biologically meaningful associations between the duration of incubation or symptomatic periods and the reported host, pathogen and environmental characteristics. Overall, we found that the distributions of incubation and symptomatic periods for norovirus infections are fairly constant and showed little differences with regard to the host, pathogen and environmental characteristics we analysed.

Download Full-text

Onchocerciasis control in Ghana (1974–2016)

Parasites & Vectors ◽

10.1186/s13071-020-04507-2 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Nana-Kwadwo Biritwum ◽

Dziedzom K. de Souza ◽

Odame Asiedu ◽

Benjamin Marfo ◽

Uche Veronica Amazigo ◽

...

Keyword(s):

Confidence Interval ◽

Vector Control ◽

Control Strategy ◽

Financial Support ◽

Control Programme ◽

Ivermectin Treatment ◽

Mobile Community ◽

The Mean ◽

The Impact ◽

Onchocerciasis Control

Abstract Background The control of onchocerciasis in Ghana started in 1974 under the auspices of the Onchocerciasis Control Programme (OCP). Between 1974 and 2002, a combination of approaches including vector control, mobile community ivermectin treatment, and community-directed treatment with ivermectin (CDTI) were employed. From 1997, CDTI became the main control strategy employed by the Ghana OCP (GOCP). This review was undertaken to assess the impact of the control interventions on onchocerciasis in Ghana between 1974 and 2016, since which time the focus has changed from control to elimination. Methods In this paper, we review programme data from 1974 to 2016 to assess the impact of control activities on prevalence indicators of onchocerciasis. This review includes an evaluation of CDTI implementation, microfilaria (Mf) prevalence assessments and rapid epidemiological mapping of onchocerciasis results. Results This review indicates that the control of onchocerciasis in Ghana has been very successful, with a significant decrease in the prevalence of infection from 69.13% [95% confidence interval) CI 60.24–78.01] in 1975 to 0.72% (95% CI 0.19–1.26) in 2015. Similarly, the mean community Mf load decreased from 14.48 MF/skin snip in 1975 to 0.07 MF/skin snip (95% CI 0.00–0.19) in 2015. Between 1997 and 2016, the therapeutic coverage increased from 58.50 to 83.80%, with nearly 100 million ivermectin tablets distributed. Conclusions Despite the significant reduction in the prevalence of onchocerciasis in Ghana, there are still communities with MF prevalence above 1%. As the focus of the GOCP has changed from the control of onchocerciasis to its elimination, both guidance and financial support are required to ensure that the latter goal is met.

Download Full-text

Can Health-Promoting Schools Contribute to Better Health Behaviors? Physical Activity, Sedentary Behavior, and Dietary Habits among Israeli Adolescents

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18031183 ◽

2021 ◽

Vol 18 (3) ◽

pp. 1183

Author(s):

Hila Beck ◽

Riki Tesler ◽

Sharon Barak ◽

Daniel Sender Moran ◽

Adilson Marques ◽

...

Keyword(s):

Physical Activity ◽

Health Behavior ◽

Confidence Interval ◽

Health Behaviors ◽

Sedentary Behavior ◽

Dietary Habits ◽

Group Differences ◽

Time Behavior ◽

Health Promoting ◽

The Mean

Schools with health-promoting school (HPS) frameworks are actively committed to enhancing healthy lifestyles. This study explored the contribution of school participation in HPS on students’ health behaviors, namely, physical activity (PA), sedentary behavior, and dieting. Data from the 2018/2019 Health Behavior in School-aged Children study on Israeli adolescents aged 11–17 years were used. Schools were selected from a sample of HPSs and non-HPSs. Between-group differences and predictions of health behavior were analyzed. No between-group differences were observed in mean number of days/week with at least 60 min of PA (HPS: 3.84 ± 2.19 days/week, 95% confidence interval of the mean = 3.02–3.34; non-HPS: 3.93 ± 2.17 days/week, 95% confidence interval of the mean = 3.13–3.38). Most children engaged in screen time behavior for >2 h/day (HPS: 60.83%; non-HPS: 63.91%). The odds of being on a diet were higher among more active children (odds ratio [OR] = 1.20), higher socio-economic status (OR = 1.23), and female (OR = 2.29). HPS did not predict any health behavior. These findings suggest that HPSs did not contribute to health behaviors more than non-HPSs. Therefore, health-promoting activities in HPSs need to be improved in order to justify their recognition as members of the HPS network and to fulfill their mission.

Download Full-text

Evaluating Endoscopic Ipsilateral Endonasal Corridor Approaches to the Anterolateral Wall of the Maxillary Sinus: A Computerized Tomography Study

International Archives of Otorhinolaryngology ◽

10.1055/s-0041-1724092 ◽

2021 ◽

Author(s):

Navarat Vatcharayothin ◽

Pornthep Kasemsiri ◽

Sanguansak Thanaviratananich ◽

Cattleya Thongrong

Keyword(s):

Confidence Interval ◽

Maxillary Sinus ◽

Inferior Turbinate ◽

Radial Access ◽

Sinus Wall ◽

Nasal Floor ◽

Significant Difference ◽

Anterolateral Wall ◽

The Mean ◽

Maxillary Sinuses

Abstract Introduction The endoscopic access to lesions in the anterolateral wall of the maxillary sinus is a challenging issue; therefore, the evaluation of access should be performed. Objective To assess the accessibility of three endoscopic ipsilateral endonasal corridors. Methods Three corridors were created in each of the 30 maxillary sinuses from 19 head cadavers. Accessing the anterolateral wall of the maxillary sinus was documented with a straight stereotactic navigator probe at the level of the nasal floor and of the axilla of the inferior turbinate. Results At level of the nasal floor, the prelacrimal approach, the modified endoscopic Denker approach, and the endoscopic Denker approach allowed mean radial access to the anterolateral maxillary sinus wall of 42.6 ± 7.3 (95% confidence interval [CI]: 39.9–45.3), 56.0 ± 6.1 (95%CI: 53.7–58.3), and 60.1 ± 6.2 (95%CI: 57.8–62.4), respectively. Furthermore, these approaches provided more lateral access to the maxillary sinus at the level of the axilla of the inferior turbinate, with mean radial access of 45.8 ± 6.9 (95%CI: 43.3–48.4) for the prelacrimal approach, 59.8 ± 4.7 (95% CI:58.1–61.6) for the modified endoscopic Denker approach, and 63.6 ± 5.5 (95%CI: 61.6–65.7) for the endoscopic Denker approach. The mean radial access in each corridor, either at the level of the nasal floor or the axilla of the inferior turbinate, showed a statistically significant difference in all comparison approaches (p < 0.05). Conclusions The prelacrimal approach provided a narrow radial access, which allows access to anteromedial lesions of the maxillary sinus, whereas the modified endoscopic Denker and the endoscopic Denker approaches provided more lateral radial access and improved operational feasibility on far anterolateral maxillary sinus lesions.

Download Full-text

Subcritical Transmission in the Early Stage of COVID-19 in Korea

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18031265 ◽

2021 ◽

Vol 18 (3) ◽

pp. 1265

Author(s):

Yong Sul Won ◽

Jong-Hoon Kim ◽

Chi Young Ahn ◽

Hyojung Lee

Keyword(s):

Incubation Period ◽

Early Stage ◽

Probability Distributions ◽

Likelihood Estimation ◽

Contact Tracing ◽

Statistical Characterization ◽

Serial Interval ◽

Imported Cases ◽

The Mean ◽

Reporting Delays

While the coronavirus disease 2019 (COVID-19) outbreak has been ongoing in Korea since January 2020, there were limited transmissions during the early stages of the outbreak. In the present study, we aimed to provide a statistical characterization of COVID-19 transmissions that led to this small outbreak. We collated the individual data of the first 28 confirmed cases reported from 20 January to 10 February 2020. We estimated key epidemiological parameters such as reporting delay (i.e., time from symptom onset to confirmation), incubation period, and serial interval by fitting probability distributions to the data based on the maximum likelihood estimation. We also estimated the basic reproduction number (R0) using the renewal equation, which allows for the transmissibility to differ between imported and locally transmitted cases. There were 16 imported and 12 locally transmitted cases, and secondary transmissions per case were higher for the imported cases than the locally transmitted cases (nine vs. three cases). The mean reporting delays were estimated to be 6.76 days (95% CI: 4.53, 9.28) and 2.57 days (95% CI: 1.57, 4.23) for imported and locally transmitted cases, respectively. The mean incubation period was estimated to be 5.53 days (95% CI: 3.98, 8.09) and was shorter than the mean serial interval of 6.45 days (95% CI: 4.32, 9.65). The R0 was estimated to be 0.40 (95% CI: 0.16, 0.99), accounting for the local and imported cases. The fewer secondary cases and shorter reporting delays for the locally transmitted cases suggest that contact tracing of imported cases was effective at reducing further transmissions, which helped to keep R0 below one and the overall transmissions small.

Download Full-text

Longer Residence in the United States is Associated With More Physical Function Limitations in African Immigrant Older Adults

Journal of Applied Gerontology ◽

10.1177/0733464820977608 ◽

2020 ◽

pp. 073346482097760

Author(s):

Manka Nkimbeng ◽

Yvonne Commodore-Mensah ◽

Jacqueline L. Angel ◽

Karen Bandeen-Roche ◽

Roland J. Thorpe ◽

...

Keyword(s):

United States ◽

Older Adults ◽

Confidence Interval ◽

Physical Function ◽

Racial Discrimination ◽

African Immigrants ◽

The United States ◽

African Immigrant ◽

High Discrimination ◽

The Mean

Acculturation and racial discrimination have been independently associated with physical function limitations in immigrant and United States (U.S.)-born populations. This study examined the relationships among acculturation, racial discrimination, and physical function limitations in N = 165 African immigrant older adults using multiple linear regression. The mean age was 62 years ( SD = 8 years), and 61% were female. Older adults who resided in the United States for 10 years or more had more physical function limitations compared with those who resided here for less than 10 years ( b = −2.62, 95% confidence interval [CI] = [–5.01, –0.23]). Compared to lower discrimination, those with high discrimination had more physical function limitations ( b = −2.51, 95% CI = [–4.91, –0.17]), but this was no longer significant after controlling for length of residence and acculturation strategy. Residing in the United States for more than 10 years is associated with poorer physical function. Longitudinal studies with large, diverse samples of African immigrants are needed to confirm these associations.

Download Full-text

The Probability That a Measurement Falls within a Range of Standard Deviations from an Estimate of the Mean

ISRN Applied Mathematics ◽

10.5402/2012/710806 ◽

2012 ◽

Vol 2012 ◽

pp. 1-8 ◽

Cited By ~ 2

Author(s):

Louis M. Houston

Keyword(s):

Confidence Interval ◽

Sample Size ◽

General Equation ◽

Sample Sizes ◽

The Mean ◽

Standard Deviations ◽

Intermediate Value ◽

Theoretical Results

We derive a general equation for the probability that a measurement falls within a range of n standard deviations from an estimate of the mean. So, we provide a format that is compatible with a confidence interval centered about the mean that is naturally independent of the sample size. The equation is derived by interpolating theoretical results for extreme sample sizes. The intermediate value of the equation is confirmed with a computational test.

Download Full-text

Long-Term Testosterone Administration Increases Visceral Fat in Female to Male Transsexuals1

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jcem.82.7.4078 ◽

1997 ◽

Vol 82 (7) ◽

pp. 2044-2047 ◽

Cited By ~ 2

Author(s):

Jolanda M. H. Elbers ◽

Henk Asscheman ◽

Jacob C. Seidell ◽

Jos A. J. Megens ◽

Louis J. G. Gooren

Keyword(s):

Confidence Interval ◽

Visceral Fat ◽

Causal Relation ◽

Magnetic Resonance Images ◽

Visceral Fat Area ◽

Cross Sectional ◽

Fat Depots ◽

Testosterone Administration ◽

The Mean

The amount of intraabdominal (visceral) fat is an important determinant of disturbances in lipid and glucose metabolism. Cross-sectional studies in women have found associations between high androgen levels and visceral fat accumulation. The causal relation between these phenomena is unknown. We, therefore, studied prospectively the effect of testosterone administration on body fat distribution in 10 young, nonobese, female to male transsexuals undergoing sex reassignment. Before, after 1 yr, and after 3 yr of testosterone administration, magnetic resonance images were obtained at the level of the abdomen, hip, and thigh to quantify both sc and visceral fat depots. After 1 yr of testosterone administration, sc fat depots at all levels showed significant reductions compared to baseline measurements. The mean visceral fat area did not change significantly, but subjects who gained weight in the first year after testosterone administration showed an increase in visceral fat. After 3 yr of testosterone administration, sc fat depots were no longer significantly lower compared to pretreatment measurements, but the mean visceral fat depot had increased significantly by 13 cm2 (95% confidence interval, 4–22 cm2), a relative increase of 47% (95% confidence interval, 8–91%) from baseline. The increase in visceral fat was most pronounced in those subjects who had gained weight. We conclude that long term testosterone administration in young, nonobese, female subjects increases the amount of visceral fat. In addition, an increase in weight in this hyperandrogenic state leads to a preferential storage of fat in the visceral depot.

Download Full-text

Effect of Hope-oriented group counseling on mental health of infertile women with failed IVF cycles: a randomized controlled trial

BMC Psychiatry ◽

10.1186/s12888-021-03280-5 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Roya Rahimi ◽

Shirin Hasanpour ◽

Mojgan. Mirghafourvand ◽

Khalil Esmaeilpour

Keyword(s):

Mental Health ◽

Confidence Interval ◽

Group Counseling ◽

Controlled Trial ◽

Intervention Group ◽

Mean Difference ◽

Control Group ◽

The Mean ◽

And Control

Abstract Background Considering the prevalence of infertility in the community and the consequences of failure of infertility treatments on women’s mental health, interventions that can control stress, anxiety and depression in infertile women with a history of IVF failure will be very helpful. This study aimed to determine the effects of hope-oriented group counseling on mental health (primary outcome) and quality of life (QoL) (secondary outcome) of women with failed IVF cycles. Method This randomized controlled trial was conducted on 60 women with failed IVF cycles visiting Infertility Clinic at Al-Zahra Teaching Hospital of Tabriz- Iran. Participants were allocated to the intervention group (n = 30) and control group (n = 30) based on a randomized block design. Hope-oriented group counseling was provided to the intervention group in six 45–60 min sessions (once a week). The control group only received routine care to undergo another IVF cycle. The Depression Anxiety Stress Scale-21 (DASS-21) and the SF-12 Quality of Life Scale were filled out by interviewing the participants before the intervention and one week and one month after the intervention. After intervention 26 participants in each group were included in the analysis. Results There was no significant difference between the intervention and control groups in the socio-demographic profile of participants (P > 0.05). The post-intervention mean score of stress (adjusted mean difference = − 1.7, 95% confidence interval: − 3.2 to − 0.3, P = 0.018) and depression (adjusted mean difference = − 1.3, 95% confidence interval: − 4.7 to − 1.5, P < 0.001) was significantly lower in the intervention group compared to the control. Although the mean anxiety score was lower in the intervention group compared to the control, the difference between them was not statistically significant (adjusted mean difference = − 1.1, 95% confidence interval: − 2.6 to 0.4, P = 0.153). The mean score of QoL was significantly higher in the intervention group than that of the control group (adjusted mean difference = 6.9, 95% confidence interval: 5.1 to 8.8, P < 0.001). Conclusion Hope-oriented group counseling was effective in reducing stress and depression and improving QoL in women with failed IVF cycles. It is recommended to use this counseling approach, along with other methods, to improve the mental health of women with failed IVF cycles. Trial registration TCT Registration Number: TCTR 20191017003, registered on October 17, 2019.

Download Full-text