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bioRxiv2018

Assessment of Menstrual Hygiene Management and Its Determinants among Adolescent Girls: A Cross-Sectional Study in School adolescent girls in Addis Ababa, Ethiopia.

IntroductionManaging menstruation is essentially dealing with menstrual flow and also in continuing regular activities like going to school, working etc. However, menstruation can place significant obstacles in girls access to health, education and future prospects if they are not equipped for effective menstrual hygiene management.\n\nObjectiveTo assess the menstrual hygiene management and its determinant among school girls in Addis Ababa, Ethiopia.\n\nMethodsCross-sectional study design with quantitative method was carried out among 770 systematically selected adolescent school girls of Addis Ababa from April 1 to May 5, 2017. A self-administered pre-test close ended Amharic questionnaire at school setting was used for data collection. The coding was done using the original English version and entered to EPI-7 software. The quantitative file exported to statistical package for social science (SPSS) version 25.0 software for analysis. Total mean score was used to categorize individuals as good and poor while AOR; 95% CI with p < 0.05 was used to determine factors of menstrual hygiene management practice.\n\nResultThis study had 98% response rate. 530 (70.1%) and 388(51.3%) respondents had good knowledge and practice of menstrual hygiene respectively. The findings also showed a significant positive association between good knowledge of menstruation and girls from mothers whose education were secondary (AOR = 10.012, 95 % CI = 3.628-27.629). Wealth index quantile five (AOR = 9.038, 95 % CI = 3.728-21.909) revealed significant positive association with good practice of menstrual hygiene.\n\nConclusion and recommendationMajority of participants had good knowledge and practice of menstrual hygiene and majority of them were from private school. Although knowledge was better than practice, girls should be educated about the process, use of proper pads or absorbents and its proper disposal.

epidemiology↗

bioRxiv2018

Bayesian phylodynamics of avian influenza virus H9N2 in Asia with time-dependent predictors of migration

Model-based phylodynamic approaches recently employed generalized linear models (GLMs) to uncover potential predictors of viral spread. Very recently some of these models have allowed both the predictors and their coefficients to be time-dependent. However, these studies mainly focused on predictors that are assumed to be constant through time. Here we inferred the phylodynamics of H9N2 viruses isolated in 12 Asian countries and regions under both discrete trait analysis (DTA) and structured coalescent (MASCOT) approaches. Using MASCOT we applied a new time-dependent GLM to uncover the underlying factors behind H9N2 spread. We curated a rich set of time-series predictors including annual international live poultry trade and national poultry production figures. This time-dependent phylodynamic prediction model was compared to commonly employed time-independent alternatives. Additionally the time-dependent MASCOT model allowed for the estimation of viral effective sub-population sizes and their changes through time and these effective population dynamics within each country were predicted by a GLM. International annual poultry trade is a strongly supported predictor of virus migration rates. There was also strong support for geographic proximity as a predictor of migration rate in all GLMs investigated. In time-dependent MASCOT models, national poultry production was also identified as a predictor of virus genetic diversity through time and this signal was obvious in mainland China and Bangladesh. Our application of a recently introduced time-dependent GLM predictors integrated rich time-series data in Bayesian phylodynamic prediction. We demonstrated the contribution of poultry trade and geographic proximity (potentially unheralded wild bird movements) to avian influenza spread in Asia. To gain a better understanding of the drivers of H9N2 spread, we suggest increased surveillance of the H9N2 virus in countries that are currently under-sampled as well as in wild bird populations in the most affected countries.\n\nAuthor summaryWhat drives the geographic dispersal and genetic diversity of H9N2 avian influenza virus in Asia? We used two model-based approaches, DTA and MASCOT, to reconstruct the phylogeographic dynamics of the virus. Further, multiple potential predictors were used to inform the virus spread and population dynamics by GLMs. Here, we maximised the power of time-series predictors in Bayesian phylodynamic prediction. For the first time, we were able to quantify the contribution of both time-series and constant predictors to both migration rates and effective population sizes in a structured population. We identified a positive association of international poultry trade and national poultry production time-series with virus migration rates and effective population sizes respectively. We also identify geographic proximity as a strongly supported driver to virus migration rates and this points to the potential role of wild bird populations in virus dispersal across countries. Our study is a practical exemplar of the use of temporal information in predictors to model heterogeneous spatial diffusion and population dynamic processes and provides direction to H9N2 control efforts in Asia.

epidemiology↗

bioRxiv2018

Perfect Counterfactuals for Epidemic Simulations

Simulation studies are often used to predict the expected impact of control measures in infectious disease outbreaks. Typically, two independent sets of simulations are conducted, one with the intervetnion, and one without, and epidemic sizes (or some related metric) are compared to estimate the effect of the intervention. Since it is possible that controlled epidemics are larger than uncontrolled ones if there is substantial stochastic variation between epidemics, uncertainty intervals from this approach can include a negative effect even for an effective intervention. To more precisely estimate the number of cases an intervention will prevent within a single epidemic, here we develop a single world approach to matching simulations of controlled epidemics to their exact uncontrolled counterfac-tual. Our method borrows concepts from percolation approaches prune out possible epidemic histories and create potential epidemic graph that can be realized to create perfectly matched controlled and uncontrolled epidemics. We present an implementation of this method for a common class of compartmental models, and its application in a simple SIR model. Results illustrate how, at the cost of some computation time, this method substantially narrows confidence intervals and avoids non-sensical inferences.

epidemiology↗

bioRxiv2018

Feeding the disparities: the geography and trends of breastfeeding in the United States

There is scientific consensus on the importance of breastfeeding for the present and future health of newborns, in high- and low-income settings alike. In the United States, improving breast milk access is a public health priority but analysis of secular trends are largely lacking. Here, we used data from the National Immunization Survey of the CDC, collected between 2003 and 2016, to illustrate the temporal trends and the spatial heterogeneity in breastfeeding. We also considered the effect sizes of two key determinants of breastfeeding rates. We show that, while access to breast milk both at birth and at 6 months old has steadily increased over the past decade, large spatial disparities still remain at the state level. We also find that, since 2009, the proportion of households below the poverty level has become the strongest predictor of breastfeeding rates. We argue that, because variations in breastfeeding rates are associated with socio-economic factors, public health policies advocating for breastfeeding are still needed in particular in underserved communities. This is key to reducing longer term health disparities in the U.S., and more generally in high-income countries.

epidemiology↗

bioRxiv2018

Seasonal patterns of dengue fever in rural Ecuador: 2009-2016

Season is a major determinant of infectious disease rates, including arboviruses spread by mosquitoes, such as dengue, chikungunya, and Zika. Seasonal patterns of disease are driven by a combination of climatic or environmental factors, such as temperature or rainfall, and human behavioral time trends, such as school year schedules, holidays, and weekday-weekend patterns. These factors affect both disease rates and healthcare-seeking behavior. Seasonality of dengue fever has been studied in the context of climatic factors, but short-and long-term time trends are less well-understood. With 2009-- 2016 medical record data from patients diagnosed with dengue fever at two hospitals in rural Ecuador, we used Poisson generalized linear modeling to determine short-and long-term seasonal patterns of dengue fever, as well as the effect of day of the week and public holidays. In a subset analysis, we determined the impact of school schedules on school-aged children. With a separate model, we examined the effect of climate on diagnosis patterns. In the first model, the most important predictors of dengue fever were annual sinusoidal fluctuations in disease, long-term trends, day of the week, and hospital. Seasonal trends showed single peaks in case diagnoses, during April. Compared to an average day, cases were more likely to be diagnosed on Tuesdays (risk ratio (RR): 1.26, 95% confidence interval (CI) 1.05--1.51) and Thursdays (RR: 1.25, 95% CI 1.02--1.53), and less likely to be diagnosed on Saturdays (RR: 0.81, 95% CI 0.65--1.01) and Sundays (RR: 0.74, 95% CI 0.58--0.95). Public holidays were not significant predictors of dengue fever diagnoses, except for an increase in diagnoses on the day after Christmas (RR: 2.77, 95% CI 1.46--5.24). School schedules did not impact dengue diagnoses in school-aged children. In the climate model, important climate variables included the monthly total precipitation (RR: 2.14, 95% CI 1.26--3.64), an interaction between total precipitation and monthly absolute minimum temperature (RR: 0.93, 95% CI 0.88--0.98), an interaction between total precipitation and monthly precipitation days (RR: 0.90, 95% CI 0.82--0.99), and a three-way interaction between minimum temperature, total precipitation, and precipitation days (RR: 1.01, 95% CI 1.00--1.02). This is the first report of long-term dengue fever seasonality in Ecuador, one of few reports from rural patients, and one of very few studies utilizing daily disease reports. These results can inform local disease prevention efforts, public health planning, as well as global and regional models of dengue fever trends.\n\nAuthor summaryDengue fever exhibits a seasonal pattern in many parts of the world, much of which has been attributed to climate and weather. However, additional factors may contribute to dengue seasonality. With 2009-- 2016 medical record data from rural Ecuador, we studied the short-and long-term seasonal patterns of dengue fever, as well as the effect of school schedules and public holidays. We also examined the effect of climate on dengue. We found that dengue diagnoses peak once per year during April, but that diagnoses are also affected by day of the week. Dengue was also impacted by regional climate and complex interactions between local weather variables. This is the first report of long-term dengue fever seasonality in Ecuador, one of few reports from rural patients, and one of very few studies utilizing daily disease reports. This is the first report on the impacts of school schedules, holidays, and weekday-weekend patterns on dengue diagnoses. These results suggest a potential impact of human behaviors on dengue exposure risk. More broadly, these results can inform local disease prevention efforts and public health planning, as well as global and regional models of dengue fever trends.

epidemiology↗

bioRxiv2018

Building Key Populations HIV Treatment Cascades in Data-Scarce Environments: Towards a participatory stakeholder methodology for cascades construction, adoption, and utilization

IntroductionRecent HIV key populations (KP) surveillance studies in South Africa, including female sex workers (FSW) and men who have sex with men (MSM), demonstrate the disproportionate burden of HIV they bear compared to the general population. The national response for KP has lagged due to relatively scarce KP data focused narrowly on urban areas. We adopted a participatory data triangulation approach with stakeholders to overcome the challenges of KP program planning in KP data-scarce districts. Here we describe our methodology for achieving consensus on population size estimates (PSE) and treatment cascade indicator estimates derived from FSW and MSM surveillance data and applied across the country.\n\nMethodsThe South African National AIDS Council (SANAC) convened the group; technical advisors from the University of California San Francisco (UCSF) facilitated; and stakeholders from government, non-government, academic, and KP-led advocacy organizations involved in program implementation and research provided input through three in-person meetings covering four phases of work: surveillance data analysis; cascades data extraction; presentation for feedback; and data extrapolation.\n\nResultsTechnical advisors presented eight cascades (three FSW, five MSM) to stakeholders, recommending data-informed extrapolation factors for each population. Stakeholders adopted recommendations by consensus with few adjustments. FSW cascades displayed high awareness of HIV status and steep breakpoints towards ART uptake; MSM cascades displayed less HIV status awareness, but relatively good ART uptake, with metropolitan areas displaying better uptake than rural districts.\n\nConclusionThe participatory process enabled KP stakeholders to vet disparate data sources against programmatic experience and recommend consistency in cascades data; participatory triangulation of additional surveillance and program data will follow. The considerable time and resource investments in this process had downstream benefits, including consistency in sub-national HIV implementation plans. We recommend this consensus-based approach as a transparent, consistent, and sound methodology for cascades construction in KP data-scarce environments.

epidemiology↗

bioRxiv2018

Alcohol consumption is associated with widespread changes in blood DNA methylation: analysis of cross-sectional and longitudinal data

BackgroundDNA methylation may be one of the mechanisms by which alcohol consumption is associated with the risk of disease. We conducted a large-scale, cross-sectional, genome-wide DNA methylation association study of alcohol consumption and a longitudinal analysis of repeated measurements taken several years apart.\n\nMethodsUsing the Illumina Infinium HumanMethylation450 BeadChip, DNA methylation measures were determined using baseline peripheral blood samples from 5,606 adult Melbourne Collaborative Cohort Study (MCCS) participants. For a subset of 1,088 of them, these measures were repeated using blood samples collected at follow-up, a median of 11 years later. Associations between alcohol intake and blood DNA methylation were assessed using linear mixed-effects regression models adjusted for batch effects and potential confounders. Independent data from the LOLIPOP (N=4,042) and KORA (N=1,662) cohorts were used to replicate associations discovered in the MCCS.\n\nResultsCross-sectional analyses identified 1,414 CpGs associated with alcohol intake at P<10-7, 1,243 of which had not been reported previously. Of these 1,243 novel associations, 1,078 were replicated (P<0.05) using LOLIPOP and KORA data. Using the MCCS data, we also replicated (P<0.05) 403 of 518 associations that had been reported previously. Interaction analyses suggested that associations were stronger for women, non-smokers, and participants genetically predisposed to consume less alcohol. Of the 1,414 CpGs, 530 were differentially methylated (P<0.05) in former compared with current drinkers. Longitudinal associations between the change in alcohol intake and the change in methylation were observed for 513 of the 1,414 cross-sectional associations.\n\nConclusionOur study indicates that, for middle-aged and older adults, alcohol intake is associated with widespread changes in DNA methylation across the genome. Longitudinal analyses showed that the methylation status of alcohol-associated CpGs may change with changes in alcohol consumption.

epidemiology↗

bioRxiv2018

Nutritional status and morbidity profile of children with contact to leprosy in the rural community.

IntroductionChildhood leprosy reflects upon the disease transmission in the community. So, this study aimed to find out the children with contact to leprosy in their surroundings, prevalence of leprosy or subclinical infections in them and to assess their nutritional status. The study was conducted for 2 months and analysed 70 children in the rural community who were living with a household contact of leprosy.\n\nMethods70 children in the rural areas surrounding Chengalpattu living with leprosy contacts were selected for carrying out the study. Information regarding their demographic characteristics, socioeconomic factors, environmental conditions, feeding practices, food habits and any present health problems or in the recent past were collected. The children were then subjected to anthropometric measurements. The children were clinically evaluated by a dermatologist qualified in paediatric leprosy and children who were diagnosed as cases of leprosy were classified according to Ridley-Jopling classification. Slit skin smears for acid fast bacilli was done in all children with suspicious skin lesions.\n\nResultsOut of the 70 children taken into the study, 41 were boys and 29 were girls. 7-22% of boys and 3-6% of girls and overall,4-15% children are severely malnourished. 19 out of the 70 children had clinical pallor. Among the 70 leprosy contact children, 3 children were diagnosed to have leprosy (4.28%).Of the 3, 2 children had multibacillary leprosy while 1 had paucibacillary leprosy, according to the WHO classification and all 3 were classified as cases of Borederline Tuberculoid Leprosy according to Ridley-Jopling classification. All these 3 children had contact to leprosy for 10 or more years living with them.\n\nConclusionIt can be concluded that malnutrition, the closeness and duration of contact to leprosy are significant risk factors for leprosy. Regular contact screening and early case detection are essential strategies to prevent further transmission in the endemic areas. Diagnostic methods for detection of subclinical infection in contacts needs further research.

epidemiology↗

bioRxiv2018

Reporting of \"dialysis adequacy\" as an outcome in randomised trials conducted in adults on haemodialysis: a systematic review

BackgroundClinical trials are most informative for evidence-based decision-making when they consistently measure and report outcomes of relevance to stakeholders, especially patients, clinicians, and policy makers. However, sometimes terminology used is interpreted differently by different stakeholders, which might lead to confusion during shared decision making. The construct dialysis adequacy is frequently used, suggesting it is an important outcome both for health care professionals as for patients.\n\nObjectiveTo assess the scope and consistency of the construct dialysis adequacy as reported in randomised controlled trials in hemodialysis, and evaluate whether these align to the insights and understanding of this construct by patients.\n\nMethodsTo assess scope and consistency of dialysis adequacy by professionals, we performed a systematic review searching the Cochrane Central Register of Controlled Trials (CENTRAL) up to July 2017. We identified all randomised controlled trails (RCT) including patients on hemodialysis and reporting dialysis adequacy, adequacy or adequacy of dialysis and extracted and classified all reported outcomes. To explore interpretation and meaning of the construct of adequacy by patients, we conducted 10 semi-structured interviews with HD patients using thematic analysis. Belgian registration number B670201731001.\n\nFindingsFrom the 31 included trials, we extracted and classified 98 outcome measures defined by the authors as adequacy of dialysis, of which 94 (95%) were biochemical, 3 (3%) non-biochemical surrogate and 2 (2%) patient-relevant. The three most commonly reported measures were all biochemical. None of the studies defined adequacy of dialysis as a patient relevant outcome such as survival or quality of life.\n\nPatients had a substantially different understanding of the construct dialysis adequacy than the biochemical interpretation reported in the literature. Being alive, time spent while being on dialysis, fatigue and friendliness of staff were the most prominent themes that patients linked to the construct of dialysis adequacy.\n\nConclusion Adequacy of dialysis as reported in the literature refers to biochemical outcome measures, most of which are not related with patient relevant outcomes. For patients, adequate dialysis is a dialysis that enables them to spend as much quality time in their life as possible.

epidemiology↗

bioRxiv2018

Mortality in trauma patients admitted during, before, and after national academic emergency medicine and trauma surgery meeting dates in Japan

Annually, many physicians attend national academic meetings. While participating in these meetings can have a positive impact on daily medical practice, attendance may result in reduced medical staffing during the meeting dates. We sought to examine whether there were differences in mortality after trauma among patients admitted to the hospital during, before, and after meeting dates. Using the Japan Trauma Data Bank, we analyzed in-hospital mortality in patients with traumatic injury admitted to the hospital from 2004 to 2015 during the dates of two national academic meetings - the Japanese Association for Acute Medicine (JAAM) and the Japanese Association for the Surgery of Trauma (JAST). We compared the data with that of patients admitted with trauma during identical weekdays in the weeks before and after the meetings, respectively. We used multiple logistic regression analysis to compare outcomes among the three groups. A total of 7,491 patients were included in our analyses, with 2,481, 2,492, and 2,518 patients in the during, before, and after meeting dates groups, respectively; their mortality rates were 7.3%, 8.0%, and 8.5%, respectively. After adjusting for covariates, no significant differences in in-hospital mortality were found among the three groups (adjusted odds ratio [95% CI] of the before meeting dates and after meeting dates groups; 1.18 [0.89-1.56] and 1.23 [0.93-1.63], respectively, with the during meeting dates group as the reference category). No significant differences in in-hospital mortality were found among trauma patients admitted during, before, and after the JAAM and JAST meeting dates.

epidemiology↗

bioRxiv2018

Strongyloides stercoralis: spatial distribution of a highly prevalent and ubiquitous soil-transmitted helminth in Cambodia

BackgroundStrongyloides stercoralis is a neglected soil-transmitted helminth that occurs worldwide and can cause long-lasting and potentially fatal infections due to its ability to replicate within its host. S. stercoralis causes gastrointestinal and dermatological morbidity. The objective of this study was to assess the S. stercoralis infection risk, and using geostatistical models, to predict its geographical distribution in Cambodia.\n\nMethodology / Principal FindingsA nation-wide community-based parasitological survey was conducted among the population aged 6 years and above. S. stercoralis was diagnosed using a serological diagnostic test detecting antigens in urine. Data on demography, hygiene and knowledge about helminth infection were collected. S. stercoralis prevalence among 7,246 participants with complete data record was 30.5% and ranged across provinces between 10.9% and 48.2%. The parasite was ubiquitous in Cambodia, with prevalence rates below 20% only in five south-eastern provinces. Infection risk increased with age both in men and women although girls aged less than 13 years and women aged 50 years and above had lower odds of infection than their male counterparts. Open defecation was associated with higher odds of infection while declaring having some knowledge about health problems caused by worms was protective. Infection risk was positively associated with night maximum temperature, minimum rainfall, and distance to water, and negatively associated with land occupied by rice fields.\n\nConclusions / SignificanceS. stercoralis infection is ubiquitous and rampant in Cambodia. The parasite needs to be addressed by control programs delivering ivermectin. However the high cost of this drug in Cambodia currently precludes control implementation. Donations, subsidization or the production of affordable generic production are needed so S. stercoralis, which infests almost a third of the Cambodian population, can be addressed by an adequate control program.\n\nAuthors SummaryThe threadworm, Strongyloides stercoralis, is a most neglected worm infection transmitted through infective larvae on the soil. Threadworms occur worldwide and particularly in tropical climates. It may cause long-lasting and potentially fatal infections due to its ability to replicate within its host. This study aimed to assess the risk of threadworm infection in at the national level in Cambodia.\n\nWe conducted a nation-wide community-based parasitological survey among the population aged 6 years and above. The threadworm was diagnosed using a serological diagnostic test detecting antigens in urine. Data on demography, hygiene and knowledge about helminth infection were collected. The threadworm infection risk was calculated by using geostatistical models to predict its geographical distribution in Cambodia. About one third (30.5%) of the enrolled study participants (n=7,246) were infected with threadworms. The lowest and hightest infection rates a province level was 10.9% and 48.2%, respectively. Prevalence rates below 20% were found only in five south-eastern provinces. The risk of an infection with threadworms increased with age in men and women. Open defecation was associated with higher risk of infection while declaring having some knowledge about health problems caused by worms was protective. Furthermore, the threadworm infection risk was positively associated with environmental factors such as night maximum temperature, minimum rainfall, and distance to water, and negatively associated with land occupied by rice fields.\n\nThreadworm infection is highly prevalent in Cambodia and adequate control measures are warranted, including access to treatment, in order to address the burden of this NTD in Cambodia.

epidemiology↗

bioRxiv2018

Association between chronic hepatitis C virus infection and myocardial infarction in people living with HIV in the United States

Hepatitis C virus (HCV) is common among people living with HIV (PLWH). The potential for extrahepatic manifestations of HCV, including myocardial infarction (MI), is a topic of active research. MI is classified into types, predominantly atheroembolic Type 1 MI (T1MI) and supply-demand mismatch Type 2 MI (T2MI). We examined the association between HCV and MI in the CFAR Network of Integrated Clinical Systems (CNICS), a multi-center clinical cohort of PLWH. MIs were centrally adjudicated and categorized by type using the Universal MI definition. We estimated the association between chronic HCV (RNA+) and time to MI adjusting for demographic characteristics, cardiovascular risk factors, clinical characteristics and substance use. Among 24,755 PLWH aged [≥]18, there were 336 T1MI and 330 T2MI during a median of 4.2 years of follow-up. HCV was associated with a 68% greater risk of T2MI (adjusted hazard ratio (aHR) 1.68, 95% CI: 1.22, 2.30) but not T1MI (aHR 0.96, 95% CI: 0.63, 1.45). In a cause-specific analysis of T2MI, HCV was associated with a 2-fold greater risk of T2MI attributed to sepsis (aHR 2.26, 95% CI: 1.34, 3.81). Extrahepatic manifestations of HCV in this high-risk population are an important area for continued research.

epidemiology↗

bioRxiv2018

The Maudsley Environmental Risk Score for Psychosis

Risk prediction algorithms have long been used in health research and practice (e.g., in prediction of cardiovascular disease, diabetes, etc.) However, similar tools have not been developed for mental health problems, despite extensive research on risk factors. For example, for psychotic disorders, attempts to sum environmental risk are rare, usually unsystematic and dictated by available data. In light of this, we sought to develop a valid, easy to use measure of the total environmental risk for psychotic disorders, which can be used in research and clinical practice.\n\nWe first reviewed the literature to identify well-replicated and validated environmental risk factors for psychosis and, then, used the largest available meta-analyses to derive current best estimates of risk. We devised a method of scoring individuals based on the level of exposure to each risk factor, using odds ratios from the meta-analyses, to produce an Environmental Risk Score (ERS).\n\nSix risk factors (ethnic minority status, urbanicity, high paternal age, obstetric complications, cannabis use, and childhood adversity) were used to generate the ERS. A distribution for different levels of risk based on permuted data showed that most of population would be at low/moderate risk with a small minority at increased environmental risk for psychosis.\n\nThis is the first systematic approach to develop an aggregate measure of environmental risk for psychoses. This can be used as a continuous measure of liability to disease or transformed to a relative risk. Its predictive ability will improve with the collection of additional, population specific data.

epidemiology↗