Comparison of epidemiologic factors and eye manifestations of twin children with controls.

PURPOSE: The present study was aimed to compare the epidemiological and ocular findings of twin children in comparison with non- twin age matched individuals as their control. METHODS: In this cross sectional study, a total of 90 twins (180 cases) were compared with 182 non- twin matched children. All the study participants were examined by a comprehensive ophthalmic examination including measurement of the best corrected visual acuity (BCVA), cycloplegic refraction, ocular deviation, strabismus as well as the anterior and posterior ophthalmic examinations. Demographic information of children were collected by using an organized questionnaire. Monozygotic twins were considered if there were similarity of their phenotypic characteristics and gender, otherwise the twins were considered as dizygotic. RESULTS: The mirror- image twins (MIT) was defined according to the laterality of symmetrical ocular characteristics of twins. In this study, the mean age of the study participants was 7.08±4.42 and 7.58±3.99 years in twins and non-twins groups, respectively (P=0.253). Among the twins, 27 (30%) were monozygotic. Refractive form of MIT was seen in 5 twins (2.8%). The spherical refractive error was more hyperopic in twins compared to non- twins (P=0.041). BCVA in the twin group (0.07±0.16LogMAR) was significantly worse than non-twins (0.03±0.08LogMAR, P < 0.001) and higher percentage of them were amblyopic (37.2% versus 10.4%, P=0.005). Twin and controls had strabismus in 17.2% and 1.6%, respectively (P < 0.001). Regarding the comparison between mono- and dizygotic twins, more significant percentage of monozygotic twins had amblyopia (P=0.004) and strabismus (P=0.047). Multivariate analysis showed significant correlation among low gestational age and female gender, low birth weight and seizure. CONCLUSION: Female sex, less gestational age, low birth weight, amblyopia and strabismus were significantly higher in twins. Therefore, it is important to check their refractive error, amblyopia and strabismus to prevent their further complications.

A Changing Landscape of Health Opportunity in the United States: Increases in the Strength of Association Between Childhood Socioeconomic Disadvantage and Adult Health Between the 1990s and the 2010s.

Understanding the changing health consequences of childhood socioeconomic disadvantage (SED) is highly relevant to policy debates on inequality and national and state goals to improve population health. However, changes in the strength of association between childhood SED and adult health over historic time are largely unexamined in the United States. The present study begins to address this knowledge gap. Data were from 2 national samples of adults collected in 1995 (n = 7,108) and 2012 (n = 3,577) as part of the Midlife in the United States study. Three measures of childhood SED (parents' occupational prestige, childhood poverty exposure, and parents' education) were combined into an aggregate index and examined separately. The association between childhood SED (aggregate index) and 5 health outcomes (body mass index, waist circumference, chronic conditions, functional limitations, and self-rated health) was stronger in the 2012 sample than the 1995 sample, with the magnitude of associations being approximately twice as large in the more recent sample. Results persisted after adjusting for age, sex, race, marital status, and number of children, and were similar across all 3 measures of childhood SED. The findings suggest that the socioeconomic circumstances of childhood might have become a stronger predictor of adult health in recent decades.

Determinants of completing recommended antenatal care utilization in sub-Saharan from 2006 to 2018: evidence from 36 countries using Demographic and Health Surveys.

BACKGROUND: Every day in 2017, approximately 810 women died from preventable causes related to pregnancy and childbirth, with 99% of these maternal deaths occurring in low and lower-middle-income countries. Sub-Saharan Africa (SSA) alone accounts for roughly 66%. If pregnant women gained recommended ANC (Antenatal Care), these maternal deaths could be prevented. Still, many women lack recommended ANC in sub-Saharan Africa. This study aimed at determining the pooled prevalence and determinants of recommended ANC utilization in SSA. METHODS: We used the most recent standard demographic and health survey data from the period of 2006 to 2018 for 36 SSA countries. A total of 260,572 women who had at least one live birth 5 years preceding the survey were included in this study. A meta-analysis of DHS data of the Sub-Saharan countries was conducted to generate pooled prevalence, and a forest plot was used to present it. A multilevel multivariable logistic regression model was fitted to identify determinants of recommended ANC utilization. The AOR (Adjusted Odds Ratio) with their 95% CI and p-value ≤0.05 was used to declare the recommended ANC utilization determinates. RESULTS: The pooled prevalence of recommended antenatal care utilization in sub-Saharan Africa countries were 58.53% [95% CI: 58.35, 58.71], with the highest recommended ANC utilization in the Southern Region of Africa (78.86%) and the low recommended ANC utilization in Eastern Regions of Africa (53.39%). In the multilevel multivariable logistic regression model region, residence, literacy level, maternal education, husband education, maternal occupation, women health care decision autonomy, wealth index, media exposure, accessing health care, wanted pregnancy, contraceptive use, and birth order were determinants of recommended ANC utilization in Sub-Saharan Africa. CONCLUSION: The coverage of recommended ANC service utilization was with high disparities among the region. Being a rural residence, illiterate, low education level, had no occupation, low women autonomy, low socioeconomic status, not exposed to media, a big problem to access health care, unplanned pregnancy, not use of contraceptive were determinants of women that had no recommended ANC utilization in SSA. This study evidenced the existence of a wide gap between SSA regions and countries. Special attention is required to improve health accessibility, utilization, and quality of maternal health services.

Association of mammography and ultrasound features with MammaPrint in patients with estrogen receptor-positive, HER2-negative, node-positive invasive breast cancer.

BACKGROUND: MammaPrint is a 70-gene signature microarray assay that predicts the likelihood of recurrence of breast cancer and chemotherapeutic benefits. PURPOSE: To investigate the association between mammography and ultrasound (US) features and MammaPrint results in patients with estrogen receptor (ER)-positive, HER2-negative, node-positive invasive breast cancer, and to identify the predictive factors for high risk of recurrence. MATERIAL AND METHODS: This retrospective study included 251 patients with ER-positive, HER2-negative, 1-3 node-positive invasive breast cancer. Mammography and US findings were reviewed according to the BI-RADS criteria. The association between MammaPrint results and the clinicopathological and imaging features was evaluated. Logistic regression analysis was performed to identify independent predictors for high risk of recurrence. RESULTS: Of the patients, 143 (57.0%) and 108 (43.0%) had low and high risks for recurrence on MammaPrint, respectively. Young age (odds ratio [OR] 1.08; 95% confidence interval (CI) 1.04-1.12; P<0.001), posterior enhancement on US (OR 2.45; 95% CI 1.16-5.20; P = 0.019), absence of posterior shadowing on US (OR 3.19; 95% CI 1.17-8.62; P = 0.023), high histologic grade (OR 113.36; 95% CI 6.79-1893.53; P = 0.001), and high Ki-67 level (OR 4.90; 95% CI 2.62-9.17; P<0.001) were independently associated with high risk of recurrence on multivariate logistic regression analysis. CONCLUSION: Posterior features in US may predict a high risk of recurrence in patients with ER-positive, HER2-negative, node-positive invasive breast cancer, which may be useful in enhancing the diagnostic value of MammaPrint and aid in the decision-making process regarding treatment.

Measurability of the epidemic reproduction number in data-driven contact networks.

The basic reproduction number is one of the conceptual cornerstones of mathematical epidemiology. Its classical definition as the number of secondary cases generated by a typical infected individual in a fully susceptible population finds a clear analytical expression in homogeneous and stratified mixing models. Along with the generation time (the interval between primary and secondary cases), the reproduction number allows for the characterization of the dynamics of an epidemic. A clear-cut theoretical picture, however, is hardly found in real data. Here, we infer from highly detailed sociodemographic data two multiplex contact networks representative of a subset of the Italian and Dutch populations. We then simulate an infection transmission process on these networks accounting for the natural history of influenza and calibrated on empirical epidemiological data. We explicitly measure the reproduction number and generation time, recording all individual-level transmission events. We find that the classical concept of the basic reproduction number is untenable in realistic populations, and it does not provide any conceptual understanding of the epidemic evolution. This departure from the classical theoretical picture is not due to behavioral changes and other exogenous epidemiological determinants. Rather, it can be simply explained by the (clustered) contact structure of the population. Finally, we provide evidence that methodologies aimed at estimating the instantaneous reproduction number can operationally be used to characterize the correct epidemic dynamics from incidence data.

Effectiveness of Aspirin in COPD: Biases in the Observational Studies.

Several observational studies report decreased incidence of mortality and of exacerbations with aspirin use in patients with chronic obstructive pulmonary disease (COPD), with calls for a large randomized trial. Aspirin does have local and systemic pulmonary mechanisms of action that could make this drug beneficial in the treatment of COPD. However, the potential for biases in the observational studies has not been examined. We searched the literature for all observational studies reporting on the effect of aspirin in COPD patients on exacerbation and mortality. We reviewed the studies for the presence of time-related and other biases. We identified eight observational studies reporting an overall reduction in all-cause mortality or exacerbation with aspirin use of 21% (pooled rate ratio (RR) 0.79; 95% CI 0.71-0.86). We found two studies affected by immortal time bias (pooled RR 0.81; 95% CI 0.74-0.89), three studies affected by collider-stratification bias (pooled RR 0.66; 95% CI 0.55-0.79) and three that involved some exposure misclassification (pooled RR 0.85; 95% CI 0.78-0.92). Moreover, while adjusting for cardiovascular factors, six of the eight studies did not adjust for important markers of COPD severity and thus remain susceptible to confounding bias. In conclusion, all observational studies reporting on the effectiveness of aspirin on major outcomes of COPD are affected by biases known to exaggerate the effectiveness of a drug. As these studies cannot be used to support a beneficial effect for aspirin in COPD, it would be premature to consider a randomized trial to investigate this question until methodologically rigorous studies are available.

Geographical Distribution and Epidemiologic Factors of Chigger Mites on Apodemus agrarius during Autumn in Korea.

A nationwide survey of chigger mites causing scrub typhus and an investigation of epidemiologic factors for chigger mites was conducted at 16 localities in 8 provinces in Korea during autumn 2009, 2012, and 2013. A total of 233 Apodemus agrarius were captured, and all were infested with chigger mites. The chigger index was highest in Chungcheongbuk-do in 2009 (358.3) and 2012 (290.1) and Chungcheongnam-do in 2013 (294.4). The predominant chigger mite species was Leptotrombidium pallidum in the northern and central parts and L. scutellare in the southern and western parts, Korea. L. pallidum was not found in Jellanam-do and Gyeongsangnam-do and the distribution of L. scutellare had been expanded in the northern parts of Korea. The chigger index of L. pallidum was positively correlated with temperature and negatively correlated with humidity. The incidence of scrub typhus is dependent on L. scutellare index. These findings could be helpful to monitor the distribution of chigger mites and to develop a preventive measures for scrub typhus in Korea.

Window Collisions by Birds in Brazil: Epidemiologic Factors and Radiographic and Necropsy Assessments.

Birds are among the most visually proficient group of animals on the planet; however, their inability to visualize and discriminate translucent glass structures results in an extreme number of deaths worldwide from high-speed collisions. Despite reports of avian glass collisions in North America, only a few studies have been developed to understand this problem in South America, and none evaluated radiographic and postmortem findings. One hundred cadavers were examined radiographically and postmortem, and data from 186 collision reports were analyzed for seasonality (website and manual reports and cadavers). A total of 34 different species of birds within 22 families were evaluated for this study, with the rufous-bellied thrush (Turdus rufiventris; n = 12), eared dove (Zenaida auriculata; n = 12), and ruddy ground dove (Columbina talpacoti; n = 10) being the most common species. Only 6 (27.7%) migratory species were reported: Sick's swift (Chaetura meridionalis), small-billed elaenia (Elaenia parvirostris), Black Jacobin (Florisuga fusca), Great kiskadee (Pitangus sulphuratus), Double-collared seedeater (Sporophila caerulescens), and Creamy-bellied thrush (Turdus amaurochalinus). Males (51) were more frequently reported than females (5), and 50.1% of the males had active gonads. Sex was unable to be determined in 44 birds. The most common radiographic lesion, noted in 16 of 82 (19.5%) animals, was loss of coelomic definition, suggestive of hemorrhage. Prevalent postmortem findings included skull hemorrhages (58/75, 77.3%) and encephalic contusions (47/73, 64.4%), followed by coelomic hemorrhages (33/81, 40.7%). Most of the window collisions (61/186, 32.8%) occurred during spring, the most common breeding season of avian species in Brazil. Cranioencephalic trauma was identified as the primary cause of mortality associated with birds flying into glass windows. Migration does not appear to be the main predisposing factor for window collisions by birds in Brazil. Increased activity and aggression related to breeding season, especially in males, may be a more important predisposing factor for window collision accidents.

Using Evidence Factors to Clarify Exposure Biomarkers.

A study has 2 evidence factors if it permits 2 statistically independent inferences about 1 treatment effect such that each factor is immune to some bias that would invalidate the other factor. Because the 2 factors are statistically independent, the evidence they provide can be combined using methods associated with meta-analysis for independent studies, despite using the same data twice in different ways. We illustrate evidence factors, applying them in a new way in investigations that have both an exposure biomarker and a coarse external measure of exposure to a treatment. To illustrate, we consider the possible effects of cigarette smoking on homocysteine levels, with self-reported smoking and a cotinine biomarker. We examine joint sensitivity of 2 factors to bias from confounding, a central aspect of any observational study.

The National Cooperative Trial on Multifactorial Prevention of First Heart Attacks and Coronary Mortality in Free-Living, High-Risk, Middle-Aged American Men, Also Known as JUMBO: A Short Story.

The concept of a multiple risk-factor intervention trial (MRFIT) originated in mid-20th century efforts to determine whether modifying the "risk factors" established by cardiovascular disease epidemiology would prevent heart attacks. The term "MRFIT" probably first appeared in the 1968 report to the National Heart Institute from investigators of the National Diet-Heart Feasibility Study. Based on their pilot experience, they recommended a trial of diet alone. Aware, however, that authorities might agree with the rationale but not the implementation of such a massive and risky undertaking, they also proposed an alternative: whether coronary heart disease was preventable at all by simultaneous intervention on several risk factors; that is, a multiple risk-factor intervention trial. After some years agonizing by serial expert committees, the National Heart Institute opted against an explanatory diet trial and for a pragmatic multiple risk-factor intervention, one designed by Institute staff and operated under contract. Meanwhile, an impatient community of investigators met together in the Makarska Conference, outlined a broad cardiovascular disease prevention policy, and submitted their idealized version of a multiple risk-factor trial, called JUMBO. But the National Heart Institute, because of the plan for its own trial, had no funds left for an investigator-initiated proposal. Hence, this background and story of the MRFIT that wasn't.

Evaluation of Epidemiologic Factors, Radiographic Features, and Pathologic Findings for Predicting Peritumoral Brain Edema in Meningiomas.

BACKGROUND: Despite several treatment options that are available for meningiomas, surgery is the only method currently practiced. Peritumoral brain edema (PTBE) in meningiomas causes difficulty marginalizing the dissection in an intraoperative setting. PURPOSE: To evaluate whether the epidemiological variables, imaging characteristics, and pathologic parameters are correlated with the presence of PTBE in meningiomas. STUDY TYPE: Retrospective study from 2015 to 2018. SUBJECTS: In all, 550 patients with histopathologically confirmed meningioma were included. After exclusion of patients with extradural, spinal, and intraventricular meningiomas and those with image artifacts, a total of 441 patients were included in the final analysis. FIELD STRENGTH/SEQUENCE: Images were performed with 3T MR scanners and axial/sagittal T1 WI, axial/coronal T2 WI and axial/sagittal/coronal contrast-enhanced T1 WI after administration of 0.1 mmol/kg of body weight of Gd-DTPA. ASSESSMENT: Fourteen variables were patients' age, sex, skull changes, calcification, density, location, margin, volume, cerebrospinal fluid (CSF) cleft, signal intensity (SI) on T2 WI, degree and pattern of contrast enhancement, WHO histological classification, and Ki-67 labeling index. STATISTICAL TESTS: The relationship between each factor and the formation of PTBE was examined by multivariate logistic regression analysis. RESULTS: After multivariate logistic regression, the absence of CSF cleft (odds ratio [OR]: 63.43, 95% confidence interval [CI]: 27.24-121.42, P = 1.2 × 10-8 ), non-skull base location (OR: 15.32, 95% CI: 5.81-28.23, P = 0.0008), high SI on T2 WI (OR: 5.05, 95% CI: 2.27-14.88, P = 0.01), and G I uncommon subtypes (OR: 4.75, 95% CI: 1.42-15.94, P = 0.01) were found to be significant independent factors associated with the occurrence of PTBE in meningiomas. In patients with PTBE-positive meningiomas, there was no significant correlation between the volume of PTBE and the volume of the tumor (r = 0.17, P = 0.60). DATA CONCLUSION: These factors may be suggestive of anticipating the formation of PTBE. LEVEL OF EVIDENCE: 3 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2020;52:174-182.

Optimal Virulence, Diffusion and Tradeoffs.

In this work we propose a variant of a classical SIR epidemiological model where pathogens are characterized by a (phenotypic) mutant trait x. Imposing that the trait x mutates according to a random walk process and that it directly influences the epidemiological components of the pathogen, we studied its evolutionary development by interpreting the tenet of maximizing the basic reproductive number of the pathogen as an optimal control problem. Pontryagin's maximum principle was used to identify the possible optimal evolutionary strategies of the pathogen. Qualitatively, three types of optimal evolutionary routes were identified and interpreted in the context of virulence evolution. Each optimal solution imposes a different tradeoff relation among the epidemiological parameters. The results predict (mostly) two kinds of infections: short-lasting mild infections and long-lasting acute infections.

Tuberculosis infection and epidemiological characteristics in Haidian District, Beijing, 2005-2018.

BACKGROUND: This study was aimed to investigate the epidemiological characteristic of pulmonary tuberculosis (PTB) in Haidian District, Beijing from 2005 to 2018 and to provide suggestions for controlling tuberculosis (TB) development. METHODS: Epidemiological data about TB were obtained by the Infectious Disease Reporting System at different levels of medical institutions in Haidian District of Beijing from 2005 to 2018. The epidemiological methods combined with χ2 test were used to analyze the distribution of TB in population, time, region and TB diagnosis. RESULTS: In total, 14,449 cases of TB patients were reported in Haidian District from 2005 to 2018 and the average annual morbidity was 31.67/10,000. Of the total cases, housework and unemployed people (20.73%; 2996/14,449) accounted for the highest proportion of occupational distribution, followed by students, accounting for 17.18% (2482/14,449). 2433 patients with the age of 65 years and over accounting for 16.83% (2433/14,449); Laboratory confirmed diagnosis of TB was 26.60% and the diagnostic delays accounted for 54.96%. CONCLUSIONS: From 2005 to 2018, TB incidence was falling gradually in Haidian District. However, particular attention should be paid to the elderly and student groups, and the policy publicity and education should be strengthened to reduce the diagnosis delay of TB.

Prevalence and determinants of gestational weight gain among pregnant women in Niger.

Low gestational weight gain (GWG) and low mid-upper arm circumference (MUAC) are associated with adverse pregnancy outcomes. We aimed to assess the prevalence and determinants of low GWG and low MUAC among pregnant women in rural Zinder, Niger. A community-based survey was conducted among 1,384 pregnant women in the catchment areas of 18 integrated health centers in the region of Zinder, Niger. Weight and MUAC were measured during an in-home visit and again 1 month later, when haemoglobin concentration and micronutrient status were also assessed. The prevalence of low GWG was defined based on the 2009 United States Institute of Medicine (U.S. IOM) guidelines (<0.35 kg/week) and less than the third centile of the International Fetal and Newborn Growth Consortium for the 21st Century (INTERGROWTH-21st) standards. Factors associated with GWG and MUAC were identified using logistic regression models adjusting for season, village, and gestational age. The median (interquartile range) age was 25.0 (20.7, 30.0) years, and 16.4% were ≤19 years. The prevalence of low GWG were 62.9% and 27.5% according to 2009 IOM and less than the third INTERGROWTH-21st centile, respectively; 24.9% had low MUAC. Higher α-1-acid glycoprotein (OR = 1.7, 95% CI [1.1, 2.8]) and C-reactive protein (OR = 1.2, 95% CI [1.02, 1.50]) increased the odds of low GWG. Adolescents (OR = 2.7, 95% CI [1.8, 4.0]), housewives (OR = 1.97, 95% CI [1.36, 2.86]), and those who reported recent food assistance (OR = 1.80, 95% CI [1.04, 3.11]) had higher odds of low MUAC. Prevalence of low GWG and low MUAC was high among pregnant women. Determinants of GWG and MUAC included socio-economic, demographic, and biological factors, although only markers of inflammation were consistent predictors across different definitions of low GWG.

RIDDLE: Race and ethnicity Imputation from Disease history with Deep LEarning.

Anonymized electronic medical records are an increasingly popular source of research data. However, these datasets often lack race and ethnicity information. This creates problems for researchers modeling human disease, as race and ethnicity are powerful confounders for many health exposures and treatment outcomes; race and ethnicity are closely linked to population-specific genetic variation. We showed that deep neural networks generate more accurate estimates for missing racial and ethnic information than competing methods (e.g., logistic regression, random forest, support vector machines, and gradient-boosted decision trees). RIDDLE yielded significantly better classification performance across all metrics that were considered: accuracy, cross-entropy loss (error), precision, recall, and area under the curve for receiver operating characteristic plots (all p < 10-9). We made specific efforts to interpret the trained neural network models to identify, quantify, and visualize medical features which are predictive of race and ethnicity. We used these characterizations of informative features to perform a systematic comparison of differential disease patterns by race and ethnicity. The fact that clinical histories are informative for imputing race and ethnicity could reflect (1) a skewed distribution of blue- and white-collar professions across racial and ethnic groups, (2) uneven accessibility and subjective importance of prophylactic health, (3) possible variation in lifestyle, such as dietary habits, and (4) differences in background genetic variation which predispose to diseases.

Determinants of low birth weight in neonates born in three hospitals in Brong Ahafo region, Ghana, 2016- an unmatched case-control study.

BACKGROUND: Each year, about 20 million Low Birth Weight (LBW) babies are born with very high proportion (96.5%) occuring in developing countries. In the last decade, the incidence of LBW in Ghana has not declined. Brong Ahafo Region of Ghana recorded a LBW prevalence of 11% which was higher than the the national average of 10%. This study identifed determinants of LBW delivery in the Brong Ahafo Region. METHODS: We conducted a 1:2 unmatched case control study among mothers with singleton deliveries in 3 major health facilities in the Brong Ahafo Region. A case was defined as a mother who delivered a baby weighing less than 2500g in any of the three selected health facilities between 1st December, 2015 and 30th April, 2016. A control was defined as a mother who within 24 h of delivery by a case, delivered a baby weighing at least 2500g and not exceeding 3400g in the same health facility. Deliveries that met the inclusion criteria for cases were selected and two controls were randomly selected from the pool of deliveries that meet criteria for controls within 24 h of delivery of a case. A total of 120 cases and 240 control were recruited for the study. We computed odds ratios at 95% confidence level to determine the associations between low birth weight and the dependent factors. RESULTS: After controlling for confounders such as planned pregnancy, mode of delivery, parity and previous LBW in stepwise backward logistic regression, first trimester hemoglobin < 11 g/dl (aOR 3.14; 95%CI: 1.50-6.58), delivery at 32-36 weeks gestation (aOR 13.70; 95%CI: 4.64-40.45), delivery below 32 weeks gestation (aOR 58.5; 95%CI 6.7-513.9), secondary education of mothers (aOR 4.19; 95%CI 1.45-12.07), living with extended family (aOR 2.43; 95%CI 1.15-5.10, living alone during pregnancy (aOR 3.9; 95%CI: 1.3-11.7), and not taking iron supplements during pregnancy (aOR 3.2; 95%CI: 1.1-9.5) were found to be significantly associated with LBW. CONCLUSION: Determinants of LBW were: preterm delivery, mothers with secondary education, living alone during pregnancy, not taking daily required iron supplementation and mothers with first trimester hemoglobin below 11 g/dl. Education during antenatal sessions should be tailored to address the identified risk factors in the mother and child health care services.

Determinants and outcomes of access-related blood-stream infections among Irish haemodialysis patients; a cohort study.

BACKGROUND: Infections are the second leading cause of death and hospitalisation among haemodialysis (HD) patients. Rates of access-related bloodstream infections (AR-BSI) are influenced by patient characteristics and local protocols. We explored factors associated with AR-BSI in a contemporary cohort of HD patients at a tertiary nephrology centre. METHODS: A retrospective cohort of 235 chronic HD patients was identified from a regional dialysis programme between Jan 2015 and Dec 2016. Data on demographics, primary renal disease, comorbid conditions and dialysis access type were obtained from the Kidney Disease Clinical Patient Management System (KDCPMS). Data on blood cultures were captured from the microbiology laboratory. Poisson regression with robust variance estimates was used to compare infection rates and relative risk of AR-BSI according to the site and type of vascular access. RESULTS: The mean age was 65 (± 15) years, 77% were men, and the median follow up was 19 months (IQR: 10-24 months), accumulating 2030 catheter-months and 1831 fistula-months. Overall rates of AR-BSI were significantly higher for central venous catheter (CVC) compared to arteriovenous fistula (AVF), (2.22, 95% (CI): 1.62-2.97) versus 0.11 (0.01-0.39) per 100 patient-months respectively), with a rate ratio of 20.29 (4.92-83.66), p < 0.0001. This pattern persisted across age, gender and diabetes subgroups. Within the CVC subgroup, presence of a femoral CVC access was associated with significantly higher rates of AR-BSI (adjusted RR 4.93, 95% CI: 2.69-9.01). Older age (75+ versus < 75 years) was not associated with significant differences in rates of AR-BSI in the unadjusted or the adjusted analysis. Coagulase negative Staphylococcus (61%) and Staphylococcus aureus (23%) were the predominant culprits. AR-BSIs resulted in access loss and hospitalisation in 57 and 72% of events respectively, and two patients died with concurrent AR-BSI. CONCLUSIONS: Rates of AR-BSI are substantially higher in CVC than AVF in contemporary HD despite advances in catheter design and anti-infective protocols. This pattern was consistent in all subgroups. The policy of AVF preference over CVC should continue to minimise patient morbidity while at the same time improving anti-infective strategies through better care protocols and infection surveillance.

Evolution and Manipulation of Vector Host Choice.

The transmission of many animal and plant diseases relies on the behavior of arthropod vectors. In particular, the specific preference for infected or uninfected hosts observed in many vector species is expected to affect the circulation of vector-borne diseases. Here I develop a theoretical framework to study the epidemiology and evolution of the manipulation of host choice behavior of vectors. I show that vector preference strategies have dramatic epidemiological consequences. I also explore the evolution of vector host choice under different scenarios regarding control of the vector behavior by the pathogen. This analysis yields multiple evolutionary outcomes and explains the diversity of host choice behaviors observed in a broad range of vector-borne diseases. In particular, this analysis helps us understand why several pathogens have evolved manipulation strategies that vary with the infectious status of their vector species while other pathogens seem unable to evolve such complex conditional strategies. I argue that contrasting the behavior of infected and uninfected vectors is key to revealing the mechanistic constraints acting on the evolution of the manipulation of vector behavior.