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BackgroundMask mandates for children during the COVID-19 pandemic varied in different locations. A risk-benefit analysis of this intervention has not yet been performed. In this study, we performed a systematic review to assess research on the effectiveness of mask wearing in children.MethodsWe performed database searches up to February 2023. The studies were screened by title and abstract, and included studies were further screened as full-text references. A risk-of-bias analysis was performed by two independent reviewers and adjudicated by a third reviewer.ResultsWe screened 597 studies and included 22 in the final analysis. There were no randomised controlled trials in children assessing the benefits of mask wearing to reduce SARS-CoV-2 infection or transmission. The six observational studies reporting an association between child masking and lower infection rate or antibody seropositivity had critical (n=5) or serious (n=1) risk of bias; all six were potentially confounded by important differences between masked and unmasked groups and two were shown to have non-significant results when reanalysed. Sixteen other observational studies found no association between mask wearing and infection or transmission.ConclusionsReal-world effectiveness of child mask mandates against SARS-CoV-2 transmission or infection has not been demonstrated with high-quality evidence. The current body of scientific data does not support masking children for protection against COVID-19.

Objective To evaluate the implementation of switch from intravenous-to-oral antibiotic therapy with amoxicillin in neonates with early-onset infection (EOI). Design, setting and patients A population-based multicentre cohort study. All term-born neonates with EOI were prospectively included between 1 December 2018 to 30 November 2020. Intervention Intravenous-to-oral switch antibiotic therapy in clinically stable neonates. Main outcome measures The primary outcome was readmission due to infection. Secondary outcomes were days of hospitalisation and antibiotic use in the pre-implementation versus post implementation period. Results During 2 years, 835 neonates commenced antibiotics for EOI (1.5% (95% CI 1.4% to 1.6%)) of all term live births). Of those, 554 (66%) underwent a full course of treatment. There were 23 episodes of culture-proven infection (0.42 per 1000 term live births (95% CI 0.27 to 0.63)). A total of 478 of 531 (90%) neonates with probable infection underwent switch therapy. None was readmitted due to infection. The median duration of hospitalisation was 3.0 days (IQR 2.5–3.5) and 7.4 days (IQR 7.0–7.5) in the switch and intravenous therapy groups, respectively. According to antibiotic surveillance data, 1.2% underwent a full course of treatment following implementation of oral switch therapy (2019–2020), compared with 1.2% before (2017–2018). Conclusion In clinical practice, switch therapy was safe and used in 9 of 10 neonates with probable EOI. Knowledge of the safety of antibiotic de-escalation is important as home-based oral therapy ameliorates the treatment burden for neonates, caregivers and healthcare systems. Despite the ease of oral administration, implementation of switch therapy did not increase the overall use of antibiotics., Objective: To evaluate the implementation of switch from intravenous-to-oral antibiotic therapy with amoxicillin in neonates with early-onset infection (EOI). Design, setting and patients: A population-based multicentre cohort study. All term-born neonates with EOI were prospectively included between 1 December 2018 to 30 November 2020. Intervention: Intravenous-to-oral switch antibiotic therapy in clinically stable neonates. Main outcome measures: The primary outcome was readmission due to infection. Secondary outcomes were days of hospitalisation and antibiotic use in the pre-implementation versus post implementation period. Results: During 2 years, 835 neonates commenced antibiotics for EOI (1.5% (95% CI 1.4% to 1.6%)) of all term live births). Of those, 554 (66%) underwent a full course of treatment. There were 23 episodes of culture-proven infection (0.42 per 1000 term live births (95% CI 0.27 to 0.63)). A total of 478 of 531 (90%) neonates with probable infection underwent switch therapy. None was readmitted due to infection. The median duration of hospitalisation was 3.0 days (IQR 2.5-3.5) and 7.4 days (IQR 7.0-7.5) in the switch and intravenous therapy groups, respectively. According to antibiotic surveillance data, 1.2% underwent a full course of treatment following implementation of oral switch therapy (2019-2020), compared with 1.2% before (2017-2018). Conclusion: In clinical practice, switch therapy was safe and used in 9 of 10 neonates with probable EOI. Knowledge of the safety of antibiotic de-escalation is important as home-based oral therapy ameliorates the treatment burden for neonates, caregivers and healthcare systems. Despite the ease of oral administration, implementation of switch therapy did not increase the overall use of antibiotics.

Clinical expertise in infectious diseases is crucial in treating patients with infectious complications. The new board certification in infectious diseases will establish this expertise in Germany. The role of the specialty of infectious diseases in German hospitals and the definition for clinical services in hospitals (levels 2 and 3) are outlined here., Spezifische infektiologische Kompetenz verbessert die stationäre Versorgung von Patienten mit Infektionskrankrankheiten. Mit der neuen Facharztbezeichnung Innere Medizin und Infektiologie wird diese Expertise auch in Deutschland zugänglich. Die strukturelle Einbindung der Infektiologie und die Definition einer Leistungsgruppe in Kliniken der Level 2 und 3 werden dargestellt.

Objective: To estimate the incidence of neonatal herpes simplex virus (HSV) infection and the number of neonates with suspected invasive bacterial infection (IBI) needed to treat (NNT) with acyclovir to ensure prompt treatment of invasive HSV infections. Design: A nationwide population-based cohort study. Setting: All neonatal and paediatric emergency departments in Denmark from 1 January 2010 to 31 December 2019. Patients: Neonates aged 0-28 days with HSV infection. Main outcome measures: The main outcome measures were incidence and NNT. The NNT was calculated based on neonates with invasive HSV infection whose onset symptoms resembled IBI and the estimated number of Danish neonates who received antibiotics for suspected IBI. Results: Fifty-four neonates with HSV infection were identified, that is, an incidence of 9 per 100 000 live births. Twenty presented with symptoms resembling IBI, all within the first 14 days of life. Of 18 (78%) neonates, 14 had elevated C reactive protein, 14 of 19 (74%) had elevated alanine aminotransferase and 11 of 17 (65%) had thrombocytopaenia. The estimated NNTs with empiric acyclovir at postnatal ages 0-3, 4-7 and 8-14 days were 1139 (95% CI 523 to 3103), 168 (95% CI 101 to 726) and 117 (95% CI 48 to 198), respectively. Conclusions: The incidence of neonatal HSV infection was higher than in previous decades; however, the estimated NNT with empiric acyclovir was high. Therefore, we propose not to treat all neonates suspected of IBI with empiric acyclovir, as current European guidelines suggest. However, HSV should be considered in neonates with signs of infection, especially after the third postnatal day and in neonates with high alanine aminotransferases and thrombocytopaenia.

Measures to reduce the spread of COVID-19 have been associated with reduction in other respiratory infections. Results of a national Swedish cohort study of infant pertussis during April 2020-September 2021 were compared with those during January 2014-March 2020. The number of pertussis cases decreased significantly during the COVID-19 pandemic, from an average of 21 infant cases per quarter of a year before the pandemic to an average of 1 case per quarter during the pandemic. Swedish strategies to mitigate the spread of COVID-19 seem to have had an impact on pertussis incidence in infants. Measures to prevent the spread of COVID-19 have also reduced other respiratory viral infections in children. This study from Sewden found that the number of infant pertussis infections also fell during the COVID-19 pandemic. The authors discuss the implications of this finding., First published online: December 2, 2021

To evaluate the performance of oral saliva swab (OSS) reverse transcription PCR (RT-PCR) compared with RT-PCR and antigen rapid diagnostic test (Ag-RDT) on nasopharyngeal swabs (NPS) for SARS-CoV-2 in children.

Aims: to analyze the current Brazilian and of the state of Rio Grande do Sul epidemiological situation of visceral leishmaniasis (LVH) in the elderly and verifythe mortality coefficient.Methods: This is a cross-sectional study with a secondary data source, taken from SINAN data from January 2013 to December 2017, with confirmed visceral leishmaniasis in Brazil and Rio Grande do Sul, which are tabulated in Excel and analyzed with Epiinfo 7.Results: cases of LVH in the elderly have increased in the last 5 years, within the Brazilian and the state of Rio Grande do Sul settings. Although not widely reported, it is frequent to compromise and increase the proportion of elderly people who die from LVH, which was 20,3% of the cases in the period from 2013 to 2017, demonstrating the seriousness of the infection in this public. In our study we also found a strong relation between age and the increase in the lethality coefficient, reaching 46.87% in 2016.Discussion: One of the recent strategies in the fight against HVL is the slaughter of dogs that contains the parasite responsible for the transmission of the disease, but this method of control has not been very effective. Thus, the immunoprophylactic measurement by Leish-Tec® vaccine has a favorable effect in the fight against the disease only in animals that are not in high transmission areas., Objetivo: analisar a atual situação epidemiológica brasileira e gaúcha da leishmaniose visceral (LVH), em idosos e verificar o coeficiente de letalidade.Métodos: trata-se um estudo transversal realizado com fonte de dados secundária, em consulta à base de dados do Sistema de Informação de Agravos de Notificação (SINAN), de janeiro de 2013 a dezembro de 2017, de casos confirmados de leishmaniose visceral no Brasil e no Rio Grande do Sul, que foram tabulados em Excel e analisados com Epiinfo 7.0.Resultados: casos de LVH em idosos têm aumentado nos últimos 5 anos, dentro do cenário brasileiro e gaúcho. Embora pouco divulgado, é frequente o comprometimento e o aumento da proporção de idosos que vão a óbito pelo LHV, que foi de 20,3% dos casos no período de 2013 a 2017, demonstrando a gravidade da infecção nesse público. Em nosso estudo também encontramos forte relação da idade com o aumento do coeficiente de letalidade, chegando a 46,87% em 2016.Discussão: uma das estratégias recentes no combate à LVH é o abate de cães que contêm o parasita responsável pela transmissão da doença, porém esse método de controle não tem sido muito efetivo. Com isso, constata-se que a medida imunoprofilática, através da vacina Leish-Tec®, tem um efeito favorável no combate à doença somente em animais que não estão em áreas de alta transmissão.

Infectious disease management of Staphylococcus aureus bacteremia (SAB) was surveyed through the Emerging Infections Network. Although there were areas of consensus, we found substantial practice variation in diagnostic evaluation and management of adult patients with SAB. These findings highlight opportunities for further research and guidance to define best practices.

[Introducción] Una de las principales herramientas para optimizar el uso de los antibióticos es la formación de los prescriptores. El objetivo de este trabajo es conocer la opinión de los estudiantes de Medicina españoles sobre la formación en enfermedades infecciosas., [Material y métodos] Se distribuyó un cuestionario on line anonimizado entre estudiantes de sexto curso a través de distintos canales. El cuestionario incluyó 45 preguntas sobre conocimientos, actitudes y percepciones sobre el diagnóstico, resistencia antimicrobiana, uso de antibióticos y la formación de pregrado en enfermedades infecciosas., [Resultados] Se recibieron un total de 441 encuestas de 21 facultades. Se obtuvieron 374 respuestas (84,8%) de las 8 facultades más representadas, con una tasa de respuesta del 28,9%. La mayoría de los alumnos se sentían preparados para identificar los signos clínicos de infección (418; 94,8%) y para interpretar correctamente las pruebas de laboratorio (382; 86,6%). Reconocieron saber elegir un antibiótico con seguridad sin consultar libros ni guías (178; 40,4%). Solo 107 alumnos (24,3%) consideraron haber recibido suficiente formación en el uso prudente de los antimicrobianos. Respecto a los métodos de aprendizaje, se percibieron como más útiles la discusión de casos clínicos, los rotatorios en servicios o unidades de enfermedades infecciosas y los talleres de pequeños grupos: se evaluaron favorablemente en un 76,9; en un 76 y en un 68,8% de los casos, respectivamente., [Conclusión] Los estudiantes de Medicina se encuentran más seguros en el diagnóstico de enfermedades infecciosas que en el tratamiento antibiótico. Asimismo, sienten la necesidad de recibir mayor formación en antibioterapia y uso prudente en antibióticos., [Introduction]] One of the main tools to optimize antibiotics use is education of prescribers. The aim of this article is to study undergraduate education in the field of infectious diseases, antimicrobial resistance and antibiotic stewardship from the perspective of Spanish medical students., [Material and methods] An anonymous online questionnaire was distributed among sixth grade students using different channels in Europe, within the ESGAP Student-Prepare survey. The questionnaire included 45 questions about knowledge, attitudes and perceptions about diagnosis, bacterial resistance, use of antibiotics and undergraduate training in infectious diseases. We present here the Spanish results., [Results] A total of 441 surveys were received from 21 medical schools. A total of 374 responses (84.8%) were obtained from the 8 most represented faculties, with a response rate of 28.9%. Most students felt adequately prepared to identify clinical signs of infection (418; 94.8%) and to accurately interpret laboratory tests (382; 86.6%). A total of 178 (40.4%) acknowledged being able to choose an antibiotic with confidence without consulting books or guidelines. Only 107 (24.3%) students considered that they had received sufficient training in judicious use of antibiotics. Regarding learning methods, the discussion of clinical cases, infectious diseases units rotatories and small group workshops were considered the most useful, being evaluated favorably in 76.9%, 76% and 68.8% of the cases., [Conclusion] Medical students feel more confident in the diagnosis of infectious diseases than in antibiotic treatment. They also feel the need to receive more training in antibiotics and judicious antibiotic use.

BackgroundTuberculosis (TB) is the leading cause of infectious disease deaths worldwide and is the leading cause of death among people with HIV. The World Health Organization (WHO) has called for collaboration between public and private healthcare providers to maximize integration of TB/HIV services and minimize costs. We systematically reviewed published models of public-private sector diagnostic and referral services for TB/HIV co-infected patients.MethodsWe searched PubMed, the Cochrane Central Register of Controlled Trials, Google Scholar, Science Direct, CINAHL and Web of Science. We included studies that discussed programs that linked private and public providers for TB/HIV concurrent diagnostic and referral services and used Review Manager (Version 5.3, 2015) for meta-analysis.ResultsWe found 1,218 unduplicated potentially relevant articles and abstracts; three met our eligibility criteria. All three described public-private TB/HIV diagnostic/referral services with varying degrees of integration. In Kenya private practitioners were able to test for both TB and HIV and offer state-subsidized TB medication, but they could not provide state-subsidized antiretroviral therapy (ART) to co-infected patients. In India private practitioners not contractually engaged with the public sector offered TB/HIV services inconsistently and on a subjective basis. Those partnered with the state, however, could test for both TB and HIV and offer state-subsidized medications. In Nigeria some private providers had access to both state-subsidized medications and diagnostic tests; others required patients to pay out-of-pocket for testing and/or treatment. In a meta-analysis of the two quantitative reports, TB patients who sought care in the public sector were almost twice as likely to have been tested for HIV than TB patients who sought care in the private sector (risk ratio [RR] 1.98, 95% confidence interval [CI] 1.88-2.08). However, HIV-infected TB patients who sought care in the p

BackgroundTuberculosis (TB) is the leading cause of infectious disease deaths worldwide and is the leading cause of death among people with HIV. The World Health Organization (WHO) has called for collaboration between public and private healthcare providers to maximize integration of TB/HIV services and minimize costs. We systematically reviewed published models of public-private sector diagnostic and referral services for TB/HIV co-infected patients.MethodsWe searched PubMed, the Cochrane Central Register of Controlled Trials, Google Scholar, Science Direct, CINAHL and Web of Science. We included studies that discussed programs that linked private and public providers for TB/HIV concurrent diagnostic and referral services and used Review Manager (Version 5.3, 2015) for meta-analysis.ResultsWe found 1,218 unduplicated potentially relevant articles and abstracts; three met our eligibility criteria. All three described public-private TB/HIV diagnostic/referral services with varying degrees of integration. In Kenya private practitioners were able to test for both TB and HIV and offer state-subsidized TB medication, but they could not provide state-subsidized antiretroviral therapy (ART) to co-infected patients. In India private practitioners not contractually engaged with the public sector offered TB/HIV services inconsistently and on a subjective basis. Those partnered with the state, however, could test for both TB and HIV and offer state-subsidized medications. In Nigeria some private providers had access to both state-subsidized medications and diagnostic tests; others required patients to pay out-of-pocket for testing and/or treatment. In a meta-analysis of the two quantitative reports, TB patients who sought care in the public sector were almost twice as likely to have been tested for HIV than TB patients who sought care in the private sector (risk ratio [RR] 1.98, 95% confidence interval [CI] 1.88-2.08). However, HIV-infected TB patients who sought care in the p

Evidence-based guidelines for implementation and measurement of antibiotic stewardship interventions in inpatient populations including long-term care were prepared by a multidisciplinary expert panel of the Infectious Diseases Society of America and the Society for Healthcare Epidemiology of America. The panel included clinicians and investigators representing internal medicine, emergency medicine, microbiology, critical care, surgery, epidemiology, pharmacy, and adult and pediatric infectious diseases specialties. These recommendations address the best approaches for antibiotic stewardship programs to influence the optimal use of antibiotics.

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.

Immune heterogeneity in wild host populations indicates that disease-mediated selection is common in nature. However, the underlying dynamic feedbacks involving the ecology of disease transmission, evolutionary processes, and their interaction with environmental drivers have proven challenging to characterize. Plague presents an optimal system for interrogating such couplings: Yersinia pestis transmission exerts intense selective pressure driving the local persistence of disease resistance among its wildlife hosts in endemic areas. Investigations undertaken in colonial India after the introduction of plague in 1896 suggest that, only a decade after plague arrived, a heritable, plague-resistant phenotype had become prevalent among commensal rats of cities undergoing severe plague epidemics. To understand the possible evolutionary basis of these observations, we developed a mathematical model coupling environmentally forced plague dynamics with evolutionary selection of rats, capitalizing on extensive archival data from Indian Plague Commission investigations. Incorporating increased plague resistance among rats as a consequence of intense natural selection permits the model to reproduce observed changes in seasonal epidemic patterns in several cities and capture experimentally observed associations between climate and flea population dynamics in India. Our model results substantiate Victorian era claims of host evolution based on experimental observations of plague resistance and reveal the buffering effect of such evolution against environmental drivers of transmission. Our analysis shows that historical datasets can yield powerful insights into the transmission dynamics of reemerging disease agents with which we have limited contemporary experience to guide quantitative modeling and inference.

As Ebola has spread beyond West Africa, the challenges confronting health care systems with no experience in managing such patients are enormous. Not only is Ebola a significant threat to a population's health, it can infect the medical personnel trying to treat it. As such, it represents a major challenge to those in public health, emergency medical services (EMS), and acute care hospitals. Our academic medical center volunteered to become an Ebola Treatment Center as part of the US effort to manage the threat. We developed detailed policies and procedures for Ebola patient management at our university hospital. Both the EMS system and county public health made significant contributions during the development process. This article shares information about this process and the outcomes to inform other institutions facing similar challenges of preparing for an emerging threat with limited resources. The discussion includes information about management of (1) patients who arrive by ambulance with prior notification, (2) spontaneous walk-in patients, and (3) patients with confirmed Ebola who are interfacility transfers. Hospital management includes information about Ebola screening procedures, personal protective equipment selection and personnel training, erection of a tent outside the main facility, establishing an Ebola treatment unit inside the facility, and infectious waste and equipment management. Finally, several health policy considerations are presented.

During an evolving public health emergency, a simple algorithm for initial patient identification and management is essential for providers on the front lines. This article recommends a 3-pronged system of Identify, Isolate, Inform to describe the actions necessary in the first few minutes of encountering a potential Ebola patient. Application of the "vital sign zero" triage concept of early recognition of potential threats coupled with this novel algorithm will optimize protection of health care workers and the public health while concurrently providing a safe method for individual patient care.

During an evolving public health emergency, a simple algorithm for initial patient identification and management is essential for providers on the front lines. This article recommends a 3-pronged system of Identify, Isolate, Inform to describe the actions necessary in the first few minutes of encountering a potential Ebola patient. Application of the "vital sign zero" triage concept of early recognition of potential threats coupled with this novel algorithm will optimize protection of health care workers and the public health while concurrently providing a safe method for individual patient care.

Recent changes in the Fungal Code of Nomenclature and developments in molecular phylogeny are about to lead to dramatic changes in the naming of medically important molds and yeasts. In this article, we present a widely supported and simple proposal to prevent unnecessary nomenclatural instability.

As Ebola has spread beyond West Africa, the challenges confronting health care systems with no experience in managing such patients are enormous. Not only is Ebola a significant threat to a population's health, it can infect the medical personnel trying to treat it. As such, it represents a major challenge to those in public health, emergency medical services (EMS), and acute care hospitals. Our academic medical center volunteered to become an Ebola Treatment Center as part of the US effort to manage the threat. We developed detailed policies and procedures for Ebola patient management at our university hospital. Both the EMS system and county public health made significant contributions during the development process. This article shares information about this process and the outcomes to inform other institutions facing similar challenges of preparing for an emerging threat with limited resources. The discussion includes information about management of (1) patients who arrive by ambulance with prior notification, (2) spontaneous walk-in patients, and (3) patients with confirmed Ebola who are interfacility transfers. Hospital management includes information about Ebola screening procedures, personal protective equipment selection and personnel training, erection of a tent outside the main facility, establishing an Ebola treatment unit inside the facility, and infectious waste and equipment management. Finally, several health policy considerations are presented.

BackgroundFew population-based studies have described characteristics and management of patients with chronic hepatitis B (CHB) in the USA.MethodsWe retrospectively studied adults with CHB in the Northern California Kaiser Permanente Medical Care Program (KPNC) from July 2009 to December 2010 (n = 12,016). Laboratory tests, treatment patterns, and hepatocellular carcinoma (HCC) surveillance were ascertained during a "recent" 18-month study window (July 2009-December 2010), or as "ever" based on records dating to 1995.ResultsThe mean age was 49 years; 51 % were men, 83 % Asian, and 87 % KPNC members >5 years. Overall, 51 % had ≥ 1 liver-related visit, 14 % with gastroenterology or infectious disease specialists, and 37 % with primary care providers (PCP) only. Less than 40 % of patients had both hepatitis B virus (HBV) DNA and ALT testing conducted recently, while 56 % of eligible patients had received HCC surveillance. Recent laboratory testing and HCC surveillance were more frequent in patients seen by a specialist versus PCP only (90 vs. 47 % and 92 vs. 73 %, respectively, p values <0.001). During the study period, 1,649 (14 %) received HBV treatment, while 5 % of untreated patients had evidence of treatment eligibility. Among 599 patients newly initiated on HBV therapy, 76 % had guideline-based indications for treatment.ConclusionsMost patients initiated on HBV treatment met eligibility, and very few patients with evidence of needing treatment were left untreated. However, monitoring of ALT and HBV DNA levels, as well as HCC surveillance, were not frequent, underestimating the proportion of patients that warranted HBV therapy. Viral monitoring and cancer surveillance are therefore important targets for improving the scope of CHB care in the community setting.

Background: A survey was performed in 2008 to evaluate the profiles of patients with chronic hepatitis B cared for by Italian Infectious Diseases Centers (IDCs).This analysis describes: i) factors associated with access to the anti-HBV treatment in a cohort of HIV/HBV co-infected patients cared for in tertiary centers of a developed country with comprehensive coverage under the National Health System (NHS); ii) consistency of current anti-HBV regimens with specific European guidelines in force at the time of the study and factors associated with the receipt of sub-optimal regimens. Methods. The study focuses on 374 (87.6%) treated patients at some point in their life out of the 427 tested HIV/HBV positive. It is multicentre, cross-sectional in the design. To account for missing values, a Multiple Imputation method is used. Results: Three hundred and thirty-four (89.3%) patients were currently treated. The most common current regimen was combination therapy of tenofovir (TDF) plus LAM/FTC (lamivudine/emtricitabine) (n = 235, 70.4%), as part of antiretroviral treatment.In the multivariate analysis, an increased chance of getting treated was independently associated with increasing years since HBV diagnosis (2-10 years, p <0.001; >10 years, p <0.001).Patients consistently treated with European AIDS Clinical Society (EACS) 2008 guidelines were 255 (76.6%), of whom 202 (79.2%) with an indication to an anti-HIV treatment, 30 (11.8%)without an indication, and 21 (8.2%) with cirrhosis. Among the 78 not-consistent patients, LAM mono-therapy (n = 60, 76.9%) was the most common regimen, 34 (56.7%) of them showing HBV DNA load below 1x10§ssup§3§esup§ IU/mL.Previous anti-HBV treatment (p = 0.01) and a triple HDV co-infection (p = 0.03) reduced the chance of not-consistent regimens. Conversely, HCV co-infection was independently associated with an increased odds ratio of being inconsistently treated (p = 0.004). Conclusion: Our study shows that Italian IDCs treat for HBV infectio

BackgroundThe negative binomial distribution is used commonly throughout biology as a model for overdispersed count data, with attention focused on the negative binomial dispersion parameter, k. A substantial literature exists on the estimation of k, but most attention has focused on datasets that are not highly overdispersed (i.e., those with k>or=1), and the accuracy of confidence intervals estimated for k is typically not explored.MethodologyThis article presents a simulation study exploring the bias, precision, and confidence interval coverage of maximum-likelihood estimates of k from highly overdispersed distributions. In addition to exploring small-sample bias on negative binomial estimates, the study addresses estimation from datasets influenced by two types of event under-counting, and from disease transmission data subject to selection bias for successful outbreaks.ConclusionsResults show that maximum likelihood estimates of k can be biased upward by small sample size or under-reporting of zero-class events, but are not biased downward by any of the factors considered. Confidence intervals estimated from the asymptotic sampling variance tend to exhibit coverage below the nominal level, with overestimates of k comprising the great majority of coverage errors. Estimation from outbreak datasets does not increase the bias of k estimates, but can add significant upward bias to estimates of the mean. Because k varies inversely with the degree of overdispersion, these findings show that overestimation of the degree of overdispersion is very rare for these datasets.

BackgroundThe negative binomial distribution is used commonly throughout biology as a model for overdispersed count data, with attention focused on the negative binomial dispersion parameter, k. A substantial literature exists on the estimation of k, but most attention has focused on datasets that are not highly overdispersed (i.e., those with k>or=1), and the accuracy of confidence intervals estimated for k is typically not explored.MethodologyThis article presents a simulation study exploring the bias, precision, and confidence interval coverage of maximum-likelihood estimates of k from highly overdispersed distributions. In addition to exploring small-sample bias on negative binomial estimates, the study addresses estimation from datasets influenced by two types of event under-counting, and from disease transmission data subject to selection bias for successful outbreaks.ConclusionsResults show that maximum likelihood estimates of k can be biased upward by small sample size or under-reporting of zero-class events, but are not biased downward by any of the factors considered. Confidence intervals estimated from the asymptotic sampling variance tend to exhibit coverage below the nominal level, with overestimates of k comprising the great majority of coverage errors. Estimation from outbreak datasets does not increase the bias of k estimates, but can add significant upward bias to estimates of the mean. Because k varies inversely with the degree of overdispersion, these findings show that overestimation of the degree of overdispersion is very rare for these datasets.