Wild-Type Transthyretin Cardiac Amyloidosis is Not Rare in Elderly Subjects: the CATCH Screening Study

BACKGROUND

Wild-type transthyretin cardiac amyloidosis (ATTRwt-CA) affects older adults and is currently considered as a rare disorder.

OBJECTIVE

We investigated for the first time the prevalence of ATTRwt-CA in elderly individuals from the general population.

METHODS

General practitioners from Pisa, Italy, proposed a screening for ATTRwt-CA to all their patients aged 65-90 years, until 1,000 accepted. The following red flags were searched: interventricular septal thickness ≥12 mm, any echocardiographic, ECG or clinical hallmark of CA, or high sensitivity-troponin T ≥14 ng/L. Individuals with at least one red flag (n=346) were asked to undergo the search for a monoclonal protein and bone scintigraphy, and 216 accepted.

RESULTS

Four patients received a non-invasive diagnosis of ATTRwt-CA. All complained of dyspnea on moderate effort. A woman and a man aged 79 and 85 years, respectively, showed an intense cardiac tracer uptake (grade 3), left ventricular (LV) wall thickening, grade 2 to 3 diastolic dysfunction, and N-terminal pro-B-type natriuretic peptide (NT-proBNP) >1,000 ng/L. Two other patients (a man aged 74 years and a woman aged 83 years) showed a grade 2 uptake, an increased LV septal thickness, but preserved diastolic function, and NT-proBNP <300 ng/L. The prevalence of ATTR-CA in subjects ≥65 years was calculated as 0.46% (i.e., 4 out of the 870 subjects completing the screening, namely 654 not meeting the criteria for Step 2 and 216 progressing to Step 2).

CONCLUSIONS

ATTRwt-CA is uncommon in elderly subjects from the general population, but more frequent than expected for a rare disease.

Ocular findings in a population of geriatric equids in the United Kingdom

BACKGROUND

There are a growing number of horses, ponies, and donkeys aged 15 years or older in the United Kingdom, yet there have been no studies utilising a complete ophthalmic examination to investigate the prevalence of ophthalmic pathology within this population.

OBJECTIVES

To investigate the prevalence of ophthalmic pathology and associations with signalment, in a convenience sample of geriatric equids in the United Kingdom.

STUDY DESIGN

Cross sectional.

METHODS

Horses, ponies, and donkeys aged 15 years or older based at The Horse Trust charity underwent a full ophthalmic examination including slit lamp biomicroscopy and indirect ophthalmoscopy. Relationships between signalment and pathology were assessed using Fisher's exact and Mann-Witney U tests.

RESULTS

Fifty animals were examined ranging from 15 to 33 years (median 24, interquartile range [IQR] 21, 27). The prevalence of ocular pathology was 84.0% (95% confidence interval [CI] 73.8, 94.2%; n = 42). Four animals (8.0%) had adnexal pathology, while 37 (74.0%) and 22 (44.0%) had at least one form of anterior or posterior segment pathology, respectively. Of those with anterior segment pathology, 26 animals (52.0%) had cataract in at least one eye, with the most common location being anterior cortical (65.0% of those animals with cataract). Animals with posterior segment pathology included 21 animals (42.0%) with fundic pathology, with senile retinopathy being the most common (42.9% of all animals with fundic pathology). Despite the high prevalence of ocular pathology, all eyes examined remained visual. The most common breeds were Irish Draught (24.0%, n = 12), Shetland (18.0%, n = 9) and Thoroughbred (10%, n = 5); the majority were geldings (74.0%, n = 37). There was a statistically significant relationship between the presence of anterior segment pathology and breed (p = 0.006), with all Cobs and Shetlands examined having anterior segment pathology. The presence of posterior segment pathology and senile retinopathy were associated with older median age (posterior segment pathology: 26.0 years [interquartile range {IQR} 24.0, 30.0 years] vs. 23.5 years [IRQ 19.5, 26.5 years], p = 0.03; senile retinopathy: 27.0 years [IQR 26.0, 30 years] vs. 24.0 years [IQR 20.0, 27.0], p = 0.04). None of the pathologies investigated were more prone to affect one versus both eyes (p > 0.05; 71.4% of ocular pathologies were bilateral while 28.6% were unilateral).

MAIN LIMITATIONS

Data were obtained from a relatively small sample size of a single cohort of animals that lacked a control group.

CONCLUSIONS

There was a high prevalence and wide range of ocular lesions in this subset of geriatric equids.

Evaluation of Respondent-Driven Sampling Prevalence Estimators Using Real-World Reported Network Degree

Respondent-driven sampling (RDS) is used to measure trait or disease prevalence in populations that are difficult to reach and often marginalized. The authors evaluated the performance of RDS estimators under varying conditions of trait prevalence, homophily, and relative activity. They used large simulated networks (N = 20,000) derived from real-world RDS degree reports and an empirical Facebook network (N = 22,470) to evaluate estimators of binary and categorical trait prevalence. Variability in prevalence estimates is higher when network degree is drawn from real-world samples than from the commonly assumed Poisson distribution, resulting in lower coverage rates. Newer estimators perform well when the sample is a substantive proportion of the population, but bias is present when the population size is unknown. The choice of preferred RDS estimator needs to be study specific, considering both statistical properties and knowledge of the population under study.

Host genetic identity determines parasite community structure across time and space in oyster restoration

Intraspecific variation in host susceptibility to individual parasite species is common, yet how these effects scale to mediate the structure of diverse parasite communities in nature is less well understood. To address this knowledge gap, we tested how host genetic identity affects parasite communities on restored reefs seeded with juvenile oysters from different sources-a regional commercial hatchery or one of two wild progenitor lines. We assessed prevalence and intensity of three micro- and two macroparasite species for 4 years following restoration. Despite the spatial proximity of restored reefs, oyster source identity strongly predicted parasite community prevalence across all years, with sources varying in their relative susceptibility to different parasites. Oyster seed source also predicted reef-level parasite intensities across space and through time. Our results highlight that host intraspecific variation can shape parasite community structure in natural systems, and reinforce the importance of considering source identity and diversity in restoration design.

Geographic accessibility to public and private health facilities in Kenya in 2021: An updated geocoded inventory and spatial analysis

Objectives

To achieve universal health coverage, adequate geographic access to quality healthcare services is vital and should be characterized periodically to support planning. However, in Kenya, previous assessments of geographic accessibility have relied on public health facility lists only, assembled several years ago. Here, for the first time we assemble a geocoded list of public and private health facilities in 2021 and make use of this updated list to interrogate geographical accessibility to all health providers.

Methods

Existing health provider lists in Kenya were accessed, merged, cleaned, harmonized, and assigned a unique geospatial location. The resultant master list was combined with road network, land use, topography, travel barriers and healthcare-seeking behavior within a geospatial framework to estimate travel time to the nearest (i) private, (ii) public, and (iii) both (public and private-PP) health facilities through a travel scenario involving walking, bicycling and motorized transport. The proportion of the population within 1 h and outside 2-h was computed at 300 × 300 spatial resolution and aggregated at subnational units used for decision-making. Areas with a high disease prevalence for common infections that were outside 1-h catchment (dual burden) were also identified to guide prioritization.

Results

The combined database contained 13,579 health facilities, both in the public (55.5%) and private-for-profit sector (44.5%) in 2021. The private health facilities' distribution was skewed toward the urban counties. Nationally, average travel time to the nearest health facility was 130, 254, and 128 min while the population within 1-h was 89.4, 80.5, and 89.6% for the public, private and PP health facility, respectively. The population outside 2-h were 6% for public and PP and 11% for the private sector. Mean travel time across counties was heterogeneous, while the population within 1-h ranged between 38 and 100% in both the public sector and PP. Counties in northwest and southeast Kenya had a dual burden.

Conclusion

Continuous updating and geocoding of health facilities will facilitate an improved understanding of healthcare gaps for planning. Heterogeneities in geographical access continue to persist, with some areas having a dual burden and should be prioritized toward reducing health inequities and attaining universal health coverage.

Comprehensive analysis of ADA2 genetic variants and estimation of carrier frequency driven by a function-based approach

BACKGROUND

Deficiency of adenosine deaminase 2 (DADA2) is an autoinflammatory disease caused by deleterious ADA2 variants. The frequency of these variants in the general population, and hence the expected disease prevalence, remain unknown.

OBJECTIVE

We aimed to characterize the functional impact and carrier frequency of ADA2 variants.

METHODS

We performed functional studies and in silico analysis on 163 ADA2 variants, including DADA2-associated variants and population variants identified in the Genome Aggregation Database. We estimated the carrier rate using the aggregate frequency of deleterious variants.

RESULTS

Functional studies of ADA2 variants revealed that 77 (91%) of 85 of DADA2-associated variants reduced ADA2 enzymatic function by >75%. Analysis of 100 ADA2 variants in the database showed a full spectrum of impact on ADA2 function, rather than a dichotomy of benign versus deleterious variants. We found several in silico algorithms that effectively predicted the impact of ADA2 variants with high sensitivity and specificity, and confirmed a correlation between the residual function of ADA2 variants in vitro and the plasma ADA2 activity of individuals carrying these variants (n = 45; r = 0.649; P < .0001). Using <25% residual enzymatic activity as the cutoff to define potential pathogenicity, integration of our results with the database population data revealed an estimated carrier frequency of at least 1 in 236 individuals, corresponding to an expected DADA2 disease prevalence of ~1 in 222,000 individuals.

CONCLUSIONS

Functional annotation guides the interpretation of ADA2 variants to create a framework that enables estimation of DADA2 carrier frequency and disease prevalence.

Detection of two dissimilar chronic wasting disease isolates in two captive Rocky Mountain elk (Cervus canadensis) herds

Chronic wasting disease (CWD) continues to spread in both wild and captive cervid herds in North America and has now been identified in wild reindeer and moose in Norway, Finland and Sweden. There is limited knowledge about the variety and characteristics of isolates or strains of CWD that exist in the landscape and their implications on wild and captive cervid herds. In this study, we evaluated brain samples from two captive elk herds that had differing prevalence, history and timelines of CWD incidence. Site 1 had a 16-year history of CWD with a consistently low prevalence between 5% and 10%. Twelve of fourteen naïve animals placed on the site remained CWD negative after 5 years of residence. Site 2 herd had a nearly 40-year known history of CWD with long-term environmental accrual of prion leading to nearly 100% of naïve animals developing clinical CWD within two to 12 years. Obex samples of several elk from each site were compared for CWD prion strain deposition, genotype in prion protein gene codon 132, and conformational stability of CWD prions. CWD prions in the obex from site 2 had a lower conformational stability than those from site 1, which was independent of prnp genotype at codon 132. These findings suggest the existence of different CWD isolates between the two sites and suggest potential differential disease attack rates for different CWD strains.

Assessing Prevalence and Carrier Frequency of Succinic Semialdehyde Dehydrogenase Deficiency

Pathogenic variants in ALDH5A1 cause succinic semialdehyde dehydrogenase (SSADH) deficiency, with >180 cases reported worldwide. However, a nonspecific neurologic presentation and inconsistent variant nomenclature have limited diagnoses. In this study, pathogenic variants in ALDH5A1 were curated and variant prevalence assessed in the Genome Aggregation Database (gnomAD) to determine a minimum carrier frequency and to estimate disease prevalence. Stringent population variant analysis, including 98 reported disease-associated ALDH5A1 variants, indicates a pan-ethnic carrier frequency of ∼1/340, supporting a prevalence of SSADH deficiency of ∼1/460 000 worldwide, with highest carrier frequencies observed in East Asian and South Asian populations. Because heterozygous loss of function alleles are rare in gnomAD and >60% of reported disease-causing variants were missense changes that were not present in gnomAD, the pan-ethnic carrier frequency for SSADH deficiency is likely not fully represented in this study. Additional analyses to investigate the potential impact of more common ALDH5A1 variants with reduced but not deficient enzyme activity, including analysis in diverse populations, are needed to fully assess the prevalence of this ultra-rare disease.

Understanding the Patterns of Serological Testing for COVID-19 Pre- and Post-Vaccination Rollout in Michigan

Testing for SARS-CoV-2 antibodies is commonly used to determine prior COVID-19 infections and to gauge levels of infection- or vaccine-induced immunity. Michigan Medicine, a primary regional health center, provided an ideal setting to understand serologic testing patterns over time. Between 27 April 2020 and 3 May 2021, characteristics for 10,416 individuals presenting for SARS-CoV-2 antibody tests (10,932 tests in total) were collected. Relative to the COVID-19 vaccine roll-out date, 14 December 2020, the data were split into a pre- (8026 individuals) and post-vaccine launch (2587 individuals) period and contrasted with untested individuals to identify factors associated with tested individuals and seropositivity. Exploratory analysis of vaccine-mediated seropositivity was performed in 347 fully vaccinated individuals. Predictors of tested individuals included age, sex, smoking, neighborhood variables, and pre-existing conditions. Seropositivity in the pre-vaccine launch period was 9.2% and increased to 46.7% in the post-vaccine launch period. In the pre-vaccine launch period, seropositivity was significantly associated with age (10 year; OR = 0.80 (0.73, 0.89)), ever-smoker status (0.49 (0.35, 0.67)), respiratory disease (4.38 (3.13, 6.12)), circulatory disease (2.09 (1.48, 2.96)), liver disease (2.06 (1.11, 3.84)), non-Hispanic Black race/ethnicity (2.18 (1.33, 3.58)), and population density (1.10 (1.03, 1.18)). Except for the latter two, these associations remained statistically significant in the post-vaccine launch period. The positivity rate of fully vaccinated individual was 296/347(85.3% (81.0%, 88.8%)).

[Prevalence of health problems in midlife Swiss warm-blooded horses]

INTRODUCTION

The breeding of a healthy horse is the basic requirement for optimal performance. This is also specifically stated in the breeding goal of the Swiss warmblood horse and should be achieved through a strict selection of the stallions. The aim of this retrospective study was to assess the current state of the population to optimize breeding. Data on the health status of Swiss warmblood horses in the age between 6 and 16 years (midlife) were collected by a telephone survey and analyzed descriptively. Following the heritability of the most common health problems were estimated. Data on 1,861 horses were collected between 2016 and 2018. Lameness (34%), colic (22%), sarcoids (19%), and pastern dermatitis (16%) were among the most common health problems, followed by back problems (13%), cough (10%), urticaria (10%), free fecal water syndrome (9%), nasal discharge (8%) and sweet itch (4%). Lameness was observed in 49% of the cases in the forelimbs, in 25% in the hindlimbs and in 26% in both. 27% of horses with colic have been hospitalized once and 8% have undergone colic surgery. Sarcoids became fewer or smaller in 89% of the treated and in 58% of the untreated horses. A significant relationship between treatment and the status of the sarcoids was demonstrated (p .

Sex Proportionality in Pre-clinical and Clinical Trials: An Evaluation of 22 Marketing Authorization Application Dossiers Submitted to the European Medicines Agency

This study assessed to what extent women were included in all phases of drug development; whether the clinical studies in the marketing authorization application dossiers include information per sex; and explored whether there are differences between women and men in the drugs' efficacy and safety. Data were extracted from dossiers submitted to the European Medicines Agency. Twenty-two dossiers of drugs approved between 2011 and 2015 for the treatment of various diseases were included. Female animals were included in only 9% of the pharmacodynamics studies, but female and male animals were included in all toxicology studies. Although fewer women than men were included in the clinical studies used to evaluate pharmacokinetics (PK) (29 to 40% women), all dossiers contained sex-specific PK parameter estimations. In the phase III trials, inclusion of women was proportional to disease prevalence for depression, epilepsy, thrombosis, and diabetes [participation to prevalence ratio (PPR) range: 0.91–1.04], but women were considered underrepresented for schizophrenia, hepatitis C, hypercholesterolemia, HIV, and heart failure (PPR range: 0.49-0.74). All dossiers contained sex-specific subgroup analyses of efficacy and safety. There seemed to be higher efficacy for women in one dossier and a trend toward lower efficacy in another dossier. More women had adverse events in both treatment (73.0 vs. 70.6%, p < 0.001) and placebo groups (69.5 vs. 65.5%, p < 0.001). In conclusion, women were included throughout all phases of clinical drug research, and sex-specific information was available in the evaluated dossiers. The included number of women was, however, not always proportional to disease prevalence rates.

%svy_freqs: A Generic SAS Macro for Creating Publication-Quality Three-Way Cross-Tabulations

Cross-tabulations are a simple but important tool for understanding the distribution of socio-demographic characteristics among participants in epidemiological studies. We developed a generic SAS macro, %svy_freqs, to create publication-quality tables from cross-tabulations between a factor and a by-group variable given a third variable using survey or non-survey data. The macro also performs two-way cross-tabulations and provides extra features not available in existing procedures such as ability to incorporate parameters for survey design and replication-based variance estimation methods, performing validation checks for input parameters, transparently formatting variable values from character into numeric and allowing for generalizability. We demonstrate the macro using the 2013-2014 National Health and Nutrition Examination Survey (NHANES), a complex survey designed to assess the health and nutritional status of adults and children in the United States.

Assessing the Impact of the COVID-19 Pandemic in Spain: Large-Scale, Online, Self-Reported Population Survey

BACKGROUND

Spain has been one of the countries most impacted by the COVID-19 pandemic. Since the first confirmed case was reported on January 31, 2020, there have been over 405,000 cases and 28,000 deaths in Spain. The economic and social impact is without precedent. Thus, it is important to quickly assess the situation and perception of the population. Large-scale online surveys have been shown to be an effective tool for this purpose.

OBJECTIVE

We aim to assess the situation and perception of the Spanish population in four key areas related to the COVID-19 pandemic: social contact behavior during confinement, personal economic impact, labor situation, and health status.

METHODS

We obtained a large sample using an online survey with 24 questions related to COVID-19 in the week of March 28-April 2, 2020, during the peak of the first wave of COVID-19 in Spain. The self-selection online survey method of nonprobability sampling was used to recruit 156,614 participants via social media posts that targeted the general adult population (age >18 years). Given such a large sample, the 95% CI was ±0.843 for all reported proportions.

RESULTS

Regarding social behavior during confinement, participants mainly left their homes to satisfy basic needs. We found several statistically significant differences in social behavior across genders and age groups. The population's willingness to comply with the confinement measures is evident. From the survey answers, we identified a significant adverse economic impact of the pandemic on those working in small businesses and a negative correlation between economic damage and willingness to stay in confinement. The survey revealed that close contacts play an important role in the transmission of the disease, and 28% of the participants lacked the necessary resources to properly isolate themselves. We also identified a significant lack of testing, with only 1% of the population tested and 6% of respondents unable to be tested despite their doctor's recommendation. We developed a generalized linear model to identify the variables that were correlated with a positive SARS-CoV-2 test result. Using this model, we estimated an average of 5% for SARS-CoV-2 prevalence in the Spanish population during the time of the study. A seroprevalence study carried out later by the Spanish Ministry of Health reported a similar level of disease prevalence (5%).

CONCLUSIONS

Large-scale online population surveys, distributed via social media and online messaging platforms, can be an effective, cheap, and fast tool to assess the impact and prevalence of an infectious disease in the context of a pandemic, particularly when there is a scarcity of official data and limited testing capacity.

Prevalence of osteoporosis and osteopenia diagnosed using quantitative CT in 296 consecutive lumbar fusion patients

OBJECTIVE

Osteoporosis is a metabolic bone disease that increases the risk for fragility fractures. Screening and diagnosis can be achieved by measuring bone mineral density (BMD) using quantitative CT tomography (QCT) in the lumbar spine. QCT-derived BMD measurements can be used to diagnose osteopenia or osteoporosis based on American College of Radiology (ACR) thresholds. Many reports exist regarding the disease prevalence in asymptomatic and disease-specific populations; however, osteoporosis/osteopenia prevalence rates in lumbar spine fusion patients without fracture have not been reported. The purpose of this study was to define osteoporosis and osteopenia prevalence in lumbar fusion patients using QCT.

METHODS

A retrospective review of prospective data was performed. All patients undergoing lumbar fusion surgery who had preoperative fine-cut CT scans were eligible. QCT-derived BMD measurements were performed at L1 and L2. The L1-2 average BMD was used to classify patients as having normal findings, osteopenia, or osteoporosis based on ACR criteria. Disease prevalence was calculated. Subgroup analyses based on age, sex, ethnicity, and history of abnormal BMD were performed. Differences between categorical groups were calculated with Fisher's exact test.

RESULTS

Overall, 296 consecutive patients (55.4% female) were studied. The mean age was 63 years (range 21-89 years). There were 248 (83.8%) patients with ages ≥ 50 years. No previous clinical history of abnormal BMD was seen in 212 (71.6%) patients. Osteopenia was present in 129 (43.6%) patients and osteoporosis in 44 (14.9%). There were no prevalence differences between sex or race. Patients ≥ 50 years of age had a significantly higher frequency of osteopenia/osteoporosis than those who were < 50 years of age.

CONCLUSIONS

In 296 consecutive patients undergoing lumbar fusion surgery, the prevalence of osteoporosis was 14.9% and that for osteopenia was 43.6% diagnosed by QCT. This is the first report of osteoporosis disease prevalence in lumbar fusion patients without vertebral fragility fractures diagnosed by QCT.

Familial Hypocalciuric Hypercalcemia Type 1 and Autosomal-Dominant Hypocalcemia Type 1: Prevalence in a Large Healthcare Population

The calcium-sensing receptor (CaSR) regulates serum calcium concentrations. CASR loss- or gain-of-function mutations cause familial hypocalciuric hypercalcemia type 1 (FHH1) or autosomal-dominant hypocalcemia type 1 (ADH1), respectively, but the population prevalence of FHH1 or ADH1 is unknown. Rare CASR variants were identified in whole-exome sequences from 51,289 de-identified individuals in the DiscovEHR cohort derived from a single US healthcare system. We integrated bioinformatics pathogenicity triage, mean serum Ca concentrations, and mode of inheritance to identify potential FHH1 or ADH1 variants, and we used a Sequence Kernel Association Test (SKAT) to identify rare variant-associated diseases. We identified predicted heterozygous loss-of-function CASR variants (6 different nonsense/frameshift variants and 12 different missense variants) in 38 unrelated individuals, 21 of whom were hypercalcemic. Missense CASR variants were identified in two unrelated hypocalcemic individuals. Functional studies showed that all hypercalcemia-associated missense variants impaired heterologous expression, plasma membrane targeting, and/or signaling, whereas hypocalcemia-associated missense variants increased expression, plasma membrane targeting, and/or signaling. Thus, 38 individuals with a genetic diagnosis of FHH1 and two individuals with a genetic diagnosis of ADH1 were identified in the 51,289 cohort, giving a prevalence in this population of 74.1 per 100,000 for FHH1 and 3.9 per 100,000 for ADH1. SKAT combining all nonsense, frameshift, and missense loss-of-function variants revealed associations with cardiovascular, neurological, and other diseases. In conclusion, FHH1 is a common cause of hypercalcemia, with prevalence similar to that of primary hyperparathyroidism, and is associated with altered disease risks, whereas ADH1 is a major cause of non-surgical hypoparathyroidism.

Identifying obesity-related multimorbidity combinations in the United States

Interest in understanding the effects of multimorbidity on outcomes has increased in recent years. This paper presents the most common obesity-related groupings of multimorbidity in the United States. Using Cerner HealthFacts data, we applied the frequent pattern growth algorithm to identify prevalent multimorbidity groupings of 3 or more diseases (one being obesity) by race using a dataset of 574 172 patients with obesity from all over the United States. We set the minimum prevalence to 10% and identified groupings of ICD10-CM diagnoses that occur in our dataset at or above the minimum prevalence level. We provide binomial proportion confidence interval estimates to demonstrate the validity of the proportions. We performed g-test for independence to validate differences in prevalence by race. We found 18 multimorbidity combinations with prevalence higher than or equal to 10%. Our results indicate that there are multiple common multimorbidities groupings for patients with obesity. Each multimorbidity combination is composed of diseases from the following clinical categories: endocrine, nutritional and metabolic diseases; diseases of the circulatory system; diseases of the digestive system; diseases of the nervous system; and diseases of the musculoskeletal system and connective tissue. For each multimorbidity pattern, the prevalence was found to be significantly different by race according to the g-test with P-value < .001. Most frequent patterns include essential hypertension or disorder of lipid metabolism. This study identifies common groupings of multimorbidity. We believe our data can be useful for those developing integrated care plans, particularly for those serving diverse communities.

Variation in Tolerance to Parasites Affects Vectorial Capacity of Natural Asian Tiger Mosquito Populations

Globally, diseases transmitted by arthropod vectors, such as mosquitoes, remain a major cause of morbidity and mortality [1]. The defense responses of mosquito and other arthropod vectors against parasites are important for understanding disease transmission dynamics and for the development of novel disease-control strategies. Consequently, the mechanisms by which mosquitoes resist parasitic infection (e.g., immune-mediated killing) have long been studied [2, 3]. However, the ability of mosquitoes to ameliorate the negative fitness consequences of infection through tolerance mechanisms (e.g., tissue repair) has been virtually ignored (but see [4, 5]). Ignoring parasite tolerance is especially taxing in vector biology because unlike resistance, which typically reduces vectorial capacity, tolerance is expected to increase vectorial capacity by reducing parasite-mediated mortality without killing parasites [6], contributing to the recurrent emergence of vector-borne diseases and its stabilization and exacerbation. Despite its importance, there is currently no evidence for the evolution of tolerance in natural mosquito populations. Here, we use a common-garden experimental framework to measure variation in resistance and tolerance to dog heartworm (Dirofilaria immitis) between eight natural Aedes albopictus mosquito populations representing areas of low and high transmission intensity. We find significant inter-population variation in tolerance and elevated tolerance where transmission intensity is high. Additionally, as expected, we find that increased tolerance is associated with higher vectorial capacity. Consequently, our results indicate that high transmission intensity can lead to the evolution of more competent disease vectors, which can feed back to impact disease risk.

Industrial bees: The impact of apicultural intensification on local disease prevalence

It is generally thought that the intensification of farming will result in higher disease prevalences, although there is little specific modelling testing this idea. Focussing on honeybees, we build multi-colony models to inform how "apicultural intensification" is predicted to impact honeybee pathogen epidemiology at the apiary scale.We used both agent-based and analytical models to show that three linked aspects of apicultural intensification (increased population sizes, changes in population network structure and increased between-colony transmission) are unlikely to greatly increase disease prevalence in apiaries. Principally this is because even low-intensity apiculture exhibits high disease prevalence.The greatest impacts of apicultural intensification are found for diseases with relatively low R0 (basic reproduction number), however, such diseases cause little overall disease prevalence and, therefore, the impacts of intensification are minor. Furthermore, the smallest impacts of intensification are for diseases with high R0 values, which we argue are typical of important honeybee diseases. Policy Implications: Our findings contradict the idea that apicultural intensification by crowding honeybee colonies in large, dense apiaries leads to notably higher disease prevalences for established honeybee pathogens. More broadly, our work demonstrates the need for informative models of all agricultural systems and management practices in order to understand the implications of management changes on diseases.

Captive Psittacine Birds in Ontario, Canada: a 19-Year Retrospective Study of the Causes of Morbidity and Mortality

Psittacines (e.g. parrots, macaws and cockatoos) are common companion animals that are also kept in zoos and private breeding collections. Despite this popularity, long-term, comprehensive studies of diagnostic data from captive psittacines are rare. This study was conducted to assess trends in disease prevalence and to describe causes of morbidity and mortality in psittacines submitted for post-mortem examination to the veterinary hospital and diagnostic laboratory at the University of Guelph, Ontario, Canada. Post-mortem reports of 1,850 psittacines from 1998 to 2017 were assessed and included 110 species from 45 genera. Birds were often diagnosed with infectious disease processes (n = 823; 44.5%), including viral (n = 428; 23.1%), bacterial (n = 284; 15.4%) and fungal (n = 161; 8.7%). Non-infectious disease processes (n = 1,076; 58.2%) were most commonly degenerative (n = 465; 25.1%), metabolic (n = 392; 21.2%) or haemodynamic (n = 270; 14.6%). Exploratory statistical analyses, used to guide further research, revealed significant correlations and associations among disease processes and genera, age categories and sex. This 19-year retrospective study is the first to be conducted in Canada for psittacine birds and provides a broad overview of disease prevalence that can be used as a baseline to inform other studies addressing common and uncommon diseases affecting these birds in the future.

Consortium of Plant Growth-Promoting Rhizobacteria Strains Suppresses Sweet Pepper Disease by Altering the Rhizosphere Microbiota

Beneficial microorganisms have been extensively used to make plants more resistant to abiotic and biotic stress. We previously identified a consortium of three plant growth-promoting rhizobacteria (PGPR) strains (Bacillus cereus AR156, Bacillus subtilis SM21, and Serratia sp. XY21; hereafter “BBS”) as a promising and environmentally friendly biocontrol agent. In this study, the effect of BBS on a soil-borne disease of sweet pepper was evaluated. Application of BBS significantly reduced the prevalence of phytophthora blight and improved fruit quality and soil properties relative to the control. BBS was able to alter the soil bacterial community: it significantly increased the abundances of Burkholderia, Comamonas, and Ramlibacter, which were negatively associated with disease severity, relative to the control. A redundancy analysis suggested that BBS-treated soil samples were dominated by Burkholderia, Comamonas, Ramlibacter, Sporichthya, Achromobacter, and Pontibacter; abundance of these genera was related to total organic carbon (TOC), total nitrogen (TN), ammonium nitrogen (AN), total potassium (TP), and available phosphorus (AP) contents. This suggests that BBS treatment shifted the microbe community to one that suppressed soil-borne disease and improved the soil chemical properties.

Estimating prevalence for limb-girdle muscular dystrophy based on public sequencing databases

PURPOSE

Limb-girdle muscular dystrophies (LGMD) are a genetically heterogeneous category of autosomal inherited muscle diseases. Many genes causing LGMD have been identified, and clinical trials are beginning for treatment of some genetic subtypes. However, even with the gene-level mechanisms known, it is still difficult to get a robust and generalizable prevalence estimation for each subtype due to the limited amount of epidemiology data and the low incidence of LGMDs.

METHODS

Taking advantage of recently published exome and genome sequencing data from the general population, we used a Bayesian method to develop a robust disease prevalence estimator.

RESULTS

This method was applied to nine recessive LGMD subtypes. The estimated disease prevalence calculated by this method was largely comparable with published estimates from epidemiological studies; however, it highlighted instances of possible underdiagnosis for LGMD2B and 2L.

CONCLUSION

The increasing size of aggregated population variant databases will allow for robust and reproducible prevalence estimates of recessive disease, which is critical for the strategic design and prioritization of clinical trials.

Estimating the Real-World Cost of Diabetes Mellitus in the United States During an 8-Year Period Using 2 Cost Methodologies

BACKGROUND

Diabetes is associated with substantial clinical and economic burdens on patients and on the US healthcare system. Treatment options for patients with type 1 or type 2 diabetes have increased significantly, from only 3 drug classes in 1995 to more than 12 distinct classes today. Although several of the newer treatments are reported to have improved efficacy and safety profiles, they are often substantially more costly than older medications. Consequently, as drug options increase, the cost of diabetes management continues to grow.

OBJECTIVES

To estimate the annual real-world costs of type 1 and 2 diabetes, as well as diabetes prevalence, treatment patterns, care quality, and resource utilization during 8 years.

METHODS

In this cross-sectional study, we examined 8 annual cohorts of patients with type 1 or type 2 diabetes, on a biennial basis, using claims data from the HealthCore Integrated Research Database between 2006 and 2014. Patients were matched with controls by age, sex, residency, and health plan type. We assessed the prevalence of diabetes, treatment patterns, care quality measures, and all-cause and diabetes-related healthcare costs using 2 methods. Method 1 calculated the annual costs as the difference in all-cause costs between patients with diabetes and matched controls. Method 2 calculated the costs for healthcare encounters based on specific codes for a diabetes diagnosis or for antidiabetes medications.

RESULTS

Between 346,486 and 410,234 patients with type 2 diabetes and between 21,176 and 26,228 patients with type 1 diabetes were included in each study year cohort. Between 2007 and 2014, the prevalence of type 2 diabetes increased from 4.9% to 6.3%. The costs associated with using Method 1 were almost double the cost estimates in Method 2 during most of the study period. For patients with type 1 diabetes, the associated costs were twice greater with Method 1 than with Method 2. Projections to the entire US population in 2014 indicated a total of 19.3 million individuals with diabetes and associated direct costs of $314.8 billion that year.

CONCLUSION

Cost estimates can guide the prioritization of healthcare expenditures. The results of this study showed that costs attributable to diabetes differed by approximately 2-fold, depending on the estimation method. The management of the escalating expenses for diabetes management in the United States requires judicious selection of the methods for estimating costs.

Prevalence of owner-reported ocular problems and veterinary ocular findings in a population of horses aged ≥15 years

BACKGROUND

Previous studies suggest that ocular disease is common among aged horses but owners may fail to identify or underestimate their clinical relevance.

OBJECTIVES

To document the prevalence of owner-reported ocular disease in horses aged ≥15 years. In a subset of these horses, to document ophthalmic findings from veterinary examination and compare with owner-reported ocular disease, and to determine risk factors for veterinary ophthalmic findings.

STUDY DESIGN

Cross-sectional study.

METHODS

Owners of aged horses completed a survey on management, clinical signs and medical history. Risk factors for the presence of ocular disease as reported by the owner were determined. A subset of these horses underwent an ophthalmological examination. Risk factors for the presence of ocular disease detected during this examination were determined. Agreement between owner-reported data and veterinary ophthalmic findings was assessed.

RESULTS

Abnormal ocular findings were detected in 287/327 horses aged ≥15 years that underwent a complete ophthalmic examination, whereas the presence of ocular disease as reported by the horse-owners was only 3.3%. Agreement between owner-reported ocular disease and results of the veterinary examination was low for all categories analysed. An owner-reported history of ocular discharge was associated with increased odds of veterinary-reported diminished vision. Increasing age was associated with increased odds of the presence of an eye abnormality (any) and cataracts. Appaloosa horses had increased odds of cataract compared with other breeds. Horses in work were less likely to have an eye abnormality.

MAIN LIMITATIONS

Volunteer bias may have influenced our results with owners of sick horses or those more concerned about their horses more likely to volunteer at the initial recruitment phase.

CONCLUSIONS

This study showed a high prevalence of ocular lesions in aged horses which was not reflected in owner-reported disease. This has highlighted problems in obtaining information on ocular conditions from horse-owners.

Gender differences in clinical registration trials: is there a real problem?

AIMS

Several studies have reported the under-representation of women in clinical trials, thereby challenging the external validity of the benefit/risk assessments of launched drugs. Our aim was to determine the extent to which women have been included in clinical trials used for drug registration and to analyse the fraction of women participating in phases I, II and III.

METHODS

We conducted cross-sectional, structured research into publicly available registration dossiers of Food and Drug Administration (FDA)-approved drugs that are prescribed frequently. Furthermore, we analysed compounds with high hepatic clearance and a known gender-related difference in drug response. In a sensitivity analysis, we compared figures with US disease prevalence data.

RESULTS

For 38 of the initial 137 drugs (28%), sufficient data were reported and publicly available. For these drugs, 185 479 trial participants were included, of whom 47% were female and 44% were male; gender was not reported for 9% of participants. However, the number of female participants varied with the phase of the trial, with 22% females in phase I trials vs. 48% and 49%, respectively, in phase II and III trials. When compared with US disease prevalence data, 10 drugs (26%) had a greater than 20% difference between the proportion of females affected with the disease compared with representation in clinical trials.

CONCLUSIONS

From these publicly available data, there was no evidence of any systematic under-representation of women in clinical trials.

Time Trends in the Prevalence of Neurocognitive Disorders and Cognitive Impairment in the United States: The Effects of Disease Severity and Improved Ascertainment

BACKGROUND

Trends in the prevalence of cognitive impairment (CI) based on cognitive assessment instruments are often inconsistent with those of neurocognitive disorders (ND) based on Medicare claims records.

OBJECTIVE

We hypothesized that improved ascertainment and resulting decrease in disease severity at the time of diagnosis are responsible for this phenomenon.

METHODS

Using Medicare data linked to the Health and Retirement Study (1992-2012), we performed a joint analysis of trends in CI and ND to test our hypothesis.

RESULTS

We identified two major contributors to the divergent directions in CI and ND trends: reductions in disease severity explained more than 60% of the differences between CI and ND prevalence over the study period; the remaining 40% was explained by a decrease in the fraction of undiagnosed individuals.

DISCUSSION

Improvements in the diagnoses of ND diseases were a major contributor to reported trends in ND and CI. Recent forecasts of CI and ND trends in the U.S. may be overly pessimistic.

Prevalence of ADHD in Publicly Insured Adults

OBJECTIVE

To estimate the prevalence of adult ADHD diagnosis and treatment in U.S. Medicaid beneficiaries.

METHOD

Using outpatient, inpatient, and pharmacy billing records for patients eligible for Medicaid fee-for-service benefits within 29 states from 1999 to 2010, we estimated the annual prevalence of ADHD diagnosis and treatment.

RESULTS

The prevalence of ADHD diagnosis increased from 2.20 per 1,000 patients in 1999 to 10.57 in 2010. Likewise, prevalence of ADHD treatment increased from 1.95 per 1,000 patients in 1999 to 13.16 in 2010. Between 40% and 65%, patients had ADHD drug prescription fills 6 months after ADHD diagnosis, whereas 45% to 55% of the beneficiaries with an ADHD drug prescription fill had ADHD diagnoses within 6 months before the prescription.

CONCLUSION

In publicly insured adults, the prevalence of ADHD diagnosis and treatment increased dramatically over the years. Approximately half of the diagnosed patients are not treated, whereas half of the treated adults are not diagnosed.

Prevalence of HBsAg/HBeAg amongst 1 936 801 couples preparing for pregnancy in rural China: An observational study

There are few extant studies on the prevalence of HBV infection in couples preparing for pregnancy. We assessed the prevalence of hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) in couples preparing for pregnancy in rural China, and the association between HBV prevalence and the statuses of HBsAg/HBeAg and ALT in the spouses. We performed a nationwide cross-sectional study, using data from a health check-up program for 1 936 801 rural couples from 31 provinces preparing for pregnancy between 2010 and 2012. ELISA was used to test serologic samples, and we defined couples who were either discordant or both positive for HBsAg as "POSITIVE COUPLES" (PC). Amongst the 1 936 801 couples, 202 816 (10.47%; 95% CI, 10.43%-10.51%) were PC. HBeAg (high infectiousness) was detected in 56 474 (27.84%; 95% CI, 27.65%-28.04%) of 202 816 HBsAg-positive couples. Multivariate models showed that the prevalence of HBV infection in wives increased along with the positive statuses for HBsAg/HBeAg and alanine aminotransferase (ALT) of their husbands (adjusted odds ratio increased from 2.31 to 4.98), after adjustment for potential confounders. Similarly, the prevalence of HBV infection in husbands was associated with the positive statuses of HBsAg/HBeAg and ALT of their wives (adjusted odds ratio increased from 2.04 to 4.93). The prevalence of POSITIVE COUPLES in couples preparing for pregnancy in rural China was high, and the prevalence of HBV infection was independently associated with the positive statuses of HBsAg/HBeAg and ALT of the spouses. Instead of solely focussing on mothers prior to becoming pregnant, POSITIVE COUPLES should be taken as an important unit of care.

Valgus malalignment and prevalence of lateral compartmental radiographic knee osteoarthritis (OA): The Wuchuan OA study

AIM

To evaluate whether knee alignment explains the higher prevalence of lateral compartment tibiofemoral radiographic osteoarthritis (TFROA) among rural Chinese compared with that among Whites.

METHODS

The Wuchuan OA Study is a population-based longitudinal study of risk factors for knee OA. At baseline 1030 participants had home interviews, clinical examinations and weight-bearing posteroanterior semi-flexed radiographs of the tibiofemoral joints. Anatomic knee alignment was measured using an e-film workstation and divided into three categories: normal (182°-184°), valgus (> 184°), and varus (< 182°) alignment. A knee was defined as having medial or lateral compartmental ROA if its Kellgren and Lawrence grade was ≥ 2 and joint space narrowing ≥ 1 in the medial or lateral compartment, respectively. We examined the association between knee alignment with prevalent medial or lateral knee ROA separately using multiple logistic regression.

RESULTS

Among 1030 participants, the proportions of knees with normal, valgus and varus alignment were 29.9%, 56.5% and 13.7%, respectively. The prevalence of medial and lateral ROA was 16.0% and 4.3%, respectively. Valgus alignment was associated with prevalence of lateral compartment ROA (odds ratio [OR] = 5.0, 95% CI: 2.4-10.5), while varus alignment was associated with medial compartment ROA (OR = 6.1, 95% CI: 4.4-8.6). The ratio of prevalence of lateral versus medial compartment TFROA was greater in Wuchuan than that in the Framingham OA Study and valgus malalignment was more common in Wuchuan than in the Rotterdam study.

CONCLUSIONS

The prevalence of compartment-specific TFROA differs between rural Chinese and Whites. This difference is likely due to relatively high prevalence of valgus malalignment in rural Chinese compared with that in Whites.

Distribution and population structure of the anther smut Microbotryum silenes-acaulis parasitizing an arctic-alpine plant

Cold-adapted organisms with current arctic-alpine distributions have persisted during the last glaciation in multiple ice-free refugia, leaving footprints in their population structure that contrast with temperate plants and animals. However, pathogens that live within hosts having arctic-alpine distributions have been little studied. Here, we therefore investigated the geographical range and population structure of a fungus parasitizing an arctic-alpine plant. A total of 1437 herbarium specimens of the plant Silene acaulis were examined, and the anther smut pathogen Microbotryum silenes-acaulis was present throughout the host's geographical range. There was significantly greater incidence of anther smut disease in more northern latitudes and where the host locations were less dense, indicating a major influence of environmental factors and/or host demographic structure on the pathogen distribution. Genetic analyses with seven microsatellite markers on recent collections of 195 M. silenes-acaulis individuals revealed three main genetic clusters, in North America, northern Europe and southern Europe, likely corresponding to differentiation in distinct refugia during the last glaciation. The lower genetic diversity in northern Europe indicates postglacial recolonization northwards from southern refugia. This study combining herbarium surveys and population genetics thus uniquely reveals the effects of climate and environmental factors on a plant pathogen species with an arctic-alpine distribution.

Age-Associated Pathology in Rhesus Macaques (Macaca mulatta)

The rhesus macaque (Macaca mulatta) is one of the most extensively used nonhuman primate models for human diseases. This article presents a literature review focusing on major organ systems and age-associated conditions in humans and primates, combined with information from the Wisconsin National Primate Research Center Electronic Health Record database to highlight and contrast age-associated lesions in geriatric rhesus macaques with younger cohorts. Rhesus macaques are excellent models for age-associated conditions, including diabetes, osteoarthritis, endometriosis, visual accommodation, hypertension, osteoporosis, and amyloidosis. Adenocarcinoma of the large intestine (ileocecocolic junction, cecum, and colon) is the most common spontaneous neoplasm in the rhesus macaque. A combination of cross-sectional and longitudinal studies is required to truly define mechanisms of maturation, aging, and the pathology of age-associated conditions in macaques and thus humans. The rhesus macaque is and will continue to be an appropriate and valuable model for investigation of the mechanisms and treatment of age-associated diseases.

Prevalence of Diagnosed and Undiagnosed Hepatitis C in a Midwestern Urban Emergency Department

BACKGROUND

Targeted hepatitis C virus (HCV) screening is recommended. Implementation of screening in emergency department (ED) settings is challenging and controversial. Understanding HCV epidemiology in EDs could motivate and guide screening efforts. We characterized the prevalence of diagnosed and undiagnosed HCV in a Midwestern, urban ED.

METHODS

This was a cross-sectional seroprevalence study using de-identified blood samples and self-reported health information obtained from consecutively approached ED patients aged 18-64 years. Subjects consented to a "study of diseases of public health importance" and were compensated for participation. The Biochain ELISA kit for Human Hepatitis C Virus was used for antibody assay. Viral RNA was isolated using the Qiagen QIAamp UltraSens Virus kit, followed by real-time reverse transcription polymerase chain reaction using a Bio-Rad CFX96 SYBR Green UltraFast program with melt-curve analysis.

RESULTS

HCV antibody was detected in 128 of 924 (14%; 95% confidence interval [CI], 12%-16%) samples. Of these, 44 (34%) self-reported a history of HCV or hepatitis of unknown type and 103 (81%; 95% CI, 73%-87%) were RNA positive. Two additional patients were antibody negative but RNA positive. Fully implemented birth cohort screening for HCV antibody would have missed 36 of 128 (28%) of cases with detectable antibody and 26 of 105 (25%) of those with replicative HCV infection.

CONCLUSIONS

HCV infection is highly prevalent in EDs. Emergency departments are likely to be uniquely important for HCV screening, and logistical challenges to ED screening should be overcome. Birth cohort screening would have missed many patients, suggesting the need for complementary screening strategies applied to an expanded age range.

Current challenges and the management of chronic hepatitis C in mainland China

Despite decreasing prevalence, new cases of hepatitis C in China are increasing recently with growing percentage of patients who are with advanced disease, aging, or not eligible for interferon-based treatments. Hepatitis C infection represents a serious public health burden. This review was based on expert's consensus during a medical forum on hepatitis sponsored by the Beijing Wu Jie-Ping Medical Foundation. The literature searches were conducted in PubMed and critical publications in Chinese journals. Data on hepatitis C prevalence, risk factors, viral or host features, and treatment modalities were extracted and reviewed. Recent large-scale surveys reported reducing prevalence of hepatitis C to approximately 0.4% in China, partly because of regulation changes to safer medical practices and illegalizing commercial blood donations. Patient demographics evolved from being dominated by former paid blood donors to include intravenous drug users and others. Although hepatitis C genotype 1 is the most common, other genotypes are emerging in prevalence. The current standard of care is interferon-based without direct acting antivirals. However, many patients failed therapy because of high treatment costs, substantial needs to manage side effects, difficulties with treatment monitoring in the rural areas, and growing populations of elderly and cirrhotic patients. The lack of high efficacy therapies with good safety profile and low disease awareness in China resulted in increasing public burden of advanced hepatitis C disease. Despite significant reduction of hepatitis C prevalence, iatrogenic, nosocomial, and community transmissions are still significant. In addition to promoting disease awareness, interferon-free regimens are needed to reduce the public health burden.

Patterns of chronic co-morbid medical conditions in older residents of U.S. nursing homes: differences between the sexes and across the agespan

OBJECTIVE

There are limited data on combinations of co-morbid conditions to guide efforts to improve therapeutic strategies in patients with multiple co-morbid conditions. To some extent, this may be due to limited data on combinations of co-morbid conditions in patient groups. Our goal was to determine the most common co-morbid medical conditions in older residents of U.S. nursing homes and identify sex differences in prevalences and changes across the agespan of nursing residents.

DESIGN

Cross sectional analysis of National Nursing Home Survey (NNHS)--a nationally representative sample with comprehensive medical data on nursing home residents.

SETTING

1174 Nursing homes.

PARTICIPANTS

Long term stay residents of U.S. Nursing Homes aged 65 years and older (11,734 :8745 women, 2989 men).

MEASUREMENTS

Determination of the prevalences of the most frequent two and three disease combinations identified using Clinical Classifications Software (CCS) for ICD-9-CM and a composite vascular disease diagnosis (atherosclerosis and/or coronary artery disease, and/or peripheral arterial disease, and/or cerebrovascular disease or stroke) from the most recent and only NNHS survey with comprehensive medical diagnosis information.

RESULTS

Frequent 2-disease combinations were: hypertension (HTN) + dementia (DEM) in 27%, HTN + any Vascular (Vasc) disease (26%), HTN + depression(DEP) 21%, HTN + arthritis(ARTH) 20%, DEM + Vasc (21%), DEM+Depression 19%, Arthritis + DEM 17%, DEP + Vasc (16%), ARTH + Vasc (15%), followed by HTN + GERD (14%) and ARTH + DEP (14%). Frequent 3-disease combinations: HTN +VASC+ DEP in 13%, HTN +DEM +DEP (11%), and HTN+Arthritis+DEM (10%). HTN was in 80% of the top 3-disease combinations, Vasc in 50%, HTN+VASC in 35%, DEM or DEP in 40%, ARTH in 25% and GERD in 20%. Combinations with anemia, arthritis, dementia, heart failure, osteroporosis, thyroid disease were higher in women, COPD combinations higher in men. As age increased, dementia, depression, arthritis, and anemia with hypertension were common co-morbid combinations, diabetes and heart failure were not.

CONCLUSIONS

Hypertension, vascular disease, dementia, arthritis, depression, and gastro-esophageal reflux disease were part of the most prevalent co-morbid conditions. Multimorbidity patterns can be identified in nursing home residents and vary with age and by sex.

Randomized comparison of universal and targeted HIV screening in the emergency department

OBJECTIVE

Universal HIV screening is recommended but challenging to implement. Selectively targeting those at risk is thought to miss cases, but previous studies are limited by narrow risk criteria, incomplete implementation, and absence of direct comparisons. We hypothesized that targeted HIV screening, when fully implemented and using maximally broad risk criteria, could detect nearly as many cases as universal screening with many fewer tests.

METHODS

This single-center cluster-randomized trial compared universal and targeted patient selection for HIV screening in a lower prevalence urban emergency department. Patients were excluded for age (<18 and >64 years), known HIV infection, or previous approach for HIV testing that day. Targeted screening was offered for any risk indicator identified from charts, staff referral, or self-disclosure. Universal screening was offered regardless of risk. Baseline seroprevalence was estimated from consecutive deidentified blood samples.

RESULTS

There were 9572 eligible visits during which the patient was approached. For universal screening, 40.8% (1915/4692) consented with 6 being newly diagnosed [0.31%, 95% confidence interval (CI): 0.13% to 0.65%]. For targeted screening, 37% (1813/4880) had no testing indication. Of the 3067 remaining, 47.4% (1454) consented with 3 being newly diagnosed (0.22%, 95% CI: 0.06% to 0.55%). Estimated seroprevalence was 0.36% (95% CI: 0.16% to 0.70%). Targeted screening had a higher proportion consenting (47.4% vs. 40.8%, P < 0.002), but a lower proportion of ED encounters with testing (29.7% vs. 40.7%, P < 0.002).

CONCLUSIONS

Targeted screening, even when fully implemented with maximally permissive selection, offered no important increase in positivity rate or decrease in tests performed. Universal screening diagnosed more cases, because more were tested, despite a modestly lower consent rate.

Border health in the shadow of the Hispanic paradox: issues in the conceptualization of health disparities in older Mexican Americans living in the Southwest

Mexican Americans have demonstrated lower than what would be expected mortality rates and disease prevalence, given their overrepresentation among those living in poverty. However, Mexican Americans living along the US-Mexico border have been documented as carrying a higher burden of disease and disability that seems to contradict or at least challenge evidence in support of a "Hispanic Paradox". The purpose of this paper is to evaluate the concept of border health as it relates to the conceptualization and measurement of health outcomes in older Mexican Americans living in the Southwest United States. Data for this study comes from the Hispanic Established Populations for the Epidemiologic Studies of the Elderly (Hispanic EPESE) wave 1 and mortality files up to wave 5. Border residence was determined using La Paz Agreement county and distance from a port of entry classifications. Statistical analysis was conducted to assess border versus non-border differences in cause of death, disability, disease prevalence and premature mortality. Adjusted regression models were used to predict cause of death, disability and disease-free life expectancy and premature mortality (i.e. occurring before life expectancy). Interaction models between border/non-border and median income were also performed. Finally, distance from the US-Mexico border was used to determine the effect of distance to the US-Mexico border in border-residing participants. The findings from this study indicate that participants in the HEPESE were more likely to be alive at Wave 5 if they resided in a border county, however more likely to transition into ADL disability status. These findings were not explained by behaviors, duration in the US or sociocultural characteristics of where they lived. Additionally, Hispanic EPESE subjects that lived in the border region were more likely to have died from old age and were less likely to be lost to follow up. Interaction models revealed significant effects for diabetes as a cause of death. Moreover, distance from a US-Mexico port of entry was significant for being alive at wave 5 for border-residing participants. Relative to non-border residing participants, border residing Mexican Americans in the Hispanic EPESE did not carry a uniformly higher burden of disease, however had a significantly greater odds of 10 year survival. These findings bring up issues of measurement and the importance of geographic location when it comes to evaluating disease burden and mortality in Mexican Americans.

Frequency of the cholesteryl ester storage disease common LIPA E8SJM mutation (c.894G>A) in various racial and ethnic groups

Cholesteryl ester storage disease (CESD) and Wolman disease are autosomal recessive later-onset and severe infantile disorders, respectively, which result from the deficient activity of lysosomal acid lipase (LAL). LAL is encoded by LIPA (10q23.31) and the most common mutation associated with CESD is an exon 8 splice junction mutation (c.894G>A; E8SJM), which expresses only ∼3%-5% of normally spliced LAL. However, the frequency of c.894G>A is unknown in most populations. To estimate the prevalence of CESD in different populations, the frequencies of the c.894G>A mutation were determined in 10,000 LIPA alleles from healthy African-American, Asian, Caucasian, Hispanic, and Ashkenazi Jewish individuals from the greater New York metropolitan area and 6,578 LIPA alleles from African-American, Caucasian, and Hispanic subjects enrolled in the Dallas Heart Study. The combined c.894G>A allele frequencies from the two cohorts ranged from 0.0005 (Asian) to 0.0017 (Caucasian and Hispanic), which translated to carrier frequencies of 1 in 1,000 to ∼1 in 300, respectively. No African-American heterozygotes were detected. Additionally, by surveying the available literature, c.894G>A was estimated to account for 60% (95% confidence interval [CI]: 51%-69%) of reported mutations among multiethnic CESD patients. Using this estimate, the predicted prevalence of CESD in the Caucasian and Hispanic populations is ∼0.8 per 100,000 (∼1 in 130,000; 95% CI: ∼1 in 90,000 to 1 in 170,000).

CONCLUSION

These data indicate that CESD may be underdiagnosed in the general Caucasian and Hispanic populations, which is important since clinical trials of enzyme replacement therapy for LAL deficiency are currently being developed. Moreover, future studies on CESD prevalence in African and Asian populations may require full-gene LIPA sequencing to determine heterozygote frequencies, since c.894G>A is not common in these racial groups.

The relationship between self-rated health and objective health status: a population-based study

BACKGROUND

Self-rated health (SRH), a subjective assessment of health status, is extensively used in the public health field. However, whether SRH can reflect the objective health status is still debatable. We aim to reveal the relationship between SRH and objective health status in the general population.

METHODS

We assessed the relationship between SRH and objective health status by examining the prevalence of diseases, laboratory parameters, and some health-related factors in different SRH groups. Data were collected from 18,000 residents randomly sampled from the general population in five cities of China (3,600 in each city). SRH was assessed by a single-item health measure with five options: "very good," "good," "fair," "bad," and "very bad." The differences in prevalence of diseases, laboratory parameters, and health-related factors between the "healthy" (very good plus good), "relatively healthy" (fair), and "unhealthy" (bad plus very bad) groups were examined. The odds ratios (ORs) referenced by the healthy group were calculated using logistic regression analysis.

RESULTS

The prevalence of all diseases was associated with poorer SRH. The tendency was more prominent in cardio-cerebral vascular diseases, visual impairment, and mental illnesses with larger ORs. Residents with abnormalities in laboratory parameters tended to have poorer SRH, with ORs ranging from 1.62 (for triglyceride) to 3.48 (for hemoglobin among men) in a comparison of the unhealthy and healthy groups. Most of the health-related factors regarded as risks were associated with poorer SRH. Among them, life and work pressure, poor spiritual status, and poor quality of interpersonal relationships were the most significant factors.

CONCLUSIONS

SRH is consistent with objective health status and can serve as a global measure of health status in the general population.

Estimation and testing of the relative risk of disease in case-control studies with a set of k matched controls per case with known prevalence of disease

The analysis of case-control studies with matched controls per case is well documented in the medical literature. Of primary interest is the estimation of the relative risk of disease. Matched case-control studies fall into two scenarios: the probability of exposure is constant within each of the case and control groups, or the probability of exposure varies within each group. Numerous estimation procedures have been developed for both scenarios. Often these procedures are developed under the rare disease assumption, where the relative risk of disease is approximated by the odds ratio. In this paper, without making the rare disease assumption, we develop consistent estimators of the relative risk of disease for both scenarios. Exact derivations of the relative risk of disease are provided. Estimators, confidence intervals, and test statistics for the relative risk of disease are developed. We then make the following observations based on extensive simulations. First, our estimators are as close or closer to the relative risk of disease than other estimators. Second, our estimators produce mean square errors for the relative risk of disease that are as good as or better than these other estimators. Third, our confidence intervals provide accurate coverage probabilities. Therefore, these new estimators, confidence intervals, and test statistics can be used to either estimate or test the relative risk of disease in matched case-control studies.

Associations of carotid artery intima-media thickness (IMT) with risk factors and prevalent cardiovascular disease: comparison of mean common carotid artery IMT with maximum internal carotid artery IMT

OBJECTIVE

The goal of this study was to compare internal carotid artery (ICA) intima-media thickness (IMT) with common carotid artery (CCA) IMT as global markers of cardiovascular disease (CVD).

METHODS

Cross-sectional measurements of the mean CCA IMT and maximum ICA IMT were made on ultrasound images acquired from the Framingham Offspring cohort (n = 3316; mean age, 58 years; 52.7% women). Linear regression models were used to study the associations of the Framingham risk factors with CCA and ICA IMT. Multivariate logistic regression models and receiver operating characteristic (ROC) curve analysis were used to compare the associations of prevalent CVD with CCA and ICA IMT and determine sensitivity and specificity.

RESULTS

The association between age and the mean CCA IMT corresponded to an increase of 0.007 mm/y; the increase was 0.037 mm/y for the ICA IMT. Framingham risk factors accounted for 28.6% and 27.5% of the variability in the CCA and ICA IMT, respectively. Age and gender contributed 23.5% to the variability of the CCA IMT and 22.5% to that of the ICA IMT, with the next most important factor being systolic blood pressure (1.9%) for the CCA IMT and smoking (1.6%) for the ICA IMT. The CCA IMT and ICA IMT were statistically significant predictors of prevalent CVD, with the ICA IMT having a larger area under the ROC curve (0.756 versus 0.695).

CONCLUSIONS

Associations of risk factors with CCA and ICA IMT are slightly different, and both are independently associated with prevalent CVD. Their value for predicting incident cardiovascular events needs to be compared in outcome studies.